Overexpression of tyrosine phosphorylated proteins in reproductive tissues of polycystic ovary syndrome rats induced by letrozole

Objective:To identify the alteration of tyrosine phosphorylated protein expression in rats with polycystic ovary syndrome(PCOS).Methods:Sixteen female Sprague-Dawley rats were divided into the control and letrozole-induced PCOS groups.The oestrus cycle of rats was performed by vaginal smear.Sex hormones and morphology of the ovary,oviduct,and uterus were observed.Expressions and intensity of androgen receptor and tyrosine phosphorylated proteins of reproductive organs were investigated by Western blot.Results:Various polycysts and increased androgen receptor expression were present in the ovary of the PCOS group.The levels of follicle-stimulating hormone and testosteone were significantly higher in the PCOS group while progesterone and estradiol levels were significantly decreased as compared with the control group(P<0.05).Only the size of uterus in the PCOS group was significantly smaller than the control group.However,the density of collagen fibers observed in PCOS uterus was greater than the control group.Moreover,tyrosine phosphorylated proteins were significantly overexpressed in ovary(52,42,and 28 kDa),oviduct(72,56,42,and 28 kDa),and uterus(53 and 42 kDa)of the PCOS group compared to the control group.Conclusions:Presence of tyrosine phosphorylated proteins in the ovary,oviduct and uterus suggests that overexpression of tyrosine phosphorylated proteins may be involved in potential mechanism of female infertility especially in PCOS.

Evaluation of antioxidant capacity and reproductive toxicity of aqueous extract of Thai Mucuna pruriens seeds

Objective: In traditional medicine, the seeds of Thai Mucuna pruriens(T-MP) are used to treat male dysuria and are believed to enhance fertility. However, information pertaining to the toxicity of T-MP and its interaction with other properties is limited. This study was thus conducted to evaluate the antioxidant capacity and subacute toxicity of T-MP in the reproductive system.Methods: Total phenolic content and antioxidant capacity of T-MP seed extract were determined using total phenolic content, 2,2-diphenyl-1-picrylhydrazyl and ferric reducing antioxidant power assays.Male and female adult rats were treated orally with T-MP at a dosage of 150 or 300 mg/kg body weight for 14 consecutive days. Sex hormones and functional parameters in the liver and kidney were evaluated.Histopathology of all tissue was conducted using Masson’s trichrome staining. Sperm parameters, including concentration, morphology, acrosome reaction status and DNA damage, were also examined.Expression of tyrosine phosphorylated protein(Tyr Pho), androgen receptor and A-kinase-anchoring protein 4(AKAP4) were investigated using the Western blot technique.Results: T-MP seed extract contained phenolic compounds and exhibited high antioxidant capacity with no toxicity at the tested doses. It did not affect liver or kidney function parameters in the male rats, but increased estradiol, aspartate aminotransferase and alanine aminotransferase levels in the females.Additionally, it decreased serum progesterone and alkaline phosphatase levels in female rats. Serum and intratesticular testosterone levels were significantly lower in male rats that received a high dosage of T-MP. Histopathological changes were not observed in any tissue treated with T-MP. T-MP also significantly increased sperm concentration(but did not affect sperm parameters), and enhanced testicular Tyr Pho protein and androgen receptor and expression of AKAP4 in sperms.Conclusion: T-MP seed extract exhibited antioxidant capacity and was not harmful to reproductive tissues. It also had a phytoestrogenic effect on females and increased the expression of testicular and sperm markers of male fertility.

Momordica charantia fruit extract with antioxidant capacity improves the expression of tyrosine-phosphorylated proteins in epididymal fluid of chronic stress rats

Objective:Although the protective effects of Momordica charantia L.(MC)extract on chemical-induced testicular damage have been studied,the preventive effects of MC extract on functional proteins in the epididymis under chronic stress have never been reported.This study investigated the protective effects of MC fruit extract on protein secretion,especially tyrosine-phosphorylated proteins,in the epididymis of rats exposed to chronic unpredictable stress(CUS).Methods:Total phenolic compounds(TPC),total flavonoid compounds(TFC)and antioxidant capacities of MC extract were measured.Adult male rats were divided into 4 groups:control group,CUS group,and 2groups of CUS that received different doses of MC extract(40 or 80 mg/kg).In treated groups,rats were given MC daily,followed by induction of CUS(1 stressor was randomly applied from a battery of 9 potential stressors)for 60 consecutive days.Plasma corticosterone and testosterone levels were analyzed after the end of experiment.Expressions of heat-shock protein 70(HSP-70)and tyrosine-phosphorylated proteins present in the fluid of the head and tail of the epididymis were quantified using Western blot.Results:MC extract contained TPC of(19.005±0.270)mg gallic acid equivalents and TFC of(0.306±0.012)mg catechin equivalents per gram,and had 2,2-diphenyl-1-picrylhydrazyl antioxidant capacity of(4.985±0.086)mg trolox equivalents per gram,radical 50%inhibitory concentration of(2.011±0.008)mg/mL and ferric reducing antioxidant power of(23.697±0.819)μmol Fe(Ⅱ)per gram.Testosterone level in the epididymis was significantly increased,while the corticosterone level was significantly improved in groups treated with MC extract,compared to the CUS animals.Particularly,an 80 mg/kg dose of MC extract prevented the impairments of HSP-70 and tyrosine-phosphorylated protein expressions in the luminal fluid of the epididymis of CUS rats.Conclusion:MC fruit extract had antioxidant activities and improved the functional proteins secreted from the head and tail of the epididymis.It is possible to develop the MC fruit extract as a male fertility supplement for enhancing functional sperm maturation in stressed men.