Bioactive metabolites involved in the antioxidant, anticancer and anticalpain activities of Ficus carica L., Ceratonia siliqua L. and Quercus ilex L. extracts

Abstract

Ficus carica L., Ceratonia siliqua L. and Quercus ilex L. are natural products that are used as an advantageous rich source of bioactive compounds of high economic value because of its use in cosmetic, pharmaceutical and agriculture industries. These crops were studied for its phytochemical contents and were investigated for antioxidant activities and its effects on reactive oxygen species (ROS) production, calpain activity and antiproliferative effects. Results showed that extremely high total contents of phenolics, flavonoids and ortho-diphenols were detected in Quercus ilex, while proanthocyanidin level was higher in Ficus carica. Ceratonia siliqua pods showed more carotenoids and had the highest lightness value (L*). Quercus ilex and Ceratonia siliqua extracts were very effective in scavenging free radicals. The best hydroxyl radical scavenging activity was attributed to Quercus ilex with 80.51±0.20% while nitric oxide assay showed no significant differences between extracts. Ficus carica presented a higher reducing ability with 638.23±0.43mg gallic acid equivalents/100g, while Quercus ilex was very potent in reducing power assays. Percentages of metal chelating capacities of Quercus ilex and Ficus carica extracts were 87.87±0.34 and 73.17±0.16%, respectively. These two samples were also able to scavenge hydrogen peroxide efficiently. At 250μg/mL, Quercus ilex presented the best xanthine oxidase inhibition, 89.81±0.36%. Ceratonia siliqua and Quercus ilex extracts presented the best capacities of ROS inhibition and reduced cell viability in a concentration dependent manner. All samples decreased calpain activity. These extracts could be further exploited as a source of natural products with antioxidant and anticancer effects.