Effects of Phytosterols as Food Additives on Adrenal and Reproductive Endocrine Function during Sexual Maturation in Male Japanese Quail (<i>Coturnix coturnix japonica</i>)

Abstract

Varying amounts of phytosterols (PS) occur naturally in several foods of plant origin. PS, which are structurally and functionally similar to cholesterol, have been shown to reduce plasma total cholesterol (TC) and low-density lipoprotein-cholesterol (LDL-C) levels.Moreover, PS disrupts endocrine function in certain animals. In the present study, we investigated the effects of high doses of PS on adrenal and reproductive endocrine function during sexual maturation in Japanese male quails. Two experiments were conducted; in the first experiment, quail chicks were subjected to long-term chronic feeding of PS (8, 80, and 800 mg/kg body weight [BW]) and the chemicals were gavaged into the crop sac from 7-50 days post-hatching. From the forty-fourth day, half of the animals in each group were subjected to a 6-day adrenocorticotropic hormone (ACTH) challenge for artificial stimulation of the adrenal gland and evaluation of long-term PS effects; in the second experiment, single doses of PS were subcutaneously injected (SC) into adult males (10-weeks-old) to assess the acute direct effect. Results indicated that chronically PS-fed animals showed a better adrenal response to ACTH challenge, and the corticosterone levels were higher (P < 0.05) than those of the controls. Moreover, corticosterone levels were also high (P < 0.05) 3 h after SC injection of PS. In contrast, testosterone levels and the testes weights were significantly lower (P < 0.05) in the groups chronically administered with PS. No differences were observed in the testosterone levels in the acute experiment or luteinizing hormone (LH) levels in either experiment. In conclusion, the differential effects of PS on the adrenal gland and testis might be due to preferential use of different lipoprotein-cholesterol forms for steroid production. In addition, PS might locally perturb testosterone production by its accumulation or delay in testicular maturation.

Effects of a new thyrotropic drug isolated from Potentilla alba on the male reproductive system of rats and offspring development

“…The long-term treatment of male rats with β-sitosterol resulted in decreased testicular weight and sperm concentration [ 28 ]. A more recent publication investigated the effects of phytosterols on the adrenal and reproductive functions of Japanese male quails [ 29 ]. Quail chronically fed with phytosterols significantly reduced testicular weight and testosterone levels.…”

Veganism and animal welfare, scientific, ethical, and philosophical arguments

“…The authors of a study of goldfish (Carassius auratus) found that when exposed to alimentation with β-sitosterol, their blood levels of sex steroids decreased, accompanied by a reduction in the gonadal capacity to perform steroidogenesis (Maclatchy and Vanderkraak 1995). Qasimi et al (2018) conducted studies with quails (Coturnix japonica) in which they administered phytoestrogens. They concluded that the adrenal glands and gonads preferred cholesterol for performing steroidogenesis (Qasimi et al 2018).…”

“…Qasimi et al (2018) conducted studies with quails (Coturnix japonica) in which they administered phytoestrogens. They concluded that the adrenal glands and gonads preferred cholesterol for performing steroidogenesis (Qasimi et al 2018). The testicles use LDL-C for this purpose, and when vegan or vegetarian diets rich in phytoestrogens were provided, this type of cholesterol decreased, as did steroidogenesis.…”