Investigation of Selected North Western Himalayan Plants for Anti malarial Activity

Abstract

newline viii newlineABSTRACT newlineObjective: To investigate the anti-malarial activity of the extracts and fractions of Spilanthes acmella, Bergenia ciliata, Morus rubra, Nicandra physalodes and Xanthium strumarium. newlineBackground: Plants selected for evaluation in this study have ethno-medicinal history as antimalarials but literature review shows that only whole extracts of selected plants for this study have been evaluated. newlineMethods: The selected plants (leaves of Morus rubra, Nicandra physalodes and Xanthium strumarium; and whole plants of Bergenia ciliata and Spilanthes acmella) were evaluated for in vitro antimalarial activity using parasite invasion inhibition assay at 2.5, 5 and 10 and#956;g/mL against P. falciparum chloroquine sensitive strain (3D7). Further, cytotoxicity of fractions was evaluated at 100 and 200 and#956;g/mL against Human Embryonic Kidney (HEK) cell line by MTT assay. The active plant fractions were evaluated using Peter s four day suppressive test at dose of 100, 250 and 500 mg/kg/day. The active dose of selected fractions were evaluated for body weight change, mean survival time, organ wet weight, histopathology and necropsy, blood and serum parameters (PCV, LFT, RFT and TNF and#945;). Plant fractions were standardized by HPTLC technique. newlineResults: The alkaloidal fraction of B. ciliata (BC-Alk), ethyl acetate fraction of M. rubra (MR-EA), dichloromethane fraction of N. physalodes (NP-NA) and its isolate (NP-C), X. strumarium (XS-NA) and hexane fraction of S. acmella (SP-HX) were selected on basis of in vitro antimalarial activity and cytotoxicity. The selected fractions were further evaluated for in vivo antimalarial activity on BALB/c mice infected with P. berghei strain (chloroquine sensitive strain). The BC-Alk, NP-NA, XS-NA and NP-C showed and#8805; 40% suppression in parasite count on day 7 at 100 and 10 mg/Kg/day. The active fractions were further evaluated at 250 and 500 mg/Kg/day and while NP-C was evaluated at 50 and 100 mg/Kg/day. The NP-NA showed highest parasite suppression of 73% at 500 mg/kg/day while XS-NA and BC-Alk showed 71% and 70% of parasite suppression. The NP-C showed 50% parasite suppression at 100 mg/kg/day. The BC-Alk, NP-NA, XS-NA and NP-C showed protective role in body weight change and mean survival time was higher as compared to the infected newlineix newlinecontrol group. The NP-NA and BC-Alk showed highest mean survival time of 18 days while lowest was showed by NP-C of 15 days compared with infected control group. The BC-Alk, NP-NA, XS-NA and NP-C show improvement in LFT, RFT and PCV, which were supported by improved histopathological data of liver, spleen and kidney. The highest inhibition of the pro inflammatory cytokine TNF and#945; was showed by BC-Alk while lowest inhibition by NP-C. The ethyl acetate fraction of B. ciliata and hexane extract of S. acmella were standardized by HPTLC using bergenin and lupeol as chemical standards, respectively. Ethyl acetate fraction of B. ciliata showed weak in vitro antimalarial activity while hexane extract of S. acmella showed potent activity (IC50 lt 5 and#956;g/mL). A withanolide (NP-C) reported from DCM (Non alkaloidal) fraction of N. physalodes with molecular formula of C28H36O7. The compound showed moderate activity (IC50 7.3 and#956;g/mL) against Plasmodium falciparum. newlineConclusion: The oral administration of dichloromethane fraction of N. physalodes and its isolate, dichloromethane fraction of X. strumarium and alkaloidal fraction of B. ciliata showed antimalarial activity by inhibiting the parasitemia in mice infected with P. berghei. These findings further confirm the ancient traditional knowledge and use of selected plants as an antimalarial agent. newlineKeywords: Antimalarial, P. berghei, P falciparum, B. ciliata, M. rubra, N. physalodes, Peter s four day suppressive test