NUTRITIONAL and PHYSIOLOGICAL IMPLICATIONS of SAPONINS: a Revievtr

NUTRITIONAL AND PHYSIOLOGICAL IMPLICATIONS OF SAPONINS: A REVIEvtr

Department of Animar science, or"s:;!;"2Hif!rrity, corvauis, oregon e7331. oreson Agricultural Experiment Station Technical Paper No.2966, received iecember 17, 1970, accepted luly 21,1971. INTRODUCTION Saponins are widely distribute.d in plants of agricultural impo,rtance, and in par- ticular, in leguminous forage species such as ilfatfa. they have been obseried to elicit a number of responses, mostly detrimental, in animals consuming them. A review of U.S. Department of Agriculture studies on the relationship of alfalfa saponins to bloat has been published (Lindahl et aL, 1,957), but information on other aspects of saponin influences in ruminants and monogastrics is scattered through the literature. A review of present knowledge of saponins and their effects on livestock is desirable, not only because considerable information on their biological effects has been collected but also because many gaps still exist in the under- standing of their mode of action.

CHEMICAL AND PHYSICAL PROPERTIES OF SAPONINS saponins are glycosides; that is, they are composed of carbohydrate and non- carbohydrate, or aglycone, portions. The aglycones are often referred to as sapo. qlnins. The sapogenin nucleus may be either of steroid or triterpenoid structlure (Farnsworth, 1966; Robinson, 1963) : G-l HF h a\v aif"f /-\./vr_,2aYYcooH ,oW' Ho&J

For personal use only. STEROID TRITERPENOID SAPOGENIN SAPOGENIN Saponins in common forage legumes are of the triterpenoid type (Lindahl et al.,1957). commercially available saponins may be steioids, deiived. from yucca o1 the triterpenoid Quillaja saponin. The latter, which has been fairly exten- sively used in biological research, is obtained from a South American tree. Quillaia saponaria. In both steroid and triterpenoid saponins, the carbohydrate side chain is usually attached at carbon-3 of ihe sapogenin (Robinson, igar. Difierent saponins may have the same nucleus but diherent carbohvdrate side chains (Robinson 1963). In alfalfa saponins, the predominant monosaccha- Can. J. Anim. Sci. Downloaded from pubs.aic.ca by 114.79.53.84 on 10/07/12 rides in the side chain are galactose, glucose and rhamnose, with trace amounts of arabinose and xylose (Jackson and Shaw, 1959; Lindahr et ar., lg57). The steroid saponin digitonin is composed of the digitogenin nucleus and a side chain of one xylose, two glucoses and two galactoses lRobinson, 7963). while the triterpenoids may be found in plants is either the saponin or the sapogeirein, the steroids never occur in the free sapogenin form (Farnsworth , lgeel . rPublication in the Canadian Journal ol Animal Science of review articles which document the existing state of knowledge in specific fields of animal science has been-recommended by the Canadian Society of Animal Science. H. T. Fredeen. Editor. Can. J. Anim. Sci.51: 621-632 (Dec. lg7l)

621 622 cANADIAN JoURNAL oF ANIMAL scIENcE within Legume saponins difter qualitativgly and quantitltively- both among and con' ,pJ"i"r. Coulson and Davies (1962) founa at least 10 and possibly 12 relative amounts .iiGtrt saponins in alfalfa. Genetic differences in the types and alfalfahavebeenreported ({a1son etal., 1963; three vrcNairy"i."p"ri"i"severalcultivarsof et al., 1963;Pedersen et at.,1967). In the case of Ladino clover, saponins have been identified (Walter et al', 1955) carbo- Saponins possess surface-active or detergent properties because the fat-solubls' hydrate portion of the molecule is water-soluble while the sapogenin is solutions; This detergent property leads to considerable foaming of aqueous lapottt the characteristic honJy-somb froth produced is often employgd in plant-scre^ening 1966) work as presumptive evidence of the presence of saponins (Farnsworth , ' oq py The stability anO ,t engitr oi torug" saponin foams are closely dependent roles of saponin in fUurrgurr, igSg), a facior which iray be related to implicated development of bloat in ruminants. polar Isolation of saponins from plant material involves extraction with a saponins in- solvent, followed bf various purification techniques. _Alfatfa forq soluble addition complexes with cholesterol, wliile othe_r- legume saponins have been isolated uy cryst'a[ization (Lindahl et a]., lg57). various chrornatographic the procedures tt"r, be used to further sepgale-individTljTeonins.from -uy al., iaponin mixture (Coulson and Davies, 1962;Lindahl et al., 1957;Yan Atta et (Scardavi and Elliot' f q?il. Bioassays for alfalfa saponin, employing a fungus 1967) andfish (Jones and Elliott, 1969), rtave ueen used in alfalfa breeding work for identificaton of low-saponin plants. BIOLOGICAL BFFECTS OF SAPONINS and meta- Ingested saponins have been observed to influence animal performance to bolism in a number of ways. Among the responses which have been attributed For personal use only. saponins are: 1. ErYthrocYte hemolYsis' 2. Effects on blood and liver cholesterol lwels' 3. Effects on growth. 4. Bloating of ruminants. 5. Inhibition of smooth muscle activity' 6. Enzr./me inhibition. 7. Effects on nutrient absorPtion' l. Erythrocyte hemolYsis Can. J. Anim. Sci. Downloaded from pubs.aic.ca by 114.79.53.84 on 10/07/12 Reaction-.of Saponins have pronounced hemolytic properties (Sollman, :?57)' the saponin wi^th cholesterol in ihe erythrocyte w-a!, resulting in permeability 1962) changJs, may be r".pootibt" for the hemolytic acJivity (GJanert et al" (Jones and' attnJugtr a number oi hemolytic saponins do not form cholesteroids Elliottl tg6g). Ewart (193f) for a number of species hasclassified susceptibility > man' of eryttrrocytes to hemolysis as follows: guinea pig, horse t tat'rabbit 9ot' not prg i gout, ,h""p, The hemolltic eff&ti of saponins are apparently correlated with other"attll. properties; no relationship hqs been^noted between foam strength (Lindahl et it., igSl; Woodward and Alsberg, !916), bloat-producing abilit! (Lindahl et al., 1957), or acute toxicity in monogastrics (Lindahl et al', 1957) and the hemolytic properties of saponins' CHEEKE-SAPONINS: A REVIEW 623

