Antioxidant potential and radical scavenging effects of various extracts from Abutilon indicum and Abutilon muticum

Abstract

Abutilon indicum L. (Malvaceae) and Abutilon muticum DC. (Malvaceae) are traditional medicinal herbs used for analgesic, anthelmintic, hepatoprotective, and hypoglycemic properties. These effects may be correlated with the presence of antioxidant compounds. Extracts in organic solvents from the aerial parts and roots of both species were prepared and evaluated for their total antioxidant capacity (TAC), total phenolic content, and total flavonoid content. The Trolox equivalent antioxidant capacity (TEAC) of all the extracts of both plants was found, employing ABTS and FRAP assays. TEAC values ranged from 3.019 to 10.5 μM for n-hexane and butanol fractions of Abutilon indicum and from 2.247 to 14.208 μM for n-hexane and butanol fractions of Abutilon muticum, respectively, using the ABTS assay. The FRAP assay showed reducing powers of the fractions in the order of butanol > ethyl acetate > chloroform > n-hexane and butanol > chloroform > hexane > ethyl acetate for Abutilon indicum and Abutilon muticum, respectively. EC₅₀ and T_EC50 values for the extracts of both plants were determined using the DPPH free radical assay. The reaction kinetics with this free radical indicated the presence of both slow reacting and fast reacting antioxidant components in the extracts of both plants. The antioxidant/radical scavenging capacity of the extracts was found to be a dose-dependent activity. The results obtained in the present study indicate that both Abutilon species are potential sources of natural antioxidants.

Keywords::

• ABTS·⁺
• Abutilon indicum
• Abutilon muticum
• antioxidant activity
• peroxidation inhibition
• polyphenol
• scavenging effects

Acknowledgements

The authors would like to thank Plant Taxonomist, Dr. Zaheer-ud-Din Khan (Department of Botany, GC University, Lahore, Pakistan) for the collection of plant material, and to Dr. Islam-Ullah Khan (Material Chemistry Laboratory, Department of Chemistry, GC University, Lahore, Pakistan) for research facilities.

Declaration of interest

The authors are grateful to the Higher Education Commission of Pakistan for research grant No. 042-121289-PS2-212. No additional support of funding has been received by the authors to carry out this study. This work is a part Ph.D (scholarship based).