Comparative Study of Phenolics and Antioxidant Activity of Phytochemicals of T.chebula Extracted Using Microwave and Ultrasonication

The extraction of active compounds from plants is one of the most critical steps in the commercial development of natural products for medicinal and health benefits. In view of the large number of plant species potentially available for study, it is essential to have efficient systems for the rapid and efficient extraction of phytochemicals for further investigation on their properties. The present study involves the use of microwave and ultrasonication as methods to extract phytochemicals from the fruits of Terminalia chebula. The effect of the extraction methods were studied by determining the total phenolic content, tannin content and the antioxidant activity of the extracts. The total phenolic content, tannin content and the antioxidant activity were determined by the Folin Ciocalteau method, Indigo carmine method and the DPPH free radical scavenging assay method respectively. The study revealed a 17.6% increase in the yield of phenolics and a 14% increase in the tannin content of the microwave extracts. A 20.6% increase in the antioxidant activity of the microwave extract was also obtained. The sonication extracts showed an increase of 0.6%, 5% and 9.69% in the yield of phenolics, tannins and antioxidant activity respectively. On comparison with the typical aqueous extraction method the extraction efficiency was highest for microwave treatment followed by ultrasonication. INTRODUCTION: Medicinal herbs are moving to mainstream use with greater number of people seeking to utilize plant-based products for the prevention and cure of different human diseases. Due to the adverse effects of synthetic drugs considerable attention has been paid to natural remedies which are safe and effective. This growing interest in plant secondary metabolites has prompted the need to review the traditional phytochemical extraction technologies and develop new economical, efficient and rapid extraction technologies for enhancing the concentration of phytochemicals. The traditional techniques of solvent extraction of plant materials are mostly based on the correct choice of solvents and the use of heat or/and agitation to increase the solubility of the desired compounds and improve the mass transfer. Usually the traditional technique requires longer extraction time thus running a severe risk of thermal degradation for most of the phytoconstituents . The fact that one single plant can contain up to several thousand secondary metabolites, makes the need for the development of high performance and rapid extraction methods an absolute necessity .