Hydroxymethyl Furfural in Chinese Herbal Medicines: Its Formation, Presence, Metabolism, Bioactivities and Implications

Background: Chinese herbal medicines (CHMs) must be processed before being prescribed to patients. During the processing, some CHMs became brown and as such 5-hydroxymethyl furfural (HMF) generated. Increasing attention is being paid to the safety and effectiveness of HMF. Methods: This paper summarized previous and recent reports on HMF formation, its presence in CHMs, its metabolism and bioactivities, together with its implications for CHMs. Results: HMF had been detected in 41 CHMs, and increased by about 12~1200 times after heat processing in some CHMs. Current data showed that HMF has limited genotoxicity but various bioactivities, such as anti-oxidative, anti-apoptotic, anti-inflammatory, anti-hypoxic, anti-microbial, and inhibiting sickling of red blood cells. Conclusion: Accumulation of HMF during heat processing of CHMs indicates that Maillard reaction and caramelization occurred. The other products of the two browning reactions deserve more attention in the following investigations on heat processed CHM.