Taurine alleviates high-fat-high-glucose-induced pancreatic islet ß-cell oxidative stress and apoptosis in rat.

The effect of taurine (TAU) as a specific regulatory mediator on pancreatic function in obese rats induced by a high-fat-high-glucose (HFHG) diet was investigated. We fed male Sprague-Dawley rats under different conditions, namely the control, HFHG, TAU, and HFHG + TAU treatment groups for 4 months. Compared with the HFHG group, TAU supplementation significantly reduced malondialdehyde levels and increased superoxide dismutase, total antioxidant capacity, and glutathione levels in the rat pancreas. In addition, TAU significantly decreased the level of reactive oxygen species, and markedly increased the activity of heme oxygenase 1 (HO-1), Kelch-like ECH-associated protein 1 (KEAP-1), and nuclear factor erythrocyte-2-related factor 2 (Nrf2) in the rat pancreas. Notably, HFHG diet could induce pancreatic injury in the rats through the Nrf2/HO-1 signaling pathway and activate the mitochondrial channel-mediated apoptotic signaling pathway. The addition of TAU significantly improved the pancreatic tissue injury induced by the HFHG diet in the rats and reduced the protein expression of Caspase-3, Cleaved-caspase-3, Caspase-9 and Bcl-2 associated protein X (BAX), and increased the protein expression of B-cell lymphoma-2 (Bcl-2). In conclusion, this experiment confirmed that TAU could alleviate the oxidative stress and apoptosis induced by the HFHG diet in rat pancreatic ß-cells.

Melatonin: Potential avenue for treating iron overload disorders.

Iron overload as a highly risk factor, can be found in almost all human chronic and common diseases. Iron chelators are often used to treat iron overload; however, patient adherence to these chelators is poor due to obvious side effects and other disadvantages. Numerous studies have shown that melatonin has a high iron chelation ability and direct free radical scavenging activity, and can inhibit the lipid peroxidation process caused by iron overload. Therefore, melatonin may become potential complementary therapy for iron overload-related disorders due to its iron chelating and antioxidant activities. Here, the research progress of iron overload is reviewed and the therapeutic potential of melatonin in the treatment of iron overload is analyzed. In addition, studies related to the protective effects of melatonin on oxidative damage induced by iron overload are discussed. This review provides a foundation for preventing and treating iron homeostasis disorders with melatonin.

Biological Effects of Hypomagnetic Field: Ground-Based Data for Space Exploration.

The future of mankind is tied to the exploration and eventual colonization of space. Currently, people have resided in orbit at a space station. In the future, we will have opportunities to stay on the moon, Mars, or in deeper space, where astronauts are exposed to the hypomagnetic field (HMF), which refers to an extremely weak magnetic field environment compared with the geomagnetic field. However, the potential risks of HMF exposure to human health are often overlooked. Here, we summarize the literature related to the biological effects of HMF and calculate the magnitude of the effect. Briefly, HMF impairs multiple animal systems, especially in the central nervous system. Additionally, HMF is a stress factor in plant growth and reproduction. Finally, HMF combined with other space environments, such as radiation and microgravity, can affect organisms. Further studies are required to explore (i) countermeasures to the adverse effects of HMF, (ii) combined effects of HMF with other factors, and (iii) the intensity-effect relationship. © 2021 Bioelectromagnetics Society.

Static Magnetic Field (2-4 T) Improves Bone Microstructure and Mechanical Properties by Coordinating Osteoblast/Osteoclast Differentiation in Mice.

Static magnetic field (SMF), with constant magnetic field strength and direction, has a long history of basic and clinical research in bone biology. Numerous studies demonstrate that exposure to moderate SMF (1 mT-1 T) can increase bone mass and bone density. However, few studies pay attention to the effects of high SMF (>1 T) on the skeletal system. To investigate the physiological effects of high SMF on bone, mice were exposed to 2-4 T SMF for 28 days. Bone microstructure and mechanical properties were examined. The activity of osteoblasts and osteoclasts involved in bone remodeling was evaluated in vivo and in vitro. Compared with the unexposed group, 2-4 T significantly improved the femoral microstructure and tibial mechanical properties. For bone remodeling in vivo, the number of osteoblasts and bone formation was increased, and the osteoclastic number was decreased by 2-4 T. Moreover, the expression of marker proteins in the femur and concentrations of biochemical indicators in serum involved in bone formation were elevated and bone resorption was reduced under 2-4 T SMF. In vitro, osteoblast differentiation was promoted, and the osteoclastic formation and bone resorption ability were inhibited by 2 T SMF. Overall, these results demonstrate that 2-4 T SMF improved bone microarchitecture and strength by stimulating bone formation and restraining bone resorption, and imply that high SMF might become a potential biophysical treatment modality for bone diseases with abnormal bone remodeling. Bioelectromagnetics. © 2021 Bioelectromagnetics Society.

