Evaluation of 2,2-diphenyl-1-picrylhydrazyl scavenging activity and ferric reducing antioxidant power assays of six cephalosporin antibiotics

Cephalosporins are the most commonly used antibiotic class, with a broad spectrum of action. However, little is known about their radical scavenging activity. Therefore, the objective of this study is to evaluate the antioxidant activities of six cephalosporin antibiotics (cephalexin, cefuroxime, cefdinir, cefixime, cefditoren, cefpodoxime) using the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assay by spectrophotometry. It was found that the cephalosporins showed significant DPPH radical scavenging activity with an IC50 range from 2.875 to 12.52 mg/mL (23.3-68%) at 0.5073 mmol/L. Cephalexin showed the highest antioxidant activity with an IC50 of 2.875 mg/mL, followed by cefdinir (3.946 mg/mL), cefixime (5.102 mg/mL), cefditoren (6.278 mg/mL), cefuroxime (11.00 mg/mL), and cefpodoxime (12.52 mg/mL) as compared to the standard ascorbic acid (1.984 mg/mL). The radical scavenging activities of cephalosporins in terms of FRAP assay ranged from 16-46 µmol Fe2+/100 g, where cefdinir showed the highest scavenging activity (46 µmol Fe2+/100 g), followed by cephalexin (43 µmol Fe2+/100 g), cefixime (34 µmol Fe2+/100 g), cefditoren (32 µmol Fe2+/100 g), cefuroxime (19 µmol Fe2+/100 g), and cefpodoxime (16 µmol Fe2+/100 g). The findings imply that the studied cephalosporin antibiotics have direct scavenging activity against free radicals.    KEY WORDS: Reactive oxygen species, 2,2-Diphenyl-1-picrylhydrazyl, Ferric reducing antioxidant power, Antioxidant activity, Antibiotics, Cephalosporin Bull. Chem. Soc. Ethiop. 2026, 40(1), 223-235.                                                  DOI: https://dx.doi.org/10.4314/bcse.v40i1.18