Standardized extract of Bacopa monnieri (CDRI-08): Effect on germ cell dynamics and possible mechanisms of its beneficial action on spermatogenesis and sperm quality in male mice

A network pharmacological approach for the identification of potential therapeutic targets of Brahmi Nei - a complex traditional Siddha formulation

Brahmi Nei (BN), a traditional Indian polyherbal formulation has been described in classical texts for the treatment of anxiety and depression, as well as to fortify the immune system. The individual herbs of BN have been used for treatment of wide range of disorders including cognition, inflammation, skin ailments and cancer etc., This diverse basket of therapeutic activity suggests that BN may possess therapeutic benefits to other disorders. So, the present study aims to identify the potential therapeutic targets of BN using a network pharmacological approach to comprehend the multi target action of its multiple phytoconstituents. We have employed Randić Index for the first time to calculate the contribution score of module segregated targets towards diseases. Our results suggests that BN targets could also be effective in other diseases such as lysosomal storage disorders, respiratory disorders etc., apart from neurological disorders. The key targets with highest topological measures of Targets-(Pathway)-Targets network were identified as potential therapeutic targets of BN. And the top hit target PTGS2, a gene encoding for cyclooxygenase-2 was further evaluated using molecular docking, molecular dynamic simulation and in vitro studies. Our findings open up new therapeutic facets for BN that can be explored systematically in future.Communicated by Ramaswamy H. Sarma.

Adropin, a novel hepatokine: localization and expression during postnatal development and its impact on testicular functions of pre-pubertal mice

Adropin, a multifaceted peptide, was identified as a new metabolic hormone responsible for regulating gluco-lipid homeostasis. However, its role in the testicular function is not yet understood. We aimed to investigate the localization and expression of adropin and GPR19 during different phases of postnatal development. Immunohistochemical study revealed the intense reactivity of adropin in the Leydig cells during all phases of postnatal development, while GPR19 showed intense immunoreactivity in the pachytene spermatocytes and mild immunoreactivity in Leydig cells as well as primary and secondary spermatocytes. Western blot study revealed maximum expression of GPR19 in pre-pubertal mouse testis that clearly indicates maximum responsiveness of adropin during that period. So, we hypothesized that adropin may act as an autocrine/paracrine factor that regulates pubertal changes in mouse testis. To examine the effect of adropin on pubertal onset, we gave bilateral intra-testicular doses (0.5 and 1.5 µg/testis) to pre-pubertal mice. Adropin treatment promoted testicular testosterone synthesis by increasing the expression of StAR, 3β-HSD, and 17β-HSD. Adropin also promoted germ cell survival and proliferation by upregulating the expression of PCNA and downregulating the Bax/Bcl2 ratio and Caspase 3 expression resulting in fewer TUNEL-positive cells in adropin-treated groups. FACS analysis demonstrated that adropin treatment not only increases 1C to 4C ratio but also significantly increases the 1C (spermatid) and 1C to 2C ratio which demarcates accelerated germ cell differentiation and turnover of testicular cells. In conclusion, adropin promotes steroidogenesis, germ cell survival, as well as the proliferation in the pre-pubertal mouse testis that may hasten the pubertal transition in an autocrine/paracrine manner.

Ontogeny of TRα1 expression in the mouse testis and epididymis during postnatal development

Thyroid hormone (T₃ ) acts on the testis via thyroid hormone receptor alpha 1 (TRα1), though the cellular localization of TRα1 in testis remains controversial. Studies on the presence of TRα1 in the epididymis are also lacking. The present study, therefore, examined the cellular localization and expression pattern of TRα1 in testis and epididymis of Parkes mice during postnatal development. Immunohistochemical results showed localization of TRα1 in interstitial and tubular compartments of the testis all through the development. On postnatal day (PND) 14, only leptotene spermatocytes showed TRα1-immunoreactivity in the testis, while at PND 28, 42, and 90, a diverse staining pattern for TRα1 was seen in almost all the seminiferous tubules mainly in leptotene spermatocytes, round and elongating spermatids, and in Leydig cells. Further, qRT-PCR and immunoblot analyses showed that TRα1 was expressed in the testis at the transcript as well as protein level throughout the postnatal development. TRα1 was also seen in principal cells of the epididymis, with maximal expression at PND 90. TRα1 was also present in cauda epididymidal spermatozoa of adult mice at PND 90. The results suggest that TRα1 is expressed in the testis and epididymis and that it may help to regulate the spermatogenic process and male fertility.

