Synthesis, characterization, and evaluation of the anticancer properties of pH-responsive carvacrol-zinc oxide quantum dots on breast cancer cell line (MDA-MB-231).

Since most solid tumors have a low pH value, a pH-responsive drug delivery system may offer a broad method for tumor-targeting treatment. The present study is used to analyze the anticancer activity of carvacrol-zinc oxide quantum dots (CVC-ZnO QDs) against breast cancer cells (MDA-MB-231). CVC-ZnO QDs demonstrate pH responsive and are specifically released within the acidic pH tumor microenvironment. This property enables targeted drug delivery exclusively to cancer cells while minimizing the impact on normal cells. To the synthesized ZnO QDs, the CVC was loaded and then examined by X-ray diffraction, ultraviolet-visible, Fourier transform infrared spectrophotometer, scanning electron microscopy-energy dispersive X-ray, and transmission electron microscopy. For up to 20 h, CVC release was examined in different pH-buffered solutions. The results showed that carvacrol release was stable in an acidic pH solution. Further, cytotoxicity assay, antioxidant, and lipid peroxidation activity, reactive oxygen species, mitochondrial membrane potential, nuclear damage, and the ability of CVC-ZnO QDs to cause apoptosis were all examined. Apoptosis markers such as Bcl2, Bax, caspase-3, and caspase-9, were also studied. In conclusion, the CVC-ZnO QDs destabilized the MDA-MB-231cells under its acidic tumor microenvironment and regulated apoptosis.

Anti-inflammatory and anticancer effects of p-methoxycinnamic acid, an active phenylpropanoid, against 1,2-dimethylhydrazine-induced rat colon carcinogenesis.

p-methoxycinnamic acid (p-MCA) is an active phenolic acid found in rice bran, turmeric, brown rice, Kaempferia galanga, buckwheat inflorescence, etc. Earlier, we have reported that p-methoxycinnamic acid possesses antioxidant and antilipidperoxidative effects on 1,2-dimethylhyrdrazine (DMH)-induced colon carcinogenesis. The purpose of this study is to unravel the anti-inflammatory and anticancer properties of p-MCA against DMH-induced colon carcinogenesis. Male albino Wistar rats were randomly divided into six groups. Group 1 served as control, group 2 rats received 40 mg/kg b.wt. of p-MCA in 0.1% carboxymethylcellulose (CMC) every day, and colon cancer was induced in groups 3-6 using DMH at the dose of (20 mg/kg b.wt. subcutaneously) once a week for 15 weeks. In addition, along with DMH, groups 4 (initiation), 5 (post initiation) and 6 (entire period) rats received p-MCA (40 mg/kg b.wt.) p.o. every day during different time periods for the total experimental period of 30 weeks. Colon of animals treated with DMH showed an increased number of aberrant crypt foci (ACFs), increased nuclear translocation of transcription factor NF-κB p65 subunit, increased expression of inflammatory markers (iNOS, COX-2), cytokines (tumour necrosis factor-α, interleukin-6), cyclin D1, antiapoptotic protein (Bcl-2), metastasis marker (matrix metalloproteinase-2 (MMP-2)) and angiogenic marker (vascular endothelial growth factor VEGF) and decreased expression of pro-apoptotic proteins (Bax, caspases 3 and 9). On supplementing with p-MCA (40 mg/kg b.wt.) throughout the entire experimental period, DMH-induced pathological alterations reversed significantly to normal.

Preventive effect of D-carvone during DMBA induced mouse skin tumorigenesis by modulating xenobiotic metabolism and induction of apoptotic events.

