Antioxidant, anti-inflammatory and antibacterial activities of methanol extract and essential oil of two varieties of <i>Citrus sinensis</i> L. in Iran

This study aimed to investigate the antioxidant, anti-inflammatory, antifungal, and antibacterial properties of skin and Flesh methanol extract and essential oil of two varieties of species of <i>Citrus sinensis</i> L in Iran (northern and southern oranges). This study evaluated total phenol and flavonoid contents and the antioxidant activity of methanol extracts at different concentrations (25, 50, 100, 200, and 400 μg/ml). Albumin denaturation inhibition and RBC membrane immobilisation assays were used as an <i>in vitro</i> model to investigate the anti-inflammatory effects. Based on the results, the highest phenol and flavonoid contents and antioxidant activity were related to the northern orange skin. This extract also had the most significant impact on albumin denaturation inhibition and RBC membrane immobilisation by IC₅₀ of 365 ± 12 µg/ml and 940 ± 22 µg/ml, respectively. In antimicrobial assays, only the skin and flesh of northern orange positively affected Gram-positive bacteria.