CHAPTEE 11

'M OF LlTEEATUEfi Weeds are as old as agriculture itself. They form one of the most deleterious and expensive component in agriculture. It is of scientific interest that man has failed to control this persistent problem. On the other hand, he has seen them helplessly to create problems by their growing, spreading and disseminating seeds freely. About 30,000 weed species are widely distributed in the world; 1800 of which cause crop yield losses every year that make up about 9.7% of total crop production. Weed control has always been an important aspect of environmental protection. Over the past century, chemical herbicides have been effectively employed to control various weeds. However, they have caused many serious side-effects such as herbicide resistant weed populations, reduction of soil and water quality, and detrimental effects of herbicide residues on non-target organisms etc. (Te Beest and Templeton, 1985). Over the last decade, weed science research has shifted it's focus from herbicide discovery and its physiology to the study of weed biology and ecology. An overriding question is what makes a species a successful agricultural weed? This central question has been tackled fi-om a variety of angles, identifying and characterizing attributes contributing to weed success. Now a day's tools of physiology, molecular biology and genomic research are being utilized increasingly in these efforts.

In India, weeds in general have remained neglected for many decades, even though they affect economy of agriculture. Literature reveals that, the work on weed bracteolata Lam. in country and outside as well has progressed along the following lines like weed survey, physiology, phytochemistry, pharmacognosy, ecology, pathology, and microbiology etc.

Aristolochia is an important genus of order from the sub-family Aristolochoideae of family and represented by 500 species (Kiew, 1999).

Etymology

The name Aristolochia (meaning the best delivery or birth) is thought to be of ancient Greek origin and reflects centuries of use in obstetrics aristos meaning "best" or, originally, "most fitting" and lochia which means "delivery." This is due to its original use to expel the placenta after childbirth. Other traditional uses include

12 treatment for snakebite, scorpion stings, fever, infection, diarrhea, and inflammation (Arlt et al, 2002, Jimenez - Ferrer et ai, 2005). Aristolochia hracteolata Lam. is commonly known as English - Wormkiller, bracteated Birthwort; Hindi- Gandan, Kidmari; Sanskrit - Dhomapatra, Gridhrani, Kitkaha, Kitari; Gujrati - Kidmari; Marathi - Gandhan, Gandhati; Kanada - Kattackirubangida; Malayalam - Aduthinnapala; Orya - Paniri; Tamil - Adulthinnapalai; Telgu - Gadugagudupa (Kirtikarc-/a/.,2005). Origin and phylogenetic information Aristolochiaceae family has been recently the subject of more attention because of the suggestions that these basal angiosperms are phylogenetically close to the divergence of monocots from dicots. Aristolochiaceae was traditionally placed in subclass Magnoliidae and thought to be related to woody members of the subclass Annonales; however, the first morphological cladistic analyses of basal angiosperms supported relationships of the family with other predominately herbaceous (Piperales, Nymphaeales, Lactoridaceae) and the monocots. Subsequent phylogenetic studies supported relationships of Aristolochiaceae with more restricted set of paleoherbs (Lactoridaceae, Piperales, monocots), as well as Magnoliales, Laurales, and Chloranthaceae (Kelly and Gonzalez, 2003).

Phylogeny of Aristolochiaceae based on parsimony, likelihood and Bayesian analyses of tm L- tm F sequences has been done to resolve position of Aristolochiaceae in Piperales (Neinhuis, 2005). This study addresses the overall generic relationships in Aristolochiaceae and its position in Piperales based on dense taxon sampling and sequence data from the plastid tmL-F region. All members of Aristolochiaceae have anatropous, bitegmic, crassinucellate, endostomic ovules with a few exceptions (Gonzalez, 2003). Razzak et a/.,(1992) studied pollination biology of Aristolochia bracteolata Lam. and reported that it is partially Protogynous. The flower exibits fly-trapping mechanism while pollen germination takes place within the dehisced anthers and on perianth parts.

