Primary Screening for Natural Inhibitorsagainst Eukaryotic Signaltransduction from Selected Medicinal Plants in Sabah, Malaysia

The protein kinases and phosphatases in the signal transduction pathways play a vital role in mitogen activated protein (MAP) kinase signal transduction, tumorigenesis, apoptosis, and cancer metastasis. In this study, genetically engineered yeast strains were used as a model in the search for potential inhibitors against these signalling elements. Eleven species of medicinal plants were selected from various locations in Sabah,Malaysia, extracted and tested against MKK, and PP1. Preliminary results showed the presence of potential MKK1 inhibitors in the crude extracts of Alphitonia excelsa, Cordyline terminalis and Tinospora crispa. However, no inhibitor was . The crude extracts of Cordyline terminalis was further fractionated using a bioassay guided fractionation and four partially pure active fractionswere isolated.