Composition, physicochemical and biological properties of Asphodelus tenuifolius Cav. extracts

Abstract

In this study, we evaluated the chemical composition, biological properties and physical stability of Asphodelus tenuifolius Cav. extracts, which was collected from Metlili region in the district of Ghardaia. To find out why Asphodelus tenuifolius have a diverse ethnobotanical use? To test the chemical composition the UHPLC/MS was used. The results displayed that A. tenuifolius contained 265 secondary metabolites with many biological activities, but the most dominant metabolites were antifungal (Hydroxycoumarins, Luteolinidin, Emodin and Kievitone), antibacterial (Chrysin and Sophoraflavanone B) and antioxidant (Epicatechin and Catechin). These results count for the diversity of the plant ethnobotanical usage and explain why A. tenuifolius is most useful in treating microbes and infection. To confirm that A. tenuifolius is effective against fungal species three antifungal tests were performed on many local fungal strains. We found using 10% of A. tenuifolius aqueous extract against Al. infectoria, the mycelial growth was inhibited by 47%.and the sporulation was totally inhibited (100%). Moreover, the minimum fungicidal concentration of the butanol fraction was 12.5 mg/mL against Al. infectoria. To observe the damages infected by A. tenuifolius extract against fungi on the cellular level, we developed a technic based on the slide culture method. The results showed A. tenuifolius exert its fungal inhibition by deteriorating the fungal wall and membrane. Moreover, the butanol fraction of A. tenuifolius had the highest concentration of phenolic compounds, which correlate with its results for the antibacterial (against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa) and the antioxidant activity. The physical stability of the aqueous extract was tested by following the turbidity and the acidity of the extract. The turbidity and the acidity of the extract increase in storage, with a decrease in the extract fungal activity. We recommend using natural extracts freshly made if the extracts need to be stored it is better to use it within 7 days period.