cytochrome-c-t and tetrahydrocurcumin

Curcumin (CUR), a widely used food additive, is derived mainly from Curcuma species that has been applied traditionally for the treatment of various diseases, including hepatocellular carcinoma (HCC). However, its poor systemic bioavailability hampers its clinical application, which may be related to its wide metabolism. Tetrahydrocurcumin (THC) is a major metabolite of CUR and has been reported to have multiple biologic activities. We investigated, for the first time, the efficacy and associated mechanism of action of THC and CUR in a H22 ascites tumor-bearing model in mice. THC evoked a significant dose-dependent promotion of survival and was significantly more effective than CUR in inhibiting tumor growth, including increased body weight, abdominal circumference, ascites volume, and the viability of cancer cells. Experiments on essential immune organs indicated that THC had a more favorable margin of safety than the reference drug cyclophosphamide. THC induced the apoptosis of H22 cells obviously by increasing the level of p53 and decreasing the level of murine double minute 2. THC also decreased the expression of Bcl-2 significantly and increased the expression of Bcl2-associated X, resulting in the release of cytochrome C. THC significantly activated and induced cleavage of caspase-3 and caspase-9 to induce the apoptosis of H22 cells. Taken together, these results indicate that THC was more effective than CUR in inhibiting the apoptosis of H22-induced ascites tumor cells and achieved it via regulation of a mitochondrial apoptosis pathway. THC might be a bioactive anti-tumor form of CUR and represented a potentially effective agent for HCC treatment.

Topics: Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Ascites; Cell Line, Tumor; Curcumin; Cytochromes c; Gene Expression Regulation, Neoplastic; Humans; Liver Neoplasms; Male; Mice; Mitochondria

High levels of homocysteine (Hcy) known as hyperhomocysteinemia (HHcy), contribute to autophagy and ischemia/reperfusion injury (I/R). Previous studies have shown that I/R injury and HHcy cause increased cerebrovascular permeability; however, the associated mechanism remains obscure. Interestingly, during HHcy, cytochome-c becomes homocysteinylated (Hcy-cyto-c). Cytochrome-c (cyto-c) transports electrons and facilitates bioenergetics in the system. However, its role in autophagy during ischemia/reperfusion injury is unclear. Tetrahydrocurcumin (THC) is a major herbal antioxidant and anti-inflammatory agent. Therefore, the objective of this study was to determine whether THC ameliorates autophagy during ischemia/reperfusion injury by reducing homocysteinylation of cyto-c in hyperhomocysteinemia pathological condition. To test this hypothesis, we employed 8-10-week-old male cystathionine-beta-synthase heterozygote knockout (CBS⁺/⁻) mice (genetically hyperhomocystemic mice). Experimental group was: CBS⁺/⁻, CBS⁺/⁻ + THC (25 mg/kg in 0.1% DMSO dose); CBS ⁺/⁻/I/R, and CBS⁺/⁻/I/R + THC (25 mg/kg in 0.1% DMSO dose). Ischemia was performed for 30 min and reperfusion for 72 h. THC was injected intra-peritoneally (I.P.) once daily for a period of 3 days after 30 min of ischemia. The infarct area was measured using 2,3,5-triphenyltetrazolium chloride staining. Permeability was determined by brain edema and Evans Blue extravasation. The brain tissues were analyzed for oxidative stress, matrix metalloproteinase-9 (MMP-9), damage-regulated autophagy modulator (DRAM), and microtubule-associated protein 1 light chain 3 (LC3) by Western blot. The mRNA levels of S-adenosyl-L-homocysteine hydrolases (SAHH) and methylenetetrahydrofolate reductase (MTHFR) genes were measured by quantitative real-time polymerase chain reaction. Co-immunoprecipitation was used to determine the homocysteinylation of cyto-c. We found that brain edema and Evans Blue leakage were reduced in I/R + THC-treated groups as compared to sham-operated groups along with reduced brain infarct size. THC also decreased oxidative damage and ameliorated the homocysteinylation of cyto-c in-part by MMP-9 activation which leads to autophagy in I/R groups as compared to sham-operated groups. This study suggests a potential therapeutic role of dietary THC in cerebral ischemia.

Topics: Animals; Antioxidants; Autophagy; Brain Ischemia; Curcumin; Cytochromes c; Hyperhomocysteinemia; Male; Mice; Mice, Knockout; Reperfusion Injury