Variation in antioxidant and antimicrobial activities in Lantana camara L. flowers in relation to extraction methods

The present work was designed to appraise how different extraction solvents and techniques affect the extractability of antioxidant and antimicrobial components from Lantana camara (L. camard) flowers.

Four extraction solvents including 100% methanol, 80% methanol, 100% ethanol and 80% ethanol coupled with three extraction techniques namely stirring, microwave-assisted stirring and ultrasonic-assisted stirring employed to isolate extractable components from the flowers of L. camara. The extracts produced were evaluated for their antioxidant and antimicrobial attributes.

The yield of extractable components varied over a wide range 4.87-30.00% in relation to extraction solvent and techniques. The extracts produced contained considerable amounts of total phenolics (8.28-52.34 mg GAE/100 g DW) and total flavonoids (1.24-7.88 mg CE/100 g DW). Furthermore, a promising antioxidant activity in terms of DPPH° scavenging, inhibition of linoleic acid peroxidation and reducing power, as well as antimicrobial potential of the extracts were recorded against the selected bacterial and fungal strains.

It was concluded that both extraction solvent and techniques employed affected the antioxidant and antimicrobial attributes of the extracts from L. camara flowers. With few exceptions, overall methanolic extracts produced by ultrasonic-assisted stirring offered superior activities followed by the microwave-assisted stirring and then stirring. The results advocate the use of appropriate extraction strategies to recover potent antioxidant and antimicrobial agents from the flowers of L. camara for nutraceutical and therapeutic.