Antioxidant, antimicrobial and antiscalant properties of selected species of FICUS

Abstract

World over, Ficus is recognized to be an important genus containing more than 850 species, out of which 14 are native to Pakistan. Ficus species are widely distributed and easily available throughout Pakistan. Different parts of the Ficus plants have been used in folk medicines since centuries. These are reported to possess multiple such as antidiarrheal, antidysenteric, antidiabetic antiasthmatic, antimicrobial, analgesic, laxative, and haemostatic activities. The present work has been designed with the main purpose to evaluate antioxidant, antimicrobial and antiscalant properties of different parts of selected species of Ficus distributed in Pakistan. Four solvents (absolute ethanol, absolute methanol, 80% ethanol, 80% methanol) and three techniques (orbital shaker, magnetic stirring, and sonication assisted extraction) were employed to evaluate the influence of extraction process on the yield and activities of extractable components. Antioxidant properties of the extracts were evaluated following different in-vitro antioxidant assays such as determination of total phenolic contents, estimation of total flavonoids, measurement of DPPH radical scavenging capacity, measurement of %age inhibition of linoleic acid peroxidation and reducing potential. The most potent extract from each sample was used to identify and quantify individual phenolic acids and flavonoids with the help of RP-HPLC. Furthermore, the most potent extract for each sample was also evaluated for its antimicrobial and antiscalant activities. Antimicrobial activities were assessed against selected strains of bacteria and moulds using disc diffusion and resazurine indicator methods. Antiscalant activity of the extracts was evaluated through conductivity measurement and by microscopic examination. Sonication assisted extraction technique and 80% methanol proved to be the most effective extraction system and offered higher extraction yields of active components as compared to other combinations of technique and solvent employed. The extracts obtained by using 80% methanol as solvent and sonication as extraction technique also constituted higher total phenolic and total flavonoid contents as well as exhibited better antioxidant activities as compared to the extracts obtained by other combinations of solvent and extraction techniques. HPLC analysis revealed the occurrence of four phenolic acids (caffeic acid, chlorogenic acid, gentisic acid and sinapic acid) and two flavonoids (rutin and quercetin) in almost all the fruit, leave and bark samples of the Ficus species investigated. Leaves and fruit extracts of the selected samples exhibited moderate antibacterial activity although none of the sample demonstrated antifungal activity. All the samples showed fairly good antiscalant activity. Overall, from the findings of this comprehensive study, it could be understandable that an appropriate extraction system is necessary for recovery of optimum amount of potent antioxidants, and antimicrobial and antifungal agents from these materials. The present results advocate the utilization of different parts of the local Ficus species for isolation of valuable bio-actives for functional food, neutralceutical and water treatment plants.