Antiviral activity of baicalin against influenza A (H1N1/H3N2) virus in cell culture and in mice and its inhibition of neuraminidase

Abstract

Scutellaria baicalensis Georgi, a Chinese herbal decoction, has been used for the treatment of the common cold, fever and influenza virus infections. In previous studies, we found that oral administration of baicalein resulted in the inhibition of influenza A virus replication in vivo, which was linked to baicalin in serum. However, the effective dose and underlying mechanisms of the efficacy of baicalin against influenza A virus have not been fully elucidated. In this study, the antiviral effects of baicalin in influenza-virus-infected MDCK cells and mice were examined. The neuraminidase inhibition assay was performed to investigate the mechanism of action of baicalin. In vitro results showed that baicalin exhibited a half-maximal effective concentration (EC50) of 43.3 μg/ml against the influenza A/FM1/1/47 (H1N1) virus and 104.9 μg/ml against the influenza A/Beijing/32/92 (H3N2) virus. When added to MDCK cell cultures after inoculation with influenza virus, baicalin demonstrated obvious antiviral activity that increased in a dose-dependent manner, indicating that baicalin affected virus budding. Baicalin had clear inhibitory effects against neuraminidases, with half-maximal inhibitory concentration (IC50) of 52.3 μg/ml against the influenza A/FM1/1/47 (H1N1) virus and 85.8 μg/ml against the influenza A/Beijing/32/92 (H3N2) virus. In vivo studies showed that an intravenous injection of baicalin effectively reduced the death rate, prolonged the mean day to death (MDD) and improved the lung parameters of mice infected with influenza A virus. These results demonstrate that baicalin acts as a neuraminidase inhibitor, with clear inhibitory activities that are effective against different strains of influenza A virus in both cell culture and a mouse model, and that baicalin has potential utility in the management of influenza virus infections.

In vitro Broad Antiviral Function against HBV, HSV, H3N2 Replication by Baicalin and Oroxylin A-7-O-Β-D-Glucoside

“…Baicalin was previously reported to have anti-viral activity [29,30]. In our study, we evaluated the anti-viral activity of baicalin against IAV H3N2 by measuring the virus CPE.…”

Antibacterial, anti-inflammatory, and antioxidant effects of Yinzhihuang injection

“…Domestic ducks four days old were supplied by Southwest University Laboratory Animal Center (Chongqing, China). Animals were allowed free access to their standard diet and sterile water in a restricted access room with controlled temperature (22)(23)(24)(25)(26) o C), humidity (50-60%), and a 12-hour light/dark cycle in the Laboratory Animal Center of Southwest University (Rongchang, Chongqing, China). The experimental protocol was in accordance with the Guidelines for Animal Experiments of Southwest University and approved by the Institutional Authority for Laboratory Animal Care.…”

“…It is generally used to treat oxidative stress, H 2 O 2 -induced cytotoxicity, and collagen-induced arthritis [21][22][23][24]. Contemporary research has shown that baicalin has a positive effect on antibiosis functions [25][26][27].…”

Protective Effects of Baicalin on Experimental Myocardial Infarction in Rats

“…It is the main active component of Radix Scutellariae [4] . Baicalin has a wide range of pharmacological effects, which are mainly presented in the antioxidant, free radical scavenging, anti-inflammatory, anti-tumor, blocking calcium channel, inhibiting aldose reductase, antiviral and anti-allergic aspects [5-8] . In addition, baicalin has protective effects on the immune, cardiovascular, digestive and nervous system [9-11] .…”