Effect of curcumin analog on gamma-radiation-induced cellular changes in primary culture of isolated rat hepatocytes in vitro.

The present study was aimed to evaluate the radioprotective effect of curcumin analog, on gamma-radiation-induced toxicity in primary cultures of isolated rat hepatocytes. Hepatocytes were isolated from the liver of rats by collagenase perfusion. The DNA damage was analysed by single cell gel electrophoresis (comet assay). An increase in the severity of DNA damage was observed with the increase in gamma-radiation dose at 1-4 Gy in cultured rat hepatocytes. The levels of lipid peroxidative indices like thiobarbituric acid reactive substances (TBARSs) were increased significantly, whereas the levels of reduced glutathione (GSH) and antioxidant enzymes were significantly decreased in gamma-irradiated groups. The maximum damage to hepatocytes was observed at 4Gy gamma-irradiation. Pretreatment with different concentrations of curcumin analog (1.38, 6.91 and 13.82 microM) shows a significant decrease in the levels of TBARS and DNA damage. Pretreatment with curcumin analog prevents the loss of enzymic and non-enzymic antioxidants like GSH upon gamma-irradiation. The maximum protection of hepatocytes was observed at 6.91 microM of curcumin analog pretreatment. Thus, our result shows that pretreatment with curcumin analog protects the hepatocytes against gamma-radiation-induced cellular damage.

Chemoprevention of colon cancer by a synthetic curcumin analog involves amelioration of oxidative stress.

The modulating effects of a bisdemethoxycurcumin analog (BDMC-A) on 1,2-dimethylhydrazine (DMH)-induced oxidative stress during colon carcinogenesis was investigated in male Wistar rats. The effects were compared with those of curcumin, a known anticarcinogen. All the animals given a weekly subcutaneous injection of DMH (20 mg/kg body wt.) for 15 weeks developed colon tumors. The colon and intestine administered DMH showed a decrease in lipid peroxidation with a concomitant increase in the activities of GSH-dependent enzymes (glutathione peroxidase, glutathione S-transferase) when compared to untreated control rats. In groups of animals given DMH and BDMC-A no tumors were observed, and the lipid peroxidation as well as the GSH-dependent enzymes showed a pattern similar to that of untreated control rats. We speculate that BDMC-A modulates DMH-induced oxidative stress and offers chemoprevention against colon carcinogenesis, and the modulatory effect is comparable with that of curcumin. Thus, lipid peroxidation and antioxidant status together could be used as markers of colon cancer chemoprevention by BDMC-A.

Protective Role of a Novel Curcuminoid on Alcohol and PUFA-Induced Hyperlipidemia.

Alcohol use is contributing to an unprecedented decline in life expectancy. It induces hyperlipidemia when taken at higher concentrations. Alcoholics usually after a heavy binge of alcohols take fried food items normally made up of polyunsaturated fatty acids (PUFAs). The combined ingestion of alcohol and PUFAs is considered to be dangerous and known to result in hyperlipidemic conditions. Previous studies have shown that curcumin, an active principle of turmeric (Curcuma longa), has antihyperlipidemic properties. So in the present work we have synthesized an analog of curcumin and tested the protective role of that synthetic curcuminoid on alcohol and thermally oxidized sunflower oil-induced hyperlipidemia. Male Albino rats of Wistar strain were used for the experimental study. Antihyperlipidemic activity of the synthetic curcuminoid was evaluated by analyzing the levels of lipids (cholesterol, triglycerides [TGs], phospholipids [PLs], and free fatty acids [FFAs]) in different tissues and histopathological changes in the liver. The results showed that the levels of cholesterol, TGs, and FFAs were increased significantly in alcohol, thermally oxidized sunflower oil (Delta PUFA), and alcohol + Delta PUFAs treated groups. Administration of synthetic curcuminoid effectively reduced these levels. The phospholipid (PL) levels, which were decreased in the liver and kidney and increased in the heart in the alcohol, Delta PUFA, and alcohol + Delta PUFA groups, were positively modulated by treatment with synthetic curcuminoid (CA). Our histopathological observations were also in correlation with the biochemical parameters. From the results obtained, we could conclude that the synthetic curcuminoid effectively protects the system against alcohol and Delta PUFA-induced hyperlipidemia and may become an effective therapeutic agent for the treatment of hyperlipidemia.

Protection of pancreatic beta-cell by the potential antioxidant bis-o-hydroxycinnamoyl methane, analogue of natural curcuminoid in experimental diabetes.

