Capsaicin Inhibits Intracellular Growth by Inducing Autophagy.

Antibiotic treatment plays an essential role in preventing infection. However, incidences of global rise in antibiotic resistance create a major challenge to treat bacterial infection. In this context, there is an urgent need for newer approaches to reduce burden. This study largely focuses on the role of the herbal compound capsaicin (Caps) in inhibiting growth and evaluating the molecular mechanism behind bacterial clearance. Here, we show for the first time that Caps inhibits intracellular growth by inducing autophagy. Activation of autophagy by Caps is mediated through transcription factor TFEB, a master regulator of autophagosome biogenesis. Caps induced the nuclear localization of TFEB. Activation of TFEB further induces the gene transcription of autophagosomal genes. Our findings revealed that the inhibition of autophagy by silencing TFEB and Atg5 induces bacterial growth. Hence, Caps-induced autophagy is one of the key factors responsible for bacterial clearance. Moreover, Caps restricted the intracellular proliferation of -resistant strain. The efficacy of Caps in reducing growth was confirmed by an animal model. This study showed for the first time that infection can be inhibited by inducing autophagy. Overall observations suggest that Caps activates TFEB to induce autophagy and thereby combat infection.