The role of taurine in male reproduction: Physiology, pathology and toxicology.

Taurine, a sulfur-containing amino acid, has a wide range of biological effects, such as bile salt formation, osmotic regulation, oxidative stress inhibition, immunomodulation and neuromodulation. Taurine has been proved to be synthesized and abundant in male reproductive organs. Recently, accumulating data showed that taurine has a potential protective effect on reproductive function of male animals. In physiology, taurine can promote the endocrine function of the hypothalamus-pituitary-testis (HPT) axis, testicular tissue development, spermatogenesis and maturation, delay the aging of testicular structure and function, maintain the homeostasis of the testicular environment, and enhance sexual ability. In pathology, taurine supplement may be beneficial to alleviate pathological damage of male reproductive system, including oxidative damage of sperm preservation in vitro, testicular reperfusion injury and diabetes -induced reproductive complications. In addition, taurine acts as a protective agent against toxic damage to the male reproductive system by exogenous substances (e.g., therapeutic drugs, environmental pollutants, radiation). Related mechanisms include reduced oxidative stress, increased antioxidant capacity, inhibited inflammation and apoptosis, restored the secretory activity of the HPT axis, reduced chromosomal variation, enhanced sperm mitochondrial energy metabolism, cell membrane stabilization effect, etc. Therefore, this article reviewed the protective effect of taurine on male reproductive function and its detailed mechanism, in order to provide reference for further research and clinical application.

Effects of Genistein on Common Kidney Diseases.

Genistein is a naturally occurring phytoestrogen (soy or soybean products) that is classified as an isoflavone, and its structure is similar to that of endogenous estrogens; therefore, genistein can exert an estrogen-like effect via estrogen receptors. Additionally, genistein is a tyrosine kinase inhibitor, which enables it to block abnormal cell growth and proliferation signals through the inhibition of tyrosine kinase. Genistein is also an angiogenesis inhibitor and an antioxidant. Genistein has effects on kidney cells, some of the kidney's physiological functions, and a variety of kidney diseases. First, genistein exerts a protective effect on normal cells by reducing the inflammatory response, inhibiting apoptosis, inhibiting oxidative stress, inhibiting remodeling, etc., but after cell injury, the protective effect of genistein decreases or even has the opposite effect. Second, genistein can regulate renin intake to maintain blood pressure balance, regulate calcium uptake to regulate Ca2+ and Pi balances, and reduce vasodilation to promote diuresis. Third, genistein has beneficial effects on a variety of kidney diseases (including acute kidney disease, kidney cancer, and different chronic kidney diseases), such as reducing symptoms, delaying disease progression, and improving prognosis. Therefore, this paper reviews animal and human studies on the protective effects of genistein on the kidney in vivo and in vitro to provide a reference for clinical research in the future.

Effects of Lipoic Acid on Ischemia-Reperfusion Injury.

Ischemia-reperfusion (I/R) injury often occurred in some pathologies and surgeries. I/R injury not only harmed to physiological functions of corresponding organ and tissue but also induced multiple tissue or organ dysfunctions (even these in distant locations). Although the reperfusion of blood attenuated I/R injury to a certain degree, the risk of secondary damages was difficult to be controlled and it even caused failures of these tissues and organs. Lipoic acid (LA), as an endogenous active substance and a functional agent in food, owns better safety and effects in our body (e.g., enhancing antioxidant activity, improving cognition and dementia, controlling weight, and preventing multiple sclerosis, diabetes complication, and cancer). The literature searching was conducted in PubMed, Embase, Cochrane Library, Web of Science, and SCOPUS from inception to 20 May 2021. It had showed that endogenous LA was exhausted in the process of I/R, which further aggravated I/R injury. Thus, supplements with LA timely (especially pretreatments) may be the prospective way to prevent I/R injury. Recently, studies had demonstrated that LA supplements significantly attenuated I/R injuries of many organs, though clinic investigations were short at present. Hence, it was urgent to summarize these progresses about the effects of LA on different I/R organs as well as the potential mechanisms, which would enlighten further investigations and prepare for clinic applications in the future.

Effects of mindfulness-based stress reduction on anxiety symptoms in young people: A systematic review and meta-analysis.

In this study, we evaluated the efficacy of mindfulness-based stress reduction (MBSR) for young people with anxiety symptoms. We used many databases, including PubMed, PsycINFO, Web of Science, EMBASE, CINAHL and Cochrane Library (from inception to May 2019). We included randomized controlled trials (RCTs) comparing MBSR with various control conditions, including didactic lecture course, health education, treatment as usual, didactic seminar and cognitive behavioral program in young people with anxiety symptoms. Finally, we selected fourteen studies comprising 1489 participants comparing with control conditions. The meta-analysis suggested that MBSR significantly reduced anxiety symptoms compared to control conditions at post-treatment (Standardized Mean Difference, SMD = -0.14, 95% CI -0.24 to -0.04). However, the effect of MBSR on anxiety symptoms in young people may be affected by different intervention duration, especially the significance in a short-term intervention (less than 8 weeks). In addition, the meta-analysis indicated publication bias for anxiety symptoms. Using the trim-and-fill method, we found the adjusted standardized mean difference, which indicated that MBSR was still significantly superior to the other control conditions. The sensitivity analysis showed that the result was reliable. Current evidence indicates MBSR has superior efficacy compared with control conditions in treating young people with anxiety symptoms. Based on this, we suggest there is a significant effect of MBSR on young people with anxiety symptoms, especially the effects of long-term intervention for future studies.

Roles of taurine in cognitive function of physiology, pathologies and toxication.

Taurine is a key functional amino acid with many functions in the nervous system. The effects of taurine on cognitive function have aroused increasing attention. First, the fluctuations of taurine and its transporters are associated with cognitive impairments in physiology and pathology. This may help diagnose and treat cognitive impairment though mechanisms are not fully uncovered in existing studies. Then, taurine supplements in cognitive impairment of different physiologies, pathologies and toxicologies have been demonstrated to significantly improve and restore cognition in most cases. However, elevated taurine level in cerebrospinal fluid (CSF) by exogenous administration causes cognition retardations only in physiologically sensitive period between the perinatal to early postnatal period. In this review, taurine levels are summarized in different types of cognitive impairments. Subsequently, the effects of taurine supplements on cognitions in physiology, different pathologies and toxication of cognitive impairments (e.g. aging, Alzheimer' disease, streptozotocin (STZ)-induced brain damage, ischemia model, mental disorder, genetic diseases and cognitive injuries of pharmaceuticals and toxins) are analyzed. These data suggest that taurine can improve cognition function through multiple potential mechanisms (e.g. restoring functions of taurine transporters and γ-aminobutyric acid (GABA) A receptors subunit; mitigating neuroinflammation; up-regulating Nrf2 expression and antioxidant capacities; activating Akt/CREB/PGC1α pathway, and further enhancing mitochondria biogenesis, synaptic function and reducing oxidative stress; increasing neurogenesis and synaptic function by pERK; activating PKA pathway). However, more mechanisms still need explorations.