Antioxidant and anti-inflammatory activities of selected endemic plants of Sri Lanka

Abstract

Plants have been a source of natural healing compounds since ancient times. Plant extracts are frequently used as complementary treatment for many chronic diseases, due to their demonstrated beneficial properties such as antioxidant, anti-inflammatory and anticancer activities. The present study was designed to assess the total phenolic content (TPC), in vitro free radical scavenging activity and anti-inflammatory activity of three endemic plants in Sri Lanka: Lasia spinosa, Polyscias balfouriana, and Elaeocarpus serratus. The cleaned, dried, and finely powdered leaves of P. balfouriana and E. serratus, and rhizome of L. spinosa were subjected to extraction with Ethanol. The Antioxidant properties of total phenolic content (TPC) and free radical scavenging activity of plant extracts were assessed using the Folin-Ciocalteu and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, respectively. Anti-inflammatory activity of plant extracts was evaluated by Bovine Serum Albumin (BSA) degradation Assay. E. serratus extract showed the highest TPC value; 27.59±0.02 mg gallic acid equivalent (GAE) per g dry weight, followed by L. spinosa; 0.1±0.01 mg GAE g-1 dry weight. L. spinosa extract showed the highest DPPH radical scavenging activity of 89±2 % followed by E. serratus 87±2%. E. serratus and L. spinosa significantly inhibited the denaturation of BSA demonstrating anti-denaturation activity of 57±3% and 54.9±1%, respectively than the other tested extracts. All the analyzed plant extracts demonstrated the presence of polyphenols, along with antioxidant and anti-inflammatory activities. Oxidative stress and chronic inflammation have been reported to promote the development of cancer. Therefore, the tested plant extracts may have anticancer properties due to the observed antioxidant and anti-inflammatory activities. These activities are known to play important roles in countering cancer progression and inhibiting the growth of cancer cells. Therefore, further investigations are required to assess the anti-cancer potential of these plant extracts and isolate potential lead compounds with anti-inflammatory and anti-cancer properties.