Studies on the mechanism of action of the bioflavonoid Hesperidin methyl chalcone in causing vascular and intestinal smooth muscle to relax

This thesis constitutes a report on a series of studies undertaken on possible mechanisms of action of the bioflavonoid, hesperidin methyl chalcone (HMC), in causing smooth muscle to relax. The term bioflavonoid refers to several compounds that can be extracted from the mesocarp of citrus fruits. They have been the subject of investigation and controversy since 1936. Much of this is covered in a eview by Vogin (1). As mentioned in the review, Szenti-Gyorgyi observed first that crude citrus extracts were more efficient in relieving experimental scurvy than pure extract containing only Vitamin C. The subject of scurvy has been covered in many reviews, and no purpose would be served in describing all these factors at this time. However, since Szent-Gyorgi’s observation, there has been considerable study of the possibility that bioflavonoids are a factor in capillary integrity. Despite all the activity, the necessity of bioflavonoids as a dietary adjuvant has not been established. At this date, almost thirty years after the initial studies, the literature is replete with contradictory statements on almost every phase of bioflavonoid activity. The possibility that HMC might have a direct action on smooth muscle indicated that both in vivo and in vitro studies should be utilized. The in vivo studies consisted of observations on blood pressure and nictitating membranes of cats. The in vitro studies were performed on sections of rabbit ileum