EVALUATION OF ANTIOXIDANT ACTIVITY OF RESINS OF BOSWELLIA SERRATA ROXB. EX COLEBR., COMMIPHORA MUKUL (HOOKS EX STOCKS) ENGL., GARDENIA RESINIFERA ROTH. AND SHOREA ROBUSTA GAERTN.

Ujwala C. Bapat*, Smita H. Gaurea and Alka Bapat

ABSTRACT

Resins are amorphous mixtures of essential oils, oxygenated products of terpenes and carboxylic acids and are secreted as exudates from specialized structures in a wide range of plants. They probably function as plant defenses. Resins are insoluble in water but usually dissolve in alcohol, ether or carbon di sulphide and other solvents. The well known resins of Boswellia serrata Roxb. ex Colebr., Commiphora mukul (Hooks ex Stocks) Engl., Gardenia resinifera Roth. and Shorea robusta Gaertn. were selected to evaluate their antioxidant activity. The resins of these plants have been used traditionally for treatment of various diseases like rheumatism, obesity, hyperlipidemia and skin ailments. The antioxidant activity assays performed were - free radical scavenging activity using DDPH proposed by Mothlanka et al, total antioxidant capacity using phosphomolybdenum reagent described by Prito et al and reducing power assay adopted by Oyaizu. As phenolics and flavonoids are known antioxidants, the antioxidant activity of these resins was correlated with their phenolic and flavonoid contents. Total phenolic and flavonoid contents were determined by the standard methods. All the resin samples exhibited presence of phenolics and flavonoids and antioxidant activity. The highest antioxidant activity was found in G. resinifera and C. mukul. Shorea robusta showed highest flavonoid content. There was a positive correlation between the total antioxidant capacity and total phenolic and flavonoid content in all the resin extracts. The IC50 values obtained indicated that the resin of G. resinifera has the maximum antioxidant potential.

Keywords: Resins, Boswellia serrata, Commiphora mukul, Gardenia resinifera, Shorea robusta, antioxidant activity, phenols, flavonoids.