儿茶素类化合物的抗结核活性研究进展

近年来，耐多药结核病(multidrug-resistant tuberculosis，MDR-TB)的出现及人类免疫缺陷病毒(human immunodeficiency virus，HIV)与结核分枝杆菌合并感染日益增多，使结核病的防治面临更加严峻的挑战，人们急需开发新型抗结核药物及天然低毒的辅助治疗药物。绿茶中的儿茶素类化合物具有多种生物活性，对多种疾病有一定的辅助疗效。多项研究显示，儿茶素类化合物也具有抗结核活性，其机制包括抑制二氢叶酸还原酶活性、影响分枝菌酸及细胞壁的合成、下调富含色氨酸天冬氨酸的膜蛋白(tryptophan-aspartate containing coat protein，TACO)基因表达以抑制结核分枝杆菌的胞内寄生，降低氧化应激水平，下调结核分枝杆菌85B蛋白和宿主肿瘤坏死因子α(tumor necrosis factor α，TNF-α)表达，从而改善炎症水平。有研究显示，喝绿茶可降低结核分枝杆菌感染风险，儿茶素类化合物可辅助治疗结核病并与抗结核药物有协同治疗作用，但目前对其作用机制的研究还不够深入，需进一步探讨。

Catechins show potent anti-tuberculosis activity

In recent years, the emergence of multidrug-resistant tuberculosis (MDR-TB) and the increase of co-infection of human immunodeficiency virus (HIV) and tuberculosis have led to more severe challenges in the prevention and treatment of tuberculosis. It is urgent to develop new anti-tuberculosis drugs and natural adjuvant therapy with low toxicity. The catechins in green tea have a variety of biological activities, and have shown a certain adjuvant therapeutic effect on many diseases. Studies have shown that catechins also have anti-tuberculosis activities, and the mechanisms include inhibition of dihydrofolate reductase, affecting mycolic acid and cell wall synthesis, down-regulation of tryptophan-aspartate containing coat protein (TACO) gene expression to inhibit the growth of intracellular Mycobacterium tuberculosis, reducing oxidative stress, down-regulation of Mycobacterium tuberculosis 85B and tumor necrosis factor α (TNF-α) levels to alleviate the inflammation. It is also proved that drinking green tea can reduce the susceptibility to tuberculosis, and catechins can be an adjuvant therapy of tuberculosis and have a synergistic effect with anti-tuberculosis drugs. However, the anti-tuberculosis mechanisms of catechins are unclear, and more trials are needed to confirm the anti-tuberculosis activity of catechins.