Ginseng extract a possible multi-target therapeutic tool against diabetes: Chinese review
Ginseng is one of the oldest and most well-known TCM herbs, having been widely used in China and several other Asian countries for thousands of years.
Emerging evidence seems to be confirming ginsenosides' effects against diabetes and its related conditions, such as type 1 and type 2 diabetes, diabetic nephropathy, and diabetes-induced cognitive dysfunction, cerebral infarction, cardiomyopathy and erectile dysfunction.
These effects include gluconeogenesis reduction, improved insulin resistance and glucose tolerance, glucose transport, hepatoprotective, renoprotective and neuroprotective activity, anti-inflammatory action, myocardial protection, and gut flora metabolism and lipid regulation.
Medicinal mechanisms
Researchers at the China Academy of Chinese Medical Sciences in Beijing sought to highlight the underlying pharmacological mechanisms of ginsenosides' anti-diabetes properties by conducting a review of in vitro and in vivo studies on Pubmed, published from December 2012 to December 2017.
They found that ginsenosides improve insulin resistance by inhibiting cortisone reductase, an enzyme that triggers type 2 diabetes. Through this action, blood glucose is also reduced.
Another way in which ginsenosides reduce blood glucose is by regulating gut flora metabolism. Gut flora characteristics in diabetics may be noticeably altered, and regulating its metabolism could well alleviate the effects of diabetes.
Additionally, ginsenosides enhance autophagy through signalling pathway activation, reducing lipid accumulation caused by a combination of high glucose and oleic acid and in turn, markedly improving glucose tolerance.
With low-grade inflammation a key cause of type 2 diabetes, ginsenosides' anti-inflammatory effect has proven useful in fighting diabetes. This is achieved via the inhibition of the inflammatory pathway involved in the disease, as well as the signalling pathway to prevent type 2 diabetes with fatty liver disease.
This also allows ginsenosides to "exert anti-apoptotic and anti-inflammatory effects", thereby lowering total cholesterol, triglyceride, and LDL cholesterol, all of which are closely linked to the development of diabetes.
Diabetics typically face the risk of death from cardiovascular complications, and ginsenosides were shown to help lower this risk. They were reported to have lowered the "percentage of apoptotic myocardial cells and increased the parameters of cardiac function", thereby reducing the diabetes-related risk of death from cardiac events.
Non-alcoholic fatty liver disease is another condition related to diabetes. In this regard, ginsenosides were reported to decrease lipid accumulation in the liver by activating certain signalling pathways, inducing autophagy to alleviate non-alcoholic fatty liver disease.
Not the perfect solution
Despite its numerous purported positive effects, the use of ginsenosides to prevent and treat diabetes and its complications has highlighted some issues.
A clinical trial found ginsenoside ineffective in ameliorating insulin sensitivity in diabetics with impaired glucose tolerance, or in newly diagnosed overweight and obese individuals.
Another study found that it had not been detected in human plasma, possibly due to its low bioavailability. The researchers wrote that the solution to this might be nanotechnology, adding that "current aptamer-based drug delivery technology is being developed for therapeutic use".
They concluded: "This might be a good method to provide a targeting tool for direct ginsenoside-loaded nanoparticle therapy. This article is limited to the study of mechanisms in vivo and in vitro experiments because of the lack of clinical trials.
"Nevertheless, ginsenosides could be considered for future development as a multi-target agent for (the) therapeutic application of diabetes and its complications, and more clinical trials are needed."
Source: Frontiers in Pharmacology
https://doi.org/10.3389/fphar.2018.00423
"Therapeutic Potential of Ginsenosides as an Adjuvant Treatment for Diabetes"
Authors: Litao Bai, et al.