The structural integrity and excellent immune system of the skin makes it a protective covering, inspite of its exposure to hazardous compounds. In the present study, the chemopreventive efficacy of D-carvone was studied in 7, 12-dimethylbenz[a]anthracene (DMBA) induced skin carcinogenesis. DMBA (25 µg in 0.1 m L-1acetone) was used to induce skin cancer in Swiss albino mice. Animals were randomly divided into six groups of six animals in each. Different concentrations of D-carvone (10, 20, 30 mg/kg body weight) were used to assess its anticancer effect. Tumor incidence, tumor volume, tumor burden, histological examination and levels of phase I and phase II detoxification agents were analyzed in experimental animals. Further, expression of p53 and various apoptotic proteins including- Bcl-2, Bax was analyzed using immunohistochemistry and enzymatic expression of apoptotic proteins caspase-3 and caspase-9 was carried out by using ELISA. We observed 100% tumor incidence in DMBA-painted animals and our results showed that D-carvone at 20 mg dose significantly prevents skin carcinogenesis. Our results also showed decreased levels of phase I enzymes (Cyt P450 and-Cyt b5) with increased levels of phase II enzymes (GR, GST and GSH) and increased expression of Bax, caspase-3 and caspase-9 with decreased expression of mutated p53 and Bcl-2 in animals treated with DMBA and D-carvone at 20 mg dose. The results of the present study suggest that D-carvone can be used as a chemopreventive agent against skin cancer, as it induces apoptosis in cancer. However, further studies are warranted to check chemopreventive efficacy of D-carvone on cell proliferation, angiogenesis, and metastasis before going to human trial.

Asiatic acid abridges pre-neoplastic lesions, inflammation, cell proliferation and induces apoptosis in a rat model of colon carcinogenesis.

The utmost aim of this present study was to investigate the anti-inflammatory, antiproliferative and proapoptotic potential of Asiatic acid (AA) on 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis in experimental rats. Rats were divided into six groups and received modified pellet diet for 32 weeks. Group 1 served as control rats. Group 2 received AA (4 mg/kg b.w. p.o.). Group 3-6 rats received 15 DMH (20 mg/kg b.w., s.c.) injections once a week starting from the 4th week. Besides DMH, rats received AA (4 mg/kg b.w. p.o.) in group 4 starting 2 weeks before carcinogen treatment till the end of the last DMH; group 5 starting 2 days after last DMH till the end of the experiment; and group 6 throughout the experiment. Pre-neoplastic lesions, xenobiotic metabolizing enzymes, inflammation, cell proliferation and apoptotic markers were analysed in our study. Our results ascertained AA supplementation to DMH-exposed rats significantly decreased the incidence of aberrant crypt foci (ACF) and phase I xenobiotic enzymes; and increased the phase II xenobiotic enzymes and mucin content as compared to DMH-alone-exposed rats. Moreover the increased expressions of mast cells, argyrophilic nucleolar organizer regions (AgNORs), proliferating cell nuclear antigen (PCNA) and cyclin D1 observed in the DMH-alone-exposed rats were reverted and were comparable with those of the control rats, when treated with AA. Concordantly AA also induced apoptosis by downregulating the expression of Bcl-2 and upregulating Bax, cytochrome c, caspase-3 and -9 in the DMH-alone-exposed rats. Thus AA was able to inhibit DMH-induced colon carcinogenesis by detoxifying the carcinogen, decreasing the preneoplastic lesions by virtue of its anti-inflammatory, antiproliferative and proapoptotic effects. Therefore our findings suggest that AA could be used as an effective chemopreventive agent against DMH induced colon carcinogenesis.

Antihyperlipidemic and antiapoptotic potential of zingerone on alcohol induced hepatotoxicity in experimental rats.

The ultimate aim of this present study was to investigate the antihyperlipidemic and antiapoptotic potential of zingerone (ZO) on alcohol induced hepatotoxicity in experimental rats. Male albino wistar rats were divided in four groups. Groups 1 and 2 rats received isocaloric glucose and dimethyl sulphoxide (2% DMSO), liver toxicity was induced in groups 3 and 4 by supplementing 30% ethanol post orally for 60 days. In addition to, groups 2 and 4 received zingerone (20 mg/kg body weight in 2% DMSO) daily during the final 30 days of the experimental period. Ethanol alone administered rats showed increased levels/activities of plasma total cholesterol (TC), triglycerides (TG), free fatty acids (FFA), phospholipids (PL), low density lipoproteins (LDL), very low density lipoproteins (VLDL), tissue TC, TG, FFA, PL, HMG-CoA reductase, phase I xenobiotic enzymes, collagen and fat accumulation, DNA damage and increased Bax, caspase-3 and caspase-9 expressions and decrease in the levels/activities of plasma high density lipoproteins (HDL), lipoprotein lipase (LPL), lecithin cholesterol acyl transferase (LCAT), phase II xenobiotic enzymes and a decreased Bcl-2 expression. Zingerone supplementation was able to counter and reverse the ethanol induced changes in all the above parameters in experimental rats. Together results portray zingerone exhibits antihyperlipidemic and antiapoptotic potential on alcohol induced hepatotoxicity.

