Chidamide is a novel histone deacetylase (HDAC) inhibitor that increases the acetylation of histone H3 by inhibiting the activity of HDAC1 and HDAC2. We previously found that treatment of human colon cancer cells with chidamide led to cell apoptosis and cell cycle arrest at G0/1 phase in vitro. The present study extended the observations in vivo and explored the underlying molecular mechanisms. In nude mice bearing human colon cancer LoVo cell xenografts, chidamide alone or in combination with 5-flurouracil (5-Fu) reduced the expression of HDAC1 and HDAC2, accompanied with increased acetylation of histone H3. Chidamide alone inhibited the tumor growth and induce cell apoptosis in tumor-bearing mice. Combined treatment of chidamide with 5-Fu enhanced the anti-tumor activity of 5-Fu. Western blotting analysis showed that chidamide alone or in combination with 5-Fu upregulated the expressions of cleaved Caspase-3 and cleaved poly-ADP (adenosine diphosphate)-ribose polymerase (PARP). In addition, chidamide alone or in combination with 5-Fu increased the p53, phosphorylated-p53 (p-p53), p21 and γH2AX levels, but suppressed cyclin dependent kinase 4 (CDK4) expression in tumor cells. Chidamide alone or in combination with 5-Fu down regulated the expressions of p-AKT, p-mammalian target of rapamycin (mTOR), p-p70S6K, p-Raf, and p44/42 mitogen activated protein kinase (Erk1/2), indicating the blockage of these signaling pathways. The results demonstrated that chidamide alone or in combination with 5-Fu exerted anti-tumor activity in nude mice bearing human colon cancer LoVo cell xenografts, and several signaling pathways might be involved in the chidamide-induced tumor growth inhibition and tumor cell apoptosis.

Ulcerative colitis (UC) is the major type of inflammatory ailment with elevated prevalence worldwide. Dieckol (DEK) is a phlorotannin that is extensively found in marine algae and has been found to have different pharmacological properties. Nevertheless, the impact of DEK in UC has not been investigated earlier. Therefore, we appraised DEK's function in dextran sulfate sodium (DSS)‐induced UC in the mouse. An overall of 30 mice was randomized into 5 equal groups. Control mice treated with a standard diet (group I), colitis mice challenged with 3% of DSS through drinking water for 7 consecutive days (group II), DEK was supplemented via oral gavage from day 1 to 10 at the dosages of 5, 10, and 15 mg/kg b.wt, respectively. All animals were sacrificed on the 11th day. The body weight (bwt), colon length, disease activity index, malondialdehyde (MDA), myeloperoxidase (MPO), and histological features were observed using suitable techniques, and COX‐2 expression was investigated by immunohistochemistry. Moreover, TNF‐α, IL‐1β, p65, IκBα, HO‐1, and Nrf2 expressions were measured using ELISA and RT‐PCR techniques, respectively. DEK treatment to the colitis mice considerably lessened, DSS‐challenged alterations in body weight, DAI, colonic length shortening and histological changes. DEK exhibited potent antioxidant effects due to the reduced MDA and MPO, and Nrf2 expression markers while the HO‐1 marker was augmented. Additionally, DEK also suppressed the expression s of TNF‐α, IL‐1β, and the p‐p65, p‐IκBα, and p65 and augmented the expression of IκBα, which eventually proved the anti‐inflammatory potential of DEK against the DSS‐challenge. Based on these results, DEK has been found effective in mitigating colitis, conceivably alleviating colon inflammation through the NF‐κB inhibition and triggering of Nrf2/HO‐1 signaling cascade.

We investigated the rosiglitazone (RSG) effect on adriamycin (ADM)‐induced cardio toxicity in experimental animals. Forty adult Wistar male rats were separated into four groups as follows: normal control; RSG (10 mg/kg)‐treated; ADM (10 mg/kg)‐administered; and ADM (10 mg/kg) + RSG (10 mg/kg)‐treated. Serum lipid level, different biochemical biomarkers, histological analysis, and nuclear factor erythroid 2‐related factor/heme oxygenase‐1 (Nrf2/HO‐1), Caspase 3, B‐cell lymphoma 2 (Bcl‐2), and Bax gene expression were assessed in serum and cardiac tissue samples. Our results show that RSG treatment in ADM‐administered animals significantly diminished low‐density lipoprotein cholesterol, triglyceride, and total cholesterol, and increases high‐density lipoprotein cholesterol (HDL‐c) in comparison with the ADM group. RSG treatment reduced the effect of ADM administration on cardiac dysfunction markers such as cardiac troponin T Creatine Kinase‐MB, aspartate aminotransferase, and lactate dehydrogenase, showing the amelioration of cardio toxicity in ADM‐administered rats. Additionally, RSG treatment significantly decreased the level of malondialdehyde and nitric oxide in cardiovascular tissue. RSG‐treated rats in combination with ADM likewise showed a significant increase in reduced glutathione, superoxide dismutase, catalase content, and the activity of glutathione peroxidase (GPx) as compared with ADM group. Moreover, RSG treatment in ADM rats significantly increased an Nrf2 and HO‐1 expression in comparison with ADM group. While in apoptosis parameters, RSG treatment in ADM rats significantly diminished a cleaved caspase‐3 and Bax expression as well as expanded Bcl‐2 expression when contrasted with ADM group of rats. In conclusion, RSG is capable of protecting heart toxicity in ADM‐treated animals through defensive effects on oxidative stress and biochemical markers.