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

Prevention of seminal vesicle damage by Mucuna pruriens var. pruriens seed extract in chronic unpredictable mild stress mice

CONTEXT

Thai Mucuna pruriens (L.) DC. var. pruriens (Fabaceae) or T-MP seed extract has been shown to improve sexual performance and sperm quality.

OBJECTIVE

This study investigates the preventive effects of T-MP against seminal vesicle damage, apoptotic and Nrf2 protein expression in mice under chronic unpredictable mild stress (CUMS).

MATERIALS AND METHODS

Forty-eight male ICR mice were divided into four groups: control, CUMS, T-MP300 + CUMS and T-MP600 + CUMS. Mice in control and CUMS groups received distilled water, while those in treated groups were pretreated with T-MP extract (300 or 600 mg/kg BW) for 14 consecutive days. The CMUS and co-treated groups were exposed to one random stressor (of 12 total) each day for 43 days. Components and histopathology of the seminal vesicle were examined, along with localization of androgen receptor (AR) and caspase 3. Expression of seminal AR, tyrosine phosphorylated (TyrPho), heat shock protein 70 (Hsp70), caspases (3 and 9) and nuclear factor erythroid 2-related factor 2 (Nrf2) proteins was investigated.

RESULTS

T-MP extract at a dose of 600 mg/kg BW improved seminal epithelial damage and secretion of fluid containing essential substances and proteins in CUMS mice. It also increased the expression of AR and TyrPho proteins. Additionally, T-MP increased expression of Nrf2 and inhibited seminal vesicular apoptosis through the suppression of Hsp70 and caspase expression.

CONCLUSION

T-MP seeds have an antiapoptotic property in chronic stress seminal vesicle. It is possible to apply this extract for the enhancement of seminal plasma quality.

Antioxidant activity of Flemingia praecox and Mucuna pruriens and their implications for male fertility improvement

Globally, 15-24% couples are unable to conceive naturally and 50% of cases of this problem are due to infertility in males. Of this, about 50% of male infertility problems are developed due to unknown reasons called as idiopathic infertility. It is well established that, reactive oxygen species (ROS) have negative impact on male fertility and are involved in 80% of total idiopathic male infertility cases. Medicinal plants are considered as an alternative approach for mitigating the health problems. The plants with good antioxidant capacity can improve the male infertility symptoms generated by ROS. Such medicinal plants can be used to alleviate the symptoms of male infertility with their diverse phytoconstituents. Mucuna pruriens is a well-accepted herb, with its seeds being used to improve the male fertility in various ways and one of the ways is by eliminating the ROS. In our field survey, another plant, Flemingia praecox, although less known, its roots are used in all problems related to the male fertility by tribal people of the Gadchiroli district of Maharashtra, India. The study was conducted to determine in vitro antioxidant potential of F. praecox and compared the results with the well-established male fertility improving plant M. pruriens with special emphasis on medicinally important roots of F. praecox and seeds of M. pruriens. The objective of the study was investigated by studying their total phenol (TPC) and flavonoid (TFC) content, antioxidant parameters (DPPH, FRAP, ABTS, DMPD, β-carotene bleaching and TAA) and finally DNA damage protection capacity of the plant extracts was studied. The plant parts used for the medicinal purposes have been investigated along with other major parts (leaves, stem and roots of both the plants) and compared with synthetic antioxidants, BHA, BHT and ascorbic acid. Moreover, the inhibition of two male infertility enzyme markers, PDE5 and arginase by F. praecox root and M. pruriens seed extract was also studied in vitro. The results showed that F. praecox possesses higher antioxidant activity than M. pruriens in the majority of studies as observed in TFC, DPPH, TAA, ABTS and DMPD assays. However, M. pruriens seeds showed best results in TPC, FRAP and DNA damage protection assay. F. praecox root extract also gave better PDE5 inhibition value than M. pruriens seeds. This study will help to establish the authenticity of F. praecox used by tribal people and will encourage its further use in managing the male infertility problems.

