A scoping review of Ayurvedic rasayana adaptogens in oncology

INTRODUCTION: Rasayanas are Ayurvedic natural products that have adaptogenic effects. The extensive research on rasayanas in oncology is not currently well summarized. The aim of this review is to investigate the range and nature of the current body of research, identify gaps in knowledge, and to summarize the existing literature as it relates to Ayurvedic rasayanas and oncology. MATERIALS AND METHODS: A comprehensive literature search of fifteen Ayurvedic adaptogen rasayanas was conducted using three main concepts: Ayurvedic herbal terms, neoplasm terms, and oncological pathways. After screening was performed, key variables were extracted (tagged) including type of adaptogen, cancer type, type of study design, constituent type, and mechanisms of action (MOA). The results were synthesized and summarized using descriptive statistics and narrative summaries. RESULTS: Five hundred and eighty-four articles were reviewed and tagged. The two most tagged adaptogens were Glycyrrhiza glabra (Yashthimadhu/licorice) (n = 166 (28.4 %)) and Withania somnifera (Ashwagandha) (n = 151 (25.9 %)). The most frequently tagged cancer diagnostic categories were gastrointestinal (n = 175 (30 %)), and breast (n = 126 (21 %)). Most of the articles focused on in vitro studies (n = 470 (80.3 %)). Of the 12 MOA tags, the most frequently tagged was apoptosis (n = 298 (29.2 %)). CONCLUSION: A large body of pre-clinical literature exists on adaptogen rasayanas in oncology, indicating this field of research is still in its early phase. Comparatively few studies focused on the effects on the immune system. Given the growing interest in immuno-oncology therapeutics and the potential impact of adaptogen rasayanas on the immune system, future research may focus more in this area, along with work that is more directly linked to future clinical studies.