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Oxidative stress induced by toxicants is known to cause various complications in the liver. Herbal drug such as Liv.52 is found to have hepatoprotective effect. However, the biochemical mechanism involved in the Liv.52 mediated protection against toxicity is not well elucidated using suitable in vitro models. Hence, in the present study, the hepatoprotective effect of Liv.52 against oxidative damage induced by tert-butyl hydroperoxide (t-BHP) in HepG2 cells was evaluated in order to relate in vitro antioxidant activity with cytoprotective effects. Cytotoxicity was measured by MTT assay. Antioxidant effect of Liv.52 was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, ferric-reducing antioxidant power (FRAP) assay, and lipid peroxidation and measurement of non-enzymic and antioxidant enzymes in HepG2 cells exposed to t-BHP over a period of 24 h. The results obtained indicate that t-BHP induced cell damage in HepG2 cells as shown by significant increase in lipid peroxidation as well as decreased levels of reduced glutathione (GSH). Liv.52 significantly decreased toxicity induced by t-BHP in HepG2 cells. Liv.52 was also significantly decreased lipid peroxidation and prevented GSH depletion in HepG2 cells induced by t-BHP. Therefore, Liv.52 appeared to be important for cell survival when exposed to t-BHP. The protective effect of Liv.52 against cell death evoked by t-BHP was probably achieved by preventing intracellular GSH depletion and lipid peroxidation. The results showed protective effect of Liv.52 against oxidative damage induced in HepG2 cells. Hence, taken together, these findings derived from the present study suggest the beneficial effect of Liv.52 in regulating oxidative stress induced in liver by toxicants.

Fine-multiple emulsions bearing 6-mercaptopurine (6-MP) in internal aqueous phase were prepared by two step emulsification using sonication technique. It was coated with Concanavalin-A (Con-A) using carbodiimide method to obtain lectin-functionalized multiple emulsions. The Con-A coated multiple emulsion was characterized for antitumour activity on murine leukemia cell line L-1210 in vitro and compared with uncoated multiple emulsion and free drug. An increased uptake and cytotoxicity were observed for Con-A coated multiple emulsion in vitro. The IC50 was decreased upto 4-fold with Con-A coated emulsion. In vivo antitumour activity was seen by recording survival times of mice injected with L-1210 cells i.v. or i.p. The mean survival time was found to increase upon treatment with Con-A coated multiple emulsion. The tumour cell count in the peritoneal cavity was decreased significantly when animal was treated by i.p. route while there was no significant difference when it was treated by i.v. route. The normal peritoneal cells remained unaltered in number and blood parameters were also restored on treatment to tumour bearing mice. The formulation was found to be effective for the treatment of cancer.

Liver is a prime target of alcohol-induced damage by inducing inflammatory cytokines especially tumor necrosis factor alpha (TNFalpha). Activator of peroxisome proliferator activator receptor gamma (PPARgamma) is protective against alcohol-induced liver injury in animals. Liv.52, one of the major herbal hepatoprotective drugs, is shown to protect the liver from toxicity and is considered to be an effective hepatoprotective agent. However, the signal pathway involved in the Liv.52-induced hepatoprotection is not understood well especially in the case of cultured liver cells treated with ethanol. Hence, the study was aimed at determining whether ethanol and Liv.52 could modulate PPARgamma and TNFalpha induction in human hepatoma cells, HepG2. The present study with RT-PCR and confocal microscopy experiments showed that ethanol (100 mM) induced suppression of PPARgamma expression in HepG2 cells. The ethanol-induced PPARgamma suppression was abrogated by Liv.52. Moreover, Liv.52 also induced upregulation of PPARgamma mRNA in liver cells as compared to the untreated cells. Further, 100 mM ethanol has also induced TNFalpha gene expression in HepG2 cells and interestingly Liv.52 abolished ethanol-induced TNFalpha. The study also shows that Liv.52 alone downregulated TNFalpha expression in HepG2 cells. Taken together, these findings suggest that Liv.52 is capable of attenuating ethanol-induced expression of TNFalpha and abrogating ethanol-induced suppression of PPARgamma in liver cells. These results indicate that Liv.52-induced PPARgamma expression and concomitant suppression of ethanol-induced elevation of TNFalpha in HepG2 cells suggest the immunomodulatory and hepatoprotective nature of Liv.52.

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