Efficacy of Tribulus terrestris extract and metformin on fertility indices and oxidative stress of testicular tissue in streptozotocin-induced diabetic male rats

Lauric acid improves hormonal profiles, antioxidant properties, sperm quality and histomorphometric changes in testis and epididymis of streptozotocin-induced diabetic infertility rats

Lauric acid, a 12‑carbon atom medium chain fatty acid (MCFA) has strong antioxidant and antidiabetic activities. However, whether lauric acid can ameliorate hyperglycaemia-induced male reproductive damage remains unclear. The study aimed to determine the optimal dose of lauric acid with glucose-lowering activity, antioxidant potential and tissue-protective effects on the testis and epididymis of streptozotocin (STZ)-induced diabetic rats. Hyperglycaemia was induced in Sprague Dawley rats by an intravenous injection of STZ at a dose of 40 mg/kg body weight (bwt). Lauric acid (25, 50 and 100 mg/kg bwt) was administered orally for eight weeks. Weekly fasting blood glucose (FBG), glucose tolerance and insulin sensitivity were examined. Hormonal profiles (insulin and testosterone), lipid peroxidation (MDA) and antioxidant enzyme (SOD and CAT) activities were measured in the serum, testis and epididymis. The reproductive analyses were evaluated based on sperm quality and histomorphometry. Lauric acid administration significantly improved FBG levels, glucose tolerance, hormones-related fertility and oxidant-antioxidant balance in the serum, testis and epididymis compared to untreated diabetic rats. Treatment with lauric acid preserved the testicular and epididymal histomorphometry, along with the significant improvements in sperm characteristics. It is shown for the first time that lauric acid treatment at 50 mg/kg bwt is the optimal dose for ameliorating hyperglycaemia-induced male reproductive complications. We conclude that lauric acid reduced hyperglycaemia by restoring insulin and glucose homeostasis, which attributes to the regeneration of tissue damage and sperm quality in STZ-induced diabetic rats. These findings support the correlation between oxidative stress and hyperglycaemia-induced male reproductive dysfunctions.

The Profertility and Aphrodisiac Activities of Tribulus terrestris L.: Evidence from Meta-Analyses

Tribulus terrestris L. (TT) is a traditional medicinal plant, which belongs to the Zygophyllaceae family. TT extracts have been widely used for diuretic, analeptic, aphrodisiac, and profertility properties. To quantitatively evaluate the profertility and aphrodisiac effects of Tribulus terrestris L., we undertook the present meta-analyses on published data. A thorough literature screening was performed to identify articles evaluating the effect of TT on spermatogenesis, male fertility, reproductive, and aphrodisiac parameters. We shortlisted 30 relevant studies conducted on humans and rodents. Meta-analyses were conducted to evaluate the quantitative impact of TT on various fertility parameters. In case of humans, the pooled analysis on 133 subjects showed significant improvements in sperm concentration ( $\text{SDM}=0.624$ , 95% $\text{CI}=0.13$ to 1.117, $p=0.013$ ) and sperm motility ( $\text{SDM}=0.742$ , 95% $\text{CI}=0.331$ to 1.152, $p=0.001$ ). TT resulted in nonsignificant increases in testosterone and LH and a nonsignificant decrease in FSH. Similar to the above, TT improved sperm count, sperm motility, and sperm viability in rodents with normal or compromised fertility. The effect on hormone levels was less credible with frequent variations across studies and animal models. The aphrodisiac activity was studied in castrated animal models or normal rodents, both of which showed significant improvements in mounting frequency and intromission frequency and significant declines in mounting latency and intromission latency. These meta-analyses suggested that TT possesses profertility and aphrodisiac activities.

Protective effects of Tribulus terrestris and Cinnamomum zeylanicum extracts and trehalose added to diluents on goat epididymal sperm freezability

This study investigates the effect of adding Tribulus terrestris ethanol extract (TEE) and Cinnamomum zeylanicum ethanol extract (CEE) and trehalose on freezability of goat epididymal spermatozoa. In Experiment 1, the treatments consist of basic extender containing 25, 50 or 100 μg/ml of TEE or CEE. The control contained no additives. Experiment 2 was carried out to compare the effect of best concentrations resulted in the first experiment with 150 mM trehalose added to basic extender. The results of experiment 1 showed that supplementation of 50 μg/ml TEE and 50 μg/ml CEE increased significantly the percentages of motility, progressive motility and viability of cryopreserved spermatozoa, while the level of malondialdehyde concentration was decreased. Moreover, the 50 μg/ml TEE treatment indicate significantly) P < 0.05) the lowest DNA fragmentation among the other treatments. The data obtained from experiment 2 show that all treatments increased significantly) P < 0.05) the percentages of total motility, viability and membrane integrity, and concurrently decreased the rate of MDA compared to control. In addition, the rates of viability and progressive motility were significantly (P < 0.05) higher in diluents contained herb extracts and trehalose. Regarding DNA fragmentation, the results demonstrate that using the extracts and trehalose in diluents decreased the DNA damages and thereby improved the rate of intact sperm heads. In conclusion, the results of this study indicate that 50 μg/ml of Tribulus terrestris and Cinnamomum zeylanicum ethanolic extracts alone and plus trehalose improved the spermatozoa quality and could be used for cryopreservation.

