Chromatographic, antimicrobial and antioxidant efficacy of <i>Acmella caulirhiza</i>

Acmella caulirhiza methanolic extract was evaluated for antioxidant, antimicrobial and high-performance liquid chromatographic analysis of alkaloids. The flowers of Acmella caulirhiza were washed, dried under shade, grounded and extracted with absolute methanol. The concentrated extract was evaluated for total phenols and flavonoids, based on standard assays. Nitric oxide scavenging, hydroxyl radical scavenging, Hydrogen peroxide, reducing power, ABTS scavenging capacity, ferric ion chelating, cupric reducing antioxidant capacity were all analyzed and compared to standard antioxidant compounds. Alkaloids were also analyzed and detected by HPLC. The extract was evaluated against four pathogenic organisms for antibacterial activity, which were Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Bacillus subtillis. The result showed the levels of total phenol as 158.20 ±2.54 mg GAE/g extract and total flavonoid as 210.99 ± 2.23 mgQE/g extract. The results of scavenging assays, iron chelation and reducing potential showed higher percentage inhibition of Acmella caulirhiza extract as compared to standard drugs. Reducing potential and iron chelation were also higher. Alkaloids found in the extract were 1,3,5-triazine -2,4,6- triamine, 2-butanamine, N - ethyl-propanamide, N-formyl-beta-alanine, indicine, Lasiocarpine and sesbanamine. Acmella caulirhiza extract also inhibited the growth of microbes, especially Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus substillis. At 50mg/ml of Acmella caulirhiza the zone of inhibition on S. aureus was 20 mm in diameter, E. coli was 0 mm in diameter, P. aeruginosa 11mm in diameter and B. substillis was 13 mm in diameter as compared with standard Gentamycin 5µg/ml. Therefore, Acmella caulirhiza possesses antioxidants, antibacterial and a source of alkaloids, which can be utilized in the pharmaceutical industry.