Chemical composition, antioxidant, anti-lipooxygenase, antimicrobial, anti-parasite and cytotoxic activities of Polyalthia longifolia seed oil

Abstract

This work investigates the chemical compositions of Polyalthia longifolia Thw. seed oil with the associated antioxidant, anti-inflammatory, anti-parasite and cytotoxicity potentials. The oil of P. longifolia seed obtained by soxhlet extraction was trans-esterified and the fatty acid profile characterized using gas chromatography mass spectrometry (GC–MS). The antioxidant activity was evaluated using DPPH and ABTS assays. The anti-bacterial and anti-fungi properties of the oil were determine on clinical isolates of the organisms using agar diffusion method. The anti-inflammatory activities, cytotoxicity and anti-parasite potential were evaluated using lipooxygenase, mammalian cell and Toxoplasma gondii assays respectively. P. longifolia seed was observed to contain oleic (30.31%), linoleic acid (19.27%) and palmitic acid (15.11%) as the major fatty acids with low proportion of tricosylic acid (6.10) and stearic acid (5.56%). The oil had significant anti-lipooxygenase activity (IC50= 0.70 ± 0.02 µg/mL) comparable to indomethacin (IC50= 0.53 ± 0.07 µg/mL). The DPPH (IC50= 55.91 ± 31.18 µg/mL) and ABTS (IC50= 16.89 ± 15.50 µg/mL) antioxidant activity of the oil was lower to the ascorbic acid (IC50= 0.34 ± 0.04 and 0.54 ± 0.04 µg/mL). The oil also showed activities against all the tested bacteria and fungi. The highest inhibition was recorded against S. aureus (17 ± 1 mm) at concentration 200 mg/mL. Further, the oils showed strong potential to restrict growth of Toxoplasma gondii in vitro, but the parasite growth inhibition was mildly abated in the presence of αtocopherol. The seed oil of the underutilized P. longifolia possesses essential fatty acids which could be responsible for the numerous biological potentials which include anti-lipooxygenase, antioxidant, anti-inflammatory, anti-parasite, antimicrobial and cytotoxic activities. The incorporation of the natural oil into pharmaceuticals or cosmetics may enhance antioxidant, anti-inflammatory, antimicrobial and cytotoxicity potential of such products.