Anti-inflammatory effects of rosmarinic acid-4-O-ß-D-glucoside in reducing acute lung injury in mice infected with influenza virus.

Rosmarinic acid-4-O-ß-D-glucoside (RAG) is a dicaffeoyl phenolic compound isolated from Sarcandra glabra (Thunb.) Nakai. Preliminary studies show that RAG has significant anti-inflammatory properties and can alleviate ear swelling in mice and the paw swelling in rats. Here, the anti-influenza effects of RAG were investigated in mice infected with A/FM/1/47 H1N1 virus. The survival rate and body weight were observed, the lung edema, virus copies, inflammatory cytokines (including IL-4, IL-5, TNF-α and IFN-γ) and oxidative damage indexes (including SOD, MDA, NO, and CAT) were measured. Moreover, immune cell recruitment in alveoli was measured with white blood cells and differential counts. Therapeutic RAG concentrations substantially improve the symptoms, mitigate body weight loss and alleviate lung edema induced by virus, thus improve survival protection effects. Furthermore, RAG was shown to regulate influenza virus-induced inflammatory cytokine expression, specifically by downregulating the Th1 cell cytokines IFN-γ, TNF-α and upregulating the Th2 cell cytokines IL-4, IL-5. Cell migration and infiltration were also diminished after RAG administration.

The roots of Ilex asprella extract lessens acute respiratory distress syndrome in mice induced by influenza virus.

ETHNOPHARMACOLOGICAL RELEVANCE: In traditional Chinese medicine, the root of Ilex asprella (Hook. & Arn.) Champ. ex Benth. (IA) has been widely used to treat influenza, lung abscess and other diseases in South China for many years. The present study is aimed at investigating the treatment effect of IA on acute respiratory distress syndrome (ARDS) induced by the H1N1 virus in mice. MATERIALS AND METHODS: After being inoculated with several viral doses of influenza A/FM/1/47 H1N1 virus, mice were given oral administration of IA extract (500 mg/kg or 12 5mg/kg per day) for five or 10 consecutive days, respectively. Mice survival rate and clinical condition were observed for 15 days after inoculation. Lung weight, pathological analysis and arterial blood gas analysis were assessed. Lung viral load was quantified by RT-PCR. Moreover, immunological analysis was measured by leukocyte counts and the levels of inflammatory cytokines, including IL-6, IL-10, TNF-α, IFN-γ, MCP-1 and IL-12p 70 in serum of mice. RESULTS: We found that the extract of Ilex asprella at dosages of 500 mg/kg could effectively diminish mortality rate, and ameliorate lung edema and inflammation. Administration of IA extract significantly depressed the expression of IL-6, TNF-α and MCP-1, and significantly increased the expression of IL-10 and IFN-γ in serum. Simultaneously, the extract was also found to reduce the lung viral load and improve pulmonary ventilation. CONCLUSION: The present study shows that the extract of IA has the potential to treat ARDS, due to its abilities of attenuation of systemic and pulmonary inflammatory responses and inhibition of viral replication.