2. Bffects on blood and tissue cholesterol levels legume saponins form insoluble addition complexes with cholesterol 91n:"-(Lindahl T1"v et aI., 1957), effects of dietary saponin on cholesierol metabolism might be anticipated. Grimingel and Fisher rrq3sl reported thar with the presence"of saponin in chick diets the plasma cholesterol level was lowered. They h-ypothesized that cholesterol in the bile combines with saponin in the gut, and in this manner is prevented from being reabsorbed. Newman et al. (r95{) no,ted that when both saponin and cholesterol were added to chick diets, the fivlr, but not the serum, cholesterol level was reduced, while there was no significant efiect of saponin when cholesterol was ornitted from the diet. Studies oi the effect of ingested saponin on tissue cholesterol levels have apparently not been conducted with gastrics. other mono- Fonnesbeck and Symons (196i) found that horses fed alfalfa hay had lower serum cholesterol levels than those receiving grass hays, and attributed the difference to the cholesterol-binding activity of affa]fi saponin.' If it is considered desirable to reduce the cholesterol iontent of ana of swine and po,gltry meat, it appears that the saponin-cholesterol interactioir"ggr, might offer possibitities to, producing animal products of greater consumer acceptab-ility No direct studies on the effects of saponin o" metabolism in ruminants have been reported, but there is some evidence"hol"rt"rol that the situation may be different from that in monogastrics. Binns and pedersen (1964) found no effect of feeding a high-sapo'nin u-lfalfu hay on the blood cholesterol rt t?p9lltt! level of calves. are degraded in the rumen, as has been demonstrated by Gutierrez et (1958) aI' and Gutierrez and Davis (1962), then an influence on cholesterol. reabsorption from the intestinal tract would be slight. rnareport (1959) of Jackson e/ al. that the serum cholesterol level increased when cattle were fed alfalfa as pasture, and that this increase was highly correlated with bloat severity, is difficult to interpret in terms of saponin ac{vity.

For personal use only. On the basis of the limited evidence available, it appears that in monogastrics dietary saponin tends to result in a reduction of tissue'ciolesterol levels, while in ruminants there is little effect. 3. Efrects on growth High levels of alfalfa meal in diets for monogastrics have growth depressing efi-ects, beyond those "by that may be accounted for effects oi ni., on caloric in_ t+"__9t_endogenous peterson nitrogen losses. lissoa, rglob) and Kodras er aI' (1951) noted that the growth inhibition caused by alfalfa meal in chick diets largely overcome by "tttg e dietary supplementation wittr lvo cholesterol, sug- Can. J. Anim. Sci. Downloaded from pubs.aic.ca by 114.79.53.84 on 10/07/12 qestinq-tl-at the saponin fraction wasinvolved. Heywang ano eiro (1954) found that alfalfa- saponin at levels of O.2Vo or more in the diet growth of chicks retarded and restricted feed intake and feed efficiency. Later siudies et al.' 1959) lrreywan! also showed a depressant effect of artarti saponin * production. Anderson fit4Tly, (1957) nored that levels of o.Lvo or more "r*alfalfa saponin in chick diets reduced growth and feed efficiency. Additi; ;i lza cholesterol completely overcame the growth depression produced by o.3vo saponirr, the highest level used. Growth depression in itricks and rats fed alfalfa;adnin was reported by coulson (1957), whb no'ted thar higher revers (2-3voi saponin were requirSd to produce growth depression- in rats. 'irrir "ruitaru why no detrimental effects -uy were observed in another study (Lindahl'"i"*ptuio i[,"tgsl) in which 624 cANADIAN JoURNAL oF ANTMAL scIENcE was observed in young vounq rats were fed I% saponin. No growth inhibition t"tui,r ,"""iuirrg a dietaiy level of 27o alfalfa saponin (Lindahl iltr?ffi'""i are species differences et al.,1957). From these reports it is evident that there poultry being much more response Uy uti-utt to dietary saponin' in -o"ogur-tri" observed that than other Cheeke (unprlUtittt"O data) has sensitive at a dietary lwel of mice are much less tolerant"i.r-"g".iti"r of alfalfa saponin t'huo *" fats; mice feed intake was 2Vo saponin, ,ro ,"rponre was noted wiih rats, while with markedly depressed ind weight loss occurred' Theimportanceofsaponin-inducedgr-owthinhibitionofmonogastribsunder In poriltry, there is anplg.evidence that levels practical circumstancel-;tli;;;t. that is of around 20c,o alfatfa meaf in chick ?ations result i" gtitlt "dep1e;9io11954;'Peterson' almost entirely due to the saponin content (I-{eywTg and Bird' into swine grower I950a,1950b). I-evefs of ZbVo alfalfa have be-en incorporated data); Bohman with no adverse efiects on growth (Cheeke, unpublished rations alfalfa in swine et (1953) havo esiatlisfred theleasibiliiy of using 3O4OVo al. high qualtty rations when economic conditions permit. UnOer somd circumstances' needs of growing meal can U" u,"6to meet a ,ignifi"unt portion of theprotein alfalfa factor limiting swine. The presenc" tup."i"s iould ptotuUty be an important the level of alfalfa that "icould be used' Usingisocaloricdiets,Bell(1960)foundthattheresponseofgrowingmiceto number of physical fibrous materials varied with the fiber source used. while a wet, and others, characteristics such ur 6uit density, tendencies to swell when -may constituents such as account for some of the differences, the effects of organic response to fiber so'rce' s'aponins may also u""o"ni for some of the difterential little attention; The effect of saponins on the growth of ruminants has received growth when alfalfa Binns and pedersen'(lge+j founi no detrimental effects on Hale et al' (1961) hay containing2.6yV) ind l.72Vo saponin was fed to calves.

