Ginseng: Mechanism of Action
Ginseng root has been used in Chinese and Korean cultures since ancient times. The plant belongs to the genus Panax, which has been in use in traditional medicine over centuries. The name ginseng comes from the Chinese words “Jen Sheng”, meaning “man-herb”, because of the humanoid shape of the root of the plant, which is the part most commonly consumed (1).
There are varieties of ginseng based upon the origin of plant from Korea, China and America. Traditionally, wild ginseng that grows naturally in mountains was handpicked and was used for medicinal purposes, but today with rising trends of its usage, cultivated varieties have also been introduced. These days, not only the fresh varieties but processed varieties (white and red ginseng) with improved shelf life are also available in the market. It is available as powders as well as extracts. Ginseng is predominantly produced in Canada, South Korea, and the U.S. Some of the top exporters of ginseng are Canada, South Korea, China, Hong Kong, and the United States. China is one of the leading ginseng consumers (2). According to an estimate, in terms of value, the global ginseng market is projected to experience a healthy compound annual growth rate of 4.8% between years 2018 and 2027. This may be due to globalization, increased consumer acceptance for oriental and Asian flavors and demand for Chinese herbal medicine (3).
With rising trends of functional foods, there have been recent advances in studying the health and pharmacological properties of ginseng root. It has been found to have following health benefits
* Antidiabetic properties
* Aids in weight loss
* Protects against cardiovascular problems
* Anti-inflammatory actions
* Protects against cancer
Active components of ginseng
Two basic functional compounds, Ginsenoside and Gintonin, have been identified in ginseng roots. Ginsenosides are steroid glycosides belonging to dammarane family of molecules. Many studies suggest that ginsenosides have antioxidant properties. They have been observed to increase internal antioxidant enzymes and act as a free-radical scavenger. In addition, they have been suggested to haveneuroprotective properties and could be useful against neurodegenerative diseases such as Alzeimer’s and Parkinson’s. These effects have been explained by the fact that these compounds are similar to steroid hormones and may act as partial agonists of steroid hormone receptors. Gintonin is a glycolipoprotein fraction derived from ginseng which is also known to be protective against neurodegenerative diseases and cancer (1, 4).
Mechanism of action
Ginseng root has been regarded to have several health benefits. Chronic conditions including cardiovascular diseases, diabetes, cancer, and obesity have complex etiologies arising from a combination of genetic, environmental and nutritional factors. therefore, nutritional factors may have a direct implication in prevention and treatment of such diseases. Although the exact mechanisms of chronic conditions on cellular level have not been defined, evidence suggests the role of involvement of gene receptors in modulating several chronic conditions. Of these receptors, peroxisome-proliferator-activated receptor (PPARs) have been a subject of extensive research. PPARs are nuclear hormone receptors which function as lipid sensors and regulate expression of several genes and thus impact on metabolic activities in body. Three basic types of PPARs, PPAR-γ, PPAR-α and PPAR-δ, have been identified. Modulation of these receptors has been proposed to decrease the rates of metabolic syndrome. At cellular level, PPARs bind with another protein RXR (retinoid X receptor). This diamer formed by combination of PPAR and RXR binds to DNA in cellular nucleus. The activation of nuclear receptors like PPAR require ligands to become activated. Ligand binding leads to conformational changes in the structure of PPAR which activates the receptor and thus regulate the expression of adjacent genes (5). Pharmacological agents have been designed as ligands for regulating the PPAR for therapeutic purposes. The active component of ginseng, Ginsenoside acts as ligand for PPAR-γ and therefore, can have therapeutic roles in chronic conditions. PPAR-γ is known to play a role at cellular level in enhancing the transcription of glucose transporters and enzymes like glucokinase and PON-1 while decreasing the gene expression for inflammatory markers. Therefore, this nuclear receptor may have several potential functions in whole body physiology.
Rest of this article explains the therapeutic properties of ginseng in common chronic conditions along with possible modes of its actions.