CYTOTOXICITIES OF ALKALOIDS FROM PROCESSED AND UNPROCESSED SEEDS OF STRYCHNOS-NUX-VOMICA

AIM: To examine the cytotoxicities of 6 crude Strychnos alkaloid fract ions from 'the seeds of Strychnos nux-vomica unprocessed or processed with various traditional processing methods and 13 pure Strychnos alka loids from the fractions. METHODS: Using cell culture, their inhibitor y effects on Vero cell growth-inhibition assay, and host cell DNA synt hesis by [H-3]thymidine ([H-3]TdR) uptake assay. RESULTS: The IC50 of processed seeds were 155 % and 212 % of unprocessed ones in cell growt h-inhibition assay and in [H-3]TdR uptake assay, respectively. The IC5 0 of 13 compounds were 0.45-0.80 mmol . L-1 and 0.50 - 12 mmol . L-1, respectively. The processing method with sand bath exhibited a wide sa fety margin compared with other traditional processing methods or no p rocessing. The isomers of Strychnos alkaloids and their N-oxides showe d much lower cytotoxicities among these alkaloids. Isobrucine N-oxide showed the lowest cytotoxicity. The contents of isomers and N-oxides o f Strychnos alkaloids were the highest in the sand processing. CONCLUS ION: Processing bf nux vomica plays a critical role in its toxicity.