Melatonin Ameliorates LPS-Induced Testicular Nitro-oxidative Stress (iNOS/TNFα) and Inflammation (NF-kB/COX-2) via Modulation of SIRT-1

Lipopolysaccharide (LPS) - an endotoxin that is being extensively used in laboratory to mimic microbial infection that adversely affects male fertility. This study investigated the protective effects of melatonin on LPS-induced testicular nitro-oxidative stress, inflammation, and associated damages in the testes of male golden hamsters, Mesocricetus auratus. Hamsters were administered with melatonin and LPS for 7 days. Testes of LPS treated hamsters showed degenerative changes (appearance of vacuoles, exfoliation, and depletion of germ cells in the seminiferous tubules), adverse effects on spermatogenesis (sperm count and viability), and steroidogenesis (declined serum and testicular testosterone). Furthermore, LPS treatment decreased melatonin content, melatonin receptor (MT1), and antioxidant potential (catalase and SOD), and simultaneously increased nitro-oxidative stress (CRP, nitrate, TNFα). LPS upregulated NF-kB, COX-2, and iNOS expressions to increase testicular inflammatory load that resulted in the decrease of germ cell proliferation and survival, thus culminating into germ cell apoptosis as indicated by AO-EB staining and caspase-3 expression. Administration of melatonin with LPS showed improved testicular histoarchitecture, sperm parameters, and testosterone level. Melatonin increased testicular antioxidant status (SOD, catalase) to counteract the LPS-induced testicular ROS and thus reduced testicular nitro-oxidative stress. Furthermore, melatonin treatment upregulated testicular SIRT-1 expression to inhibit LPS-induced inflammatory proteins, i.e., NF-kB/COX-2/iNOS expression. The rescue effect of melatonin was further supported by increased germ cell survival (Bcl-2), proliferation (PCNA), and declined apoptosis (caspase-3). In conclusion, our result demonstrated that melatonin rescued testes from LPS-induced testicular nitro-oxidative stress, inflammation, and associated damages by upregulation of SIRT-1.

In silico docking of phytocompounds to identify potent inhibitors of signaling pathways involved in prostate cancer

Androgens and androgen receptors (AR) are the master regulators in the development of prostate cancer. Majority of the patients show positive response to surgical or medical castration, while many patients show disease relapse after the treatment. Genomic profiling has proven that the deregulated PI3K, Ras/Raf, MAPK and EGFR signaling pathways confer survival and invasion advantage to the cancer cells. Thus, modulation of these interlinked growth pathways along with androgen ablation may provide attractive therapeutic benefits. The current research is focused to identify the inhibitors of these pathways with bacosides and Piperine. The quantitative estimation of bacosides enriched standard extract of Bacopa monnieri by HPTLC showed 59.38% of Bacoside A and various active compounds with anti-oxidant, anti-cancer, anti-microbial, anti-inflammatory properties were also analyzed by GC-MS analysis. The in-vitro cytotoxic study against PC3 cell lines showed dose-dependent effect of Piperine and the extract. Further, in silico docking has shown bacosides with significant molecular interactions and binding score with growth factor receptors such as EGFR, PI3K, Akt and ERK, whereas Piperine exhibited interactions with AR. Hence, a simultaneous downregulation of interlinked signaling pathways of growth factors and AR with bacosides and Piperine may produce effective cytotoxic potential against the androgen-independent prostate cancer. Further in-vitro and in-vivo experimental investigations are necessary to determine the ultimate therapeutic utility. Communicated by Ramaswamy H. Sarma.

Role of pyroglutamylated RFamide peptide43 in germ cell dynamics in mice testes in relation to energy metabolism

QRFP is a neuropeptide that regulates glucose homeostasis and increases insulin sensitivity in tissues. We have previously shown that QRFP and its receptor (GPR103) are predominantly expressed in germ cells and Sertoli cells, respectively, in mice testes. In the present study, we report that QRFP caused an increase in PCNA and a decrease in p27Kip1 expressions in the testis under both in vivo and ex vivo conditions. Besides, via an in vivo study, cell cycle analysis by FACS showed an increase in 2C cells and a decrease in 1C cells. QRFP also induced expression of GDNF and phosphorylation of Akt and ERK-1/2. Together these results suggest that QRFP has a proliferative effect on germ cells in mice testes, since it caused a proportional increase in the mitotic activity and the number of spermatogonial cells. Further, observations of increased expressions of STAT-3 and Neurog3 in treated mice suggest that QRFP treatment regulates priming of undifferentiated spermatogonia to undergo differentiation, while a decrease in c-Kit expression indicate that spermatogonia at this time point are in an undifferentiated state. In addition, QRFP administration also caused an increase in intratesticular levels of glucose and lactate, and in LDH activity accompanied by increased expressions of GLUT-3 and LDH-C in the testis. Also, the phosphorylation of IR-β and expressions of p-Akt and p-mTOR were increased under ex vivo conditions in testicular tissue. In conclusion, our findings suggest that QRFP treatment caused proliferation of germ cells independently from the hypothalamic-pituitary axis via regulation of testicular energy metabolism.