Asiatic acid attenuates pre-neoplastic lesions, oxidative stress, biotransforming enzymes and histopathological alterations in 1,2-dimethylhydrazine-induced experimental rat colon carcinogenesis.

Asiatic acid (AA), a pentacyclic triterpenoid, derived from the tropical medicinal plant Centella asiatica is known to exhibit numerous pharmacological properties. We hypothesized that AA will have chemopreventive potential against 1,2-dimethylhydrazine (DMH)-induced experimental colon carcinogenesis in male Wistar rats. Rats were arbitrarily divided into six groups. Group I rats were processed as control. Group II rats received AA (8 mg/kg b.w., p.o.) and groups III-VI rats received subcutaneous injections of DMH (20 mg/kg b.w.) once a week, for the first four weeks. In addition, groups IV-VI rats received AA at the doses of 2, 4 and 8 mg/kg b.w., respectively, for 16 weeks. Our results discovered that supplementation with AA to the DMH-exposed rats significantly decreased the incidence of polyps and Aberrant crypt foci (ACF) as compared to the DMH-alone-exposed rats. Moreover, in the AA-supplemented DMH-exposed rats, we ascertained increased activities of the antioxidants and decreased levels of lipid peroxidation (LPO) in the liver and circulation and enhanced levels of both LPO and antioxidants in the colon, which were altered in the DMH-alone-exposed rats. Furthermore, we also observed altered activities of vitamins C and E and biotransforming enzymes in DMH-alone-exposed rats, which were reversed on AA supplementation. All the observations were supported by our histological findings. Thus, we can conclude that, AA could be used as an effective chemopreventive agent against DMH-induced colon carcinogenesis.

The in vivo antineoplastic and therapeutic efficacy of troxerutin on rat preneoplastic liver: biochemical, histological and cellular aspects.

PURPOSE: Troxerutin (TXER), a trihydroxyethylated derivative of the natural bioflavonoid rutin, abundantly found in tea, various fruits and vegetables, is known to exhibit ample pharmacological properties. In the present investigation, we examined the antineoplastic, therapeutic efficacy and furthermore the possible mechanisms of action of TXER against NAFLD/NASH progression to hepatocarcinogenesis. METHODS: The effect of TXER (12.5, 25 or 50 mg/kg b.w/day) was evaluated on the nitrosodiethylamine (NDEA) model of hepatocarcinogenesis in rats, after 16 weeks of oral treatment, with special focus on liver specific enzymes, xenobiotic metabolizing enzymes, antioxidant status, lipid peroxidation profile, DNA damage, fibrosis, cell proliferation and inflammatory status. RESULTS: Administration of TXER to hepatocellular carcinoma-bearing rats restored the enzyme activities and the hepatic architecture. Furthermore, TXER significantly curtailed NDEA-induced DNA damage, cell proliferation, inflammation, fibrosis and hepatic hyperplasia. CONCLUSION: This study provides the evidence that troxerutin exerts a significant therapeutic effect against liver cancer by modulating liver function enzymes, xenobiotic enzymes, oxidative damage, inhibiting cell proliferation, suppressing inflammatory response and induction of apoptosis.

Biochemical and molecular mechanisms underlying the chemopreventive efficacy of rosmarinic acid in a rat colon cancer.

