Attached
Passiflora suberosa L. belonging to the family Passifloraceae is an important medicinal
plant used in traditional medicinal system in Sri Lanka to treat diabetes, hypertension and skin diseases. We extracted P. suberosa leaves under reflux conditions
using different solvents (hexane, chloroform, methanol and water), then subjected
to phytochemical screening. Alkaloids, flavonoids and saponins and saponins and
anthraquinones were present in hexane and chloroform extracts. Alkaloids, unsaturated
sterols, triterpenes, saponins, flavonoids and tannins were observed in both methanol
and aqueous extracts. Proanthocyanidins were observed only in the aqueous extract.
Hence, aqueous and methanol extracts with most classes of phytochemicals present
were subjected to antimicrobial, antioxidant, antihaemolytic activities and Brine
shrimp lethality studies. Antibacterial activity and minimum inhibition concentrations
were evaluated using three Gram-positive (Bacillus subtilis, Staphylococcus aureus and
Enterococcus faecium) and three Gram-negative bacteria (Pseudumonas aeruginosa,
Salmonella typhimuriam and Escherichia coli). The results indicated that only the
methanol extract of P. suberosa exhibited antibacterial activities against all the strains
of Gram-negative and Gram-positive bacterial with stronger activity against Gramnegative bacteria. DPHH (2,2-diphenyl-1-picrylhydrazy) scavenging assay was adopted
to evaluate antioxidant properties while antihaemolytic and toxic activities were studied
respectively using cow blood and Brine shrimp lethality assay. The IC50 values of the
aqueous extract in both antioxidant and antihaemolytic assays were significantly lower
than the standard ascorbic acid. Similar results were observed in the Brine shrimp
lethality assay. In conclusion both aqueous and methanol extracts of P. suberosa leaves
showed the presence of majority of phytochemicals including proanthocyanidins.
Antibacterial activity was obtained only for methanol extract with better activity against
Gram-negative bacteria. The aqueous extract showed better antioxidant, antihaemolytic
and toxic activities than the methanol extract and their respective standards. Further
investigations on the chemical composition and possible isolation of active ingredients
is warranted.