Geographic Distribution Aristolochia is the genus of shrubs, or rhizomatous perennial herbs, often twinning, mainly distributed throughout the tropics, but some species occur in warmer temperate regions also. The greatest diversity in Aristolochia species is found in Central and South America (USDA, 2010). In Malesian region 28 species have been

13 reported (Anonymous,!948). Aristolochia tagala Cham, has the largest area of distribution occurring from India and China, throughout South - East Asia to Austraha. (Kiew,1999). Species oi Aristolochia usually occurs scattered, often in primary forests, but some species are also found in secondary forest and scrub vegetation. The genus Aristolochia consists of species of herbaceous perennials, undershrubs or shrubs bearing essential oils and is widespread across tropical Asia, and South America. Most European and tropical species of Aristolochia are believed to be pollinated by small flies attracted to the flowers by the foetid odours and purple- brown colour. Flies enter the flower when the stigmas are receptive and are trapped until after the anthers dehisce (Solereder, 1889). More than 30 Aristolochia species are native to the United States and occur in almost all states (USDA 2010). Indian Status About 15 species of Aristolochia occur in India of which three namely v4. bracteolata Lam., A. indica Linn, and A. tagala Cham, are usefiil in medicine (Santapau and Henry, 1973). The presence of Aristolochic acid, a nitrophenanthrene compound with tumour inhibiting properties, appears to be characteristic of the genus (NTP, 2008). Among these, Aristolochia bracteolata Lam. is most dominant in India and globally distributed in Tropical Africa, Arabia, Sri Lanka, and Pakistan. Within India, it occurs in northern and central India from Haryana to West Bengal and southwards to Tamil Nadu and Kerala. It is one of the dominant weed species of Maharashtra often found in dry regions (Murumkar, 1993). Description Aristolochia bracteolata Lam. is a slender, decumbent, glaborous perennial with 30- 45 cm long. It is found to be distributed in hedges in the plains of Northern India from Haryana and Utter Pradesh and southwards to peninsular India up to Maharashtra and Andhra Pradesh. Leaves are varying variably in size and shape, reniform or broadly ovate, crenulate, undulate, long petioled. Flowers borne solitary, with perianth 2.2 - 5.0 cm long with subglobose base. Perianth tube cylindrical with trumpet shaped mouth and linear, dark purple coloured lip presence of glandular hairs within. Capsules are oblong-ellipsoid, 12 ribbed, glaborous. Seeds are deltoid with cordate base, rugose black on one side and whitish on the other, compressed (Wealth of India, 1982).

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Cultivation Several species of Aristolochia are grown as ornamentals chiefly on account of their remarkable, beautifiil and unusually shaped flowers. The bloom during summer as well as the monsoon, and bear a succession of highly coloured, mostly foetid flowers of variable size and shape. The individual flowers may last for a couple of days in sheltered positions. Although erroneously called 'Fly Catchers' i.e. Aristolochias are not insectivorous, but are insect pollinated plants i.e. entomophilous.

The ornamental plant requires plenty of sun, protection from hot winds and mulch in the plains for overwintering. Garden soil mixed with leaf moulds and cowdung is desirable for cultivation o\ Aristolochias. Propagation is usually by seeds or by layering and cutting taken from well matured wood in early spring or at pruning time (Bor and Raizada, 1954). Germination Reports of germination studies are meagre. Only a few reports are available stating that Aristolochia seeds exhibit seed dormancy and highlighted various treatments for breaking seed dormancy. Maekawa, (2010) reported that presence of light and temperatures at 25*'C and 30 C favoured seed germination and normal seedling formation in A. esperranzae Whereas treatment of long period of cold stratifying temperatures was required for growth of underdeveloped embryos and seed germination in A.calfornica, A Macrophylla, A.tomentosa and A.manshurensis (Christopher, 2005). Anatomy Nair and Narayanan (1962) studied the Nodal and floral anatomy of Aristolochiaceae and reported that in A. bracteolata Lam. the vascular system of the axis, immediately below the node, consists of nine large, widely separated collateral vascular bundles. All of them enter the lamina to display the characteristic palmate venation. The leaves in A.bracteolata Lam. are cordate and palmately veined. The stomata are present only on the lower surface and are of the Ranunculaceous type (Metcalfe and Chalk, 1950). Foliar stomatal development in three species of Aristolochia has been studied by Philip (1983).