Tribulus terrestris ameliorates carbon tetrachloride-induced hepatotoxicity in male rats through suppression of oxidative stress and inflammation

Hepatoprotection is a goal for the harmful effect of several hepatotoxic agents. The present study has been executed to assess the useful impacts of Tribulus terrestris (TT) and silymarin (SLM) against carbon tetrachloride (CCL₄)-induced hepatotoxicity. Forty-two male rats were partitioned into six groups: group I: received 0.3% CMC-Na in distilled water, group II: TT (500 mg/kg BW, orally), group III: SLM (200 mg/kg, orally) for 14 consecutive days (on days 11 and 12 intraperitoneal corn oil), group IV: CCL₄, group V: TT (500 mg/kg BW) plus CCL₄, and group VI: SLM (200 mg/kg orally) plus CCL₄. The CCL₄ was administered (2.0 ml/kg BW) intraperitoneal on days 11 and 12. Sera were collected for assessment of hepatic injury markers and pro-inflammatory cytokines. Additionally, liver tissue oxidative stress, lipid peroxidation, histopathological examination, and immunohistochemical analysis (Bax and bcl-2) were done. CCL₄ injection induced significant reductions in hepatic antioxidants while increased hepatic lipid peroxidation as well as serum hepatic injury biomarkers and pro-inflammatory cytokines. The histopathological examination showed necrotic and degenerative changes in the hepatic tissue, while immunohistochemical analysis revealed marked hepatic expression of activated Bax, and bcl-2, following CCL₄ injection. TT pretreatment significantly improved all examined parameters and restored the hepatic architecture. The current study illustrated that TT effectively alleviates hepatic oxidative damage, apoptosis, and inflammation, induced by acute CCL₄ intoxication. In this manner, TT has promising cytoprotective powers against hepatotoxicity induced by CCL₄.

Black Seed Thymoquinone Improved Insulin Secretion, Hepatic Glycogen Storage, and Oxidative Stress in Streptozotocin-Induced Diabetic Male Wistar Rats

Diabetes mellitus is one of the metabolic diseases having several complications. Nigella sativa oil (NSO) might have beneficial effects in the treatment of diabetic complications. Thirty-two mature male Wistar rats were equally divided into four experimental groups: control, control NSO 2 mL/kg, streptozotocin- (STZ-) induced diabetic, and diabetic (STZ-induced) treated with oral NSO 2 mg/kg for 30 days. Fasting blood glucose (FBG), insulin, and lipid profile levels were determined. Pancreatic and hepatic tissues were used for catalase and GSH. Histopathology, hepatic glycogen contents, insulin immunohistochemistry, and pancreatic islet morphometry were performed. NSO 2 mL/kg was noticed to decrease (P < 0.05) FBG and increase (P < 0.05) insulin levels in diabetic rats than in diabetic nontreated animals. Lipid profile showed significant (P < 0.5) improvement in diabetic rats that received NSO 2 mL/kg than in the diabetic group. Both pancreatic and hepatic catalase and GSH activities revealed a significant (P < 0.05) increment in the diabetic group treated with NSO than in the diabetic animals. NSO improved the histopathological picture and hepatic glycogen contents of the diabetic group as well as increased (P < 0.05) insulin immunoreactive parts % and mean pancreatic islet diameter. NSO exerts ameliorative and therapeutic effects on the STZ-induced diabetic male Wistar rats.

Male Infertility: The Effect of Natural Antioxidants and Phytocompounds on Seminal Oxidative Stress

Defective sperm function has been identified as the most common cause of infertility. The objective of this study was to review recent findings on the effects of various antioxidants on male fertility. High amounts of poly unsaturated fatty acid are found in the mammalian spermatozoa membranes, thereby making them susceptible to lipid peroxidation. Although, free radicals and reactive oxygen species (ROS) play major roles in reproduction, they are strongly associated with oxidative stress. Furthermore, factors such as obesity, inflammation, pollutants and cigarette smoking are negatively correlated with spermatogenesis. Endogenous antioxidants system exists to mediate these damages. In a normal physiological state, the seminal plasma contains antioxidant enzyme mechanism that is capable of quenching these ROS as well as protecting the spermatozoa against any likely damage. However, high level of ROS triggered by inflammatory cells and oxidation of fatty acid in obese subjects may down play antioxidant mechanism resulting in oxidative stress. Evaluation of such oxidative stress is the first step in the treatment of male infertility through administration of suitable antioxidant. Notably, antioxidant such as vitamin E and C, carotenoids and carnitine have been found beneficial in restoring a balance between ROS generation and scavenging activities. There are emerging evidences that herbal products can also boost male reproductive functions. Nonetheless, a good lifestyle, regular exercise, avoidance of stress and observing safety rules at work are habits that can reverse male infertility.