Taurine Increases Spermatozoa Quality and Function in Asthenospermia Rats Impaired by Ornidazole.

Asthenospermia has been considered as one of the crucial causes of male infertility, which was closely related to epididymal dysfunction. Lots of documents have revealed that taurine palys an important role in male reproduction, including antioxidation, membrane stabilization, stimulation of sexual hormone secretion and elevation of sperm quality. The objective of this study was to expose the effect of taurine on spermatozoa quality and function in ornidazole-induced asthenospermia rats. We found that taurine treatment could obviously recover the decline of cauda epididymal sperm count, viability and motility, and the elevation of sperm abnormality in asthenospermia animals. Spermatozoa acrosin, LDH-X, SDH and CCO activities of model rats also were notably increased by taurine administration. The present data indicated that taurine could raise spermatozoa quality and function by elevating mitochondrial energy metabolism. Notably, taurine supplementation markedly raised serum GnRH, LH and T levels in asthenospermia rays, suggesting taurine rescued asthenosperm by means of stimulating hypothalamic-pituitary-testicular axis secretion. We also found that concentrations of asthenospermia epididymal carnitine, SA, α-Glu and ACP, and mRNA expression levels of MMP7 and IDO2 were significantly rised by taurine administration, indicating taurine may protect epididymal epithelium structure, improve secretion activity, and maintain intraluminal microenvironment homeostasis. Finally, the present results showed taurine effectively increased cauda epididymal SOD, GSH and γ-GT levels in model rats, reduced ROS and MDA production, suggesting epididymal antioxidant ability of asthenospermia rats could be elevated by taurine treatment. To sum up, our results indicated that taurine can promote spermatozoa quality and function in ornidazole-induced asthenospermia rats by facilitating epididymal epithelium secretion and luminal microenvironment homeostasis.

Taurine Improves Sexual Function in Streptozotocin-Induced Diabetic Rats.

Previous studies have identified that diabetic erectile dysfunction is associated with androgen and nitric oxide deficiency resulting from hyperglycemia. It has been demonstrated that taurine can stimulate testosterone secretion, increase nitric oxide synthase (NOS) activity and nitric oxide (NO) production, and reduce blood glucose levels in the diabetic animals. Furthermore, recent studies have found that taurine relaxes both the corpus cavernosum and the vasculature. Accordingly, we hypothesized that taurine might exert beneficial effects on erectile function of the diabetic rats. Here, we assessed the effects of taurine on sexual function in streptozotocin (STZ) -induced diabetic male rats. We observed that taurine treatment could markedly increase sexual response and mating ability of STZ-diabetic rats. The serum concentration of gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH), follicle-stimulating hormone (FSH) and testosterone (T) were also significantly increased by taurine administration. Importantly, taurine supplementation notably increased mRNA levels and activity of endothelial NOS (eNOS) and neuronal NOS (nNOS), as well as NO and cGMP content, in the corpus cavernosum of the diabetic rats. In conclusion, the present data indicate that taurine can increase sexual function of STZ-induced diabetic male rats mainly by correcting the diabetes, increasing sexual desire, which is implicated in ameliorating the hypothalamic-pituitary-testicular axis function, and by improving penile erection, which requires increased signaling from the penile endothelial- and neuronal-dependent NO-cGMP pathway.

Taurine Increases Insulin Expression in STZ-Treated Rat Islet Cells In Vitro.

