Ganoderma lucidum (lingzhi) is a medicinal mushroom that possesses immunomodulatory and antitumoreffects. In Thailand, G. lucidum products are widely used as health-promoting agents but most of the products are imported. The aim of this study was to determine the immunomodulatory effects of various strains of G. lucidum grown in Thailand or imported. Flow cytometric measurement of early activation molecule CD69 expression on T lymphocytes showed that the water extract and water-insoluble fraction of unbroken spores of G. lucidum strain G9 (imported from China) at 100 μg/ml concentration gave the highest T lymphocytes proliferative responses, while the Thai-grown strain G2 could induce only 50 percent responses when compared with G9. The results from this preliminary study can be used in decision-making for G. lucidum strain selection and development in Thailand.

Key words: Ganoderma lucidum, spore, immunomodulatory, T lymphocytes, CD69