9. Conclusions and future prospects
The Naga chilli is being cultivated in the northeastern region of India since time immemorial and the indigenous people have been using it in treating various maladies. As established from the literature reviewed in this paper, Naga chilli holds immense ethnopharmacological potential, apart from being a vegetable and a spice crop. Very high capsaicin output per unit weight of dry powder renders it possible to lower down the cost of extraction of capsaicin from chilli, thereby giving it an upper hand in the national as well as international markets. Since the hotness of chilli is affected by several factors including agro-climatic conditions, particular emphasis is warranted to find out the optimum conditions to achieve the maximum pungency level of this particular variety.
While the scientific literature on the role of capsaicinoids in pain therapy and its potential as an antioxidant molecule and antimicrobial agent clearly supports the traditional application of Naga chilli in treating various ailments. However, systematic and more extensive ethnomedicinal investigations are yet to be carried out to provide new insights into the other traditional uses of this important plant. In-depth research endeavours should also be directed towards phytochemical and pharmacological investigations of Naga chilli that could lead to unearthing new bioactive compounds/activities. The impact of capsaicinoids on body temperature regulation has been established experimentally. Further research efforts should be directed towards understanding the underlying mechanisms. Capsaicin has been shown also to have potential application in anti-obesity treatments. Various experiments on the effect of capsaicinoids on obesity have provided differential response and hence, more comprehensive studies are required to understand the exact mechanisms behind it. The chemopreventive and chemotherapeutic effects of capsaicin have also been reported. Nevertheless, the researchers are still divided in their opinion regarding the role of capsaicin in carcinogenic processes, which also requires further exploration. Although capsaicin is used as part of the human diet without causing any known adverse health effects, the recent toxicological studies have revealed a large number of physiological and pharmacological effects on the biological system and hence a safe exposure level of capsaicin for human consumption needs to be established.
Acknowledgements
We are grateful to anonymous reviewers for their constructive comments and thoughtful suggestions on the manuscript. Our gratitude also goes to Dr. Guruprasad Kalthur (KMC, Manipal) and to Dr. Reji Gopalakrishnan (DRL, Tezpur) for their kind, invaluable suggestions and copyediting of the manuscript. We apologize to all our colleagues whose studies could not be cited due to space limitation.