For personal use only. of feed, im- reported that a steroiiJ.upo"i", rmiiagenin, at a level of.1'7.6 :\CkC the mechanism proved the growth tut" oiiutt"ning lairbs' They suggested- thjat of the saponin of the growth stimulating effect was due to a structur-il similarity to diethylstilbestrol. depressing effects ol The biochemical mechanisms accounting for the growth molecule is involved' saponins are not iOentinea. Apparently, the" entire siponin the sapogenins purified alfalfa uot ,oyU.utr sapo4.s inhibit chick grorrth while since (1970) demon- do not (potter and Kummero*, f954;. Cheeke and Otdnetd in intermediary strated in vitro inhibition by alfalfa saponin of enzymes, involved may be t"tult metabolism, uoO ,ogg"ri"O tLat saponin-induced gto.tft dgnr.es;ign l

Can. J. Anim. Sci. Downloaded from pubs.aic.ca by 114.79.53.84 on 10/07/12 of digestive of inhibition of Anothe'r pdsibility iJ intritition "nry-"r. For example' enzymes, whictr wouiJf"*.i""ffLriut the digestibility of certain nutrients' saponin has been demon- inhibitio,n of trypsi"n activity by soybean "na strated (IshaaYa"try-otrypri" and Birk, 1965). Partotthegrowthinhibitioncausedbysaponinsisprobablyduetoanorexic an anorexic agent in effects. Quillaja d;;tfi;;;-in fact, been employed as studies of amino acid nutrition (Netke et al',1969)' Ithasbee,'soggestedthattanninsmaycounteracttheinhibitory'effectso.f shown to be growth saponins (Ewart, 19Tit. However, since tannins have been in rats (Gli"tf. arrd Jo'lyo, lgTO), chicks (Rayudu inhibiting "t "L: !?7?)^1i!saponm- rabbits ipoltuttit" et al., 1962), their use as supplements to overcome CHEEKE-SAPONINS: A REVIEW 625 induced growth inhibitio-n is unlikely to be beneficial, unless a tannin-saponin formed which eliminates the toxicity of boih. This aspect *uiruni, rnvestrgatron.,"-"-T^pl:l.i: is interesting to note that saponins have been reported to have effects plant,-,- .r, growth. on Helmkamp and Bonner (1953) observed that saponin stimulated the growth of wheat and pea embryos. it has'been suggested ttrat saponins have a role in the regulation of seed germination (Nord and van Atta, 1960). 4. Bloat in ruminants (1959) and {1ngan McArthur, Miltimore and co-workers (1964, 1966, r969a, b, 1970) have investigated factors which are important in the etiology of bloat. These can be summarized from their work as follows: 1. Presence of foaming agents in the ingested forage. 2. Vigorous gas produition in rumen. 3. Acidic rumen pH favoring stable foam formation. 4. Low levels of natural anti_foaming agents. 5. Presence of certain cations invotvJo in foam formation. of the foaming agenr present in forages, saponins (Lindahl et aI., rgsT]L pectins (conrad et al., r958),-and certain pt"ot"ittr (Jones and Lyttleton, L969; Mangan, 1959; McArthur et aI., 1964; McArihur and Miltimora, tbaal have been studied in relation to bloat. Mangan (1959) investigated the foaming properties of various saponins, l"g"T" a "cytoplasmic protein" from red clover, and rumen riquor taken from bloated cattle. Th!."cyto-qlasmic protein" and the rumen liquor showed very similar in vitro , relationships of foam strength to pH, leadinf Muogun (1959) to conclude that the "cytoplismic protein" fr-action *ur tt pfi-ury tbaming agent in bloatin_g forages. MiArthur, Miltimore and co-work"rriuu"" further examined the soluble proteins of alfalfa, and have isolated 18S or Fraction I protein which For personal use only. they believe is the foami-ng^1cjn_t responsible for bloat iM"artrr", et ar., 1964; McArthur and Milrimot",196z, D6g;, D69b; Miltimore et ar., l97o). Some the observations of supporting the Fraction 1 protein theory might also be considered to the possible :uppglt involvement of other^foaming agents, ,i"t u, saponins, either directly in foam production, "a lctinq or acting in Jynergirii" capu"ity with the Fraction 1 protein. are'implicated more ott"ritrru' grasses in bloat; legumes are r"g-ua". higher in.both,nrggtlo_n 1 protein (McArthur and Miltimor e, 1969b) and saponins (Lindahl et al., 1957) thun ur" grasses. Birdsfoot trefoil is a non_ bloating legume (McArthur and lt4iltimor e:, r969b); it is low in both Fraction 1 protein (McArthur and Miltimo-re, r969b) and in saponin (walter, 196r). The Can. J. Anim. Sci. Downloaded from pubs.aic.ca by 114.79.53.84 on 10/07/12 rumen pH of bloated animals is acidic (McArthu, ana Iuittimore, maximum r969a); the foam strengths of ruponin, and Fraction 1 protein occur a9ja1c cold,itions (Mangan, _both under 1959). A correlation between calcium content of incidince ,lt:tl::j.91::,iis has been observed (Milrimore et at., reTo); calcium foam (Mangan, 1959) while Fraction 1 proiein mole_ crues::,,1".:::,i^T:j:t_:?,p""jn are bound together by cations such as calcium (Mangan, 1g5g; McArthur Miltimore, lg6gaiwhichirr"r"as"s and foam strength (Mangan, r95g). A correration between forage zinc and.bloat incidence was alJo observJt et at., r,970); it is of interest that luitti#or" a relationship between soil zinc urri t"rug" saponin revels has been suggested (Henrici, r9s2). Finally, roppoit i", p.iriure saponin involvement in bloat comes from the fact trrut ua-ioistration oti"!"