(A) study on the screening of anticancer agents from natural products

Abstract

For the purpose of screening of anticancer agents seven kinds of natural products which have long been used as hervals in the orient were examined. Extracts of $\mbox{\underline{Panax}}$ $\mbox{\underline{ginseng}}$, $\mbox{\underline{Glycyrrhiza}}$ $\mbox{\underline{uralensis}}$, $\mbox{\underline{Patrinia}}$ $\mbox{\underline{villosa}}$, $\mbox{\underline{Dianthus}}$ $\mbox{\underline{chinensis}}$, $\mbox{\underline{Pheretima}}$ $\mbox{\underline{communissima}}$, $\mbox{\underline{Sophora}}$ $\mbox{\underline{subpresarata}}$, and $\mbox{\underline{Sedum}}$ $\mbox{\underline{japonicola}}$ were made and added to the culture of murine leukemic cells (L1210) to detect growth inhibition acitivity if present. Dry mass of each product was sorked in distilled water and extracted for 10 hours at 105$^\circ$C. After adding a known concentration of the extract to a culture medium containing 0.5 to $1.0\times10^5$ cells per ml, the screw cap culture tube was incubated for 48 hours at 37$^\circ$C. The cell population was, then, counted using a Coulter electronic counter and the value of 50\% effective dosage ($ED_{50}$) of the product was determined. Among the natural products tested the dry materials of four species, $\mbox{\underline{P}}$. $\mbox{\underline{villosa}}$, $\mbox{\underline{S}}$. $\mbox{\underline{subpresarata}}$, $\mbox{\underline{S}}$. $\mbox{\underline{japonicola}}$ (stem, root), and $\mbox{\underline{P}}$. $\mbox{\underline{communissima}}$ showed $ED_{50}$ values of 240, 300, 400 and 420 $\mu$g/ml respectively, indicating significant activities of inhibiting the growth of the murine leukemic cells. All of the active materials were found to be heat stable and relatively long time was required to extract in the hot water from the natural products.