Antimicrobial and antioxidant activities of the plant Heliotropium strigosum
Heliotropium strigosum is an important medicinal plant and belongs to the Boraginaceae family. Traditionally, this plant is used as laxative and diuretic. The juice of the plant is used to treat gum boils, sore eyes and also as a cure for stings of nettles, insects and snake bites. The current study was carried out to evaluate the medicinal properties of this plant. The plant was collected from Malakand, Pakistan. It was dried in shade and crushed into powder. The shade dried plant powder was macerated for 15 days. A crude extract and ethyl acetate, n-hexane, chloroform and aqueous fractions were obtained. The crude extract and fractions were screened for antibacterial, antifungal and antioxidant properties. The plant showed excellent antimicrobial activity. Chloroform and n-hexane fractions inhibited the growth of all four fungal strains that were used in the antifungal assays. Crude extract showed antifungal activity against all fungal strains except Aspergillus flavus. The aqueous and ethyl acetate fractions had no antifungal activity. The plant exhibited excellent antibacterial activity against Pseudomonas aeruginosa and Staphylococcus epidermidis, moderate activity against methicillin resistant Staphylococcus aureus (MRSA) and Bacillus subtillus but was inactive against Escherichia coli and Klebsiella pneumonia. The plant showed excellent diphenyl picryl hydrazine (DPPH) scavenging activity. Antioxidant activity was shown by ethyl acetate, n-hexane and aqueous fractions. Crude extract and chloroform fractions were lacking in DPPH scavenging activity.
Key words: Heliotropium strigosum, antibacterial, antifungal, antioxidant.