Evaluation of Antioxidant and Membrane Stabilizing Activities of <i>Croton lobatus L.</i> and <i>Croton zambesicus</i> Mull. Arg. Leaves via<i>in vitro</i> and <i>ex vivo</i> studies

Inflammation is a normal and necessary protective response to harmful stimuli such as infectious agents, antigen-antibody reactions, thermal, chemical, and physical agents, and ischemia. Most drugs used as an anti-inflammatory are analgesics- to relieve pain, because pain is a primary cause of inflammation. The effects of these drugs and their high cost limit their usage by patients, hence, the search for newer Anti-inflammatory drugs, which are relatively safe, cheap, available, and potent. The total flavonoid content, total phenolic contents and DPPH radical scavenging ability of Croton lobatus and Croton zambesicus leaves methanol extracts and solvent fractions were evaluated using standard procedure. The anti-inflammatory activity of various extracts and fractions of Croton lobatus and Croton zambesicus was accessed by in vitro RBC membrane stabilization method using standard procedure. The ethyl acetate fraction of Croton zambesicus had the highest radical scavenging property of 7.14± 0.8 µg/mL. The red blood membrane stabilizing property of the DCM fraction of Croton lobatus showed the highest value of 52.9 ± 0.1% at 0.5 µg/mL. The ability of the extracts to stabilize red blood cell membrane followed the same trend as the total phenolic contents of the plants (Croton zambesicus > Croton zambesicus). This study established the relationship between phenolic compounds and red blood cell membrane stabilization.