Preliminary observations on the effects of the Chinese medicinal herbs Astragalus membranaceus and Ligustrum lucidum on lymphocyte blastogenic responses.

The biological effects of extracts of two Chinese medicinal herbs, Astragalus membranaceus and Ligustrum lucidum, on in vitro lymphocyte blastogenesis were assessed. Aqueous extracts augmented the spontaneous [3H]thymidine incorporation in the mononuclear cells (MNC) of 14 normal subjects from 273.0 to 609.3 counts per minute (cpm) and 252.9 to 656.9 cpm for the two herbs, respectively. The stimulation indices were 2.4 and 3.1, respectively (p less than 0.001). They also augmented the proliferation of normal subjects' lymphocytes induced by suboptimal concentrations of phytohemagglutinin (PHA) from 5084.6 to 23,398.3 and 221.7 to 24,132.8 cpm, of concanavalin A (con A) from 4046.5 to 15,661.5 and 677.6 to 14,644.6 cpm, and of pokeweed mitogen (PWM) from 4377.9 to 24,405.6 and 322.7 to 11,730.0 cpm, respectively (p less than 0.00). Herb extracts augmented the PHA responses of the MNC from 14 cancer patients significantly (p less than 0.01 and p less than 0.05, respectively). Extracts of L. lucidum also augmented the con A response of patients (p less than 0.05). The augmenting effect of the herbs on the PHA, con A, and PWM responses was dose dependent, and proliferation was inhibited at higher concentrations. The optimal concentration for stimulating the MNC of cancer patients was 100 micrograms/ml, compared to 10 micrograms/ml for the MNC of normal donors. MNC of seven patients depressed the mitogen responses of normal cells in a co-culture system. This was partially abrogated in five by preincubating the patients' cells in herb extracts for 45 min or by irradiation of the patients' cells. These results suggest that the herb extracts contain immunomodulatory components which may be useful in the immunotherapy of disease.