Antioxidant and DNA damage protective properties of anthocyanin-rich extracts from <i>Hibiscus</i> and <i>Ocimum</i>: a comparative study

<div><p>Anthocyanin extracts (AEs) from <i>Ocimum tenuiflorum</i> (leaf), <i>Hibiscus rosa-sinensis</i> (petal) and <i>Hibiscus sabdariffa</i> (calyx) were investigated and compared for <i>in vitro</i> antioxidant activity and DNA damage protective property. Total phenolic content (TPC) and total anthocyanin content (TAC) of the AEs were determined and the major anthocyanins were characterised. <i>In vitro</i> antioxidant activities were assessed by ferric-reducing antioxidant power (FRAP) assay, 2,2-diphenyl-1-picryl hydrazyl (DPPH) radical-scavenging activity, 2-deoxy-d-ribose degradation assay and lipid peroxidation assay. The protective property of the AEs was also examined against oxidative DNA damage by H<sub>2</sub>O<sub>2</sub> and UV using pUC19 plasmid. All the AEs particularly those from <i>O. tenuiflorum</i> demonstrated efficient antioxidant activity and protected DNA from damage. Strong correlation between antioxidant capacity and TPC and TAC was observed. Significant correlation between antioxidant capacity and TPC and TAC ascertained that phenolics and anthocyanins were the major contributors of antioxidant activity.</p></div>