15 Conservation Status All species of Aristolochia are included in list A of Schedule I of the Export (Trade) Control Order, 1988 as the export of this plant and it's derivatives is banned. Collection of plant material from Reserved Forests is restricted under the Indian Forest Act. Low Risk-Least Concerned status has been assigned to the Aristolochia bracteolata Lam. in red list medicinal plant species. Kayode and Ogunleye (2008) included A.bracteolata Lam. in rare category in his "Checklist and Status of Plant Species" which is used as spice in Kaduna State of Nigeria as is rich in natural products like Alkaloids, magnoflorine, aristolochine, aristolochic acid. Survey and Ethnobotanical Uses Members of Aristolochia has been used since ancient times in traditional herbal medicines in many parts of the world, and Aristolochic acid it contains has been reported to have antibacterial, antiviral, antifungal, and antitumor effects (Kupchan and Doskotch 1962, Zhang et ai,2004). As contemporary medicine, Aristolochia plant extracts have been used in therapies of arthritis, gout, rheumatism, and festering wounds. However, its use was discontinued in Germany and other countries after the carcinogenic and mutagenic properties of aristolochic acids were first reported in the early 1980s by Arit et al. (2002). Saha et al. (1961) presented a list of 277 medicinal plants possessing abortificient, emmenagogue as well as ecobolic properties, and Aristolochia bracteolata Lam. is one of them. Singh et a/.(1973) enlisted Aristolochia bracteolata Lam. as dominant terrestrial weed in his work on weed flora of Andhra Pradesh. Sankaranarayanan et a/., (2010) reported that this plant was used by traditional users from Villupuram district of Tamil Nadu for Ethnobotanical study of medicinal plants. The plant is used for treating foul ulcers, skin diseases etc. Leaves of this plant mixed with castor oil are applied externally to children's legs in obstinate cases of eczema, while roots used to treat male sterility. Masilamani (1997) reported that Aristolochia bracteolata Lam. is also practiced for snake-bite by Gounda Tribals of Tamilnadu. Dixit and Pandey (1984) reported that this plant is used as a folk medicine in Zansi and Lalitpur sections of Bundelkhand, Utter Pradesh. Earlier, Jamwal and Anand (1962) also reported that juice of whole plant was applied to ulcers. In Maharashtra also, this plant is used as a local medicine for curing ulcers (Deokule and Magdum,1992).

16 Conservation and Biotechnology Rao et al, (2005) reported occurrence of this weed in Ahmednagar district in Maharashtra and tried for its ex-citu conservation. Experiments on in-vitro propagation have been successfiil for A.bracteolata Lam. in India. Callus formation was observed from young leaves and roots placed on Murashige and Skoog medium supplemented with Kinetin, Naphthalene Acetic Acid and Indole Acetic Acid. Roots were initiated from callus when the concentrations of kinetin and indole acetic acid were increased. From a single nodal segment, 1-4 shoots were raised and grew 5-6 cm tall within 30 days (Gbadamosi, 2012). Whereas Sahaya (2011), standardized in vitro protocol for mass propagation of A.bracteolata Lam.using intemodal segments of explants on Murashige and Skoog's basal medium varying the concentrations of auxin and cytokinin. Similarly work of Sebastinraj (2011) emphasized the responses achieved in terms of direct regeneration from meristematic axillary bud explants oi A.bracteolata Lam. in-vitro studies. Medicinal uses

As early as in 1936, Kirtikar and Basu had reported this plant as bitter, purgative, anthelmintic and for destroying the larvae of insects. The root decoction is employed to expel roundworms and administered as a dry powder or infiision to increase uterine contractions. However, laboratory trials have failed to confirm this activity. It is also reported as an abortifacient, however, pharmacological trials have not accepted this claim. The bruised leaves mixed with castor oil are applied externally in eczema. The oil is also applied to navals of childrens in colic and also given internally with castor oil. Jamwal and Anand (1962) had reported this plant also during preliminary screening for some abortifacient indigenous plants. Other reports for traditional uses include treatment for snakebite, scorpion stings, fever, infection, diarrhoea and inflammation (Arit et al.,2002). Aristolochia is reported to be poisonous to man as well as live stock. It also possess insecticidal as well as insect repellent properties due to the presence of aristolochic acid (Chopra et a/., 1956). In the indigenous system of medicine, the decoction of leaves is used for treating skin diseases and rheumatism (Anjaria et al,2002). It has been used for treatment of roundworm infection (Nadkami and Nadkami, 1954). The root and leaves of this weed A. bracteolata Lam are bitter.