This research aims at figure out the effects and the pathway of taurine on insulin in islet cells cultured in vitro treated by STZ. In the experiment, islet cells were isolated from pancreatic tissue by in situ perfusion with collagenase V. The pancreatic islet cells, maintained in RPMI 1640 culture medium were divided into six groups: C: control, E: supplemented with 10 mmol/L of taurine, group M, T1, T2 and T3 was treated with STZ (0.5 mmol/L), at the same time, taurine were added in group T1,T2 and T3 for 30 min, and then culture medium were collected by centrifugation and then insulin levels were detected by radioimmunoassay, the cells were then rinsed with Hanks, and 0,10, 0, 5, 10, 20 mmol/L of taurine in group C, E, M, T1, T2 and T3 were added for 24 h respectively. Total RNA was extracted, then insulin gene and its transcription regulator such as PDX-1, NeuroD1 were amplified by semi-quantitative RT-PCR. The results showed that, the release of insulin from islet cells treated by STZ could be inhibited by taurine, gene expression of insulin, PDX-1 and NeuroD1 in STZ group decreased significantly, which were up-regulated by taurine administration. In conclusion, taurine exerts a certain degree of protective and reconstructive effects on islet cells treated by STZ.

Taurine Recovers Testicular Steroidogenesis and Spermatogenesis in Streptozotocin-Induced Diabetic Rats.

A great deal of investigations have verified that diabetic male reproductive impairment is associated with the dysfunction of testicular steroidogenesis and spermatogenesis resulted from insulin deficiency and hyperglycaemia-induced oxidative stress. It has been identified taurine is profitable for diabetes mellitus and diabetic implications through its insulin-like and islet cells protective activity. Furthermore, our previous studies found that taurine could increase testicular antioxidative ability, stimulate the endocrine activity of hypothalamic-pituitary-testicular axis, elevate testosterone level, raise sperm quality, suppress the deterioration of testicular function. Accordingly, we hypothesized that taurine may have beneficial effects on testicular dysfunction under diabetic mellitus status. Here, we investigated the effects of taurine on testicular steroidogenesis and spermatogenesis in streptozotocin (STZ)-induced type I diabetic rats. We observed that taurine treatment can markedly increase the body and testis weights, testicular SDH and G6PDH activities, decrease the serum fasting glucose concentration of diabetic rats. Serum contents of GnRH, LH, FSH, T, and testicular StAR, 3ß-HSD, 17ß-HSD mRNA expression levels were also obviously raised by taurine administration, indicating that taurine can improve testicular steroidogenesis in diabetic animals. Finally, we found taurine supplementation effectively elevated the sperm count and motility, reduced sperm abnormality, suggesting that taurine can increase the testicular spermatogenesis function of diabetic rat. In summary, the present data indicated that taurine can rescue the function of testicular steroidogenesis and spermatogenesis in STZ-induced type I diabetic rats possibly by increasing the endocrine activity of hypothalamic-pituitary-testicular axis.

Effects of Replacement of Methionine in Diets with Taurine on Growth Performance and Blood Index in Broilers.

We studied effects of replacement of methionine with taurine on growth performance and blood index of AA+ broilers. Six hundred 1 day broilers were divided into 5 groups, with 3 replicates of 40 broilers in each. The experiment lasted for 42 days.The control group were fed on formulated diets containing 2% methionine; the other groups were offered feed with equal nitrogen and calories to the control group, but contained 25, 50, 75 and 100% taurine in place of methionine.Compared with the control group, no significant differences were observed in growth performance of 1-21 days broilers, or the serum LDL-C, TC, IgG and SOD of the experimental groups (P> 0.05). ADG and F/G from days 1-42, ADG, ADFI and F/G from days 22-42 were significantly different between the experimental groups and the control group (P < 0.05). ADFI and Mortality in 50, 75 and 100% taurine groups were significantly different compared with the control group (P < 0.05). IgM and GSH-PX of 50 and 75% taurine groups were significantly different compared with the control group (P < 0.05). Serum HDL-C, T-AOC levels in 50, 75 and 100% taurine groups were significantly different compared with the control group (P < 0.05). Based on the quadratic regression analysis, the best replacement ratios were 58%, 61% and 61% on days 1-21, 22-42, and 1-42, respectively. In conclusion, appropriate levels of taurine supplement can improve growth performance, immune system, T-AOC, and lipid metabolism.

