Anti-inflammatory and antioxidant activities of extracts of Reissantia indica, Cissus cornifolia and Grosseria vignei

Abstract

Unpleasant side effects associated with prolonged use of current anti-inflammatory drugs have necessitated a need for new drugs with limited side effects. Plants rich in antioxidants have been suggested as potential sources of anti-inflammatory compounds. Thus, the anti-inflammatory and antioxidant activities of extracts of Reissantia indica, Grosseria vignei and Cissus cornifolia—medicinal plants with widespread use in folkloric medicine in Ghana—were evaluated in this study. The phytochemical composition and total phenolic content (TPC) of these extracts were determined using standard methods. Antioxidant potential was screened using the ferric reducing antioxidant activity, nitric oxide and hydrogen peroxide scavenging, and the phosphomolybdenum assays. The anti-inflammatory activities were evaluated using an in vivo assay. Alkaloids, flavonoids, terpenoids, glycosides and coumarins were present in extracts of all three plants. The TPC of Reissantia indica (38.44 µg/g GAE) was twice that of Grosseria vignei (19.12 µg/g GAE) whereas Cissus cornifolia (7.59 µg/g GAE) had the lowest TPC. In all antioxidant tests, activities of the plant extracts varied in the order; Reissantia indica > Grosseria vignei > Cissus cornifolia, which was in agreement with the TPC data. All extracts exhibited potent anti-inflammatory activities, with the dose of extract required to cause half-maximal reduction in edema (ED₅₀) below 80 mg/kg. Reissantia indica was the most potent anti-inflammatory extract with an ED₅₀ of 47.23 mg/kg. The ethanol extracts of Reissantia indica, Grosseria vignei, and Cissus cornifolia thus exhibited potent anti-inflammatory and antioxidant activities and may be important sources of novel antioxidant and anti-inflammatory agents.