Saponin extract from Achyranthes bidentata Blume alleviates disuse-induced muscle atrophy through PI3K/Akt signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: The roots of Achyranthes bidentata Blume are one of the regularly used herbal drugs in Chinese medicine, and has been applied for strengthening the muscle and bone for a long time. However, its effect on muscle remains unclear. AIM OF THE STUDY: This paper aims to explore the anti-muscle atrophy effect of A. bidentata, and to clarify the possible signaling pathways involved. MATERIALS AND METHODS: The saponin extract of the roots of A. bidentata (ABSE) was prepared and analyzed, and its activity on myoblast differentiation was assayed with C2C12 cell culture. ABSE was then orally administered at dosage of 35, 70 and 140 mg/kg/day to disuse-induced muscle atrophy mice. The studies on mice body weight and muscle quality were conducted, and Western blot was used for exploring the possible signaling pathways involved in the muscle protective action aided with transcriptome analysis. RESULTS: The total saponin content of ABSE was 59.1%. ABSE promoted the C2C12 cells differentiation to myotube in C2C12 differentiation assay. Further study with disuse-induced muscle atrophy mice model demonstrated that ABSE significantly increased muscle fiber diameter as well as the proportion of slow muscle fibers. Possible mechanism study aided with transcriptome analysis revealed that ABSE alleviated muscle atrophy at least through activation of PI3K/Akt pathway in vivo & vitro. CONCLUSIONS: The saponin extract of the root of A. bidentata (ABSE) has a protective effect on muscle atrophy, and showed a considerable potential in prevention and treatment of muscle atrophy.

Sulforaphane ameliorates glucose intolerance in obese mice via the upregulation of the insulin signaling pathway.

Sulforaphane (SFN) is a dietary component with multiple bioactivities; however, its role in obesity-related metabolic derangement remains unclear. Here, the effect of SFN on the glucose intolerance of obese mice and the underlying mechanism were determined. C57B/6J male mice were randomly divided into two groups, having free access to water and a normal-fat diet (ND, n = 6) or a high-fat diet (HFD, n = 33) for 8 weeks; thereafter twelve mice having the greatest weight gain among the HFD-fed mice were considered as obese mice. These obese mice were randomly divided into two groups and treated orally for 6 weeks with or without SFN (100 µmol per kg bw, 3 times per week). During this period the animals were continuously maintained on a ND or a HFD. Blood glucose and serum insulin were examined; then glucose tolerance and insulin resistance were evaluated. In addition, the expression of insulin signaling pathway-related genes in the muscle was determined. Our data showed that the obese mice presented a marked insulin resistance and glucose intolerance as compared to the control group, while SFN treatment exerted a prominently protective effect. In addition, the SFN-treated obese mice had a significantly increased insulin receptor substrate 1 (IRS-1) protein level (P < 0.05), markedly elevated Akt activation, as well as dramatically enhanced phosphorylation of PDK-1 (P < 0.05) when compared with the SFN-untreated obese mice. Moreover, the SFN-treated obese mice exhibited a significantly enhanced translocation of GLUT4 (P < 0.05) to the plasma membrane in the muscle compared to the obese mice without SFN treatment. In conclusion, our results support the notion that SFN acts as a promising agent to improve glucose tolerance through the up-regulation of insulin signaling mainly involving the IRS-1/Akt/GLUT4 pathway in the muscle.

Sulforaphane protects MLE-12 lung epithelial cells against oxidative damage caused by ambient air particulate matter.

Ambient air particulate matter with aerodynamic diameters ≤2.5 µm (PM2.5) can cause pulmonary injury. Oxidative stress is thought to be an important mechanism of PM2.5-mediated toxicity. Sulforaphane (SFN), a compound derived from cruciferous vegetables, is a well-known potent antioxidant; however, its protective effect on lung epithelial cells exposed to PM2.5 is unclear. The results showed that SFN pre-treatment markedly inhibited PM2.5-induced apoptosis of the type II alveolar epithelial cell line MLE-12 by elevating glutathione S-transferase levels and decreasing reactive oxygen species. SFN pre-treatment down-regulated the expression of the pro-apoptotic proteins Bax and Bad, and reduced the activity of caspase-3, while it up-regulated the expression of the anti-apoptotic protein Bcl-2. Moreover, SFN induced the activation of the Akt and ERK pathways, and up-regulated the expression of Nrf2 and its downstream antioxidant genes NQO-1 and HO-1. This is the first study to demonstrate that SFN could protect MLE-12 cells against PM2.5-induced oxidative damage via activation of the Nrf2 pathway and inhibition of the mitochondrial apoptotic pathway; therefore, SFN may be a promising compound for preventing PM2.5-triggered pulmonary cell damage.

[Trends of overweight and obesity in aged 7 to 18 Mongolian ethnic children and adolescents from 1985-2010].

OBJECTIVE: To study the overweight and obesity situation among Mongolian ethnic children and adolescents in the last 25 years and to provide a basis on related prevention and control measures. METHODS: A cross-sectional study was used, with 18 366 aged 7 to 18 Mongolian ethnic children and adolescents involved. Surveys on their physical health, in 1985, 2000 and 2010 were carried out. Comparison on the mean of BMI and the prevalence rates of overweight and obesity in different years, genders, location of residence (urban or rural) was also made. RESULTS: Over the past 25 years, among the aged 7 to 18 Mongolian ethnic children and adolescents, the overall trend on their means of BMI was increasing. The prevalence rates of overweight and obesity in Mongolian ethnic children and adolescents were 2.1%, 0.5% in 1985, and 6.3%, 2.4% in 2000, with an increase of 2 to 4 times during the last 15 years. The prevalence rates of overweight and obesity were substantially increasing in the year 2010, to have reached 9.1% and 6.6%, which were 4 to 12 times of the figures in 1985. The detection rates of overweight and obesity in urban boys were 1.2%, 0 in 1985, 7.9%, 3.4% in 2000 and 11.0%, 11.8% in 2010. However, the rate of obesity in the rural boys were 0.6% and 0.6% in 1985, 2.8%, 2.1% in 2000 and 9.0%, 3.4% in 2010. In 1985 the rates of overweight and obesity in urban girls were 1.8%, 0.3%, 8.1%, 4.3% in 2000 and 9.4%, 8.4% in 2010. However, among the rural girls, the prevalence rates of overweight and obesity prevalence was 8.8%, 2.2% in 1985, 4.5%, 0.9%, in 2000 and 10.2%, 4.5% in 2010. The rates of overweight and obesity among groups in different years showed significant differences (P < 0.05). CONCLUSION: Over the past 25 years, the prevalence rates on overweight and obesity increased significantly in Mongolian ethnic children and adolescents, and continued to rise, which called for reasonable and effective measures to be taken to prevent and control the occurrence of the problem.