Taurine and Chinese traditional medicine accelerate alcohol metabolism in mice.

Excessive alcohol consumption is dangerous and causes serious damage to health. The main organ capable of alcohol oxidizing is liver which is also the main organ synthesizing taurine, a sulfur-containing ß-amino acid, which is the major free intracellular amino acid presenting in many tissues of human and animals and exerting many physiologic and pharmacologic functions. To investigate the effect of taurine and Chinese traditional medicine on alcohol metabolism after acute alcoholic intake, male Kunming mice were administered with 60% alcohol (0.4 ml) intragastrically. Water, taurine, or taurine coadministration with Chinese traditional medicine was intragastrically administered to mice 30 min before or after alcohol intake. The disappearance of body-righting reflex was used to determine the intoxication of mice. Durations between alcohol intake and intoxication (tolerance time), intoxication and recovery (maintenance time) were recorded. The concentration of blood alcohol, levels of hepatic alcohol dehydrogenase (ADH), and acetaldehyde dehydrogenase (ALDH) were detected at 20, 50, 90, 120, and 150 min after alcohol intake. The results showed that taurine administered alone or together with Chinese traditional medicine could both significantly reduce the number of intoxicated mice, postpone the tolerance time, shorten the maintenance time, and could obvisouly decrease blood level of alcohol, increase hepatic levels of ADH and ALDH. The results indicated that taurine administered alone or together with traditional Chinese medicine could significantly accelerate the metabolism of alcohol, reduce the toxicity of alcohol, and coadministration of taurine and traditional Chinese medicine had better effects.

Taurine enhances the sexual response and mating ability in aged male rats.

It has been demonstrated that taurine is abundant in male reproductive organs, and can be biosynthesized by testis, but the taurine concentration will reduce with aging. The levels of serum LH, T, NOS, and NO were found to be obviously increased by taurine supplementation in aged rats in our previous study. In addition, aging will result in a significant decline in sexual response and function, which may be attributed to the androgen deficiency. Furthermore, NO has been proposed as a crucial mediator of penile erection. That makes us hypothesize that there is potential relationship between taurine decline and erection dysfunction in aged males. So the primary aim of the present study was to investigate the effect of taurine on male sexuality in rats. Taurine was offered in water to male aged (20 months old) rats for 110 days. The effects of taurine on the sexual response, mating ability, levels of serum reproductive hormones, and penile NOS and NO levels were investigated. The results showed that taurine can significantly reduce the EL and ML; obviously increase the ERF, MF, IF, and EJF; stimulate the secretion of GnRH, LH, and T; and elevate penis NOS and NO level in aged rats. The results indicated that taurine can enhance the sexual response and mating ability in aged male rats by increasing the level of testosterone and NO, but the exact mechanism of which needs to be further investigated.

Effects of taurine on male reproduction in rats of different ages.

BACKGROUND: It has been demonstrated that taurine is one of the most abundant free amino acids in the male reproductive system, and can be biosynthesized by male reproductive organs. But the effect of taurine on male reproduction is poorly understood. METHODS: Taurine and beta-alanine (taurine transport inhibitor) were offered in water to male rats of different ages. The effects of taurine on reproductive hormones, testis marker enzymes, antioxidative ability and sperm quality were investigated. RESULTS: The levels of T and LH were obviously increased by taurine supplementation in rats of different ages, and the level of E was also significantly elevated in baby rats. The levels of SOD, ACP, SDH and NOS were obviously increased by taurine administration in adult rats, but the levels of AKP, AST, ALT and NO were significantly decreased. The levels of SOD, ACP, LDH, SDH, NOS, NO and GSH were significantly elevated by taurine administration in aged rats, but the levels of AST and ALT were significantly decreased. The motility of spermatozoa was obviously increased by taurine supplement in adult rats. The numbers and motility of spermatozoa, the rate of live spermatozoa were significantly increased by taurine supplement in aged rats. CONCLUSIONS: The present study demonstrated that a taurine supplement could stimulate the secretion of LH and T, increase the levels of testicular marker enzymes, elevate testicular antioxidation and improve sperm quality. The results imply that taurine plays important roles in male reproduction especially in aged animals.