Protective effect of Mucuna pruriens (L.) DC. var. pruriens seed extract on apoptotic germ cells in ethanolic male rats

Thai Mucuna pruriens (L.) DC. var pruriens (T-MP) seed containing levodopa (L-DOPA) and antioxidant capacity has been shown to improve sexual behavior and male reproductive parameters in rats treated with ethanol (Eth). However, its protective effect on testicular apoptotic germ cells has never been reported. This study aimed to investigate the potential effects of T-MP seed extract on expressions of caspase, proliferating cell nuclear antigen (PCNA), and dopamine D2 receptor (D2R) proteins in Eth rats. Thirty-six male Wistar rats were divided into four groups (9 animals/group), including control, Eth, T-MP150+Eth, and T-MP300+Eth, respectively. Control rats received distilled water, and Eth rats received Eth (3g/kg BW; 40%v/v). The T-MP groups were treated with T-MP seed extract at a dose of 150 or 300 mg/kg before Eth administration for 56 consecutive days. The results showed that the seminiferous tubule diameter and epithelial height were significantly increased in both T-MP treated groups compared to the Eth group. Additionally, the caspase-9 and -3, and PCNA expressions were decreased, but D2R expression was markedly increased in T-MP groups. It was concluded that T-MP seed extract could protect testicular apoptosis induced by Eth via changes in caspase, PCNA, and D2R protein expressions.

Ameliorating effect of Mucuna pruriens seed extract on sodium arsenite-induced testicular toxicity and hepato-renal histopathology in rats

Background and Aim

A significant cause of arsenic poisoning is polluted groundwater. Arsenic poisoning results in the suppression of spermatogenesis and the liver and kidneys are vulnerable to the toxic effects as well. Mucuna pruriens has been identified to have fertility-enhancing and anti-lipid peroxidation properties. Based on these properties of M. pruriens, this study aimed to investigate the efficacy of M. pruriens seed extract in reducing sodium arsenite-induced testicular impairment and hepato-renal histopathology in rats.

Materials and Methods

The study was divided into two groups; short-term (45 days) and long-term (90 days) treatment groups and each group was divided into nine subgroups. Subgroups 1 and 2 served as normal and N-acetyl cysteine (NAC) controls, respectively. Subgroups 3-9 received sodium arsenite in the drinking water (50 mg/L). Subgroup-4 received NAC (210 mg/kg body weight [BW]) orally once daily. Subgroups 5-7 received aqueous seed extract of M. pruriens (350, 530, and 700 mg/kg BW, respectively) orally once daily. Subgroups 8 and 9 received a combination of NAC and aqueous seed extract (350 and 530 mg/kg BW, respectively) orally once daily. Following the treatment, animals were sacrificed and sperm parameters and DNA damage were evaluated. Testis, liver, and kidneys were analyzed for histopathology.

Results

Sodium arsenite-induced a significant reduction in sperm parameters and increase in the abnormal architecture of spermatozoa. Histology revealed tissue necrosis. The M. pruriens seed extract ameliorated the damaging effects of sodium arsenite with respect to tissue architecture and sperm parameters when coadministered.

Conclusion

Mucuna pruriens has beneficial effects against the deleterious effects of sodium arsenite on various tissues. Thus, M. pruriens (530 and 700 mg/kg BW) supplementation would reduce the adverse changes observed with sodium arsenite exposure.

Produksi Hidrolisat Protein Kacang Koro Benguk dengan Aktivitas Penghambat Kerja Enzim Pengkonversi Angiotensin melalui Kombinasi Fermentasi dan Hidrolisis Enzimatik