17 acrid, thermogenic, cathartic, anti-inflammatory, antibacterial and useful in constipation, foul ulcers, eczema and intermittent fevers (Warner et al, 1994; Joy et a/., 1998).

In Rajasthan, the seeds are employed for softening hair. The seeds yield yellowish green non-drying oil on petroleum ether extraction. Zarroug et al, (1988) observed that out of eight plants studied only Aristolochia bracteolata Lam. extracts showed larvicidal activity.

Phytochemistry

Since the Greek-Roman period, Aristolochic acid, a constituent of Aristolochia species, has been used for medicinal purposes (Pezzuto et a/., 1998). Several investigations have been carried to evaluate the role of aristolochic acid in medicine in different species of Aristolochia namely A. elegans (Shi et al, 2004), A. albida (Lagide et a/., 1993). A. papillaris (Lemos et al., 1993) A. mollissima (Yu et al., 2007), A. tringularis (Rucker et al, 1981), A. fangchi (Martinez et al, 2002), A. constricta (Rastrelli et al, 1997), A. cucurbitifolia (Wu et al, 1999), A. rodriguesii (Correa et al, 1998), A. pubescens (Nascimento and Lopes, 2003), A. anguicida (Gaitan et al, 2002), A. malmeana (Messiano et al, 2008), A. cymbifera (Leitao et al. 1992). A. hamissonis (Bomm et al, 1999), A. ringens (Larrahondo and Acevedo,1990). The taproot of ^. bracteolata Lam. bears gradually tapering branched roots and numerous fibrous rootlets. The root has no characteristic odour but has a nauseously bitter taste. The root powder exhibits a violet fluorescence in ultraviolet light when mounted on nitrocellulose. The root contains aristolochic acid, potassium chloride and nitrate in large amounts (Prasad and Vohra, 1960). Extensive investigations on the terpenoides of Aristolochia genus have been carried out by Tian -shung et al, (2004). Also Pacheco (1981, 2007, 2009) presents a compilation of large number of terpenoidcompounds, particularly diterpenes and the 13C-NMR data of 57 diterpenoids isolated from Aristolochia species. The compounds are arranged skeletonwise in each section, according to their structures, i.e., clerodane, labdane, and kaurane derivatives. Tian et al, (2011) worked on Chemical constituents and Pharmacology of the Aristolochia species and concluded that aristolochic acid concerns with nephrotoxicity. Heynauer (1960) made

18 chemotaxonomic studies to evaluate taxonomic position of Aristolochiaceae in dicots. Lopes and Bolzani (1988) had reported occurrence of lignans and diterpens from three species ofAristolochia including/i. hracteolata Lam. This plant contains several alkaloids like Aristolochic acid, aristolic acid, leutin and many other compounds (Anonymous, 1985). Saha et a/.,(1961) studied chemical constituents of Aristolochia plants and found that leaves and fruits of Aristolochia hracteolata Lam. showed presence of ceryl alcohol (Leaves, 0.38%, fruits, 0.12%), p -sitosterol and potassium chloride, besides alcoholic acid. Prasad and Vohra (1960) worked on phannacognostic activity in A.hracteolata Lam. They showed that root powder exhibited violet fluoroscence in UV light when mounted in Nitrocellulose. Isolation and characterisation of eupamatenoid derivatives was carried out by Enciquez et a/.,(1984). Whole plant A.hracteolata Lam yielded the aporphine alkaloid N. Acetylnoferine and aristolactam. (Chakravarthy et a/., 1988).

