Ginseng is a medicinal herb that has been reputed for treating a variety of disease over two thousand years. Panax ginseng is a subtype of ginseng that is grown in northeast China, Korean and far eastern Siberia.
The medicinal benefits of ginseng are attributed to the presence of the active constituents, called ginsenosides. Aside from some common advantages like boosting energy, reducing physical or mental fatigue, and fighting inflammation, ginseng and ginsenosides show anticancer activities.
Despite promising therapeutic effects, anticancer mechanisms of action of ginseng remain unknown.
Natural killer cells are a type of cytotoxic lymphocyte that belongs to the innate immune system. NK cell cytotoxicity is regarded as a critical part of immune surveillance against tumors.
Unlike immune cells that rely on antigens to detect infected cells, natural killer cells can recognize harmful cells directly and destroy them. They play a role in tumor immunosurveillance by inducing the death of tumor cells.
Scientists from Juntendo University in Tokyo, Japan set out to find out the effect of oral consumption of Panax ginseng extract on human NK cell phenotypes and cytotoxicity in human. They published their results in the journal Personalized Medicine Universe.
In the previous study published in 2015, the team of researchers demonstrated that oral consumption of Panax ginseng aqueous extract increased natural killer cell activities in mice.
The latest study aimed to examine the effects of oral intake of Panax ginseng aqueous extract on NK cell activity in human.
Ten human volunteers were recruited in a cross-over trial and given 1000 mg of Panax ginseng aqueous extract per day for two weeks. Two individuals quitted due to personal reasons.
Researchers found that although the size of the NK cell population or the expression of phenotypic markers CD56 on NK cells, NK cell cytotoxicity significantly increased in 5 out of 8 participants. Compared to the placebo group, participants who took Panax ginseng aqueous extract had much stronger NK cell cytotoxicity.
The study suggests that Panax ginseng could kill cancer cells through activating immune surveillance and inhibiting inflammation-related tumor development.