Background: Mangrove plant extracts are used in folkloric medicine as aphrodisiac, sedative,
antioxidant, antimicrobial and antimalarial. Screening for antimicrobial, phytochemical and antioxidant
activities of fourteen mangroves plant species (Aegiceras corniculatum, Acanthus ilicifolius, Avicennia
alba, Avicennia marina, Avicennia officinalis, Bruguiera cylindrica, Bruguiera gymnorhiza, Ceriops
tagel, Excoecaria agallocha, Kandelia candel, Rhizophora apiculata, Rhizophora mucronata, Sonneratia
alba, andSonneratia caseolaris) in various solvents is reported in this work.
Methods: The antimicrobial screening was carried out using agar well diffusion method. In this study,
nine pathogenic strains were used, including three Gram-positive and six Gram-negative bacteria. Phytochemical
screening, total flavonoids, total phenolic and antioxidant activity were tested by DPPH
radical scavenging assay. Four phenolic compounds (gallic acid, vanillin, tannic acid and quercetin)
were quantified by LC-MS/MS in selected mangrove species.
Results: Antimicrobial screening showed Staphylococcus aureus, Staphylococcusepidermidis, Enterococcus
faecalis and Pseudomonas aeruginosa were most susceptible to ethyl acetate extract as compared
to ethanol and methanol extract. Ethyl acetate extract of Avicennia marina and Bruguieragymnorhiza
showed strong antibacterial activity against Staphylococcus aureus, Staphylococcus epidermidis,
Enterococcus faecalis and Pseudomonas aerogenosa. Phytochemical analysis revealed the presence
of saponins, phenolics, flavonoids, alkaloids, tannins, and terpenoids, which was found to be variable
as per the solvent used for extraction. In addition, total phenolics and total flavonoids content with
different solvents were found in the range of 11.08 to 196.76 mg GAE/g and 12.92 to 110.3 mg QE/g of
extract, respectively. Moreover, antioxidant capacities expressed in terms of IC50 (mg/mL) showed that
methanol extract exhibited higher antioxidant capacity followed by ethanol extract. LC-MS/MS analysis
showed gallic acid and tannic acid present in higher concentration in Aegiceras corniculatum and Sonneratia
caseolaris than other species. The vanillin and quercetin were found in the least concentration.
Conclusion: Mangroves species are a rich source of antioxidants, phenolics and antimicrobial compounds.