Screening of this plant for alkaloid content was done by Kokai, (1983) and Zhang et a/.,(1987). Magnoflorine and aristolochic acid -I were isolated from the seeds and their pharmacologic actions studied in Aristolochia hracteolata Lam. (Tahir and Kamal, 1991). Hussein (1970), isolated an alkaloid magnoflorine and two acidic compounds aristolochic acid and aristored in pure crystalline form. In addition, two unidentified quaternary alkaloids have been separated in small amounts in a crude form. Hassan et ai, (2004) determined phytochemical constituents and fatty acid composition of the refined seed oil of Aristolochia hracteolata Lam. The results showed that seed oil was rich in linoleic acid (39.0%) and oleic acid (32.8%).Trace quantities of epoxy and hydroxyl fatty acids were also present in the seed oil. Kalpana devi et ai, (2011) screened this plant for phytochemical analysis and biological property findings.

Allelopathy: Deokule and Avachar (2006) reported allellopathic influence of Aristolochia hracteolata Lam. on seedling germination of Cucumis sativus Linn. Allelopathic effect of aqueous extracts of Artistolochia esperanzae O. Kuntze on development of Sesamum indicum L. seedlings was studied by Gatti et a/.(2010). They observed significant changes in germination behavior and seedling growth. Greatest inhibition was recorded in primary root length, number of secondary roots and reduction in size

19 of root xylem cells of Sesamum seedlings when treated with root extracts of A. esperanze. Pharmacology Anti-Inflammatory Shiwaikar and Sorashekhar (2003) studied antioxidant effect of the ethanol extract from Aristolochia bracteolata Lam. leaves using nitric oxide and l,l-diphenyl-2 picryl hydrazyl (DPPH)-induced free radical assay methods which showed free radical scavenging activity, thereby supporting its anti inflammatory properties. Anti-bacterial Negi (2003) reported antibacterial activity in Aristolochia bracteolata Lam. root extracts. In another study, Aristolochic acid from roots of Aristolochia bracteolata Lam. was found to be good antimicrobial agent (Angalaparameswari et al, 2000). Manikandar et al, (2006) studied antibacterial activity in leaf extracts of A. bracteolata Lam. The species oi Aristolochia like in Aristolochia heterophylla and Aristolochia kaempferi also showed significant antibacterial activity of distilled water and chloroform extracts (Wu et al., 2000). Nagaragan et a/.,(2009) worked on comparative antimicrobial efficacy of ethyl acetate and ethanol leaf extracts of A.bracteolata Lam. Root, stem and leaf extracts o^ A. bracteolata Lam. was tested against three clinically isolated bacteria (Kadam et al, 2012). They observed maximum antibacterial activity in root extracts. Antifungal Ramasubramania and Niranjanbabu (2011) screened Aristolochia bracteolata Lam. for phytochemical, pharmacognosical and antifiangal activity and concluded that even minimum concentrations of ethanolic extract were effective against Trichiophyton rubrum and Microsporum canis responsible for ringworm infection. Kavita and Nirmaladevi (2007) also observed positive reports of different extracts of A.bracteolata Lam. against selected fungi. Antiplasmodial Tahir (1999) studied antiplasmodial activity of this plant in selected Sudanase medicinal plants with special emphasis on A.nilotica. This plant is also used as insect repellent against flies and maggots (Secoy and Smith, 1983). The extract of Aristolochia bractelolata Lam. exhibited inhibitory activity against Plasmodium falciparum strain. Aristolochia bracteolata Lam. was found to have a trypanocidal effect against Trypanosoma evansi (Samia et al., 2006).

