Fruits of Sonneratia apetala (Buch.-Ham.), (English: mangrove apple, Bengali: keora) both seeds and pericarps, are largely consumed as food besides their enormous medicinal application. The fruit seeds have high content of nutrients and bioactive components. The seeds
powder of S. apetala was successively fractionated using
n-hexane,
diethyl ether,
chloroform,
ethyl acetate, and
methanol. The fractions were used to evaluate antibacterial, anti-diarrhoeal,
analgesic, and cytotoxic activities.
Methanol fraction of seeds (MeS) stronly inhibited Escherichia coli strains, Salmonella Paratyphi A, Salmonella Typhi, Shigella dysenteriae, and Staphylococcus aureus except Vibrio cholerae at 500 μg/disc. All the fractions strongly inhibited
castor oil induced diarrhoeal episodes and onset time in mice at 500 mg extract/kg
body weight (P<0.001). At the same concentration, MeS had the strongest inhibitory activity on diarrhoeal episodes, whereas the
n-hexane fraction (HS) significantly (P<0.05) prolonged diarrhoeal onset time as compared to positive control. Similarly, HS (P<0.005) inhibited
acetic acid induced writhing in mice at 500 mg extract/kg, more than any other fraction. HS and
diethyl ether fractions of seed strongly increased reaction time of mice in hot plate test at 500 mg extract/kg. All the fractions showed strong cytotoxic effects in brine shrimp lethality tests. Gas chromatography-mass spectrometry analysis of HS led to the identification of 23 compounds.
Linoleic acid (29.9%),
palmitic acid (23.2%),
ascorbyl palmitate (21.2%), and
stearic acid (10.5%) were the major compounds in HS. These results suggest that seeds of S. apetala could be of great use as nutraceuticals.