Seed extract of Thai Mucuna pruriens reduced male reproductive damage in rats induced by chronic stress

CONTEXT

Thai Mucuna pruriens (L.) DC. var. pruriens (Fabaceae) (TMP) is known to enrich reproduction but preventive effects on stress related adverse reproductive parameters are not documented.

OBJECTIVE

This study investigates the protective property of TMP seed extract on reproductive damage under chronic stress (CS).

MATERIALS AND METHODS

Male Sprague-Dawley rats were divided into four groups. The control and CS groups received distilled water, whereas the pre-treated rats received the aqueous TMP seed extract at doses of 150 and 300 mg/kg BW for 20 days before co-treatments with CS induction (immobilization and forced swimming) for 81 days. Serum was used to determine the cortisol and testosterone levels. Histology of testis and epididymis was observed with localization of androgen receptor (AR). Sperm parameters and the expression of steroidogenic acute regulatory (StAR), cytochrome P450 family 11 subfamily a member 1 (CYP11A1), AR, HSP70, caspases (3 and 9) and tyrosine phosphorylation (TyrPho) proteins were investigated.

RESULTS

TMP extract improved cortisol level (0.84 ± 0.02 µg/dL) and protected against the damage of reproductive tissues and sperm parameters (count [49.78 ± 3.74 million sperm/mL], viability [90.01 ± 1.17%] and precocious acrosome reaction [1.38 ± 0.48%]). Expression of testicular StAR, CYP11A1, AR and HSP70 proteins was improved. Caspase expression was decreased in treated rats. TMP increased AR expression in CS sperm. Moreover, TyrPho protein expression was corrected after TMP administration.

CONCLUSIONS

TMP seed protected against adverse reproductive parameters in CS via improvements of functionally testicular markers and reductions of apoptotic proteins. It is possible to develop the TMP beans as an alternative medicine in treating of male subfertility caused by CS.

Seed extract of Thai Mucuna pruriens (L.) DC. var. pruriens enhances sexual performance and improves male reproductive damages in ethanol-induced rats

ETHNOPHARMACOLOGICAL RELEVANCE

Thai Mucuna pruriens (L.) DC. var. pruriens (T-MP) has been traditionally used in treating depressive disorders, dysuria and enhancing male sexual desire. Although T-MP seed is demonstrated to have antioxidant capacity, its aphrodisiac and protective tissue damage properties have never been documented. Recently, ethanol (Eth) is known to cause sexual behavior dysfunction and damage reproductive system. This study aimed to investigate the protective effects of T-MP seed extract on sexual behavior dysfunction and reproductive damages in male rats admisted with Eth.

MATERIALS AND METHODS

T-MP possessing antioxidant activity was determined for L-DOPA content using NMR analysis. Thirty-six male rats were divided into four groups (9 animals/group). Control rats received DW and the ethanol (Eth) group was given with Eth (3 g/kgBW; 40%v/v). In preventive groups (T-MP150 + Eth and MP300 + Eth groups), animals were treated with T-MP extract at a dose of 150 and 300 mg/kgBW before Eth administration for consecutive 56 days. Sexual behaviors including mounting frequency (MF), intromission frequency (IF), mounting latency (ML), intromission latency (IL), ejaculation latency (EL), post-ejaculatory interval (PEI), and ejaculation frequency (EF) were evaluated. Epididymal sperm quality and daily sperm production (DSP) were examined. Testicular histology was observed using Masson's trichrome staining. The malondialdehyde (MDA) levels and expressions of androgen receptor (AR), heat shock protein 70 (HSP70), steroidogenic acute regulatory (StAR), and tyrosine-phosphorylated (TyrPho) proteins in testis were also determined.

RESULTS

T-MP extract contained L-DOPA and improved sexual behaviors including increased MF and IF and decreased ML and IL in Eth treated rats. Significantly, sperm quality, DSP, and testicular histopathology observed in Eth group were improved after T-MP treatment. T-MP also decreased the testicular MDA levels. Additionally, T-MP could correct testicular functional proteins of AR and StAR except HSP70 expression in Eth group. Expressions of TyrPho proteins in testicular and sperm lysates were improved in co-administered groups.

CONCLUSIONS

T-MP seed extract possessing L-DOPA could enhance the sexual behaviors and protect reproductive damages via improvement of testicular functional proteins.

Chronic stress affects tyrosine phosphorylated protein expression and secretion of male rat epididymis

Chronic stress (CS) is shown to decrease the semen quality with changed expression of tyrosine phosphorylated (TyrPho) proteins in testicular and seminal tissues. However, the alterations of such proteins and fluid contents in the epididymis, producing sperm maturation factors, have never been reported. Sixteen adult rats were randomly divided into 2 groups (n = 8). The control animals were not subjected to stressors whereas CS rats were immobilised within restraint cage (4 hr/day) before cold forced-water swimming (15 min/day) for 60 days. Corticosterone, testosterone, blood glucose level (BGL), malondialdehyde (MDA) and biochemical components in epididymal fluid were assayed. Expressions of heat shock protein 70 (HSP-70), androgen receptor (AR) and TyrPho protein were investigated in epididymal tissue and fluid. Significantly, CS increased the corticosterone and BGL but decreased testosterone and epididymal substance levels. MDA level in tail epididymal fluid and HSP-70 expression in both regions of epididymal tissues and fluids, except in head epididymal fluid of CS were increased. Epididymal tissues showed the decrease of AR expression. Presence and changes of many TyrPho proteins were observed in CS. In conclusion, CS could affect functional proteins particularly TyrPho in epididymis, resulted in low semen quality.

Chronic stress increases the tyrosine phosphorylation in female reproductive organs: An experimental study

BACKGROUND

Changes in tyrosine-phosphorylated (TyrPho) protein expressions have demonstrated stress in males. In females, chronic stress (CS) is a major cause of infertility, especially anovulation. However, the tyrosine phosphorylation in the female reproductive system under stress conditions has never been reported.

OBJECTIVE

To investigate the alteration of TyrPho protein expression in ovary, oviduct, and uterus of CS rats.

MATERIALS AND METHODS

In this experimental study, 16 female Sprague-Dawley rats (5 wk: 220-250 gr) were divided into control and CS groups (n = 8/group). Every day, the CS animals were immobilized within a restraint cage and individually forced to swim in cold water for 60 consecutive days. Following the stress induction, the ovary, oviduct, and uterus of all rats were observed for their morphologies. The total protein profiles of all tissues were revealed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) before detecting TyrPho proteins using western blot. Intensity analysis was used to compare the expression of proteins between groups.

RESULTS

The results showed that the morphology and weights of ovary and oviduct in the CS group were not different from control. In contrast, the CS significantly increased the uterine weight as compared to control. Moreover, the expressions of TyrPho proteins in the ovary (72, 43, and 28 kDas), oviduct (170, 55, and 43 kDas), and uterus (55, 54, and 43 kDas) were increased in CS group as compared to those of control.

CONCLUSION

The increased expressions of TyrPho proteins in ovary, oviduct, and uterus could be potential markers used to explain some machanisms of female infertility caused from chronic stress.