Inhibitory effects and related molecular mechanisms of total flavonoids in Mosla chinensis Maxim against H1N1 influenza virus

OBJECTIVE

The Shixiangru (Mosla chinensis Maxim) total flavonoids (STF) mainly contain luteolin and apigenin. The study aims to examine the inhibitory effects of STF on anti-H1N1 influenza virus and its related molecular mechanisms in pneumonia mice.

METHODS

The viral pneumonia mice were treated with Ribavirin or various doses of STF. We observed histological changes of lung by immunohistochemistry and measured lung index to value anti-influenza virus effects of STF. The concentrations of inflammatory cytokines and anti-oxidant factors were detected by ELISA. RT-PCR and western blot assays were used to determine the expression level of TLR pathway's key genes and proteins in lung tissues.

RESULTS

We found that the pathological changes of lung in the viral pneumonia mice obviously alleviated by STF treatments and the STF (288 or 576 mg/kg) could significantly decrease lung indices. Moreover, the up-regulation (IL-6, TNF-α, IFN-γ, and NO) and down-regulation (IL-2, SOD and GSH) of inflammatory cytokines and anti-oxidant factors were associated with higher clearance of virus and reduction of inflammatory lung tissue damage. Meanwhile, the expression levels of TLR3, TLR7, MyD88, TRAF3 and NF-κB p65 of the TLR pathway were reduced by STF treatment.

CONCLUSIONS

This study suggested that STF may be a promising candidate for treating H1N1 influenza and subsequent viral pneumonia.

Anti-H1N1 influenza effects and its possible mechanism of Huanglian Xiangru Decoction

ETHNOPHARMACOLOGICAL RELEVANCE

Huangliang Xiangru Decoction (HXD), which is described in a famous TCM monograph "Book of Nanyang for Life Savin", is frequently used for treating cold in summer and summer heat-dampness.

AIM OF THE STUDY

To date, no pharmacological study on the anti-H1N1 influenza properties of HXD has been reported. The aim of the present study was to evaluate the therapeutic action of HXD on HIN1-induced acute pulmonary inflammation and its anti-influenza mechanism focus to TLRs signal pathway in a mouse model.

MATERIALS AND METHODS

the mice were intranasally infected with influenza virus to induce viral pneumonia, and then treated with different doses of HXD. The Lung index and pathological changes in the lung tissue of mice were investigated to value the anti-influenza virus effect of HXD. The concentrations of cytokines (IL-2, IL-6, TNF-α and IFN-γ) and anti-oxidant factor (NO, SOD and GSH) in serum of mice were determined with ELISA. RT-PCR and Western blot were used to determine the mRNA and protein expression of TLR3, TLR7, MyD88,TRAF3 and NF-κB p65 in the lung tissues, which are the key targets of TLRs pathway.

RESULTS

Compared with the infection group, the lung index of mice in ribavirin group, HXD high dose group and HXD middle dose group were significantly decreased, the lung indexes of these groups were 10.36±1.14mg/g, 9.89±0.79mg/g, and 10.97±0.67mg/g. Moreover, pathological changes were remarkable alleviated. HXD can reduce the contents of IL-6, TNF-α and IFN-γ, NO, and increase the contents of IL-2, SOD, GSH in serum of infected-mice significantly. At the same time, HXD can reduce the mRNA and protein expression of TLR3, TLR7, MyD88,TRAF3 and NF-κB p65 in the lung tissues of infected-mice significantly.

CONCLUSIONS

HXD has significant effects on H1N1 influenza by a quantity-effect relationship, and plays its anti-influenza effect by enhancing the body's antioxidant capacity, regulating the body's immune function and the host's TLRs pathway.