To shed light on colon cancer chemoprevention, natural phytochemicals attract researchers by virtue of their beneficial biological effects. The chemopreventive potential of rosmarinic acid (RA) was tested by using the colon carcinogen, 1,2-dimethylhydrazine (DMH) by evaluating the Aberrant crypt foci (ACF), tumour incidence, lipid peroxidative byproducts, phase I & II drug metabolizing enzymes, cell proliferative and apoptotic proteins. Rats were divided into six groups and received modified pellet diet. Group 1 served as control rats, group 2 rats received RA (5mg/kg b.w. p.o.), rats in groups 3-6 received DMH (20mg/kg b.w., s.c.) for the first fifteen weeks. In addition to DMH, groups 4-6 received RA at the dose of 5mg/kg b.w. during initiation, post initiation stages and also for the entire study period. DMH treated rats showed an increase in the development of ACF, tumour formation and multiplicity and decrease in lipid peroxidative byproducts. Moreover, it modulates xenobiotic enzymes and reduces the expressions of proapoptotic proteins; increases expressions of anti apoptotic proteins at the end of the study. Supplementation with RA to carcinogen treated rats protected them from the above deleterious effects caused by DMH and thus RA may be used as a potent chemopreventive agent.

Antioxidant and anti-inflammatory role of zingerone in ethanol-induced hepatotoxicity.

Alcoholic liver disease is a direct result of alcohol-induced hepatotoxicity coupled with impaired hepatic regenerative activity. Our aim of the study was to investigate the beneficial effect of zingerone on hepatic oxidative stress and inflammation induced by ethanol in experimental rats. Male albino Wistar rats were divided into four groups. Rats of groups 1 and 2 received isocaloric glucose and dimethyl sulfoxide (2 % DMSO). Hepatotoxicity was induced in groups 3 and 4 by supplementing 30 % ethanol post orally for 60 days. Rats of groups 2 and 4 received zingerone (20 mg/kg body weight in 2 % DMSO p.o) daily during the final 30 days of the experimental period. Ethanol alone administered rats showed significant increase in the plasma and tissue lipid peroxidation markers such as thiobarbituric acid reactive substances, lipid hydroperoxides, conjugated dienes, and a significant decrease in the activities of plasma and tissue enzymic and non-enzymic antioxidants such as superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, reduced glutathione, vitamin C, and vitamin E. Moreover, the presence of mast cells and increase in the expressions of inflammatory markers such as NF-κB, COX-2, TNF-α, and IL-6 and decrease in the expression of Nrf2 in the liver was observed in ethanol-fed rats. Supplementation with zingerone to ethanol-fed rats reversed the changes induced by ethanol in the experimental rats. Thus, zingerone, through its antioxidant and anti-inflammatory effects, may represent a therapeutic option to protect against ethanol-induced hepatotoxicity.

Molecular aspects and chemoprevention of dimethylaminoazobenzene-induced hepatocarcinogenesis: A review.

The lipophilic azo dye dimethylaminoazobenzene (DAB) is a potent hepatocarcinogen accounted as a group-2B carcinogen causing risk to humans. DAB is commonly used as a coloring agent in food, pharmaceuticals, beverages, soap and polishes. The exploration of DAB-induced hepatocarcinogenesis in animal models helped to an extent to perceive the histological, biochemical and molecular mechanisms of DAB carcinogenesis and also the severity of DAB exposure to humans. In experimental animal models, it is well-proved that the procarcinogen DAB is predominantly metabolized by cytochrome P450 enzymes giving rise to the formation of toxic electrophiles and reactive oxygen species (ROS), which further forms DNA adducts leading to the development of hepatic tumors. Recently, research evidence suggests that dietary phytochemicals and plant polyphenols are promising agents to control the incidence of DAB-induced hepatocarcinogenesis by preventing the generation of toxic electrophiles and ROS thereby inhibiting the formation of DNA adducts. This review highlights the role of specific dietary factors, biotransformation of DAB, phenotypic and genotypic alterations, and significance of certain chemopreventive agents against DAB-induced hepatocarcinogenesis.

p-Methoxycinnamic acid, an active phenylpropanoid induces mitochondrial mediated apoptosis in HCT-116 human colon adenocarcinoma cell line.

