“An apple a day keeps the doctor away” is a popular proverb. It is well-known that apples are good for health but only a few people are clear that it is phytochemicals that are responsible for the health benefits of apples.
Likewise, ginseng is a popular medicinal herb widely used in herbal supplements and functional foods, and its medicinally active ingredients called ginsenosides are less known. They exhibit pharmacological activities and produce huge health-promoting benefits.
They are hundreds of ginsenosides isolated from ginseng, and they are different in molecular weights and pharmacological bioactivities.
The naturally occurring ginsenosides in ginseng are known as Prototype ginsenosides, and they can be transformed into rare ginsenosides (also known as less-polar ginsenosides) through unique processing.
Ginsenoside Rg3 is one of the best-known rare ginsenosides, and it is converted from prototype ginsenosides such as Rb1, Rb2, and Rd. It is more easily absorbable and shows stronger bioactive than its parent ginsenosides.
There are different methods for ginsenoside transformation like steaming, acid hydrolysis, and biotransformation.
These unique processing methods help increases the content of rare ginsenosides. The obtained rare ginsenosides show more potent pharmacological effects, and they are able to inhibit tumor proliferation and induce tumor deaths.
In a study published in the Journal of Functional Foods, researchers found that the ginseng extract processed by microwave irradiation increased the content of ginsenosides Rg3, Rg5, Rk1.
The ginseng extract particularly rich in Rg5 and Rk1 was found to show remarkable anticancer effects in HeLa cervical cancer cell lines and curbed the growth of human cervical cancer cells in mice models.
Rare ginsenosides also show brilliant performance in reducing multidrug resistance because they show potent toxicity against cancer while doing little harm to normal cells.
A study suggested that ginsenoside Rg3 could help suppress lung small lung tumor growth together with gefitinib. Compared with gefitinib or ginsenoside Rg3 alone, a combination of gefitinib and ginsenoside Rg3 achieved the best cytotoxic effect.
Moreover, gefitinib plus Rg3 also worked best in inducing apoptosis, inhibiting tumor cell migration, enhancing the expression of migration, and apoptosis-related proteins in NSCLC cancer cell lines.
The production of easily absorbable and highly bioactive rare ginsenosides in large amounts is not easy and it needs many innovative technologies. As a result, there are less rare ginsenoside products seen in the market.
Some rare ginsenosides available in the market include Rh2, Rg3, Rk1, Rg5, Rh3, Rk2, aPPD (S, R), aPPT (S, R), Compounds K, etc.