Comparative evaluation of antimicrobial properties of red and yellow watermelon seeds.

Abstract

Watermelon fruits are originated from the West Africa and distributed all over the world including Malaysia. Its antimicrobial properties are well known. There are two varieties of watermelon fruits are available in the Malaysian market i.e. red and yellow. In the present study, a qualitative phytochemical analysis of methanol extracts of two varieties of watermelon seeds were carried out to identify the difference in their active constituents. A detailed antimicrobial study was carried out for both of the extracts and compared. The zone of inhibition produced by the crude methanolic extract of red watermelon seeds against Streptococcus pyogenes and Staphylococcus aureus were 7-20 mm and 7-10 mm, respectively in different concentrations. At the same time crude methanolic extract of red watermelon seeds do not showed zone of inhibition against Escherichia coli and Pseudomonas aeruginosa. The methanolic extract of yellow watermelon seeds do not showed zone of inhibition against all the tested organisms. In conclusion, these results showed that methanolic extract of red watermelon seeds are good candidate for further investigation against gram positive bacteria.