Évaluation de l’activité antioxydante et anti inflammatoire des extraits hydroéthanoliques d’écorce et des déchets des graines de Cucurbita moschata

Abstract

The aim of this study is to evaluate the antioxidant and anti-inflammatory activities of hydroethanolic extracts of the peel and seed waste of Cucurbita moschata. Antioxidant activity is determined using the DPPH• radical scavenging assay, reducing power and AAPH induced hemolysis assays. Anti-inflammatory activity is determined by the inhibition of protein denaturation assay. The results obtained show that the extraction yield is 27.9% for the peel and 6.65% for the seed waste. The polyphenols content of the peel and seed waste extract is 8.18±1.91 µg GAE/mg and 7.62±1.02 µg GAE/mg, respectively and the flavonoid content is 3.93±0.15 µg QE/mg and 4.08±0.12 µg QE/mg for the peel and seed waste respectively. The β-carotene and the lycopene content is 0.026µg/g and 0.00077µg/g for the peel, besides 0.157µg/g and 0.009 µg/g for seed waste. The assessment of antioxidant activity using the DPPH• free radical scavenging assay showed that the extracts have lower antioxidant activity than the BHT standard, with IC₅₀ values of 2004.83 ± 63.66 µg/mL and 1433.52 ± 39.16 µg/mL for the peel and seed waste, respectively. The extracts exhibited a reducing effect with EC50 values of 260.75 ± 6.073µg/mL for the peel and 621.87 ± 17.58 µg/mL for the seed waste, which is lower than that of BHT. Both extracts extend the hemolysis half-time (HT 50) in a dose-dependent manner. At concentrations of 50 µg/mL for peel extract and 6.25 µg/mL for seed waste extract a significant erythrocyte antioxidant system is enhanced. Finally, the extracts studied exhibited a significant percentage of inhibition that is lower than the diclofenac standard, with a dose of 62.5 µg/mL for the peel extract and 250 µg/mL for the seed waste extract. In conclusion, the hydroethanolic extracts of the peel and seed waste of Cucurbita moschata exhibit a moderate antioxidant and anti-inflammatory activities, which may be due to the low levels of phenolic compounds or carotenoids. This waste can be used as a natural alternative in the pharmaceutical and food industries.