-"" saponins to 626 cANADIAN JouRNAL oF ANTMAL scIENcE aI., |957), althotrgh the levels ruminants does in fact cause bloating (Lindahl et However' Jackson et aI' employed were high compared *iti- intakes' (|g62)wereunabletocorrelateabloat.'u"'ityindexwiththeleveloftotal"o'-J saponins in Ladino clover forage' production includes the Additional eviOence ajain"st a role of saponin in bloat and alfalfa saponins observation that the maximum foam strengths in red clov& (Mangan, 1959) How- occur at a pH lower tnu" ir usually folund in bloat ' -o.t simulating an intra- ever, these measurements were not mide under conditions were based on the ruminal environment. It would be more valid if conclusions foamingpropertiesofsaponinsinrumen-fluid,rather-th.an.inbuffersol.utions. might be shifted, especially It is not inconceivable that the foam strength-pf{ curve inviewofMangan,s(1959)observation-thatthefoamstrengthmaximumofnitroeen and salt protoplasmic protein *ur-tnifttO considerably g.V "1,""9::-^T.1f3saponins are not important concentrations of the medium. Before *o"toaing that the foam strength- foam formation in the rumen, it is necessary to estibtish in stable with regard to the pH relationship under the conditions that exist in th" trr*"tt. prot"io ttreory, Ctarke and Reid (f 970) state: "This acceptance of the Fr;c1irrr-i pH of ,utft"t too heaviiy on comparisons between the contsntion pro;bably ilun, of leaf Ufout,-u"J tft" pff optima fot ii vitro.foam-strengths rumen contents a*irrf pectins"' As protein and of po"rifite alternative foaming agents' tuponil-ti,^1od in extrapolation Dougherty (1970) p"ifi out, there"ar6 d*gttt Ttuiltd fiy Reid (1970) also-note from in vitro foamiii-io'rn vivo foaming. clarke and Zealand work has shown that the Fraction I content of stems is low, but that New all leaves were re'rnoved' that bloat has occurred in cows fed clover stems from which Anadditionalfactortoconsiderwhenevaluatingthefoamstrength-rH.cyve1 vsry well-defined of Mangan (1959) i, tf,ut go"Linghlm (-1970)'He ha-Jreporte"d 3' smatl changes in intra- effect of temperature;; i;; streigth. suggests that For personal use only. protein foam ruminar temperature ;;;iJ have irarked effeJis on cytoprasmic stiength; po.tiUty a similar effect cotrld be seen with saponins' has not been ob- Sufficient .uiO"""L, oUtained under physiological conditions, legume bloat' It is tained to evatuate the sigmfica'n"" oi saponins in proteins and saponins may likely that under appropriate";;;i";i";iy circumstinces both soluble would indicate that be involved. The foam strength curves of Mangan. (f959) of significance the contribution of ."il;"- 6 foam formation iright be .greatest desirable to redetermine under the more acid rumen conditions. It would ue f,ighty physiological conditions' the relationstrip of saponin foam strength to pH, but undei it wonrld-be In order for the causative factors of bloai to be fully elucidated, Can. J. Anim. Sci. Downloaded from pubs.aic.ca by 114.79.53.84 on 10/07/12 factors as possiblo desirable for investigators in the area to evaluate as many Mangan (1959) simultaneous$, induffiFraction L protein, saponins_and.pectins. mucoprotein might has suggested that ,olii"o-p"unds saponins.and salivary -as foam strength' Another interact synergisticall' *itfr proiein to increase "Vi"pfasmic agents with possibility includes Jt"AVi"g tne interaitions of the various foaming (Foote et aI., 1968). poloxalene, u *n rpo*oJit uT rr"ry effectively prevents bloating Kendall(1966)reportedthatnon-bloatinglegumesconlainhighlevelsof associated with bloat have tannin (abo,ut lovo of. the dry weight) whereas-those suggestion levels (about 2%). This is i;to"rtiog in view of tle -o.f .ETutl low on biological (1931) that tannins;;; r";;;e the detriiental effects of sapo'nins levels of tannins would systems; Segelman et al." (1969) also reported that very low CHEEKE-SAPONINS: A REVIEW 627 render red blood cells immtne to hemolysis by saponins. If, as might be inferred from these observations, complei wittr saponinr, u Jxplanation for the low bloat potential -t?Trynr frr.iut" of high-tannin^legumes is that the saponin has ircen tiod ;p in a tannin-saponin comprei. rn addiion, tannins have deen postulated to pre- cipitate the soluble leaf proteins of forages and render them unavailable for foam production (Jones et at., l97O) 5. Saponin inhibition of smooth muscle activity rn an extensive series of studies, Lindalrl et at. (1957) examined the efiects alfalfa of saponin on the motility of smooth muscle. Intraruminal administration of saponin tg resulted in a pronounced reduction in rumen motility. venous lt Tp Intra- administration of saponin also resulted in reduced rumen rn these experiments, -otitity. the site of action was not identified; not all the inhibition could u.e ex-ntailea by direct efiects on the ruminal musculature. arumu saponin also found to was inhibit eructation, with e\iidence that Atect enects on the central nervous system were involved. The significance of these observations lies their relationship in to the bloat situation; besidis a possible role in stable foam formation, saponins may interfere with gas loss from th6 .rmen by inhibiting eructation. 6. Inhibition of enzymes Shaw-and JackSon (1957) found that Ladino clover extracts inhibitedithe respiration of isolated rat diaphragm tissue. Further work with alfalfa irnpucaten saponins as ttre respiratory inhibition (Jackson and Shaw, 1959; Shaw uoa lu&roo, l95t). A:*t* possible { explanation for this observation is that saponi" -uyLrriuit respiratory acfivrtv. This aspect has been examined by'ctreete *a oton"ta who"ryy\ found itgloi, that alfalfa saponin inhibits the in v{tro oxidation of succinate, iTpg:,-u^n, an fGeb's cycle iniermediate, by rat liver enzymes. Etnanolic extracts of alfalfa also inhibit in vitro succinoxidase activity (Cireeke and Oldfield