Among the eight phytochemicals (dihydrocarveol, sinapic acid, vanillic acid, ethylgallate, myrtenol, transcarveol, p-methoxycinnamic acid, and isoferulic acid) we tested, p-methoxycinnamic acid (p-MCA) [10 µM] showed the most potent in vitro growth inhibition on human colon adenocarcinoma (HCT-116 cells). Antiproliferative activity of p-MCA at 24h was associated with DNA damage, morphological changes and the results were comparable with doxorubicin. p-MCA induced phosphatidylserine translocation, increased the levels of reactive oxygen species (ROS), thiobarbituric acid reactive substances (TBARS), protein carbonyl content (PCC) and decreased enzymic antioxidant status (SOD, CAT, GPx) in HCT-116. p-MCA treatment increased the percentage of apoptotic cells, decreased the mitochondrial membrane potential and triggered cytochrome C release to cytosol. The induction of apoptosis by p-MCA was accompanied by an increase in caspase 3 and caspase 9 activities, increased expression of Bax and decreased expression of Bcl-2. Thus p-MCA induces mitochondria mediated intrinsic pathway of apoptosis in HCT-116 and has potential for treatment and prevention of colon cancer.

Combined therapeutic efficacy of carvacrol and X-radiation against 1,2-dimethyl hydrazine-induced experimental rat colon carcinogenesis.

Colon cancer is one of the most commonly diagnosed cancers, and is a major cause of cancer morbidity and mortality worldwide. The objective of the present study is to evaluate the combined therapeutic efficacy of carvacrol (CVC) and X-radiation against 1,2-dimethylhydrazine-induced colon cancer. Male albino Wistar rats were randomly divided into six groups. Group 1 served as control; group 2 received 40 mg/kg b.wt of CVC orally everyday throughout the experimental period (32 weeks); groups 3-6 received subcutaneous injections of DMH (20 mg/kg b.wt), once a week for the first 15 weeks; group 4 received a single dose of X-radiation at the 31st week; group 5 received CVC (40 mg/kg b.wt) two days after the last injection of DMH and continued everyday till the end of the experimental period; group 6 received CVC as in group 5 and radiation as in group 4. DMH-treated rats showed increased incidence of aberrant crypt foci (ACF), dysplastic aberrant crypt foci (DACF), mast cell number, argyrophilic nucleolar organizer regions; elevated activities of phase I enzymes, decreased activities of phase II enzymes, decreased mucin content and altered colonic and liver histology as compared to control rats. Though the individual treatments with CVC and X-radiation to DMH-treated rats reversed the above changes, the combined treatment with both CVC and X-radiation showed a marked effect. Our findings emphasize the potential role of combined therapeutic effect of CVC and X-radiation against DMH-induced colon carcinogenesis.

Geraniol attenuates fibrosis and exerts anti-inflammatory effects on diet induced atherogenesis by NF-κB signaling pathway.

Atherosclerosis is now generally accepted as a chronic inflammatory condition. The transcription factor nuclear factor kappa B (NF-κB) is a key regulator of inflammation, immune responses, cell survival and cell proliferation. Tissue remodeling plays a significant role during the phase of inflammation and oxidative stress. In our study we have evaluated the effect of geraniol (GOH), a natural terpenoid on oxidative stress, inflammation and tissue remodeling in experimental animals. Experimental animals (hamsters) were divided into four groups; group 1 were control animals; group 2 were animals fed GOH alone (100mg/kg b.w. p.o); group 3 were animals fed atherogenic diet (standard pellet diet+10% coconut oil+0.25% cholesterol); group 4 animals were fed atherogenic diet as in group 3+GOH (100mg/kg b.w). At the end of the experimental period animals were killed and liver, heart and aorta tissues were analyzed for lipid peroxidation markers, non enzymic antioxidants and collagen distribution using histological studies like Milligan's trichrome and Picrosirius red staining. As inflammation plays a key role in tissue remodeling we also targeted the key inflammatory cytokine, NF-κB. GOH supplementation greatly prevented the remodeling of tissues by enhancing the free radical scavenging and anti-inflammatory effects. Thus in conclusion it can be suggested that GOH (100mg/kg b.w) prevents the atherogenic diet induced fibrosis in experimental hamsters.

