Therapeutic Implications of Capsaicin in Diabetes

Capsaicin, chemically known as trans-8-methyl-N-vanillyl-6-noneamide, is a primary active principle found in members of chili peppers (Capsicum annum and Capsicum frutescens). First isolated in the nineteenth century, it is known to belong to the capsaicinoid alkaloid family, and carries a vanilloid moiety, which plays a role in its bioactivity. Through extensive research over the years, capsaicin has shown evidence of multiple biological effects, leading to it being considered a "miracle molecule" for decades and even centuries. This is mainly due to its therapeutic potential in ailments ranging from pain and obesity to urinary complications and even cancer. From the multitude of studies that have been performed to evaluate the effectiveness of capsaicin and its analogs in various medical conditions, compelling evidence for their anti-inflammatory, analgesic, anti-pruritic, antioxidant, anti-cancer, anti-apoptotic, and neuroprotective functions have been accumulated. Among these myriads of potential applications, the efficacy of capsaicin in tackling diabetes has been extensively studied, and the results have brought forth encouraging hints about its therapeutic role in the same. While the exact mechanisms remain largely unknown, it has been established that this molecule can lower blood glucose by processes inducing high levels of insulin, glycogen in diabetic rats induced by streptozotocin. Moreover, one report says that dietary intake of capsaicin rich foods has a favorable impact on glycemic control in obese (ob/ob) diabetic mice, despite causing any significant change in the incidence of an increase in body weight. More recently, capsiate, a non-pungent analog of capsaicin, has shown potential as an insulin sensitizer, sparking interest in its activity. These studies, along with numerous others, have warranted further research to explore the efficacy of capsaicinoids in metabolic syndromes such as diabetes mellitus, and this article aims to review and discuss the varied therapeutic avenues for capsaicin and its analogs in diabetes, and for evaluating its effectiveness in the same.