For personal use only. 1969, 1,91-0; Roughan, , 1965); other factors besides sap;"in are evidently involved (Cheeke and Oldfield, 1970). In vivo inhibition involved in cellular metabolism by saponins offers a tenable explanation"i "-d;for their detrimental on growth. efiec.ts Besides apparent effects on ceilular metabolisnl saponins might fluence in_ {iqe.1ti.ve enzyme}ctivity.- rshaaya and Birk (196tt;'eported thar soybean saponin inhibits cholinesterase, chymotrypsin and trypsin u"ti"rty. Further exami_ nation of the effects of saponin on-"n y^L function is'indicated. ' 7. Saponin efiects on nutrient absorption eff9-c1s--of ingesred foSe saponins on nutrient absorption havo been suggested.

Can. J. Anim. Sci. Downloaded from pubs.aic.ca by 114.79.53.84 on 10/07/12 Sollman (1957) and Ewart 110: t; cire a sr ggestion by Kofler (rgz7,Die Sapoine; Springer, Vienna) that saponins favor the iEsorption of s.rgarr. Apparently, no definitive studies have been undertaken to verify this. saponin reduces the absorption of cholesterol, as has been already discussed, by forming an insoluble addition product. It might u" unii"iput"d that saponin would combine with other sterols ol similar structure such as those with vitamin D activity and interfere with their absorption. However, coulson und Euuo, (1960) found no influence of euilllja .upo.rio on the absorption .i on on its. curative effect pudelkiewicz upon rick-ets. a1d'vtun".roo-irgsgl"[o"a"rool reported evidence of a fraction in alfalfa, thal thgy suggested might be saponin, which fered with the inter_ absorption of vitamin E. Later work-showed ihut tt" inhibitorv 628 cANADIAN JouRNAL oF ANTMAL scIENcE (1931) states that saponins fraction was not saponin (olson et al., |966). Ewart but.does not cite the source favor the absorption of .ufir of calcium and magnesigm, the absorption of various of this information. He also states that saponi-ns enhance alkaloids.sothatttretethaldoseisloweredinthepresenceofsaponins. MBTABOLISM OF SAPONINS have been reported,. to the No direct studies of the metabolism of forage saponins can be made. Saponins are author,s knowledge, t"t^" i"* l""eral obsErvations *"+g be expected to be nondialyzable tl_inoahi it)i., ,:gsl>, so their absorption toxicity studies; Sollman low. A low level of ;;;6li;' utro be deduced frorn (Igsl)statesthatsaponinsarefroml0to1000tirnesmoretoxicwhenad-"un sapom]r was fo'und to be intravenousl^y than when given orally. Alfalfa ministered than intraruminally times more toxic to sheep when given intravenously about 50 to find either (Lindahl et al', fgSt. Clstet"61 et aI'"(1968) wer-e mice"9t *t"following oral ad- saponin or sapogenin in the blood of chicks, rais and also indicated that soy- ministration of soybean saponin. However, their studies indicating that saponin, Oo ,rrt pro6""" groryttr inhibition in these species, bean of substantial potency may be t"., ittoin that oI other legume saponins' ]he.lack absorbed. Henie, these biological effects j;J b; a result-of-their nol being -id; saponins are not ab- studies cannot Uu considered as conclusive evidence that wall has not been ob- sorbed. While absorpti'on of saponins across the rumen to the rumen has been indirectly served, the passage #;;;;;il flom $e blood et al. (1957) found that intravenously administered demonstrated . Lindahl pi::T"^:Li:1",1" saponin resulted in utout io ,tteei'- eitnougtr this suggests nefvo{ls" system causrng lm- fro,m the blood to the rumen, an effect on the central paired eructation cannot be completely discounted' Destructionofsaponinsinthedigestive,tractofbothruminantsandmono- For personal use only. Gutierrez and Davis gastrics has been observed. Gutierrei et al' (195$ anq bacter\a, with the pro- (1962) reported breakdown of legume saponins by rumen Gestetner et ql- (1968) duction of volatile t"UV cart[n dioxiie and a slime. ""iOr, mice and chicks' Ingested studied the metabolism of soybean saponins in rats, soybeansaponins*"."t'yo,otyzedinto^sapogeninsandsugarsbythececalmicro- enzyme speciflcity- was flora of all three ,p""i".] A saponin-hydrolyzing .?f that.lo* it also hydrolyzed isolated frorn the cecal microflora of rais; it is in*teresiing major.sites of absorption' alfalfa saponin. Since saponin in the cecum is past the is tfr" ,i!"in'"u""" of siponin dissimilation in monogastrics """ut 'ncertain'

