ß-Amyrin, a pentacyclic triterpene, exhibits anti-fibrotic, anti-inflammatory, and anti-apoptotic effects on dimethyl nitrosamine-induced hepatic fibrosis in male rats.

Hepatic fibrosis is a leading cause of morbidity and mortality worldwide. Attenuation of fibrogenic process can significantly lower the mortality rate. However, pharmaceutical intervention at fibrogenesis stage remains a major task in medicine. So there is a need for a natural compound to treat hepatic fibrosis. This study was outlined to investigate the anti-fibrotic effect of ß-amyrin in dimethylnitrosamine (DMN)-induced hepatic fibrosis male rats. Serum liver function markers (aspartate transaminase, alanine transaminase, alkaline phosphatase and lactate dehydrogenase), oxidative stress markers (malondialdehyde, superoxide dismutase, catalase, glutathione peroxidase, glutathione reduced content and vitamin C), tissue inflammatory marker (tumor necrosis factor α (TNF-α)), apoptosis marker (caspase 3) and fibrolytic marker (tissue inhibitor of metalloproteinase 1 (TIMP-1)) were evaluated before and after ß-amyrin treatment in DMN-induced rat. ß-Amyrin treatment attenuated the altered levels of the serum enzyme markers produced by DMN and caused a subsequent recovery toward normalization. Oxidative stress markers and TNF-α levels were reduced significantly ( p < 0.001) as well as proteins' (caspase-3 and TIMP-1) expression was reduced in ß-amyrin -treated DMN rats. By virtue of ß-amyrin properties of inhibiting oxidative stress, apoptosis, inflammation, and fibrogenesis, it might act as an ideal anti-inflammatory and anti-fibrogenic agent to halt the progression of liver fibrosis to chronicity.

Responses of skeletal muscle hypertrophy in Wistar rats to different resistance exercise models.

This study aimed to compare the effects of three different resistance exercise models on the quadriceps muscle cross-sectional area, as well as on mTOR phosphorylation and other pivotal molecules involved in the upstream regulation of mTOR. Twenty-four male Wistar rats were divided into untrained (control), endurance resistance training, strength resistance training, and hypertrophy resistance training (HRT) groups (n=6). After 12 weeks of training, the red portion of the quadriceps was removed for histological and Western blot analyses. The results showed that the quadriceps weight and cross-sectional areas in the exercised groups were higher than those of the untrained rats. However, the HRT group presented better results than the other two experimental groups. This same pattern was observed for mTOR phosphorylation and for the most pivotal molecules involved in the upstream control of mTOR (increase of PKB, 14-3-3, ERK, p38 MAPK, and 4E-BP1 phosphorylation, and reduction of tuberin, sestrin 2, REDD1, and phospho AMPK). In summary, our study showed that HRT leads to high levels of mTOR phosphorylation as well as of other proteins involved in the upstream regulation of mTOR.