The cytotoxic and cytostatic effects of the bitter melon (Momordica charantia) on human lymphocytes.

We have previously reported that a crude extract from the bitter melon (Momordica charantia) killed human leukemic lymphocytes in a dose-dependent manner while not affecting the viability of normal human lymphocyte cells at these same doses (Takemoto et al., 1980). We now report that the crude preparation has both cytostatic and cytotoxic activities which are heat stable and trypsin-sensitive. Time and dose-response curves suggest that the factors act quickly, perhaps by entry into the cell. The effects of the crude extract are complete after only 2 hr of exposure. These activities are not due to the presence of the lectins from bitter melon seeds, as these purified proteins had no activity against human lymphocytic cells.