Can. J. Anim. Sci. Downloaded from pubs.aic.ca by 114.79.53.84 on 10/07/12 CONCLUSIONS Dietarysaponininhibitsthegrowthofchicks,andisafactorlimitingtheamount ofalfalfathatmaybeincorporatedintopoultryrations.othermonogastricspecies specificity in growth received less attention, but there is evidence of species have on swine to ingesteJ;;p;fi"' studies of effects of saponin response -No..direct to me€t a portion of performance fruro" U""Jieported. Since the use of alfalfa the signifi- needs oi swine'may be econcmical under some conditions' the protein such in' of alfalfa ,*io" p"tto(mance should be evaluated. cance d;i"; selection for low- formation would also be of value to plant geneticists, since Evaluation of the effects saponin alfalfa .""*. t"utiUf" lJot'u" uttd Eilioit' 1969) ' as the guinea pig and rabbit, of saponins ir, .o"r, *o"ogastiic laboratory animals CHEEKE_SAPONINS: A REVIEW 629 which are often fed hrgh-alfalfa rations, woul{ also. be appropriate. saponins may have useful applications in some instances, since in i"s they form complexes with cholesterol- -o"ogu'rt an! may help to lower tissue cholesierol levels by reducing its reabsorption from the intestinal tract. rn ruminants, neithe, growth depression nor reduced tissue cholesterol levels due to saponin ingestion have been demon- possibly because :trateq, of bacterial dissimilaiion or ti; ;;;o"in in the rumen. Saponins may 'bloat be significant factors in the development of in ruminants. Although in recent.years interest in saponio, u, iuurutive factors of bloat has their properties lugg:d, suggest that they *ota u" involved in stabte foam formation in the rumen. This review has summarized the limited knowledge of saponin metabolism and indicated some areas where further investigation ir #*.unt"a. Since saponins are a part of the diet of any animal consumin-g alfalfa o. otrr"r-for"g. l"gfi;r; i; is desirable to be aware of what efiects, if aiy, trr"r"-""-f."nds may have on metabolic processes. LITERA'IURE CITED ANDERSON' J' lg57' o' Effect of alfalfa saponin on the performance of chicks and laying hens. Poult. Sci. 36: g73_g76. BELL' J' M' 1960' A comparison of fibrous feedstuffs growth in non-ruminant rations: Effects on responses, digestibility, rates of passage and ingesta 40: 7l-82. volume. can. J. Anim, Sci. BrNNs' and w' PEDERSEN, M. w. 1964. Effect of feeding high saponin alfalfa four-month old Horstein-Frieiian hay to bulls. m*. Tirr- b."t.^;;'R""#T ri,*r,"tiorr, chioago, Ill. BOHMAN, v' R., KIDWELL, J. F. and MccoRMrcK, J. A. 1953. High levels of alfalfa in the rations of growing-fattening swine. i-ani-. sci. 12: g76-gg0. BUCKINGHAM, J. H. 1970. of pH, concentlllio1,-and temp€rarure of cytoplasmic protein _Effect on the strength foams. J. Sci. Food Aii. zt, 441_445. CHEEKE, P. R. and oLDFIELD, J. E. 1,969. In vitro inhibition of succinate and pyruvate

For personal use only. oxidation by ethanolic extracts of grasses,-i"grr-.., and dystrophogenic forages. Anim. Sci. 49: 402-4:04. can. J. CHEEKE P' R' and OLDFIELD, J. E. 1970. In vitro inhibition of succinate oxidation by alfalfa saponin. Can. J. Anim. Sci. S0: tT7_1i2. CLARKE, R. T. J. and REID, C. S. W. 1970. Irg.ume bloar. pp. 599_6O6 rn physiology digestion and metabolisrn in the ruminant, of n. r. bnitrys.n, 6ir"i prJss, ua., Newcastle_ upon-Tyne, England. "a. CONRAD, H. R., W. D., BENTLE', O. G. and FET-IER, A. W. 1958. pro_ duction of gas in 'OUNDER,rumen fermentations anc -stali" -a"* r".-uti.n ir'o- alfalfa fiber and pectic substances. J. Dairy Sci. 41: 15g6_1592. coulsoN, c. B' lg57' properties of lucerne and other saponins. Biochem. J.67: r0 p. coulsoN, c. B. and DAVrEs, T.