PURPOSE: To evaluate the antioxidant defense by bis-o-hydroxycinnamoylmethane, analogue of the naturally occurring curcuminoid bis-demethoxycurcumin in streptozotocin induced diabetes in male Wistar rats and its possible protection of pancreatic beta-cell against gradual loss under diabetic condition. METHODS: Male wistar rats were divided into five groups. Group1 served as control rats. Group2 was control rats treated intragastrically with bis-o-hydroxycinnamoyl methane at a dose of 15 mg/kg body weight for 45 days. Group3, 4 and 5 rats were injected with 40 mg /kg body weight of streptozotocin to induce diabetes. Group4 rats were treated with the drug similar to group2 and group5 rats treated with the reference drug glibenclamide intragastrically for a similar period. After 45 days, the levels of plasma glucose, glycated hemoglobin, enzymic antioxidants (SOD, CAT) and non-enzymic antioxidants Vit C, Vit E was determined. Histopathological sections of the pancreas were examined. RESULTS: The levels of plasma glucose and glycated hemoglobin which were elevated in group3 diabetic rats were reduced after treatment with the drug. The antioxidant levels showed an increase in the case of treated diabetic rats as compared to group3 diabetic rats. The islets were shrunken in group3 diabetic rats in comparison to normal rats. In the treated diabetic rats there was expansion of islets. CONCLUSIONS: The experimental drug bis-o-hydroxycinnamoylmethane enhances the antioxidant defense against reactive oxygen species produced under hyperglycemic conditions and thus protects the pancreatic b -cell against loss and exhibits antidiabetic property.

Bis-1,7-(2-hydroxyphenyl)-hepta-1,6-diene-3,5-dione (a curcumin analog) ameliorates DMH-induced hepatic oxidative stress during colon carcinogenesis.

The protective effect of a curcumin analog [bis-1,7-(2-hydroxyphenyl)-hepta-1,6-diene-3,5-dione] was investigated on hepatic lipid peroxidation (LPO) and antioxidant status during 1,2-dimethylhydrazine-induced colon carcinogenesis in male Wistar rats. The effects were compared with that of curcumin, a known antioxidant and anticarcinogen. Colon cancer was induced by sub-cutaneous injection of DMH at a dosage of 20mg/kg body weight (15 doses, at 1-week intervals). DMH administered rats developed gross tumours in the colon. Enhanced lipid peroxidation in the liver of colon tumour bearing rats was accompanied by a significant decrease in the activities of glutathione peroxidase (GPx), glutathione S-transferase (GST), superoxide dismutase (SOD) and catalase (CAT). Intragastric administration of curcumin (80mg/kg body weight) and curcumin analog (80mg/kg body weight) to DMH-injected rats significantly reduced the number and size of tumour in the colon, lowered lipid peroxidation and enhanced the activities of GPx, GST, SOD and CAT in the liver. We speculate that the curcumin analog used in the present study exerts chemoprevention against cancer development at extrahepatic sites by modulating hepatic biotransformation enzymes and antioxidant status. The effect is comparable with that of curcumin. This shows that the hydroxyl group in the aromatic ring is responsible for the protective effect rather than the methoxy group.

Anticarcinogenic effect of bis-1,7-(2-hydroxyphenyl)-hepta-1,6-diene-3,5-dione a curcumin analog on DMH-induced colon cancer model.

1,2-Dimethylhydrazine (DMH) is a toxic environmental pollutant which was reported also to be a colon-specific carcinogen. This study was performed to study the effect of bis-1,7-(2-hydroxyphenyl)-hepta-1,6-diene-3,5-dione, a bisdemethoxycurcumin analog (BDMC-A) on DMH-induced colon carcinogenesis in male Wistar rats and effects were compared with that of the reference drug, curcumin. Rats were given a weekly subcutaneous injection of DMH (20mg/kg body weight) in the groin, for 15 weeks. After a total experimental period of 32 weeks (including 2 weeks of acclimatization) tumor incidence was 100% in DMH-treated rats. Tumor was identified histologically as adenocarcinoma. Dysplasia, papillary pattern, cellular pleomorphism and carcinomatous glands were also noticed in DMH-treated rats. However, there was no colonic tumor in DMH+BDMC-A- and DMH+curcumin-treated rats but, lymphocyte infiltrations were observed. The levels of total bile acids and cholesterol in 24h fecal samples were significantly lower in DMH administered rats when compared to control rats, while, the excretion of bile acids and cholesterol were significantly increased and was near normal levels in DMH+BDMC-A- and DMH+curcumin-treated rats. In DMH-induced tumor bearing rats the levels of colonic and intestinal cholesterol was significantly increased whereas, the levels of phospholipid was decreased with a concomitant increase in the activities of phospholipase A (PLA) and phospholipase C (PLC), compared to untreated control rats. Intragastric administration of BDMC-A and curcumin to DMH administered rats significantly lowered the cholesterol content and raised the phospholipid content and lowered the activities of PLA and PLC towards near normal values. Our study shows that the protective effect of BDMC-A during DMH-induced colon carcinogenesis may be due to its modulatory effects on (i). histological changes, (ii). bile acids, (iii). cholesterol, and (iv). phospholipid metabolism in the target organ. Absence of histological changes in the colon of rats treated with BDMC-A, shows that long term administration of BDMC-A is nontoxic to experimental animals. Our study suggest that BDMC-A may emerge as a potent anticarcinogenic agent against colon cancer. As both BDMC-A and curcumin are equipotent in inhibiting the DMH-induced colon tumor incidence and normalizing histological changes, it could be concluded that the terminal phenolic group and the conjugated double bonds in the central seven carbon change may be responsible for the beneficial effects.