Infertility in humans is a problem that affects both males and females of the reproductive age. Since there are a variety of causes for infertility, different methods of treatment are needed. Some common drugs used in the treatment of infertility, include Clomiphene, HCG and HMG; yet these drugs have limited effectiveness, significant side effects, and sometimes, high prices.
Raw materials of plants and their total extracts are used in the pharmaceutical industry. Fewer side effects, low cost, and easy use are the main factors that interest people in taking herbal drugs. The purpose of this study was to investigate the effect of hydro-alcoholic extract of celery leaves on the delivery, gender ratio, and weight of infants.
According to this study, celery did not affect delivery rates in female rats. There is no experimental study performed in this regard, yet according to the results of one study, celery did not show anti-implantation effect in females (
18).
The findings of this study showed that the consumption of celery in female rats increased the number of newborns without any miscarriages or stillbirth. Celery has powerful antioxidant properties due to having flavonoids, which are a class of phytoestrogens. Phytoestrogens, through inhibiting progesterone breakdown, can enhance endometrium and have beneficial effects on progesterone (
19). It has been shown in female rats that beta-sitosterol as a phytosterol increases the activity of glucose-6-phosphate dehydrogenase in uterine, and increases the net weight of the uterus, which implies the strong estrogenic effect of phytosterols (
20). On the other hand, quercetin, which is one of the important flavonoids in celery, has been examined in numerous experimental studies. A research found that quercetin improves the endometrial thickness of both the dense and spongy layer. Moreover, it also improves the number and density of cells and glands in the endometrium in ovariectomized rats (
21,
22). In normal conditions, there is a balance between the production of free radicals and active oxygen species and antioxidant defense system. Flavonoids are one of the secondary plant metabolites that eliminate harmful free radicals. These compounds cannot be synthesized by the human body and must be received through the diet. Celery is one of the plants that are rich in flavonoids such as apigenin and apiein. It is also rich in vitamin E and C (
15). These natural antioxidants improve fertility parameters by inhibiting free radical damage (
23). On the other hand, celery probably contributes in infants health and normal delivery due to its anti-spasmodic properties and preventing aberrant uterine contractions (
24).
According to the results, celery did not affect infant’s gender due to the antioxidant properties of celery. Experimental studies have shown that changing environmental conditions and stress can disturb the balance of gender ratio, but this finding requires further research (
25). In this regard, the study of plants, such as chicory, dill, apple, and fennel, showed similar results (
25,
26). The child’s gender can be affected by the mother’s diet, but this diet must be started at least one month before pregnancy. Researches have shown that father’s diets can also affect gender determination. Foods, which contain sodium and potassium, enhance the absorption of the Y chromosome by the oocyte through an alkaline vaginal environment (
27). In this study, these effects were not observed after consumption of celery. Perhaps if the extract was administered over a month, or the male rats also received it, then we would’ve observed different results.
According to the results, administration of celery extract in female rats can reduce birth weight. Celery contains compounds such as limonene, coumarin and karvon. In an experimental study, it was found that diets containing high levels of these compounds reduce the weight of rats (
28). However, these findings are based on birth weight on the first days after delivery, and these results may change after weeks.
The results of the present study showed that the consumption of celery leaf in females was ineffective on delivery rate and gender ratio of infants, but it can increase the number of infants with weight loss. It should be noted that weight loss could be an important factor for those who consume medicinal plants in their diet. Therefore, their use should be appropriate. These results are needed for future experimental and pharmacological studies, and more investigations are required on biochemical, morphological, hormonal and histological factors to improve fertility parameters by diets of pregnant women in a safe way.