Characteristics and efficacy of irradiated keladi tikus (typhonium divaricatum (L.) decne) leaves

Keladi Tikus(Typhonium divaricatum (L.) Decne), Araceae, is one of Indonesia plants that can inhibit cancer cell growth. Preservation techniques of herbal medicine using gamma irradiation has long been used to prolong shelf life, but only a little scientific data that study the effect of irradiation on the properties of them. In this study irradiation of keladi tikus leaves with a dose of 0, 5, 7.5, 10 and 15 kGy, followed by maceration of each with n-hexane, ethyl acetate and ethanol, respectively. Effects of gamma irradiation were studied by testing the inhibitory activity against the L1210 leukemia cell for the extracts, fractionation by column chromatography, analysis by TLC, spectrophotometer and HPLC. The result of cytotoxicity test against L1210 leukemia cells showed that the ethyl acetate extract of the most active potential as anticancer IC₅₀ value respectively 11.81 μg/ml. Result of fractionation of ethyl acetate extract were obtained by column chromatography with 6 fractions. Fraction 2 was the most active fraction with the lowest IC₅₀ value of 4.14 μg/ml. Gamma irradiation dose of 15 kGy reduced the cytotoxic activity of fraction 2 against L1210 leukemia cells, but still within the active potent (IC₅₀ values ≤ 20 μg/ml) as an inhibitor to the growth of leukemia L1210. Based on the cytotoxicity data, profiles of TLC, UV-VIS spectrum and HPLC between control and irradiated samples showed that the maximum dose for irradiation of keladi tikus leaves was 7.5 kGy. (author)