Pharmacognostic characteristics and antioxidant studies of Psydrax subcordata (DC.) Bridson

Abstract

• Psydrax subcordata is a small flowering tree or shrub that grows in central and western Africa belonging to the family Rubiaceae. • Pharmacognostic (organoleptic, macroscopic, microscopic and physico-chemical) parameters of P. subcordata leaves can serve as simple means to identification and also for the quality control of the plant material. • Antioxidants are endogenous or exogenous substances that interact with and neutralize free radicals • Numerous stomata of paracytic type occurred on both the upper and lower surfaces but more abundantly on the lower surface of the plant P. subcordata . • P. subcordata leaf microscopic features include shiny, circular and irregularly shaped calcium oxalate crystals, fibres, unicellular trichomes and starch granules. Psydrax is a genus of flowering plants in the family Rubiaceae with over 80 accepted plant species. Psydrax subcordata is a small tree or shrub that grows in Central and Western Africa countries where its roots, leaves and stem are used locally by traditional healers for medicinal purposes. These local uses include the treatment of malaria fever, inflammation, haemorrhoids, enteritis, stomach ulcer, epilepsy and cardiovascular ailments. This study was carried out to examine parameters for identification of the plant and investigate potential antioxidant activity. The macroscopic, microscopic and physico-chemical characteristics of the leaf were determined using standard procedures. Antioxidant activity was also investigated using five different antioxidant models namely; DPPH Radical scavenging activity, FRAP assay, Total antioxidant capacity (Phosphomolybdenum) assay, Hydrogen peroxide scavenging assay and Reducing power assay. The leaves of the plant are simple, broad and entire. Ovate in shape, shortly acuminate apex and subcordate at the leaf base. The dark green upper surface is hairy or pubescent while greyish-green lower surface is sparely pubescent. The leaf showed microscopic mono-cyclic calcium oxalate crystals, unicellular trichomes, xylem vessels and other diagnostic features. The in-vitro antioxidant assays conducted, suggested that the extract contains antioxidant compounds. The characteristic macroscopic, microscopic and physico-chemical parameters evaluated for the plant sample can be used in rapid identification, authentication and for the quality control of the plant material before they are used for treatment and manufacturing of herbal medicines. The results of the antioxidant study showed that the extract exhibited potent antioxidant activity.