J Biomed Lab Sci 1989; 2: 201~213

ENHANCEMENT OF SPLENIC NK CYTOTOXIC ACTIVITY BY EXTRACTS OF GANODERMA LUCIDUM MYCELIUM IN MICE

SHEN-JEU WON, SHIUH-SHENG LEE, YEN-HSIU KE and MAO-TSUN LIN
Department of Microbiolog, College of Medicine, National Cheng-Kung University, Tainan,
Department of Biochemistry, National Yang-Ming Medical College, Taipei
Department of Physiology, Collegeof Medicine, National Cheng-Kung University, Tainan, Taiwan, R.O.C.

The effects of alcohol insoluble fraction of Ganoderma lucidum mycelium (GL-AI) on the splenic natural killer cell (NK) cytotoxic activity were assessed in normal mice and in tumor bearing mice. Intraperitoneal administration of GL-AI (4-400 mg/kg) augmented the splenic NK cytotoxic activity in normal C3H/HeN mice in a dose-dependent way. Augmentation of splenic NK cytotoxicity was neither mouse strain-dependent nor route administration-dependent. For an i.p. does of 40 mg/kg of GL-AI, the splienic NK activity effect began to rise at 15hrs after injection and reached its peak level at 48 hrs. The splenic NK activity returned to its normal level at 120 hrs. In addition to an enhancement in the splenic NK activity, i.p. administration of GL-AI also elevated the interferon (IFN) titers in mouse serum. The decreased splenic NK cytotoxicity of 129P hepatoma-bearing C3H/HeN or B16-F10 melanoma-bearing C57BL/6 mice could be restored by i.p. injection of 40 mg/kg of GL-AI. However, the hyporesponsiveness to splenic NK augmentation did develop following consecutive 3 or more doses of GL-AI. These data indicate that GL-AI induces the IFN production in mice, which, in turn, activates the splenic NK activity to lyse the tumor cells.
Keywords: Ganoderma lucidium, NK cell, cytotoxicity.