Review on scientific connotation of leech processed under high temperature

Abstract

Animal medicines mainly contain protein which was organic molecule with quaternary structure and had the property of thermal denaturation. When suffering from heat for a consistent time, the native conformation of protein would be destroyed. After denaturation the biological activity of protein will lose and some physicochemical and biochemical properties will be changed. Leech was a classical animal medicine in the views of traditional Chinese medicine (TCM) which had the functions of breaking stagnant and eliminating blood stasis. In the usage history, it was processed for a long time. No matter stir-frying leech with talc powder embodied in Chinese Pharmacopoeia or stir-baking with wine as a distinctive method in Beijing district, the process procedure was basically performed under high temperature. The purposes and intentions of process are mostly limited to technology conditions at specific historical period. In this article, based on existing processing procedure and its character of Leech, the changes of active components and pharmacological activities before and after processing under high temperature were summarized. The results demonstrate that the protein of leech would be denaturated; some active peptide such as hirudin were partly or totally destroyed; some toxic mineral elements, such as Pb, Hg, Cd, were decreased; at the same time, heating can promote some chemical components transforming into hypoxanthine which had the function of antihypertensive, antiasthmatic and antalgic. Consequently, after processed under high temperature, the purpose of decreasing toxicity and alleviating the strong property was achieved. Pharmacological changes of leech processed under high temperature were mainly manifested in the anticoagulant and antithrombotic activity, etc. Based on current processing research status about animal medicine leech, future research methods and directions on scientific connotation of leech processed under high temperature were put forward in this article.