Can. J. Anim. Sci. Downloaded from pubs.aic.ca by 114.79.53.84 on 10/07/12 saponins. properties -1962. rI. Fractionation and pharmacorogicar of lucerne saponins. J. Sci. Food igr. 1r3: 53_57. couLSoN' c' B' and EVANS, R' A. 1960. The effect of saponin, sterols----" and linoleic acid on the weight increases of growing rats. Brit. J. Nutr. M: tzt'-lii'.' DOLLAHITE, J' prGEoN, w" R. F. an. cAMp, B. J. 1962. The toxicitv of gallic pyrogallol, tannin acid and, acid, euercus harvardi inihe'rabbit. a-".. l.-%i. Res. DOUGHERTY, zs: 1264_1.267. R. w. 1970. Discussion of the paper by crarke and Phvsiologv of digestion Reid. pp. 607_6ll in and metaboris- i; ih"-;;"rrirunt,'a.-r.'prrilrjp."", oriel press, Ltd., Newcastle-upon-Tyne, England. "a. EWART' A. J. r93r. The poisonous action of ingested saponins. commonw. Aust. Sci. Ind. Res. Bull. No. 50. counc. *.*. re66. Biological #:*il:Ytl]r}: and phytochemicar screening of plants. J. pharm. scIENcE 630 CANADTAN JouRNAL oF ANTMAL concentration of SYMONS' L',D'-.1969' Eftect of diet on FONNESBECK, P' V. and ui*i-pr"ttu of horses' J' Anim' Sci' 28: protein, urea nitrogen, #;; ;;d;;ilt*tr "t t;"#:;,L. !' E'' RATNEY. I'' BRowN' P' B' and E., cIRouARD, R' D', I.HNST'N ' ti*i J' Dairy Sc. 51: W,,',S, W. H. 1968. poioxalene for pr"u"tiioo l-i'f"go-" 584-590. . ..Frr^rn v Fate of ingested Y' and Y'. 1968' Sovbean saponlns' GESTETNER, 8., BIRK, TENCFR' oi"t"tt"iiitmofvti" activity' J' Agr' Food soybean saponins unO tie ptvsoiogi*f uip..t Chem. 15: 1031-1035' 1962. Aotion of saponin on biological GLANERT, A. M., DTNGLE, J. T. and LUCy, J. A. -embtan"t. Nature 196:. 953-955' "eilGLICK,Z.andJOSLYN,fU'e'1970'-!^old.intakedepressionandothermetaboliceffects oitu""ic acid in the rat. J. Nutr' 100: 509-515' GRIMINGER'P.andnrsrren,rr.lg5S..D,ietarysaponinandplasmacholesterolinthe Soc. Exp. Biol' Med' 99: 42+426' .-fti"f."". Proc. bacteria from the J. and pivrs,n. n. 1962. Isolation of saponin-^.1_icqttlc GUTIERREZ, Anim' Sci' 21: 8L9-823' of bloating cattle'on-iadino clover pastures' I' rumen I' L' 1958' Dissimilation of alfalfa GUTIERREZ, J', DAVIS, R' E' and tt;umen bacteria' Science r27:-LINDAHL' 335' ;;t;;; LUTHER' II' G' L96r' The SHERMAN, W' C', REYNOLDI' W' M' and HALE, W. H., 'fa;te;i;g Lmbs and cattle' Proc' soc' Exp' value of certain steroidal sapogenins in rations of Biol. Med. 106: 486-489' et 1963' Saponin content of alfalfa C. H', KOHLER' G' O', DUDLEY aI' HANSON, '!'Yl'uu.iuUt"t' U'S' Dep' Agr' Bull' No' 34-44' as related to location, cutting, variety and ott"t or sterols to plant srowth. Hfilt#ffiili'?. u"o BONNER, L te53. some relationships Plant PhYsiol. 2E: 428436' HENRICI,M.Lg52.Comparative,Jo-dv"IthecontentofstarchandsugarsofTribuluspintzn different metereological' edaphic terrestris,lucerne, ,o-" d*.-irr"* arrd lriciiii"d", ;;ffi;ft;Ga'*"aitit"t'- oodet"t"poott J' Vet' Res' 25: 45-92' HEYWANG,B.W.andBIRD,H.R.1954'.Theeffectofalfalfa-saponinonthegrowth,33l. 239241' For personal use only. Poult. sci. and utilization of chicks. diet consumption Effect of alfalfa "fdtfi'Ji-aieic' R' and A' R' lg5g' HEYWANG, B. W., THoMpiot't, -KEMMERER' t"p"ttl" ."liying hens' Poult' Sci' 38: 968-971' ISHAAYA,I.andBIRK,Y'1965'sovbealsaponins'IV'Tl"efiectofproteinsonthey."r. J. Food sci. 30: 118-120' inhibitory activity of soybean saponins or, ""rtuii'"tt and biological-properties of a respira- JACKSON, H. D. and sirew, n. n. 1g5g. {hemical rro* urtiit"u',uiloii;: At"it' sio"h"-' Biophvs' E4:. 411416' tory inhibitor B' W' and GOETSCH' DeVAULT, R'L',- fr{cN,eJnY' S' A'' HATCIIE'F:? JACKSON, H. D., inhibitor in Ladino clover and c. D. 1962. Bloat in;;;,1":' itr r"rutior,rrrip #J.".pir""w i"'pftotpftoiot fertility oithe soil' J' Anim' Sci' 21: 235-240' W' R' and HATCHER' B' W' 1959' Blood JACKSON, H. D., SHAW, R' A', PRITCHARD' i"*ge in vitro' J' Anim' sci' lE: Can. J. Anim. Sci. Downloaded from pubs.aic.ca by 114.79.53.84 on 10/07/12 changes of caule d"ri;';;;';J"a-""tr ot tri"'"ri"rr" for saponin in individuat arfalfa i:-_-*ir. and ELLrorr, F. c. 1969. Two rapid assays plants. CroP Sci. 9: 688-691' JoNEs,W'T.andLYTTLEToN,J.w._196g.Bloatincattle.XXIX.Thefoamingpro- N'Z' J' Agr' Res' l2z 3I-46' J"iJt tt in cattle' XXXItr' "r."ei-proteins' J- W' and CLARKE' R' T' J' JONES, W. T., LYTTLETON, their'1910' relationship 'Bloat to bloat' N'z' The soluble proteins of legume forages in New ;-ril;d;;;e I. Agr. Res. 13: 149-t56' KENDALL,W.A.1966.Factorsaffectingfoamswithforagelegumes'cropsci'6: 487-488. 