Submitted to: Journal of Nutrition
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/20/2012
Publication Date: 8/1/2012
Citation: Ren, Z., Na, L., Xu, Y., Rozati, M., Wang, J., Xu, J., Sun, C., Vidal, K., Wu, D., Meydani, S. 2012. Dietary supplementation with lacto-wolfberry enhances the immune response and reduces pathogenesis to influenza infection in mice. Journal of Nutrition. 142:1596-1602. Interpretive Summary: Although vaccines have been created for influenza, commonly known as the flu, these viruses remain a major public health problem and cause of illness and death worldwide. Yearly, influenza virus causes an estimated 3-5 million cases of serious illness and from 250,000 to 500,000 deaths. Since new strains emerge constantly, people have no immunity to the newer strains even if they have been vaccinated; thus, epidemics continue to occur. Since the immune system’s response to viruses is key, it is important to develop additional ways for the body to defend itself against influenza. Wolfberry or Goji berry, a sweet red berry that has been used as a medicinal food in China for a long time, has recently been shown to improve immune response in mice. We fed adult mice a milk-based preparation of wolfberry called lacto-wolfberry for several weeks and then infected them with influenza. The lacto-wolfberry diet was continued after infection. This supplementation prevented weight loss, improved disease change in lungs, and maintained appropriate immune response during infection. Nutritional intervention that involves optimizing the intake of essential nutrients and using promising functional foods has been proposed as an effective approach to boosting immune cell functions and fighting pathogen infection. This study used a useful model to determine whether the previously reported immune-enhancing effect of wolfberry would be meaningful during influenza infection. The positive findings in this study have provided preliminary evidence suggesting that wolfberry could be a promising component in our nutritional approach to protecting humans from influenza (flu) infection, which in turn could help suppress influenza epidemics worldwide.
Technical Abstract: Despite the availability of vaccines, influenza is a significant public health problem, emphasizing the need for development of additional strategies to enhance host defense against influenza. Wolfberry or Goji berry, long used as a medicinal food in China, has recently been shown to improve immune response in mice. Since immune response plays a key role in body’s defense against pathogens, we hypothesized that wolfberry may increase host resistance to influenza infection by enhancing immune response. To test this hypothesis, we fed adult mice (4 mo) a milk-based preparation of wolfberry called Lacto-Wolfberry (LWB) for 4 wk and then infected them with Influenza A/Puerto Rico/8/34 (H1N1) while continuing the same experimental diets. In a time course post infection (p.i.), viral titer, lung pathology, and immune response were determined. LWB supplementation prevented infection-induced weight loss and reduced lung pathology on days 6 and 9 p.i. (p is less than 0.05) and tended to lower lung viral titer on day 6 p.i (p equals 0.08). LWB fed mice showed significantly higher Con-A induced splenocyte proliferation and IL-2 production and lower levels of TNF-alpha and IL-6 in lungs on day 6 p.i. There were significant positive correlations between weight loss and lung viral titer, pathology score, TNF-alpha, and IL-6 production as well as negative correlations with T cell proliferation and IL-2 production. These results indicate that LWB supplementation can attenuate symptoms and pathology of influenza infection by decreasing inflammatory cytokines in lungs while enhancing systemic T cell-mediated function.