Biological properties and polyphenols content of Algerian Cistus salviifolius L. aerial parts

This study evaluated the in vitro antioxidant properties, antibacterial and antifungal activities and in vivo anti-inflammatory properties, and identifying the phenolic compounds in Cistus salviifolius. The methanolic leaf extract showed the highest antioxidant activity with 6.1±1.60 µg/ml IC₅₀ value using DPPH^· and 55.5±0.20 µg/ml using Reducing Power Activity. The study revealed that the butanolic leaf extract and the aqueous leaf infusion exhibited the strongest growth-inhibiting effect against all Gram positive and Gram negative strains tested, respectively, whereas the methanolic leaf extract showed the strongest antifungal activity against the yeast tested. The MIC value for the butanolic leaf extract was 4 mg/ml against Staphylococcus aureus, Bacillus subtilis and Escherichia coli. The pharmacotoxicological tests proved the safety of the aqueous leaf infusion, which exhibit a moderate anti-inflammatory effect, with a significant inhibition of the oedema development equal to 44.7% compared to 59.3% for the reference product diclofenac sodium. Methanolic extracts of the leaf and flower buds showed varied contents of polyphenols, flavonoids, and hydrolysable tannins; which were 228.4±11.4 mg GAE/g, 34.2±0.6 mg QE/g, and 36.9±2.6 mg TAE/g of the dry weight for leaves; and 241.1±5.4 mg GAE/g, 47.6±4.5 mg QE/g, and 22.0±1.3 mg TAE/g of the dry weight for flower buds, respectively. Analysis of the ethereal and butanolic leaf extracts using Reversed Phase High Performance Liquid Chromatographic Method coupled with a Photodiode-Array Detector identified thirteen phenolic compounds, including ascorbic acid, vanillic acid, gallic acid, quercetin, and orientin.