Antitumor activity of Hypericum hookerianum against DLA induced tumor in mice and its possible mechanism of action

Abstract

Keywords: Hypericum hookerianum; anticancer; free radicals; hepatoprotective. INTRODUCTIONWorldwide, over ten million cancer cases, with over six million deaths, were estimated in the year 2000 (Parkin, 2001). Drug discovery from medicinal plants has played an important role in the treatment of cancer (Butler, 2004). Vinca alkaloids, epipodophyllotoxins, taxanes and camptothecins are the four main classes of anticancer agents from plants currently in clinical use and natural products isolated from medicinal plants can remain as essential components in the search for new medicines (Balunas and Kinghorn, 2005) The genus Hypericum encompasses various species used in traditional medicine in different parts of the world. Strong cytotoxic and anticancer properties have been observed in H. perforatum (Roscetti et al., 2004), H. mysorence, H. patulum (Vijayan et al., 2003b, H. polyanthemum (Ferraz et al., 2005), H. drummondii (Jayasuriya and McChesney, 1989) and several other plants of the genus Hypericum (Ferraz et al., 2005) and many of their phytoconstituents. Earlier studies carried out in our laboratories have indicated the potent cytotoxic nature of H. hookerianum against several cancerous cell lines. Among the extracts prepared from different parts of the plant, the stem extract was found to be more potent with CTC 50 (cytotoxic concentration to kill 50% cells) values of 2.02 μg/mL for RD, 10.25 μg/ mL for HEp-2 and 100.6 μg/mL for Vero cell lines. In short term cytotoxicity studies against DLA cell lines the CTC 50 was found to be 135.00 ± 0.70 μg/mL (Vijayan et al., 2003a). Except for these studies, so far, no other biological activities have been studied on H. Hookerianum and no phytoconstituents have been reported. Hence, in continuation of our studies, the methanol extract of H. hookerianum stem was investigated for its in vivo antitumor properties against the DLA tumor model in mice.The chemopreventive properties of plant anticarcinogens are either due to antilipid peroxidative action, modulating carcinogen detoxification or by improving the antioxidant defense system (Johnson, 1997). A large number of plants possessing anticancer and antioxidant properties are known (Kavitha and Manoharan, 2006). Hence, in the present study the antioxidant status of MEHH was also evaluated. A standardized extract containing 0.077% w/w of hypericin and 0.36% w/w of hyperoside was used. MATERIALS AND METHODS Plant material and extraction. Plant material Preparation of suspensions and solutions.The MEHH and standard MT were suspended in distilled water using sodium carboxy methyl cellulose (0.3%) and administered orally to the animals with the help of an intragastric catheter.Antitumor activity. Swiss Albino mice were divided in to six groups (n = 12). All the animals were injected with DLA cells (1 × 10 6 cells/mouse) intraperitoneally except for the normal group. This was taken as day 0. Group I served as normal and group II served as the tumor control. These two groups received sodium CMC suspension (0.3%). Group III ser...

Chemical characterization of the essential oil compositions from Iranian populations of Hypericum perforatum L.

“…Nowadays, biological activity of different Hypericum species have been investigated and documented in number of studies (Hasanein and Shahidi, 2011;Hernandez et al, 2010;Suntar et al, 2010;Dongre et al, 2008;Wang et al, 2008;Radulovic et al, 2007;Ferraz et al, 2005;Rabanal et al, 2005;Sanchez-Mateo et al, 2002). Most of studies on H. perforatum are focused on the hypericin and hyperforin contents.…”

Genotoxicity and antigenotoxicity evaluation of non‐photoactivated hypericin

“…In recent decades, data have been collected on various naturally occurring compounds that protect against certain types of mutagens and carcinogens and that have benefi cial effects on human health (Dongre et al, 2008;Miadokova et al, 2008;Nadova et al, 2008;Zeytinoglu et al, 2008).…”

Antitumour and Antioxidant Activity of Some Red Sea Seaweeds in Ehrlich Ascites Carcinoma in vivo

“…The post-treatment of the EAC-bearing mice with any of the tested algal extracts produced a signifi cant decrease in the serum level of CEA and AFP in comparison with the untreated EAC-bearing mice. These data indicate that the methanol extract of each alga exhibits signifi cant antitumour activity, which might be due to the antioxidant effects on EAC-bearing hosts (Dongre et al, 2008).…”