Acute exposure to perfluorononanoic acid in prepubertal mice: Effect on germ cell dynamics and an insight into the possible mechanisms of its inhibitory action on testicular functions

Perfluoroalkyl acids (PFAAs) are anthropogenic compounds used globally in a variety of commercial products. Perfluorononanoic acid (PFNA), a member of PFAAs, is detected in human blood and this has been reported to cause hepatotoxic, immunotoxic, and developmental and testicular toxic effects in laboratory animals. We have recently shown that the acute exposure to PFNA in prepubertal Parkes (P) mice impairs spermatogenesis by inducing oxidative stress and inhibiting testosterone biosynthesis in the testis. The present study was aimed to examine the effect of acute exposure to PFNA in prepubertal P mice on germ cell dynamics and to understand the possible mechanisms of action of this compound on testicular functions. PFNA (2 and 5 mg/kg body weight) was orally administered to male mice for 14 days from postnatal day 25-38. The treatment caused a decrease in overall germ cell transformation. The results also reveal that impairment in testicular functions in treated mice is associated with alterations in cholesterol and glucose homeostasis; further, an inhibition in expressions of growth hormone receptor (GHR), insulin-like growth factor-1 (IGF-1), insulin-like growth factor-1 receptor (IGF-1R), androgen receptor (AR), phosphorylated mammalian target of rapamycin (p-mTOR) and peroxisome proliferator activated receptor α (PPAR α) in the testis is also implicated in this action. The findings thus suggest involvement of multiple factors which altogether contribute to the alterations in spermatogenic process and testosterone production following acute exposure to PFNA in prepubertal mice.

Effect of gestational exposure to perfluorononanoic acid on neonatal mice testes

Perfluoroalkyl acids (PFAAs) are widely used in commercial products and are found in many goods of daily use. Perfluorononanoic acid (PFNA) is one of the PFAAs that possesses endocrine disrupting properties and we have recently shown that PFNA affects testicular functions in Parkes mice. Exposure to environmental endocrine disruptors during fetal life is believed to affect gonadal development and they might produce reproductive abnormalities in males. Therefore, the present study examined the effect of gestational exposure to PFNA on the testes of neonatal mice offspring. Pregnant Parkes mice were orally administered PFNA (2 and 5 mg/kg body weight) or distilled water from gestational day 12 until parturition. Male pups were killed on postnatal day 3. PFNA treatment decreased testosterone biosynthesis by inhibiting expression of steroidogenic acute regulatory protein, cytochrome P450scc, and 3β- and 17β-hydroxysteroid dehydrogenase; proliferation of testicular cells was also affected in treated mice. Furthermore, a marked decrease in expression of Wilms tumor 1, steroidogenic factor 1 and insulin-like factor 3 was noted in neonatal mice testes, indicating that the PFNA treatment may affect the development of the testis. Moreover, observation of the dose-related expression of anti-müllerian hormone and c-Kit in neonatal mice testes is also suggestive of an interference with gonadal development by PFNA exposure. In conclusion, the results suggest that the gestational exposure to PFNA decreased testosterone biosynthesis and altered the expression of critical factors involved in the development of the testis, thereby advocating a potential risk of PFNA to male reproductive health.

Polysaccharide from Ostrea rivularis attenuates reproductive oxidative stress damage via activating Keap1-Nrf2/ARE pathway

The purpose of this study was to investigate the effects of Ostrea rivularis polysaccharide (ORP) against testicular oxidative stress injury via kelch-like ECH-associated protein 1-nuclear erythroid 2-related factor 2/antioxidant response element (Keap1-Nrf2/ARE) pathway. In pharmacological experiments in vivo, ORP administration could dose-dependently inhibit body and testicular weight loss, ameliorate epididymal sperm quality and protect reproductive impairment in cyclophosphamide-induced male Balb/c mice. Moreover, the mechanism in vivo might be elucidated that ORP could increase expression level of Nrf2 and its downstream ARE gene battery in the testis, promote production of corresponding antioxidative enzymes and protein, and enhance Keap1-Nrf2/ARE signaling pathway to avoid male reproductive dysfunction. In addition, ORP treatment could improve survival capacity of H₂O₂-induced TM4 cells and its antioxidant mechanism in vitro also had been verified to activate Keap1-Nrf2/ARE signaling pathway. Overall, these results showed that ORP as a potent antioxidant could reduce reproductive oxidative stress damage related to Keap1-Nrf2/ARE pathway.