Phytochemical composition, in vitro antioxidant activity and antibacterial mechanisms of Neolamarckia cadamba fruits extracts.

Aqueous extracts of Neolamarckia cadamba fruits prepared at
different maturity stages were used for the analysis of various
phytochemicals, and their antioxidant and antibacterial activities
were determined. Ripe fruit extract had highest phenolics (3.14 mM
GAE/ g fruit extract) with caffeic acid, tannic acid, syringic acid and
quercetin as major phenolic compounds. The ripe fruit extract showed
lowest IC50 values in DPPH radical scavenging assay (231.33 μg fruit
extract/ mL), and highest ABTS radical scavenging activity (111.18 μM
TEAC/g). Immature fruit extract showed lowest minimum inhibitory
concentration against tested bacteria, and the antibacterial activity
was probably due to membrane permeation, as was evident by
leakage of genetic material and reduction in propidium iodide uptake
by bacterium; and by inhibition of sugar and amino acid uptake. The
appreciable amount of phenolic compounds and biological activities
in the aqueous extracts of N. cadamba fruits suggests it's potential
application as natural preservative.