4.7. Immunomodulatory Activity
Thirty six crude chloroform, methanol and water extracts of 11 medicinal plants commonly used in Thailand were screened for activating human lymphocytes and phagocytes activities [47]. The marker used for detecting lymphocyte activation and proliferation via flow cytometer were CD69 antigen expression while effects on phagocytes were detected by measuring the migration of polymorphonuclear cells towards a chemoattractant under agarose. The chloroform extract of RZZ (CEZZ) significantly stimulated T lymphocytes to express CD69 antigen by 31.6% as compared to the control group (6.2%). The MEZZ and AEZZ gave percentage stimulation of CD69 antigen of 5.8% and 2.3%, respectively. None of the crude extracts stimulated the migration of polymorphonuclear cells but CEZZ and MEZZ did suppress polymorphonuclear cells migration. Phytohemagglutinin (PHA), at the concentration of 5 μg/mL, was used as positive control drug to stimulate the CD69 expression on lymphocytes with an incubation period of 4 h and gave an approximately 46% stimulation of lymphocytes. However, no positive control was used to compare the polymorphonuclear migration rate potential of those extracts.