Antioxidant and Antitumor Activity of Plumeria acuminata in Ehrlich Ascites Carcinoma Bearing Swiss Albino Mice.

Aim: This study was designed to determine the antitumor and antioxidant properties of crude methanol extract from the leaves of Plumeria acuminata (Apocynaceae) (MEPA) against Ehrlich Ascites Carcinoma (EAC) bearing Swiss albino mice. Study Design: Study design is methodology, mentioned below. Place and Duration of Study: Division of Pharmacology, Department of Pharmaceutical Technology, Jadavpur University, Jadavpur, Kolkata, India between 2006 and 2007. Methodology: The extract was administered at the doses of 100, 250 and 500 mg/kg per day for 14 days, after 24 hr of tumor inoculation. After the administration of the last dose followed by 18 hr fasting, mice were then sacrificed for observation of antitumor activity. The effect of MEPA on the growth of transplantable murine tumor, life span of EAC bearing host, viable and non-viable cell count, packed cell volume, hematological profile and biochemical parameters such as lipid peroxidation (LPO), reduced glutathione content (GSH), superoxide dismutase (SOD) and catalase (CAT) activities were estimated. Results: MEPA caused significant (P<0.01) decrease in tumor volume, packed cell volume and viable count; and it prolonged the life span of EAC-tumor bearing mice. Hematological studies reveal that the Hb content and RBC count were decreased in EAC treated mice, whereas the restoration to near normal levels was observed in extract treated animals. MEPA significantly (P<0.05) decreased the levels of LPO and significantly increased the levels of GSH, SOD and CAT. Moreover the MEPA was found to be devoid of conspicuous short-term toxicity in the mice when administered daily for 14 days at the doses of 100, 250 and 500 mg/kg Conclusion: The results suggested that the methanol extract of Plumeria acuminata leaves exhibited antitumor effect by modulating lipid peroxidation and augmenting antioxidant defense system in EAC bearing Swiss albino mice.

Insights into mechanism of tumour promotion by mezerein.

The objective of this study was to gather insights and compare the mode of action of the non phorbol, diterpene mezerein with the phorbol ester, phorbol-12-myristate-13 acetate, in normal and transformed cells. Both phorbol-12-myristate-13 acetate and mezerein are shown to activate the signal transduction pathways involving post translational modification of proteins by poly ADP-ribosylation and by protein kinase C, but to varying extents and showed different time kinetics and cell type differences.Multiple nuclear proteins, especially histones H3d, A24 and HI served as acceptors of poly ADP-ribose in response to PMA in both NIH 3T3 and HDCS cells whereas H1 and H2B were the major acceptors in case of mezerein treatment, similarly in both NIH 3T3 and HDCS cells. The results suggest an epigenetic mechanism (s) in tumour promotion by mezerein.