Crude Extracts of Codiaeum Variegatum Stem Exhibit Potent Antioxidant and Anti-inflammatory Activities in Vitro

Abstract

Background and objectives: Codiaeum variegatum ( C. variegatum ), which is commonly known as garden croton, is a medicinal plant used for the treatment of amoebiasis in Cameroon and some Asian countries. The present study aims to evaluate the antioxidant and anti-inflammatory activities of the stem crude extracts of C. variegatum . Methods: Aqueous, hydroethanolic 70/30 (v/v) and ethanolic extracts were tested for antioxidant activity using DPPH radical scavenging, ferric iron-reducing antioxidant power (FRAP), and lipid peroxidation inhibitory assays. The anti-inflammatory activity was determined based on the inhibition of nitric oxide production on isolated mouse macrophages activated by Saccharomyces cerevisiae. Furthermore, the inhibitory effect of these extracts on 5-lipoxygenase activity and bovine serum albumin (BSA) denaturation was determined, and the activation of two lysosomal enzymes involved in phagocytosis was performed. The phytochemical screening of the plant extracts was performed using standard methods. Results: The results revealed that the ethanolic extract (EE) exhibited the highest antioxidant activity, in terms of DPPH-free radical scavenging activity, FRAP, and its potential to inhibit lipid peroxidation (IC 50 = 77.04 µg extract/mol of DPPH; EC 50 = 543.6 µg/mL and IC 50 = 21.52 µg/mL, respectively). However, this activity remained significantly lower than that of ascorbic acid ( p < 0,05). Furthermore, the hydroethanolic extract (HE) had the highest anti-inflammatory activity on isolated mouse macrophages, in terms of inhibitory activity on NO production, BSA denaturation, and 5-lipoxygenase activity (IC 50 = 8.80 µg/mL, IC 50 = 205.9 µg/mL, IC 50 = 0.08 µg/mL, respectively). However, there was no significant difference in the inhibitory activity of baicalin. Moreover, the activity of acid phosphatase and alkaline phosphatase increased in the presence of the HE (EC 50 = 10.03 µg/mL and EC 50 = 0.274 µg/mL, respectively). The phytochemical analysis of these extracts indicates the presence of phenolic compounds, and these may be responsible for the observed activities. Conclusions: Overall, these results demonstrate that the hydroethanolic and ethanolic stem extracts of C. variegatum have good antioxidant and anti-inflammatory potential.