Mucuna bean (Mucuna pruriens L.) is a legume having high protein content which has the potential as a source of bioactive peptides. One of the bioactive peptides is an angiotensin-converting enzyme (ACE) inhibitor, thus, mucuna beans might be used as a potential source of antihypertensive compounds. This study aimed to increase the functionality of proteins from mucuna beans as ACE inhibitors using a combination of fermentation and enzymatic hydrolysis followed by membrane filtration. The mucuna beans were fermented for 0, 24, 48, 96, and 144 h. The highest ACE inhibitory activity of 54.37%, was obtained by fermentation of the beans at 48 h, with a protein content of 20.82 mg/mL. The 48 h fermented mucuna beans were further hydrolyzed using alcalase or neutrase and subsequently filtered with UF membranes having 20,10 and 5 kDa cut-off. The enzymatic hydrolysis followed by membrane filtration increased the ACE inhibitory activity of mucuna beans. The neutrase hydrolysates resulting from 5 kDa membrane filtration showed the best ACE inhibitory activity (62.96% with a protein content of 10.39 mg/mL). A combination of fermentation and enzymatic hydrolysis followed by filtration using UF-membrane was able to produce ACE inhibitory peptides from mucuna beans. The potential of mucuna beans peptides as ACE inhibitors was due to the presence of negatively charged amino acid residues such as Asp and Glu, positively charged amino acids such as Arg and Lys, and hydrophobic amino acids such as Val, Leu, Ala, and Ile.

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.

Protective effects of Thai Mucuna pruriens (L.) DC. var. pruriens seeds on sexual behaviors and essential reproductive markers in chronic unpredictable mild stress mice

Background and aims

Chronic stress is a major common cause of male infertility. Many species of velvet beans are shown to be rich in l-DOPA. In Thai folklore medicine, seeds of Mucuna pruriens (L.) DC. var. pruriens (Thai Mhamui or T-MP) have been used for treating erectile dysfunction. This study aimed to determine l-DOPA levels in T-MP seed extract and investigate its preventive on sexual behaviors and reproductive parameter damages including essential proteins in chronic unpredictable mild stress (CUMS) mice.

Experimental procedure

Mice were divided into 4 groups: (I) control, (II) CUMS, (III) T-MP300 + CUMS, and (IV) T-MP600 + CUMS. Groups I and II received DW while groups III and IV were pretreated with the seed extracts (300 and 600 mg/kg BW) for 14 consecutive days before co-treatment with a randomly different CUMS/day (from 12 mild stressors) for 43 days.

Results and conclusion

T-MP seed extract contained l-DOPA approximately 10% of total dried weight. A dose of 600 mg/kg improved sexual performances and degenerative seminiferous epithelium in CUMS mice. Sperm qualities and testosterone level were elevated while corticosterone was decreased in co-treatment groups. T-MP-CUMS cotreated groups also improved expressions of AKAP4, AR, and TyrPho proteins in testis, epididymis, and sperm. T-MP increased StAR and CYP11A1 expressions in testis. It also suppressed testicular apoptosis via decreased expressions of Hsp70, caspases 3, and 9. T-MP seeds containing l-DOPA could improve sexual behaviors and essential reproductive proteins caused by CUMS.

Section

Natural Products.

Taxonomy classification by evise

Traditional Herbal Medicine; Animal Model; Histopathology.

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.

Potential Use of Tannin Extracts as Additives in Semen Destined for Cryopreservation: A Review

Cryopreservation and storage of semen for artificial insemination (AI) result in excessive accumulation of reactive oxygen species (ROS). This leads to a shortened life span and reduced motility of spermatozoa post-thawing, with consequent impairment of their function. However, certain levels of ROS are essential to facilitate the capacitation of spermatozoa required for successful fertilisation. Tannins, as well-known antioxidant compounds, may act as ROS binders/acceptors/scavengers to inhibit the damaging effects of ROS. This review comprises an analysis of the semen cryopreservation protocol and health functions of tannins, as well as the effects of ROS on fresh and cryopreserved semen's longevity and fertilisation. Additionally, we surveyed available evidence of the effects of tannin extract feed supplementation on male fertility. We furthermore interrogated existing theories on tannin use as a potential additive to semen extenders, its relationship with semen quality, and to what degree existing theories have been investigated to develop testable new hypotheses. Emphasis was placed on the effects of tannins on ROS, their involvement in regulating sperm structure and function during cryopreservation, and on post-thaw sperm motility, capacitation, and fertilising ability. The diverse effects of tannins on the reproductive system as a result of their potential metal ion chelation, protein precipitation, and biological antioxidant abilities have been identified. The current data are the first to support the further investigation of the incorporation of tannin-rich plant extracts into semen extenders to enhance the post-thaw survival, motility, and fertilising ability of cryopreserved spermatozoa.

