Herb-induced Liver Injury-A Guide to Approach. Lessons from the Tinospora cordifolia (Giloy) Case Series Story.

Background: Tinospora cordifolia (TC) is being increasingly consumed in India for its health and suggested immune-enhancing benefits in preventing and countering COVID-19. We previously published our experience of hepatotoxicity with self-medication of TC in six individuals. Since herb-induced liver injury (HILI) has been described with Tinospora crispa (TCR) consumption, it was contested that our patients may have mistakenly self-medicated with TCR which is similar in appearance to TC. Methods: We collected the four plant samples and two commercial preparations that were consumed by our patients for further analysis. The six samples underwent high performance thin layer chromatography phytochemical analysis and DNA barcoding studies for the confirmation of the genus and species. The four plant part samples which included stems and leaves were also analysed by a botanist for the characteristic morphological and microscopic features. Results: Based on morphological, microscopic, phytochemical and DNA studies, the four plant part samples were identified as TC. The two commercial preparations could not be analysed on phytochemical analysis or DNA barcoding studies due to other ingredients that most likely interfered with the analysis. The herb consumed by our study subjects was confirmed to be Tinospora cordifolia. Conclusion: We have highlighted the key morphological and phytochemical differences between these two species. We propose an algorithmic approach to accurately identify the implicated herb in cases of HILI. Future studies on causality need to focus on the serological/histopathological identification of active herb/metabolites in human tissues.