General overview of phytochemistry and pharmacological potential of rheum palmatum (chinese rhubarb)

Recent probe of medicinal plants incorporated in traditional systems for curing infection and sustaining holistic health, has exposed good sum of therapeutic efficiency against deleterious infections and chronic illnesses. Rheum palmatum (Chinese Rhubarb, family Polygonaceae) is a significant medicinal herb, which finds an extensive use in Unani (Traditional) system of medicine. It has been traditionally employed as antiseptic, liver stimulant, diuretic, diabetes, stomachic, purgative/cathartic, anticholesterolemic, antitumor, Alzheimer’s, Parkinson’s, tonic, antidiabetic, and wound healer. The most vital components from Rheum palmatum are the phenolics, flavonoids, terpenoids, saponins, and anthraquinone derivatives such as aloe-emodin, chrysophanol, physcion, rhein, emodin and its glucorhein, and glycoside. Rhubarb also contains tannins which include hydrolysable-tannins, containing glycosidic or ester bonds composed of glucose, gallic acid, and other monosaccharide’s and condensed tannins, resulting principally from the flavone derivatives leukocyanidin and catechin. In recent years, new components such asrevandchinone-1, revandchinone-2, revandchinone-3, revandchinone-4, sulfemodin8-O-b-Dglucoside, and 6-methyl-rhein and aloe-emodin have been reported from the same class. It also encompasses some macro and micro mineral elements such as Ca, K, Mn, Fe, Co, Zn, Na, Cu, and Li. Anthraquinone derivatives demonstrate evidence of anti-microbial, antifungal, anti-proliferative, anti-Parkinson’s, immune enhancing, anticancer, antiulcer, antioxidant, and antiviral activities. This review article covers published study on therapeutic uses of different constituents from rhubarb.