Estrogenic Pastures: A Source of Endocrine Disruption in Sheep Reproduction

Phytoestrogens can impact on reproductive health due to their structural similarity to estradiol. Initially identified in sheep consuming estrogenic pasture, phytoestrogens are known to influence reproductive capacity in numerous species. Estrogenic pastures continue to persist in sheep production systems, yet there has been little headway in our understanding of the underlying mechanisms that link phytoestrogens with compromised reproduction in sheep. Here we review the known and postulated actions of phytoestrogens on reproduction, with particular focus on competitive binding with nuclear and non-nuclear estrogen receptors, modifications to the epigenome, and the downstream impacts on normal physiological function. The review examines the evidence that phytoestrogens cause reproductive dysfunction in both the sexes, and that outcomes depend on the developmental period when an individual is exposed to phytoestrogen.

Decreased expression of AKAP4 and TyrPho proteins in testis, epididymis, and spermatozoa with low sexual performance of mice induced by modified CUMS

The molecular mechanism of chronic stress especially reduced motility, a major cause of male infertility, has not been proved. It is known that A-kinase anchor protein 4 (AKAP4) and tyrosine-phosphorylated (TyrPho) proteins are involved in progressive motility. This study aimed to investigate the effect of chronic unpredictable mild stress (CUMS) on sexual behaviours, sperm quality, and expressions of AKAP4 and TyrPho proteins in testis, epididymis, and spermatozoa. Sixteen male mice were divided into control and CUMS groups (n = 8/group). Animals were induced by a stressor from twelve stressors for 36 days. Sexual behaviours, corticosterone and testosterone, sperm parameters, and histopathology were observed. The expressions of AKAP4 and TyrPho proteins in testis, epididymis, and spermatozoa were examined. Results showed that CUMS significantly increased corticosterone while serum testosterone level was decreased. Sexual behaviours and sperm parameter quality were significantly decreased. CUMS mice showed vacuolisation and pyknotic cells in seminiferous epithelium and less sperm mass was observed within epididymal lumen. CUMS decreased expressions of AKAP4 and TyrPho proteins in testis, epididymis, and spermatozoa. In conclusion, the decreased expression of AKAP4 and TyrPho proteins may be a mechanism associated with low semen qualities particularly decrease of sperm motility in CUMS.

The effect of Dolichandrone serrulata (wall. ex DC.) Seem. flower extract containing antioxidant capacity and terpenoids on the male reproductive system

Although the fruit extract of Dolichandrone genus was shown to inhibit spermatogenesis, the reproductive toxicity of Dolichandrone serrulata flowers (DSFs) is not documented. Recent study aimed to evaluate the sub-chronic toxicity of DSF on male reproductive system. Antioxidant capacity and total phenolic contents of DSF extract were determined using Folin-Ciocalteu's, 2,2-diphenyl-1-picrylhydrazyl and ferric reducing antioxidant power assays. The terpenoid components were determined using nuclear magnetic resonance spectrum. Adult male rats were treated orally with DSF (100, 300 or 600 mg/kg) for 48 days. Histopathology of testis and epididymis was observed. Sperm concentration, viability, acrosome status and morphology were also examined. Expressions of heat shock protein 70 (Hsp70), tyrosine-phosphorylated (TyrPho) proteins, androgen receptor (AR) and steroidogenic acute regulatory (StAR) protein in testis were investigated. Results showed that DSF contained phenolic compounds and terpenoids (phytoandrogens; rengyolone and cleroindicin B). No reproductive histopathology was observed in DSF-treated rats. Although DSF decreased the serum testosterone level, the sperm qualities were not affected. Particularly, sperm concentration of DSF-treated animals was significantly increased. DSF changed the testicular TyrPho proteins but the expression of AR, StAR or Hsp70 was not altered. In conclusion, DSF possesses antioxidant capacity with no toxicity on male reproductive system.