January 10th, 2018
Naturally occurring polyphenols – History of drug development
Plants and microorganisms have traditionally provided compounds of clinical importance in the development of drugs and medications. For instance, Penicillium chrysogenum, a mould, provided insight into the development of antibiotics through its metabolite, penicillin, which inhibited bacterial growth (Haslam 298; Mukne, Vivek and Phadatare 13). In respect to plants, communities have used herbal preparations to cure illnesses with their use in areas such as Egypt, China and India dating back to the Neanderthal era (Saklani and Kutty 161). In the modern era, the discovery of medicinal properties of various plants has expanded the clinical applications of plant extracts. For instance, the cinchona bark contains quinine, a therapeutic agent in malaria, digitalis herbs are rich in Digitalin, a compound useful in treatment of heart conditions and Opium contains morphine, a potent analgesic (Saklan and Kutty 161; Mukne, et al. 13-14). Although early evaluation of plant polyphenols was restricted to leather and textile industries, the realization of health benefits in population consuming diets with high polyphenol content has elicited interest in their potential application in drug development (Quideau, Deffieux, Douat-Casassus and Pouysegu 587-590; Haslam 298-300), sometimes in development of candidate drugs to combat resistant bacteria strains (Mukne et al. 14).
Assays of various medicinal plants have revealed polyphenolic metabolites that may explain their therapeutic action. For instance, the root of Tree Paeony (Paeonia lactiflora) contains gallotannins, which could explain its beneficial effects in bloodstream disorders such as hypertension (Haslam 299). The leaves of Bearberry (Arctostaphylos uva-ursi) also contain gallotannins, arbutin, and esters of arbutin, which have favourable outcomes in kidney disorders and urinary tract ailments (Haslam 299). Other plant polyphenolic compounds such as proanthocyanidins, isoflavones and ellagitannins, found in plant parts such as roots, leaves, fruits, seeds (e.g. cereals) and flowers, have shown potential efficacy as antispasmodic, hormonal replacement therapy, antibiotic, anti-haemorrhagic and anti-inflammatory agents (Haslam 299; Albulescu and Popovici 545-547; Mukne, et al. 14). Go to part three here.