An Investigation of Orotic Acid Levels in the Breastmilk of Smoking and Non-Smoking Mothers

European Journal of Clinical Nutrition (2002) 56, 958–960 ß 2002 Nature Publishing Group All rights reserved 0954–3007/02 $25.00 www.nature.com/ejcn ORIGINAL COMMUNICATION An investigation of orotic acid levels in the breastmilk of smoking and non-smoking mothers

F Karatas1*

1Department of Chemistry, Firat University, Elazig 23119, Turkey

Aim: In this study; orotic acid levels in the milk of smoking and non-smoking mothers were investigated by high-performance liquid chromatography (HPLC). Results: It was found that the amount of orotic acid in the milk of smoking mothers (3.92Æ 0.20 mg=ml) was higher than that of non-smoking mothers (1.66Æ 0.15 mg=ml). Orotic acids levels in the milk of smoking mothers in comparison with non-smokers were found to be statistically signiﬁcant (P < 0.005). Conclusion: Smoking may have increased the orotic acid levels by affecting pyrimidine biosynthesis pathway. European Journal of Clinical Nutrition (2002) 56, 958 – 960. doi:10.1038/sj.ejcn.1601420

Keywords: breastmilk; orotic acid; smoking; HPLC

Introduction amounts of orotic acid were applied, the above effects Breastmilk is regarded as a perfect food for a baby. It accel- occured over longer periods (Witting, 1972; Durschlag & erates the development of the baby’s body and enhances the Robinson, 1980). It was noticed that orotic acid is one of resistance to diseases. Breastmilk is superior to all other milks the factors causing liver cancer (Rao et al, 1985). It was also in terms of the baby’s general development. It contains reported that this acid damages the DNA in liver of rats (Rao various growth factors, such as hormones, enzymes, vita- et al, 1985) and inhibits DNA synthesis (Sheikh et al, 1993). mins, nucleosides and nucleotides along with essential Constituents of breastmilk vary with the food taken by amino acids, fatty acids and all other substances that are the mother (Piccino, 1998). Smoking has a negative influ- necessary for the development of the eyes and the brain ence on breastmilk volume, and the lower growth rates of (Hamosh, 1996; Koletzko et al, 1998). infants of smoking mothers also suggest that their breastmilk One of the trace substances in breastmilk is the orotic acid output is insufficient to support the energy requirements of found in orotate anion form (Robinson, 1980). It has been their infants (Vio et al, 1991). It is known that smoking reported that the amount of orotic acid, which is an inter- damages tissues and organs of the human body. However, mediate metabolic of pyrimidine biosynthesis pathway, in interestingly, the number of smoking mothers is still increas- ruminants’ milk is higher compared to other mammals ing rapidly. (Witting, 1972; Piccino, 1998). The purpose of this study was to investigate the effect of In a study by Durschlag and Robinson (1980), it was smoking on the orotic acid levels of lactating mothers. shown that 1% orotic acid in the diet applied to rats caused fat in liver, damaged the metabolism and decreased the purine – pyrimidine ratio within 7 days. If smaller Materials and methods The amount and composition of breastmilk are influenced by the food taken by mother as well as the timing of beginning and the continuity of breastfeeding (Piccino, 1998; Hopkinson et al, 1992). Therefore, milk was taken from mothers who were healthy and had similar income levels. Since the amount of the orotic acid in milk varies *Correspondence: F Karatas, Department of Chemistry, Firat University, 23119 Elazig˘, Turkey. depending on the lactation period (Wahab & Anderson, E-mail: [email protected] 1988; Mortly et al, 1991), the milk samples were collected Orotic acid levels in smoking and non-smoking mothers F Karatas 959 from smoking and non-smoking mothers who had babies Table 1 The characteristics of smoking and non-smoking mothers and 47Æ 13 and 46Æ 12 days old, respectively. The samples were the level of orotic acid in their milk collected from 17 smoking and 20 non-smoking mothers. Smoking mothers Non-smoking mothers The average ages of smoking and non-smoking mothers were (n ¼ 17) (n ¼ 20) P 28Æ 3 and 30Æ 3, respectively. Three samples were taken Orotic acid (mg=l) 3.92Æ 0.20 1.66Æ 0.15 < 0.005 from each mother in a 5 day period. Age (y) 28.3Æ 3.0 30Æ 3 Milk samples were collected with a vacuum breast-pump Number of children 2Æ 12Æ 1 and placed into sterilized PVC tubes and transported to the Lactation period (days) 47Æ 13 46Æ 12 laboratory under refrigerated conditions. The samples were analysed as soon as they were received at the laboratory. Analytical grade chemicals from Merck (Germany) and ultrapure distilled water were used throughout the analyses. Further, the rate of abortions, stillbirths, prematurity in A portion from each sample (3 ml) was used for orotic acid smokers is much higher than in non-smokers (Arya et al, determination. The orotic acid levels in the milk were deter- 1991), and it is observed that serine, proline, alpha-amino- mined by high-performance liquid chromatography (HPLC; butyric acid, leucine and particularly arginine levels in

