Ocimum Sanctum L (Holy Basil or Tulsi) and Its Phytochemicals in the Prevention and Treatment of Cancer

Abstract

Ocimum sanctum L. or Ocimum tenuiflorum L, commonly known as the Holy Basil in English or Tulsi in the various Indian languages, is a important medicinal plant in the various traditional and folk systems of medicine in Southeast Asia. Scientific studies have shown it to possess antiinflammatory, analgesic, antipyretic, antidiabetic, hepatoprotective, hypolipidemic, antistress, and immunomodulatory activities. Preclinical studies have also shown that Tulsi and some of its phytochemicals eugenol, rosmarinic acid, apigenin, myretenal, luteolin, β–sitosterol, and carnosic acid prevented chemical-induced skin, liver, oral, and lung cancers and to mediate these effects by increasing the antioxidant activity, altering the gene expressions, inducing apoptosis, and inhibiting angiogenesis and metastasis. The aqueous extract of Tulsi and its flavanoids, orintin, and vicenin are shown to protect mice against γ-radiation-induced sickness and mortality and to selectively protect the normal tissues against the tumoricidal effects of radiation. The other important phytochemicals like eugenol, rosmarinic acid, apigenin, and carnosic acid are also shown to prevent radiation-induced DNA damage. This review summarizes the results related to the chemopreventive and radioprotective properties of Tulsi and also emphasizes aspects that warrant future research to establish its activity and utility in cancer prevention and treatment.

ACKNOWLEDGMENTS

The authors dedicate this article to Professor P. Uma Devi for her seminal studies on the radioprotective effects of Tulsi. Manjeshwar Shrinath Baliga wishes to convey his sincere thanks to his teachers Prof. G. C. Jagetia, Prof. B. S. S. Rao, Prof. M. S. Vidyasagar and Prof. Koteshwar Rao, and former colleagues Dr. R. Aruna, Dr. Vrinda Nayak, Dr. Merryline Sathyamithra, Dr. Jagdish Ullor, Dr. Kalthur Guruprasad Kamath, Dr. G. K. Rajanikant, Dr. Ponemone Venkatesh, and Dr. Ravindra Kamath for their help and support during his student days in Department of Radiobiology, Kasturba Medical College, Manipal University, Manipal, India. The authors are grateful to Rev. Fr. Patrick Rodrigues (Director), Rev. Fr. Denis D’Sa (Administrator, Father Muller Medical College), and Dr. Jayaprakash Alva (Dean, Father Muller Medical College) for their unstinted support. Dr. Rajesh Arora is grateful to Dr. Selvamurthy for his support and encouragement. The authors are also grateful to the two unknown reviewers for their constructive comments and helping us improve the article.