Preliminary Phytochemical Screening of Alternanthera bettzickiana (Regel) G. Nicholson Hydroethanolic Extract to Evaluate its Antioxidant, Anti-Inflammatory and Antimicrobial Properties

This study aimed to assess the phytochemical composition and evaluate the antioxidant, anti-inflammatory, analgesic, and antimicrobial properties of the hydroethanolic extract derived from Alternanthera bettzickiana (Regel) G. Nicholson. Initial phytochemical screening revealed a diverse array of compounds in the crude extract, potentially contributing to its observed biological activities. The research employed various methodologies to investigate these properties. Antioxidant capacity was measured using hydrogen peroxide and DPPH radical scavenging assays, utilizing UV-Vis spectrophotometry. Anti-inflammatory activity was examined through an in vitro HRBC membrane stabilization method, comprising hemolytic and membrane stabilization experiments. Hemoglobin release from damaged erythrocyte membranes was quantified at 540 nm. Analgesic effects were assessed using the acetic acid-induced writhing test in mice, while antimicrobial activity was evaluated via the disc diffusion method, comparing plant extracts with standard treatments. The phytochemical analysis identified several key secondary metabolites in the extract, including phenols, tannins, saponins, volatile oils, proteins and amino acids, flavonoids, cholesterols, carboxylic acids, and lignins.While investigating the extract's antioxidant potential through DPPH (2,2-diphenyl-1-picryl-hydrazyl) and hydrogen peroxide scavenging assays, the researchers determined that the concentration required for 50% inhibition (IC₅₀) varied significantly between the two methods, as the DPPH assay yielded an IC50 value of 229.6 µg/ml, whereas the hydrogen peroxide scavenging activity demonstrated a considerably lower IC₅₀ value of 31.67 µg/ml. In the anti-inflammatory assay, the extract at 400 µg/ml exhibited 82.23% protection against RBC hemolysis, comparable to the 83.16% inhibition shown by diclofenac sodium at the same concentration. Analysis of the analgesic properties demonstrated that, while both diclofenac sodium and A. bettzickiana extract exhibited significant writhing inhibition (p ≤ 0.01) with values spanning from 35.44% to 87.76%, their efficacy differed notably as reflected in their IC₅₀ values, where diclofenac sodium showed superior potency at 36.88 µg/ml compared to the A. bettzickiana extract's value of 101.39 µg/ml when tested against the control group. Antimicrobial testing showed that the plant extract was effective against B. megaterium (9 mm inhibition zone) and A. flavus (8 mm inhibition zone) out of six tested microorganisms. These findings suggest promising antioxidant, anti-inflammatory, antimicrobial, and analgesic (Pain-relief) effects of the A. bettzickiana hydroethanolic extract, as evidenced by both in vitro and in vivo observations.