Isolation and Characterization of Antioxidative and Anti inflammatory Small Molecular Bioactives from Bivalve Clams Villorita cyprinoides Gray and Paphia malabarica Chemnitz

Abstract

The bivalve clams are traditional seafoods occupying a leading share to the edible bivalve mollusks in the estuarine and marine ecosystems of India. Corbiculid clam Villorita cyprinoides (black clam) and venerid clam Paphia malabarica (yellow-foot clam) are recognized to be the common bivalve clam resources in the coastal areas of the southwest coast of India. The bivalve clams, though regarded as low-value by-catch, believed to possess valuable nutritional qualities and pharmacological properties. The bivalve clams, V. cyprinoides and P. malabarica collected from the estuarine system of the southwest coastal waters of India, and evaluated for their nutritional composition. A balanced essential to non-essential amino acid ratio (gt 1.0) with a greater quantity of sulfur containing amino acids in these species demonstrated that they could provide well-balanced protein depositions. P. malabarica displayed lesser atherogenicity (0.7) and thrombogenicity (0.3) indices and greater hypocholesterolemic to hypercholesterolemic ratio (1.7) when compared with those in V. cyprinoides, thereby indicating the nutritional superiority of former. A greater content of vitamin D3 (gt 150 IU), along with significant quantities of calcium and phosphorus (gt 500 mg/100 g) in clams signified their importance in preventing osteoporosis. The ethyl acetate:methanol (EtOAc:MeOH) solvent extract of V. cyprinoides and P. malabarica assessed for their bioactive potentials, namely antioxidant, anti-diabetic, antiinflammatory and anti-hypertension using various in vitro analyses. No significant difference was apparent for antioxidant potentials evaluated by 1,1-diphenyl-2-picryl-hydrazil (IC50 DPPH 0.76 mg/mL) among P. malabarica and V. cyprinoides (p gt 0.05). However, EtOAc:MeOH extract of P. malabarica demonstrated greater 2,2 -azino-bis-3-ethylbenzothiozoline-6-sulfonic acid (IC50 ABTS+ 1.27 mg/mL) radical scavenging activities along with lipid peroxidation inhibitory potentials (2.39 mM MDAEQ/kg) than those recorded with V. cyprinoides (p