Eat Ginseng to Protect Against Viral Infection and Boost Vaccine Effectiveness

​

    Vaccination is the main strategy for preventing influenza infection. However, vaccine efficacy is influenced by several factors, including age and health status. The efficacy of the influenza vaccine is much lower (17% to 53%) in individuals over 65 years of age compared with young adults (70% to 90%) (1). Increasing vaccine efficacy remains a challenge for this preventive strategy to be effective.

 

    Vaccine adjuvants are compounds that can significantly enhance/prolong the immune response to a co-administered antigen. To explore novel and effective adjuvants for influenza vaccines, a group of scientists screened 145 compounds from food additives approved in Japan. Of these 145 candidates, 41 compounds enhanced the efficacy of the split influenza hemagglutinin vaccine against lethal virus challenge in a mouse model. One of the effective food additive compounds was saponins (2).

 

    Saponins have historically been understood to be plant-derived, but they have also been isolated from marine organisms such as sea cucumber. It is found heavily in Gynostemma pentaphyllum (Gynostemma, Cucurbitaceae) in a form called gypenosides, and ginseng or red ginseng (Panax, Araliaceae) in a form called ginsenosides.

 

    It is believed that the ginseng saponins called ginsenosides are the major active constituents in Asian ginseng (Panax ginseng) and American ginseng (Panax quinquefolius L.), the two most recognized ginseng botanicals. Many health benefits of saponins have been reported including the effects on the cardiovascular system, immune system, and central nervous system as well as the anti-diabetes and anti-cancer effects (3).

 

    Ginseng’s anti-cancer effects have been considered to be linked to its activity within the immune system. Ginsenosides enhance the formation of antibodies and immune functions in cancer patients and laboratory animals. An animal study showed that the total saponin of American ginseng partially restored the activity of chemotherapy-depressed bone marrow stem cell proliferation and splenocyte proliferation in mice and enhanced production of interleukin-3 and interleukin-6-like substances from the splenocytes (3).

 

    Like Asian ginseng, American ginseng’s ginsenoside content varies among different parts of the plant. The leaf contains the highest ginsenosides (16.5%), followed by root-hair (6.9%), rhizome (5.1%), root (4.9%) and stem (2.0%) (4). The content of ginsenosides increases with the age of the plant parts, except the leaf. In general, ginsenoside Rb1, Re, Rd, Rc, Rg1, and Rb3 are the six major saponins in American ginseng, accounting for more than 70% (3).

 

    Saponins isolated from the stem-leaf of Panax ginseng (GSLS) has been reported to be useful to improve vaccination. Administration of GSLS in drinking water produced significantly better vaccination against Newcastle disease and avian influenza in chickens (5-6).

 

    The effects of the main components of ginseng, including total ginsenoside, panaxadiol saponins, panaxtrol saponin, and ginseng polysaccharide were studied in rats. Panaxadiol saponins and ginseng polysaccharide improved animal immune organ weight, plasma interleukin 2, interleukin 6, plasma gamma-interferon (IFN-γ), tumor necrosis factor-alpha (TNF-α) compared to those of the control group. Total ginsenoside and panaxtrol saponin effectively increased the concentration of spleen natural killer cells while panaxadiol saponins and ginseng polysaccharide significantly increased the concentrations of rat plasma adrenocorticotrophic hormone (ACTH), corticosterone (CORT) and thyroid-stimulating hormone (TSH). As for the effect of increasing organization nitric oxide and superoxide dismutase, glutathione and malondialdehyde, total ginsenoside was better than those of other groups. Different components in ginseng showed different effects on enhancing immunity, regulating endocrine, and resisting oxidation. Panaxadiol saponins and ginseng polysaccharide were better in enhancing immune function, and total ginsenoside showed advantages in resisting oxidation and stress (7).

 

    The impact of supplementing vaccination with the dietary intake of Korean red ginseng (RG) extract and RG saponin was investigated in mice. Mice were immunized two times intranasally with inactivated influenza A (H1N1) virus. Mice received RG extract or RG saponin orally for 14 days before the primary immunization. After the primary immunization, mice continued to receive RG extract or RG saponin until the secondary immunization. Mice vaccinated in combination with dietary intake of RG extract and RG saponin showed elevated serum anti-influenza A virus IgG titers and improved survival rates in lethal influenza A virus infection: 56% and 63% of mice receiving RG extract or RG saponin survived, respectively, while 38% of mice that only received the vaccine survived. Mice receiving RG extract supplementation recovered their body weight more quickly than those not receiving RG extract supplementation. The results showed that the dietary intake of RG extract and RG saponin enhanced the vaccine-induced immune response and aided in protecting against influenza virus infection (8).

