Phytochemical analysis and antimicrobial and antioxidant activities of Celosia argentea leaves

This study performed the phytochemical screening and bioactivity of Celosia argentea leaves. The phytochemical profile of hexane (Hex), ethyl acetate (AcOEt) and methanolic (MeOH) extracts of C. argentea leaves was observed by Thin Layer Chromatography and spectrophotometric analysis. In the susceptibility test, the disk-diffusion technique was performed. Minimum Inhibitory Concentration (MIC) was assessed by microdilution. Minimum Microbic Concentration (MMC) was determined in the extracts which presented MIC. Antioxidant activities were measured using 2,2-diphenyl-1-picril-hidrazil (DPPH), determination of reducing power and total antioxidant capacity (TAC). The results showed a higher content of phenolic compounds (252.02 ± 0.02 mg GAE/g) in the extract AcOEt, and of tannins (103.72 ± 0.004 mg/EAT/g) in MeOH; this was effective against Micrococcus luteus (inhibition of 24.7 ± 0.6 mm). MIC and CMM of the AcOEt for M. luteus were 0.06 and 0.25 mg/mL, respectively. The MeOH extract eliminated 70.4 ± 0.03% of DPPH radical, whereas AcOEt had greater reducing power (289.23 ± 0.05 mg AA/g) and TAC at a concentration of 250 µg/mL (89.6%). This study revealed that C. argentea has phytochemicals with bactericidal and fungicidal potential, in addition to elevated antioxidant power. Key words: antimicrobial, antioxidant, bioactivity.