Cecil 1100, UK) with a C18 column (25 cm, 3.9 mm i.d., 0.25 smokers are much lower than in non-smokers (Jauniaux inch o.d., Techopak) and UV detector according to the et al, 1999). It was reported that the deficiency of arginine method described by Counotte (1983) and Banditt (1994). in rats increases urea, sitric acid and orotic acid levels in the The data obtained were evaluated by Student’s t test (t-test for ureter. This deficiency results in orotic aciduria due to independent samples of the group) and results were pre- arginine deficiency (Milner et al, 1975). Furthermore, it was sented as the meansÆ s.d. (significance level of 0.005). determined that arginine-deficient diets cause the increase of endogenous synthesis of orotic acid levels (Vasudevan et al, 1994). Results and discussion On the other hand, it is a known fact that heavy metals Tobacco and smoke contain many heavy metals (Oto & decrease or inhibit the activity of many enzymes. One of 0 Duru, 1991), nicotine and derivates of nitrosamine (Richter them is uridine-5 -monophospate (UMP) and its derivatives et al, 1992). Most of these materials in cigarettes have been (Amici et al, 1994). UMP synthase catalyses the conversion of 0 reported to increase the cancer risk. It has also been proved orotic acid to orotidine 5 -monophosphate (OMP) and then that smoking plays an important role in the development of to UMP (Suttle, 1989). In a study done by Robinson et al diseases such as oral cavity, larynx, bladder and coronary (1983,1984), it was shown that with UMP deficiency the artery disease, leukaemia and is a contributing factor in the level of orotic acid in milk of cows increased. development of cancer of the lung, pancreas, stomach, Gil and Sanchez-Medina (1982) reported that breastmilk cervix, liver, penis and rectum (Sherman, 1991; Arya et al, does not contain orotic acid, although Mu¨nchberg et al 1991). (1971) had reported an orotic acid concentration of

Figure 1 The orotic acid levels in the milk of smoking and non-smoking mothers.

European Journal of Clinical Nutrition Orotic acid levels in smoking and non-smoking mothers F Karatas 960 1.6 mg=ml in human milk. This value is in agreement with Milner JA, Prior RL & Visek WJ (1975): Arginine deficiency and orotic aciduria in mammals (39020). Proc. Soc. Exp. Biol. Med. 150, 282 – the results reported here. Table 1 shows the characteristics of 288. smoking and non-smoking mothers. It is clear that smoking Mortly T, Krzeminski J, Podgurniak M, Witeszczak C & Zochowski P and non-smoking mothers have similar characteristics. (1991): Variability of orotic acid concentration in cow’s milk. As indicated in Figure 1, smoking mothers’ milk have a Endocr. Regul. 25(1 – 2), 79 – 82. Mu¨nchberg F, Tsompanidiou G & Leskova R (1971): Studies on the mean concentration of 3.92Æ 0.20 mg=ml while non-smoking presence of orotic acid in milk. 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