Effects on diabetes

In vitro studies
Study showed that American ginseng can increase insulin production and reduces the death of pancreatic beta cells.[4]

Another study suggest that effects of American ginseng in improving hyperglycemia may function by altering mitochondrial function and apoptosis cascades to ensure viability in pancreatic islet cells.[5]

Antioxidant effects

In vitro study
A principle ginsenosides for American ginseng was tested through three different antioxidant assays including: metal chelation, affinity to scavenge DPPH-stable free radical, and peroxyl (LOO*) and hydroxyl (*OH) free radicals for the purpose of characterizing mechanisms of antioxidant activity. The ability for North American Ginseng Extract (NAGE) to inhibit metal induced lipid peroxidation were in the order of Fe2+ > Cu2+ > Fe3+. NAGE also showed strong DPPH radical, site-specific and non site-specific *OH scavenging activity. In addition, NAGE effectively inhibited the non site-specific DNA strand breakage caused by Fenton agents. These results show that NAGE possesses antioxidant activity in both lipid and aqueous mediums by both chelation of metal ions and scavenging of free radicals.[6]

Cardio-protective effects

In vitro study
Study has demonstrated that American ginseng restrains oxidative stress and oxidative stress-induced cell death in cardiomyocytes by activating the Nrf2 pathway, therefore providing protection against cardiac remodeling.[7]

Animal test
Study has been conducted on Panax quinquefolium 20s-protopanaxdiolsaponins (PQDS), compounds extracted from leaves of American ginseng, in dogs with acute myocardial infarction. The results showed that PQDS has protective effect on myocardial ischemia by modifying metabolic dysfunction of FFA, preventing peroxidation of membrane lipids by free radical, uplifting endogenous antioxidase activity and enriching myocardial blood supply.[8]

Immunomodulatory Activities

Animal study
Coarse Polysaccharide from Panax quinquefolium (CPPQ) can inhibit the decrease in leukocytes number and size of lymphoid organs caused by Cyclophosphamide. It also strongly activates the phagocytosis of the reticuloendothelial system in normal and immuno-deficient mice, and enhances the differentiation of lymphocytes in spleen of the immnuo-deficient mice. These results indicate that CPPQ can strengthen both the non-specific and cell-mediated immunity in organisms.[9]

Effects on Colds

Clinical study
Ingestion of a poly-furanosyl-pyranosyl-saccharide-rich extract of the roots of North American ginseng over 4 months reduced the mean number of colds per person, the severity and the number of days which cold symptoms were reported.[10]

Anti-tumor effects

In vitro study
Researches had been done to determine if the gene expression of p21 protein, a cell cycle inhibitor, can be induced by American ginseng in hormone sensitive (MCF-7) and insensitive (MDA-MB-231) breast cancer cell lines. Northern blot was performed using human cDNA probes and cell cycle analyse was also performed. Results showed that American ginseng can induce p21 mRNA expression in both cell lines and the percentage of cells in proliferative phase (S-phase) was significantly decreased by American ginseng. Thus, American ginseng may possess the ability to inhibit breast cancer cell growth by activating the transcription of p21 gene.[11]