Effect of geraniol, a plant derived monoterpene on lipids and lipid metabolizing enzymes in experimental hyperlipidemic hamsters.

Hyperlipidemia is a major, modifiable risk factor for atherosclerosis and cardiovascular disease. In the present study, we have focused on the effect of different doses of geraniol (GOH) on the lipid profile and lipid metabolizing enzymes in atherogenic diet (AD) fed hamsters. Male Syrian hamsters were grouped into seven: group 1 were control animals; group 2 were animals fed GOH alone (200 mg/kg b.w); group 3 were animals fed AD (10 % coconut oil, 0.25 % cholesterol, and 0.25 % cholic acid); group 4 were animals fed AD + corn oil (2.5 ml/kg b.w); and groups 5, 6, and 7 were fed AD as in group 3 + different doses of GOH (50, 100, and 200 mg/kg b.w), respectively, for 12 weeks. At the end of the experimental period, animals were sacrificed by cervical dislocation and various assays were performed in the plasma and tissues. The AD hamsters showed marked changes in lipid profile and lipid metabolizing enzymes. However, supplementation with GOH counteracted the hyperlipidemia by inhibiting HMG CoA reductase and suppressing lipogenesis. The antihyperlipidemic efficacy of GOH was found to be effective at the dose of 100 mg/kg b.w. This study illustrates that GOH is effective in lowering the risk of hyperlipidemia in AD fed hamsters.

Geraniol attenuates oxidative stress by Nrf2 activation in diet-induced experimental atherosclerosis.

BACKGROUND: Preclinical and clinical studies suggest the use of antioxidants as an effective measure to reduce the progression of oxidative-stress-related disorders. Nuclear factor E2-related factor 2 (Nrf2) is a key component to cellular redox homeostasis in the attenuation of oxidative-stress-associated pathological processes. The objective of the current study was to evaluate the role of geraniol (GOH) in preserving the plasma lipid status, endothelial function, antioxidant status, and inhibition of lipid peroxidation (LPO) in hamsters fed an atherogenic diet (AD). METHODS: Male Syrian hamsters were randomly grouped into four groups: group 1 was control animals; group 2 was animals fed GOH alone (100 mg/kg bw po); group 3 was animals fed AD (standard pellet diet+10% coconut oil+0.25% cholesterol+0.25% cholic acid); and group 4 was fed AD+GOH (100 mg/kg bw) for 12 weeks. At the end of the feeding period, the animals were sacrificed and the liver, heart, and aorta from each group were analyzed for antioxidants, LPO markers, and histological changes. RESULTS: AD feeding induced a significant change in lipid profile, endothelial function marker, activities of the antioxidant enzymes, alterations in the LPO markers, Nrf2 expression, and equally significant changes in the organ histology. CONCLUSIONS: Supplementation with GOH appreciably prevented the alterations induced by the AD on all the above parameters. Thus, GOH offers marked protection against AD-induced abnormalities.

Protective effect of p-methoxycinnamic acid, an active phenolic acid against 1,2-dimethylhydrazine-induced colon carcinogenesis: modulating biotransforming bacterial enzymes and xenobiotic metabolizing enzymes.

