FREE RADICAL SCAVENGING INDEX OF CUCURBITA MAXIMA SEEDS AND THEIR LIBS BASED ANTIOXIDANT ELEMENTAL PROFILE

Objective: To assess the free radical scavenging index and antioxidant capacity of C. maxima ( Cucurbita maxima ) seed extract in vitro and its correlation with the phytoelemental profile, quantitatively assessed by LIBS (Laser-Induced Breakdown Spectroscopy). Methods: A number of in vitro antioxidant and free radical scavenging assays were performed along with standard as a reference. Reduction capacity and scavenging potential of C. maxima seeds were analyzed in addition to their IC 50 values and were compared with respective standards. Quantitative measurements of phytoelements present which is responsible for antioxidant activity is carried out by LIBS. Results: Significant Antioxidant power of the extract was validated by high values of Total Phenolics (18.42 mg/g of gallic acid equivalent) and Total Flavonoids (5.53 mg/g of quercetin equivalent). A result of Ferric Reducing Antioxidant Power (163.4 μM Fe +2 /g) clearly reflects its reduction capacity. Percentage inhibition of 2,2-diphenyl-1-picrylhydrazyl (69.25), Nitric Oxide (63.63) and 2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (62.09) radicals proves its antioxidant potential undoubtedly, which was further confirmed by their IC 50 values. Reducing power was found to increase significantly in a dose-dependent manner. Extent lipid peroxidation was also measured by comparing the results of Ferric thiocyanate assay with the Thiobarbituric acid method. LIBS analysis showed the presence of certain phytoelements viz. Mg, Ca and Na in the extract, which could be responsible for its antioxidant capacity. Conclusion: Thus, the seeds of C. maxima having a combination of antioxidant phytochemicals and phytoelements could be explored for developing as a complementary and alternative medicine for managing oxidative stress including diabetes as well as aging. Keywords: Reactive oxygen species, Cucurbita maxima , Elemental analysis, Laser spectroscopy