 

    The effect of ginseng extract and ginsenosides, the ginseng-derived triterpene, and saponin compounds, against the 2009 pandemic H1N1 virus was studied in another mice study. The mice that received the ginsenoside-pretreated virus had minimal weight loss and no mortality, which was significantly different from the results seen in the control group, which showed severe weight loss and 100% mortality within 5 days post-infection. The data showed that treatment of mice with ginsenosides protected the animals from lethal 2009 pandemic H1N1 infection and lowered viral titers in animal lungs. Ginsenosides interacted with viral hemagglutinin protein and prevented the attachment of viruses with α 2-3' sialic acid receptors present on host cell surfaces. The interference in the viral attachment process subsequently minimized viral entry into the cells and decreased the severity of the viral infection. Ginsenosides had antiviral effects on influenza viruses (9).

 

    The effect of saponin extracted from Panax ginseng on lymphocytes was studied in10 young (25-30 years) and 19 elderly (65 to 78 years) persons from Beijing. Saponin had a direct- stimulatory effect on the lymphocytes of aged people. Saponin enhanced the proliferation of lymphocytes at optimal concentrations. Otherwise, the inhibitory effect occurred at a higher or lower concentration of saponin beyond the optimal range. The stimulatory effect of saponin is dependent on the original functional status of lymphocytes. The proliferative response of lymphocytes from aged people was lower than that of young people. There was an elevated response of lymphocytes from aged person after culture with saponin, whereas saponin had inhibitory effects on those lymphocytes of young people. Besides, saponin increased the fluidity of the lymphocyte membrane of the aged. The study showed that saponin extracted from P. ginseng could play an important role in the modulation of lymphocytes in the elderly (10).

 

    Influenza viruses cause mild to severe respiratory infections in humans. Rapidly evolving and emerging influenza viruses with increased frequency of viral resistance to these drugs stress the need to explore novel antiviral compounds. The results from the various studies suggested that ginseng saponins may help to protect you from getting viral infection/reducing the severity of the symptoms if you ever get affected. Eat ginseng to protect ourselves against viral infection and boost vaccine effectiveness.

 

​References:

 

1. Goodwin K, Viboud C, Simonsen L. Antibody response to influenza vaccination in the elderly: a quantitative review. Vaccine. 2006. 24:1159–1169.

2. Feng H, Yamashita M, Wu L, Jose da Silva Lopes T, Watanabe T, Kawaoka Y. Food Additives as Novel Influenza Vaccine Adjuvants. Vaccines (Basel). 2019. 7(4). pii: E127.

3. Yuan, C.-S., Wang, C.-Z., Wicks, S. M., & Qi, L.-W. Chemical and Pharmacological Studies of Saponins with a Focus on American Ginseng. Journal of Ginseng Research. 2010. 34(3), 160–167.

4. Qu CL, Bai YP, Jin XQ, Wang YT, Zhang K, You JY, Zhang HQ. Study on ginsenosides in different parts and ages of Panax quinquefolius L. Food Chem. 2009. 115:340–346.

5. Zhai, L., Li, Y., Wang, W., Hu, S. Enhancement of humoral immune responses to inactivated Newcastle disease and avian influenza vaccines by oral administration of ginseng stem-and-leaf saponins in chickens. Poult. Sci. 2011. 90, 1955–1959.

6. Yu, J., Shi, F. S., & Hu, S. Improved immune responses to a bivalent vaccine of Newcastle disease and avian influenza in chickens by ginseng stem-leaf saponins. Veterinary Immunology and Immunopathology. 2015. 167(3-4), 147–155.

7. Jia, ZY., Xie X., Wang, XY., Jia, W. Comparative Study of Main Components of Ginseng on Immune Function of Rats. Comparative Study Zhongguo Zhong Yao Za Zhi. 2014. 39(17):3363-6.

8. Xu, ML., Kim, HJ., Choi, YR., Kim, HJ. Intake of Korean Red Ginseng Extract and Saponin Enhances the Protection Conferred by Vaccination With Inactivated Influenza a Virus. J Ginseng Res. 2012. 36(4):396-402.

9. Dong, W., Farooqui, A., Leon, A. J., & Kelvin, D. J. Inhibition of influenza A virus infection by ginsenosides. 2017. PLOS ONE, 12(2), e0171936.

10. Liu, J., Wang, S., Liu, H., Yang, L., & Nan, G. Stimulatory effect of saponin from Panax ginseng on immune function of lymphocytes in the elderly. 1995. Mechanisms of Ageing and Development, 83(1), 43–53.