茶多酚体内外抗流感病毒作用研究

研究了没食子儿茶素(Gallocatechin, GC)、表儿茶素(Epicatechin, EC)、表没食子儿茶素(Epigallocatechin, EGC)、表儿茶素没食子酸酯(Epicatechin gallate, ECG)、表没食子儿茶素没食子酸酯(Epigallocatechin gallate, EGCG)、原儿茶醛(Protocatechuic aldehyde, PAD)、原儿茶酸(Protocatechuic acid, PA)共7种茶多酚类物质在MDCK细胞中的抑制流感病毒活性。结果表明,EGCG和ECG具有显著的抑制病毒作用,对感染H₅N₁、H₁N₁和H₉N₂ 3种亚型流感病毒的MDCK细胞50%保护率浓度(EC₅₀)分别在0.04~0.11 mmol/L和0.05~0.07 mmol/L范围,其保护效果均优于阳性对照药利巴韦林（EC₅₀：0.41~0.53 mmol/L）。7种茶多酚类物质对流感病毒神经氨酸酶（NA）均有不同程度的抑制作用,EGCG和ECG对H₅N₁、H₁N₁和H₉N₂ 3种亚型流感病毒NA活性抑制浓度（IC₅₀）分别在0.03~0.14 mmol/L和0.34~0.69 mmol/L范围。茶多酚对NA的抑制活性大小与其细胞中对病毒的抑制作用基本一致,表明对NA的抑制可能是其抗流感病毒机制。本文还研究了茶多酚含量为85%的苦茶(C. assamica var. Kucha)提取物对感染流感病毒小鼠的肺炎抑制效果,结果显示,1 000 mg/(kg·d)苦茶提取物对感染H₉N₂亚型流感病毒BALB/c鼠肺炎有显著抑制作用(P﹤0.05),肺指数抑制率达37%。

Study on Anti-influenza Virus Effect of Tea Polyphenols in vitro and in vivo

Tea polyphenols gallocatechin(GC),epicatechin(EC),epigallocatechin(EGC),epicatechin gallate(ECG),epigallocatechin gallate(EGCG),protocatechuic aldehyde(PAD) and protocatechuic acid(PA) were evaluated for their ability to inhibit influenza virus in MDCK cells.Among these compounds,the EGCG and ECG showed a marked antiviral effect against influenza virus infections in MDCK cells and this effect was observed in all influenza virus subtypes tested,including H5N1,H1N1 and H9N2 virus.The 50% effective inhibitory concentrations(EC50) of EGCG and ECG for three virus subtypes were 0.04~0.11 mmol/L and 0.05~0.07 mmol/L,respectively,which were less than the EC50 value of ribavirin(0.41~0.53 mmol/L) in MDCK cells.All these tea polyphenols tested showed an inhibitory effect on the neuraminidases(NAs) from H5N1,H1N1 and H9N2 viruses.The 50% effective inhibitory concentrations(IC50) of EGCG and ECG for three NAs from virus subtypes were 0.03~0.14 mmol/L and 0.34~0.69 mmol/L,respectively.The inhibitory effect of EGCG and ECG on the NAs was similar to their antiviral effect in MDCK cells,which suggested their anti-influenza effect was due to their inhibition on the NAs.In addition,the inhibitory effect on mice infected by influenza virus of extracts from C.assamica var.Kucha containing 85% polyphenolics was evaluated.At the concentration of 1 000 mg/(kg·d),the extracts possessed potent inhibitory effect on BALB/c's pneumonia consolidation infected by influenza viruses.The inhibition of the extracts on lung index was 37%.