Bangladesh Journal of Pharmacology Volume: 11; Number 2; Year 2016 Cite this article as: Ravisankar N, Jerrine J, Radhakrishana M, Rajasekar T. In vitro cytotoxicity of methanol ex- tracts of Hypericum wightianum and Hypericum hookerianuim against 3T3L1 cell lines. Bangladesh J Pharmacol. 2016; 11: 328-29. In vitro cytotoxicity of methanol extracts of Hyperi- cum wightianum and Hypericum hookerianuim against 3T3L1 cell lines Sir, Hypericum (guttiferae or Hypericacea) is a large genus of herb, which grows widely at temperate region of the earth and used as traditional medicinal plant across the globe (Yazaki and Okada, 1994). Different species of Hypericum have been used for the treatment of wounds, eczema and burns. During the last few years antimicro- bial antifungal and anti-oxidant properties have been reported by many experimental studies (Rabanal et al., 2003). Nearly 27 species of Hypericum are reported to possess strong anticancer properties (Agostinis et al., 2002). The European H. perforatum have been studied in details for their potent anticancer properties and on its medicine value and presence of rice bioactive secondary metabolic. The present study was focused to investigate cytotoxicity properties of H. wightianum and H. hookerianum The plant materials (H. wightianum and H. kookerianum) were collected from different locations of from Kodaikanal, Southern India during the month of April 2015. Plant materials was extracted with methanol: water (60:40) using soxhlet apparatus. Cytotoxicity studies were carried out using 3T3L1- mouse adipose cell line procured from National Centre for Cell Sciences, Pune, India. The cytotoxic effect of the crude extracts from the two Hypericum species were investi- gated using MTT assay (Shahneh et al., 2013). The percentage growth inhibition was calculated and concentration of test drug needed to inhibit cell growth by 50% (CTC50) values is generated from the dose- response curves for each cell line. The cytotoxic effect of the three extracts from each Hypericum species was determined. All the extracts were tested against a panel of normal and cancer cell lines at a range of 1,000 to 62.5 μg/mL using MTT exclusion methods. The CTC50 values were shown separately for normal and cancer cell lines as in Table I for MTT assay; the CTC50 values for short term study are depicted in Figure 1. The cytotoxicity of three different extracts viz., methanolic, aqueous and hydro- methanolic from the studied species showed similar pattern with respect to their specificity towards toxicity. The toxicity of extracts are in increasing order, methanolic > hydro-methanolic > aqueous extract. The extracts also exhibited moderate cytotoxicity against cancer cell lines, among the cancer cell lines. Overall the CTC50 was found to be >1000 μg/mL. A Journal of the Bangladesh Pharmacological Society (BDPS) Bangladesh J Pharmacol 2016; 11: 328-329 Journal homepage: www.banglajol.info Abstracted/indexed in Academic Search Complete, Agroforestry Abstracts, Asia Journals Online, Bangladesh Journals Online, Biological Abstracts, BIOSIS Previews, CAB Abstracts, Current Abstracts, Directory of Open Access Journals, EMBASE/Excerpta Medica, Google Scholar, HINARI (WHO), International Pharmaceutical Abstracts, Open J-gate, Science Citation Index Expanded, SCOPUS and Social Sciences Citation Index ISSN: 1991-0088; DOI: 10.3329/bjp.v11i2.26438 Letter to the Editor Table I Cytotoxicity properties of test drugs against 3T3L1 cell line Concentra - tion (μg/mL) % Cytotoxicity CTC50 (µg/mL) H. wightianum 1000 47.2 ± 3.3 >1000 500 34.8 ± 1.9 250 26.3 ± 3.1 125 22.4 ± 4.4 62.5 19.3 ± 2.7 1000 26.3 ± 4.5 >1000 H. kookerianum 500 24.2 ± 1.0 250 23.6 ± 3.0 125 20.7 ± 1.7 62.5 10.9 ± 7.7 Figure 1: Cytotoxic effect of the H. wightianum (RR2136) and H. hookerianum (RR2137) on 3T3L1 cell line http://www.sciencedirect.com/science/article/pii/S1357272501001261 The trypan blue assay based on the assumption that the dead cells will take the dye and viable cells won’t (Unnikrishnan et al., 1988). From the study, it was observed that extracts showed moderate cytotoxic against both cancer and normal cell lines. The cytotoxicity of extracts found to be in dose dependent and non selective as reflected by uniform CTC50 values independent of cell line origin. The species from are reported to possess various biological activities (Rahul and Thangaraj 2012) from the study it was observed that extracts are found to be moderately toxic. Hence, there is important need for further investigations on identification of phytoconstituents responsible for toxicity and also studying nature of toxicity using animal models. The in vitro cytotoxicity assays offers quick, simple and cost-efficient way of testing the toxicity and forms an important tool for high throughput screening of plant extracts. From the present findings, it can be concluded that the studied extracts shows moderate toxicity against both cells irrespective of their origin. Hence the extracts need to be thoroughly studied using animal models. Narayanan Ravisankar1, Joseph Jerrine2, Manikkan Radhakrishana2 and Thirunavukkarasu Rajasekar2 1Department of Chemistry, Sathyabama University, Chennai, India; 2Centre for Drug Discovery and Development, Sathyabama University, Chennai, India. Corresponding author: email: ravisankarnarayanan@yahoo.co.in References Agostinis P, Vantieghem A, Merlevede W, de Witte PAM. Hypericin in cancer treatment: More light on the way. Int J Biochem Cell Biol. 2002; 34: 221–41. Rabanal RM, Arias A, Prado B, Hernandez-Perez M, Sanchez- Mateo CC. Antimicrobial studies on three species of Hypericum from the Canary Islands. J Ethnopharmacol. 2002; 81: 287-92. Rahul C, Thangaraj P. Total phenolic content and anti-radical property of Caralluma diffusa (Wight) N.E. Br. Asian Pac J Trop Biomed. 2012; 1: 1-4. Shahneh FZ, Valiyari S, Azadmehr A, Hajiaghaee R, Yaripour S, Bandehagh A, et al. Inhibition of growth and induction of apoptosis in fibrosarcoma cell Lines by Echinophora platyloba DC: In vitro analysis. Adv Pharmacol Sci. 2013: 5; 129-31. Unnikrishnan MC, Ramadasan K. Cytotoxicity of extracts of spices to cultured cells. Nutr Cancer. 1988: 11; 251-57. Yazaki K, Okada T. Medicinal and aromatic plants. VI. In: Biotechnology in agriculture and forestry. Bajaj YPS (ed.). Vol. 26. 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