Phytochemical analysis and hepatotoxicity assessment of braised Polygoni Multiflori Radix (Wen‐He‐Shou‐Wu)

Abstract Polygoni Multiflori Radix (PMR) is a medicinal herb commonly used in China and Eastern Asia. Recently, the discovery of hepatotoxicity in PMR has received considerable attention from scientists. Processing is a traditional Chinese medicine technique used for the effective reduction of toxicity. One uncommon technique is the braising method—also known as ‘Wen‐Fa’ in Chinese—which is used to prepare tonics or poisonous medications. Braised PMR (BPMR)—also known as ‘Wen‐He‐Shou‐Wu’—is one of the processed products of the braising method. However, the non‐volatile components of BPMR have not been identified and examined in detail, and therefore, the hepatotoxic advantage of BPMR remains unknown. In this study, we compared the microscopic characteristics of different samples in powder form using scanning electron microscopy (SEM), investigated the non‐volatile components, assessed the effects of different processed PMR products on the liver, and compared the differences between BPMR and PMR Praeparata recorded in the Chinese Pharmacopoeia (2020 edition). We found that the hepatotoxicity of BPMR was dramatically decreased, which may be related to an increase in polysaccharide content and a decrease in toxic substances. The present study provides an important foundation for future investigations of the processing mechanisms of BPMR.