Objective of the study is to evaluate the modifying potential of p-methoxycinnamic acid (p-MCA), an active rice bran phenolic acid on biotransforming bacterial enzymes and xenobiotic metabolizing enzymes in 1,2-dimethylhydrazine-induced rat colon carcinogenesis. 48 male albino wistar rats were divided into six groups. Group1 (control) received modified pellet diet and 0.1 % carboxymethylcellulose; group2 received modified pellet diet along with p-MCA (80 mg/kg b.wt. p.o.) everyday for 16 weeks; groups 3-6 received 1,2-dimethylhydrazine (DMH) (20 mg/kg b.wt.) subcutaneous injection once a week for the first 4 weeks, while groups 4-6 received p-MCA at three different doses of 20, 40 and 80 mg/kg b.wt. p.o. everyday for 16 weeks. A significant increase in carcinogen-activating enzymes (cytochrome P450, cytochrome b5, cytochrome P4502E1, NADH-cytochrome-b5-reductase and NADPH-cytochrome-P450 reductase) with concomitant decrease in phaseII enzymes, DT-Diaphorase, glutathione S-transferase, UDP-glucuronyl-transferase and gamma glutamyltransferase were observed in group3 compared to control. DMH treatment significantly increased the activities of feacal and colonic bacterial enzymes (ß-glucosidase, ß-galactosidase, ß-glucuronidase, nitroreductase, sulphatase and mucinase). p-MCA supplementation (40 mg/kg b.wt) to carcinogen exposed rats inhibited these enzymes, which were near those of control rats. The formation of dysplastic aberrant crypt foci in the colon and the histopathological observations of the liver also supports our biochemical findings. p-MCA (40 mg/kg b.wt.) offers remarkable modulating efficacy of biotransforming bacterial and xenobiotic metabolizing enzymes in colon carcinogenesis.

The effect of rosmarinic acid on 1,2-dimethylhydrazine induced colon carcinogenesis.

This study was carried out to investigate the chemopreventive potential of rosmarinic acid (RA) against 1,2-dimethylhydrazine (DMH) induced rat colon carcinogenesis by evaluating the effect of RA on tumour formation, antioxidant enzymes, cytochrome P450 content, p-nitrophenol hydroxylase and GST activities. Rats were divided into six groups and fed modified pellet diet for the entire experimental period. Group 1 served as control, group 2 received RA (10 mg/kgb.w.). Groups 3-6 were induced colon cancer by injecting DMH (20 mg/kgb.w.) subcutaneously once a week for the first four weeks (groups 3-6). In addition, RA was administered at the doses of 2.5, 5 and 10 mg/kgb.w. to groups 4-6 respectively. DMH treated rats showed large number of colonic tumours; decreased lipid peroxidation; decreased antioxidant status; elevated CYP450 content and PNPH activities; and decreased GST activity in the liver and colon. Supplementation with RA (5 mgkg/b.w.) to DMH treated rats significantly decreased the number of polyps (50%); reversed the markers of oxidative stress (21.0%); antioxidant status (38.55%); CYP450 content (29.41%); and PNPH activities (21.9%). RA at the dose of 5 mg/kgb.w. showed a most pronounced effect and could be used as a possible chemopreventive agent against colon cancer.

Anti-inflammatory role of naringenin in rats with ethanol induced liver injury.

The aim of the study was to investigate the antiinflammatory effects of naringenin in rats induced liver damage by exposure to ethanol. Rats were divided into four groups, groups 1 and 2 received isocaloric glucose; groups 3 and 4 received 20% ethanol equivalent to 6 g/kg body weight everyday for the total experimental period of 60 days. In addition, groups 2 and 4 were supplemented with naringenin (50 mg/kg p.o.) everyday for the last 30 days of the experiment. The results showed significantly elevated levels/activities/expression of serum aspartate and alanine transaminases, iron, ferritin, transforming growth factor-alpha (TNF-α), interleukin-6 (IL-6), nuclear factor-kappa B (NF-κB), cyclooxygenase-2 (COX-2), macrophage inflammatory protein 2 (MIP-2) and CD14 in ethanol fed rats as compared to those of the control. Ethanol-fed rats exhibited increased staining for the presence of inducible nitric oxide (iNOS) protein adducts in the liver. Supplementation with naringenin for the last 30 days to ethanol-fed rats, significantly decreased the levels/activities/expression of serum aspartate and alanine transaminases, iron, ferritin, TNF-α, IL-6, NF-κB, COX-2, MIP-2, CD14 and iNOS protein adducts in the liver as compared to the untreated ethanol fed rats. The inhibition of TNF-α, IL-6, NF-κB, COX-2, MIP-2, iNOS and CD14 by naringenin may contribute to its antiinflammatory activity in ethanol fed rats.