Investigation of in vitro Anti-inflammatory and Anti-oxidant Effects of Selected Natural Starches in Sri Lanka .

Abstract

Background: Starch is a naturally occurring polysaccharide derived from different sources such as rice, potatoes, and corn, and is widely used as an excipient in the pharmaceutical industry. Several research have been conducted with different natural starches as tablet excipients.

Objective: To determine the anti-inflammatory and anti-oxidant potency of alkali and methanolic extract of selected starch varieties in Sri Lanka compared to maize starch BP

Methods: Two traditional rice varieties (Oryza sativa L), Pachchaperumal and Sudu heenati (in Sinhala) and Sri Lankan Potato (Solanum tuberosum L) were selected. Starch extracts were prepared by immersing them in aqueous sodium hydroxide (0.2%) and methanol (80%) solutions for 24 hours, followed by milling, filtration (150 µm sieve size), decantation, centrifugation (6000 rpm) and drying to 50ºC. In vitro anti-inflammatory potency of these extractions was assessed by the egg albumin denaturation assay using diclofenac sodium as positive control. In vitro anti oxidant activity was assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay using ascorbic acid as the positive control.

Results: Alkali and methanolic starch extractions exhibited significant egg albumin denaturation potency with IC50 values of 11.62 mg/mL and 26.03 mg/mL for Pachchaperumal (p=0.01 and p=0.02), 35.48 and 93.75 mg/mL for Sudu heenati (p=0.04 and p=0.01), 95.58 mg/mL and 18.62 mg/mL for S. tuberosum (p=0.04 and p=0.01), respectively compared to the commercially available maize starch BP. IC50 values of diclofenac sodium was 0.907 mg/mL. Alkali and methanolic extracts demonstrated significant anti-oxidant potency with IC50 values of 9.07 mg/mL and 7.83 mg/mL for Pachchaperumal (p=0.02 and p=0.04), 8.63 mg/mL and 5.17 mg/mL for Sudu heenati (p=0.02 and p=0.02), 16.54 and 7.94 mg/mL for S. tuberosum (p=0.03 and p=0.03), respectively compared to commercially available maize starch BP and IC50 values obtained for ascorbic was 0.133 mg/mL.

Conclusion: The alkali and methanolic starch extractions of Sudu heenati and Pachchaperumal and S. tuberosum L have anti-inflammatory and anti-oxidant potency compared with maize starch BP.