1951' Chick growth depressing factor KODRAS, R., COONEY, W' T' and BUTTS' J' S' Poult' Sci' 30l. 280-292' in sun-cured ana oerryJraiei'afaffa meals' CHEEKE-SAPONINS: A REVIEW 63I LINDAHL, I. L., DAVIS' \. E., TERTELL, R.T. et ar. 1957. Alfarfa saponins. studies chemical, pharmacological and physiological -o-n^thgir properties in relation to ruminant bloat. U.S. Dep. Agr. Tech. Bull. No. 1161. Washington, O.C. MANGAN' J' L' 1959' Bloat in cattle. XL The foaming properties of proteins, saponins and rumen liquor. N.Z. J. Agr. Res.2; 47_61. McARTHUR, J. M. and MILTTMORE, J. E. 1966. pasture protein. bloat. and the role of lg-s Proc. l0rh Int. Grassl. Congr., Helsinki, Finland. pp. Sf S_iZi. McARTHUR' J. M. and MILTTMORE, J. E. 7969a. Broat investigations. The pH ot rumen contents and its rolein legume bloat. can. J. Anim. sci. 49: 59--67. . McARTHUR, J. M. and MILTTMORE, J. E. lg6gb. Bloat investigations. Studies on soluble proteins --Cin. and nucleic acids in bloating and nonbloating forages. r. Anim. Sci. 49: 69-7s. McARTHUR' J. M., MTLTTMORE, J. E. and PRATT, M. J. 1.964. Bloat investigations. The foam stabilizing protein of alfalfa. can. J. Anim. sci. 44: 200-2o6. McNATRY' s. A., coETscH, c. D., HATCHER, B. w. and JAcKsoN, H. 1963. Further D. observations on.the relationship of bloat in iattle to t".pi..tory-inhibiiion in vrtio ay alfalfa saponins. J. Anim. Sci. 22: 6I-55. MILTIMORE, J' E., M.ARTHUR, r. M., MAsoN, J. L. and ASHBy, D. L. rgio. Bloat investigations. The threshold fraction I (18s) protein concentration for 6toat and relationships betweetr,bloat and lipid, ca, Mg, Ni and zrr^concenttations in alfalfa. can. J. Anim. 50:61-68. sci. ryETKE, s' P., scorr, I,r. M. and ALLEE, G. L. 1969. Effect of excess amino acids on the utilization of the first limiting amino acid in chick diets. J. Nutr. w: ls_st. NEWMAN, H. A. KUMMEROW, I., F. A. and scorr, H. M. 1958. Dietary saponin, a factor which may reduce liver and serum cholesterol levels. poult. Sci. 37: 42_46. NORD, E. c. and vAN ATTA, G. R. 1960. saponin A seed germination inhibi,tor. Forest Sci. 6: 350-353. - oLSoN, PUDELKIEWICZ, c., w. J. and MATTERSON, L. D. 1966. Isolation of a compound from alfalfa lipids that inhibits tocopherol deposition in chick tissues. J. 90; r99-2M. Nutr. PEDERSEN' M. w.' ztMMER, D. E., McALISTER, D. R' et al. 1967. comparative- studies of saponin of several alfalfa varieties using chemical and biochemi"ut For personal use only. Crop Sci.7: 349-352. "ruyr] PETERSON' D. W. 195aa. Effect of sterols on the growth of chicks fed high alfalfa diets or a diet containing Quillaja saponin. J. Nutr. 42:, 597-6O7. PETERSEN' D. w. 1950b. Some properties of a factbr in alfalfa meal causing depression of growth in chicks. J. Biol. Chem. lE3: 647-653. POTTER' G. C. and KUMMEROW, F. A. 1954. Chemical similarity and biological activity of the saponins isolated from alfalfa and soybeans. science tz|: z2i-22s. PUDELKIEWICZ'W. J. and MATTERSON, L. D. 1959. Increased excretion of tocopherol by the chick when fed alfalfa. poul,t. Sci. 38: 1238 (abstr.). RAYUDU' c' v. N.' KADTRVEL, R., voHRA, p._""9 KRATZER, F. H. t970. Toxicity of tannic acid and its metabolites for chickens. poult. sci. 49: 957-960. Can. J. Anim. Sci. Downloaded from pubs.aic.ca by 114.79.53.84 on 10/07/12 ROBINSON' T. 1963' The organic constituents of higher -Minn.plants. Their chemistry and interrelationships. Burgess Publishing Company, Minne,afolis, ROUGHAN, P. G. 1965. A succinoxidase inhibitor associated with fresh leguminous pastures. N.Z. J. Agr. Res. 8: 607-612. SCARDAVI, A. and ELLIorr, F. c. 1967. A review of saponins in alfalfa and their bioassay utilizing Trichoderma sp. euart. Bull. Mich. Agr. r*p.3ta. soi--163_177. sEGEr MAN' A. B., FARNSWORTI{, N. R. and eurMBy, M. B. 1969. Biological and phytochemical evaluation of plants. rrr. False negative-saponin test results inducei by the presence of tannins. Lloydia 32: 5L58. SHAW' R. A. and JACKSON, H. D. 1957. Fractions from Ladino clover which inhibit biological systems. J. Anim. Sci. 16: 711-718. 632 cANADIAN JoURNAL oF ANTMAL scIENcE respiratory inhibitor from alfalfa' SHAW, R. A. and JACKSON, H. D. Lg59. Isolation of a Arch. Biochem. Biophys. E4: 405-410' to therapeutics and SoLLMAN, T. H. 1957. A manual of pharmacology and its applications ioxicology. Ed. 8' W. B' Saunders Co', Philadelphia' VANATTA,G.R.,GUGG5LZ,J.andTHOMPSON'C'R'1961'Determinationof saponins in alfalfa' J. Agr. Food Clrem' 9: 77-79' trefoil' J' Pharm' WALTER, E. D. 1961. Isolation of oleanolic acid and saponin from Sci. 50: 173. D., BICKOFF, E. M., THOMPSON, C'R', ROPINS-ON^' C' H' and DJERASSI' WALTER, E. Amer. chem. soc. 76: c. 1955. Saponin tro- iuoi"o'clover (Trifofium repens). J. 2271-2273. the surface tension of WOODWARD, H. E' and AISBERG, C' L' 1916. The relation of 109-110 (abstr')' saponin solutions to their hemolytic activity' J. Pharm. Exp. Ther. 8: For personal use only. Can. J. Anim. Sci. Downloaded from pubs.aic.ca by 114.79.53.84 on 10/07/12 This article has been cited by:

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