Capsaicin potently blocks Salmonella typhimurium invasion of Vero cells

Abstract

As at 2021, the center for disease control (CDC) reported that Salmonella causes 1.2 million illness in the United States each year, with a mortality rate approaching 500 deaths per annum. Infants, the elderly, and persons with compromised immunity are the population with higher risk of mortality from this infection. At present there is no commercially available, safe and efficacious vaccine for the control and management of Salmonella typhimurium (S. typhimurium). More so, S. typhimurium has been shown to develop resistance against most antibiotics used for treatment of the infection. Capsaicin, a bioactive compound from Capsicum chinense (C. chinenses) is undoubtedly one of the most widely used spice in the world. This heat producing compound is not only been used as food additive but have been demonstrated to possess unique properties that have pharmacological, physiological, and antimicrobial applications. In this work, the antimicrobial property of pure capsaicin or capsaicin extract against S. typhimurium is tested to determine the compounds effectiveness in S. typhimurium inhibition. Capsaicin extract showed potent inhibition of S. typhimurium growth at concentrations as low as 100 ng/ml, whereas pure capsaicin comparatively showed poorer inhibition of the bacteria. Furthermore, both capsaicin extract and pure capsaicin potently blocked S. typhimurium invasion of an animal cell line in vitro. Taken together, this work revealed that capsaicin might work synergistically with dihydrocapsaicin or the other capsaicinoids to inhibit S. typhimurium growth, whereas individually, capsaicin or dihydrocapsaicin could potently block the bacteria entry and invasion of Vero cells.