Lepidobolus

Abstract: Antitumor screening data in KB Cell Culture (KB) are presented for extracts of plant samples collected by the author from Western Australia (WA) during Aug–Oct 1981. This includes active (≤ ED50 20 µg/ml) and inactive test results received from Purdue University for 181 samples represented by 127 species in 77 genera. It also includes published and unpublished reports on other WA samples collected largely by the author and two by CSIRO–during the mid 1960’s— that were active in KB and other antitumor bioassays from screening done at the Research Triangle Institute (RTI) in North Carolina and at the National Cancer Institute (NCI). These data are summarized by family, genus, species, and plant parts. Fifty-one species in 40 genera are reported active. Although the NCI had screened samples from approximately 35,000 species of plants, 28 genera in 15 families were new discoveries for antitumor activity at the genus level based on a NCI record of all genera that had been screened by Feb 1980. Antitumor activity in Restionaceae and Stackhousiaceae were new at the family level. Root was the most frequently active plant part, especially in Fabaceae and Proteaceae. The most cytotoxic species were Daviesia podophylla (Fabaceae) and Lepidobolus quadratus (Restionaceae). In view of KB activity in Restionaceae and one species of dryland sedge in the Cyperaceae tribe Schoeneae that showed significant antitumor activity in the L1210 assay, and that essentially all plant-derived anticancer drugs discovered by the NCI were active in L1210, it is suggested that further screening of Schoeneae and the related Restionaceae will lead to discovery of new anticancer drug(s).