Evaluation of phytochemical, antioxidant and antimicrobial activities of <i style="mso-bidi-font-style: normal">Memecylon</i> L. species from Western Ghats

Abstract

The genus <i style="mso-bidi-font-style:normal">Memecylon</i> L. is a least explored group of plants and the present study reports the preliminary phytochemical and pharmacological evaluation of 32 <i style="mso-bidi-font-style: normal">Memecylon </i>species collected from the Western Ghats. Among these 4 are rare and endangered and 16 endemic. The methanolic extracts of the leaves were evaluated for their phenolic and flavonoid contents, <i style="mso-bidi-font-style:normal">in vitro</i> antioxidant and antimicrobial activities. Phenolic contents of the methanol extracts of leaves were comparatively low in the species, ranging from 89.86 mg/g(<i style="mso-bidi-font-style:normal">M. gracile</i> Bedd.) to 05.04 mg/g(<i style="mso-bidi-font-style:normal">M. depressum</i> Benth.). Flavonoid compounds were highest in <i style="mso-bidi-font-style: normal">M. grande</i> Retz. (39.56 mg/g) and lowest in<i style="mso-bidi-font-style: normal"> M. talboltianum</i> Brandis (07.60 mg/g)<i style="mso-bidi-font-style: normal">.</i> The <i style="mso-bidi-font-style:normal">in vitro</i> free radical scavenging assay was done using DPPH method and the results showed moderate activities to the leaf extracts. The highest antioxidant activity was observed for <i style="mso-bidi-font-style:normal">M. heyneanum</i> Benth. (IC₅₀=15.30 µg/mL). Antibacterial activity against three Gram- positive and six Gram- negative bacteria was tested by disc diffusion method and the leaf extracts showed remarkable broad spectrum antibacterial activity, especially for <i style="mso-bidi-font-style:normal">M. deccanense</i> Clarke<i style="mso-bidi-font-style: normal">, M. terminale</i> Dalzell<i style="mso-bidi-font-style:normal">, M. heyneanum</i> Benth.<i style="mso-bidi-font-style:normal">, M. <span style="mso-bidi-font-style:italic">clarkeanum</span></i> Cogn. and <i style="mso-bidi-font-style:normal">M. sessile</i> Benth.