20 Herbicide Myakado et «/.,(!986) reported Aristolochic acid from this plant extract having herbicidal property. Saxena (1979) concluded Aristolochic acid an insect chemosterilant from A. bracteolata Lam. Thirumal et a/.,(2012) gave detailed survey of literature of pharmacognosical, ehnobotanical, traditional as well as phytochemical and pharmacological reports on A. bracteolata Lam. Harbone (1988) reported toxicity of A. bracteolata Lam. due to supposed anthelmintic activity and trypanocidal effect. Zarrong et al. (1988) observed that out of eight plants studied only A.bracteolata Lam. showed slight larvicidal activity. Comparative lipid peroxidation inhibition of the two Aristolochia species viz A. indica and A.bracteolata was reported by Vijaykumar et a/.,(2003). Antioxidant Tiruganasampadan et a/.,(2008) observed that antioxidant properties of some medicinal Aristolochiaceae species including A. bracteolata Lam. Shirwaikar et al., (2003) observed that this plant showed positive effect on wound healing with significant increase in the level of antioxidant enzymes like super oxide dismutase and catalase in the granuloma tissue. Physiology Aristolochia bracteolata Lam. is a dominant weed of hot semiarid region persisting even in hot summer (Murumkar and Magdum, 1991). Occurrence of Crassulacean Acid Metabolism in leaves of A. bracteolata Lam. has been reported for first time by Murumkar and Deshmukh (1996). While in support of this data, Facultative CAM nature is exhibited in this plant (Kadam et a/., 2012) Aristolochic acid Aristolochic acid is characteristic feature of family aristolochiaceae and Aristolochia, spp. (Guan et al., 2005). It also has differential effects on human body. Some claim stimulation of white blood cell activity which gives remarkable healing powers, but is carcinogenic and damaging to the kidneys (Chevallier, 1996). Abdelgadir et al. (2011) have worked on isolation, characterisafion and quantification of aristolochic acid in A. bracteolata Lam. Jou et al., (2004) studied analogues of aristolochic acid and aristolactam in Aristolochia by HPLC, while Simultaneous determination of five aristolochic acids and two aristolactams in Aristolochia plants by HPLC has been confirmed by Zhang et al. (2006).

21 Rapid determination of Aristolochic acid I and II in some medicinal plants by HPLC has been given by Wei et al. (2004). Zhai et al. (2006) described method for separation and determination of Aristolochic acid in herbal medicines by microemulsion electrokinetic chromatography. The quantitative analysis of aristolochiaceae determined that all the species contain aristolic acid (Hashimoto et al., 1999). It was reported that Aristolochia produced intestinal nephritis caused by aristolic acid during treatment (Mengs and Stozen, 1993). Biosynthesis of Aristolochic acid. Biosynthesis of Aristolochic acid is illustrated by Sharma ct al, (1982). An important intermediate in the biosynthetic pathways of Aristolochic acid is the , which can be fonned from or a similar biochemical equivalent (Schutte, 1967). The incorporation of tyrosine 3, 4 dihydroxyl alanine nororientaline, orientaline(I), prestephaine(II) and Stephanine (III) into aric acid (IV) in A. hracteolata Lam showed that specific utilization of (1). Mukhopadhyay et al, (1983) in their study on Aristolochia showed that conversion of Aristolochic acid I to Aristolochic acid is one step removal of nitro group. Cytology

There are few reports on cytology of Aristolochia. In Aristolochia there are species with (n=7), aneuploid to (n=4) and polyploids (Raven, 1975). Somafic chromosomes of five species of Aristolochia including A. indica were investigated by Sharma and Verma (1959) and they concluded that A. indica, having the lowest number of diploid chromosome (2n=I2) with only one pair of chromosome and secondary constrictions, probably represents the most primitive species of the five studied. Sanjappa (1979) reported that Aristolochia bracteolata Lam. is with gametophytic number Six. Through screening of available literature on A. hracteolata Lam. depicted that this weed serves as local medicine and popular remedy among the various ethenic groups. It is interesting to note that crude as well as organic extracts of root, stem and leaves have been screened for pharmacological activities. However, the isolated principle needs to evaluate in clinical trials for the molecular mechanism of acfion in lead molecules fi-om natural resources. As global scenario is now changing towards the use of modem drugs from medicinal plants, for treatment of various diseases. Nevertheless, it must be admitted that in view of limited physiological studies in Aristolochia hracteolata Lam. the findings reported in the present investigation may

22 give broad idea about the working of important physiological processes like mineral nutrition and photosynthesis in this plant under unfavourable environmental conditions despite the possibility that these important factors are determining the response to arid conditions. It can be seen irom the forgoing account that most of the work done in Aristolochia bracteolata Lam. is in the field of pharmacology and chemical investigation. Although, antimicrobial nature is well documented in the above studies much is to be understood about the process like photosynthesis, nitrogen metabolism, effect of water stress as this is very common dominant weed in this arid region and blooms fully in summer season also.

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