In addition, current influenza computer virus vaccination confers good protection against homologous or closely related strains. saponins (also known as ginsenoids), acid polysaccharides, and phenol and polyethylene compounds.3,4 Various beneficial pharmacological effects of ginseng or its components have been reported, including anticancer, anti-allergy, anti-inflammatory, antifatigue, antistress, and immunomodulatory activities.5C16 In clinical studies, ginseng has been shown to have beneficial effects on improving the survival and the quality of life among breast cancer patients,17 in a placebo-controlled pilot trial of cancer patients,18 in patients infected with human immunodeficiency computer virus,19,20 and on reducing the occurrence of gastric cancer.21 Immunomodulatory effects are among the beneficial properties attributed to ginseng extract. The nature of these activities and their underlying mechanisms remain largely unknown and were reported to be diverse depending on types of diseases and/or biological assessment methods: some studies demonstrated anti-inflammatory activities, while others reported pro-inflammatory effects.22C26 Previous clinical studies demonstrated the beneficial effects of ginseng intake. A group of older adults who AM-1638 received daily oral administration of ginseng and influenza computer virus vaccination showed fewer cases of laboratory-confirmed influenza-like illness compared AM-1638 with the vaccination-only group.27 Also, individuals 18C65 years of age with a history of cold symptoms in the previous 12 months had reduced the mean number of colds by taking ginseng extract two times a day.28 When taken preventatively for durations of 8C16 weeks, North American ginseng preparations were demonstrated to be effective in shortening the duration of colds or acute respiratory infections in healthy adults.29 However, biological effects of ginseng on infectious disease are not well understood, and therefore further studies are important for better understanding the potential effects of ginseng. In this study, we investigated the effects of Korean red ginseng intake on contamination with the 2009 2009 pandemic H1N1 influenza computer virus in naive and vaccinated mice through the oral route. Ginseng extract intake prior to infection conferred enhanced survival rates in naive mice and improved the cross-protective efficacy against H1N1 and H3N2 viruses in vaccinated mice. In addition, ginseng extract was found to have antiviral effects on influenza computer virus. Possible mechanisms have been investigated and discussed regarding the potential beneficial effects of ginseng on influenza computer virus contamination. Materials and Methods Cells, computer virus, and reagents The 2009 2009 pandemic swine-origin influenza A H1N1 computer virus (A/California/04/2009) was kindly provided by Dr. Richard Webby (St. Jude Children’s Research Hospital, Memphis, TN, USA). The mouse-adapted influenza A virusesH1N1 subtype A/PR/8/34 computer virus and H3N2 subtype A/Philippines/82 viruswere gifts from Dr. Huan Nguyen (University of Alabama at Birmingham, Birmingham, AL, USA). Influenza viruses were produced in 11-day-old embryonated hens’ eggs and harvested as described.30 Egg allantoic fluids were harvested and stored at ?80C AM-1638 until use. MadinCDarby canine kidney (MDCK) cells purchased from the American Type PGR Culture Collection (Manassas, VA, USA) were maintained in Dulbecco’s altered Eagle’s medium and used to determine computer virus titers from egg allantoic fluids and mouse lung homogenates by a plaque assay.31 Mice were infected with serial dilutions of influenza computer virus, and the 50% lethal dose (LD50) was determined. A/PR/8/34 computer virus produced in egg allantoic fluids was purified using sucrose-gradient ultracentrifugation and inactivated using formalin (0.1%) as described.30 Korean red ginseng extract (ginseng extract), a concentrated form of the commercial ginseng product for human use, was kindly provided by Korea Ginseng Corp. (Daejeon, Korea). In brief, fresh roots of that had produced for 6 years were washed, steamed at 100C for 2C3?h, and dried. The dried red ginseng roots were boiled in 4C5 volumes of water for 3?h, and the supernatants were concentrated. This preparation was designated ginseng extract (approximately 36% water content). Treatment of mice with ginseng extract and influenza computer virus infection Ginseng extract was dissolved in sterile phosphate-buffered saline (PBS; pH 7.4), and filtered through a Millipore (Bedford, MA, USA) membrane (pore size, 0.4?m). For animal experiments, AM-1638 8C10-week-old BALB/c mice (Harlan Laboratories, Indianapolis, IN, USA) were lightly anesthetized by isoflurane inhalation, and then ginseng extract was orally administered in a dose ranging from 10 to 100?mg/kg of weight. Oral administration was carried out using a 0.9?mm39?mm stainless steel feeding needle with a silicone tip to avoid damage to the esophagus and trachea. To determine the effects of ginseng extract treatment on influenza computer virus contamination, mice (contamination with mixtures of ginseng extract and computer virus Different concentrations of ginseng extract (0.5?mg or 2?mg in 25?L of PBS) or a PBS buffer control (25?L).