Synthesis, characterization, anti-inflammatory, antioxidant and antibacterial activity of ZnO nano material from Cassia sieberina

M.O. Kyene, E. Droepenu, F. Aryeetey, G.N. Yeboah, M. Archer, D. Kumadoh, S. Mintah, P.K. Gordon, A.A. Appiah
Centre for Plant Medicine Research,

Keywords: anti-inflammatory, antioxidant, antimicrobial, cassia sieberiana, green synthesis, zinc oxide nanoparticles


The exploitation of plant materials for the green synthesis of nanoparticles is considered an eco- friendly technology since it does not involve the use of toxic chemicals. In this study, zinc oxide nanoparticles (ZnO NPs) were synthesized for the first time using the root bark methanolic extract of Cassia sieberiana. Synthesized ZnO NPs were characterized by UV–Vis spectroscopy, FTIR, SEM, TEM and EDX. Anti-inflammatory activity was investigated in-vitro by egg albumin (EA) denaturation assay, whereas antioxidant activity was examined using a DPPH free radical assay. The antimicrobial activity of ZnO NPs were tested against S. aureus (gram-positive), E. coli (gram-negative), S. typhi (gram-negative) as well as the yeast, C. albicans by agar diffusion method. Preliminary phytochemical screening of the plant extract revealed the presence of flavonoids, saponins, anthracenosides, triterpenes and polyphenols. The average particle size (TEM) determined was 78 ±1.2 nm with spherical shapes. ZnO NPs demonstrated good antioxidant activity with an IC50 value of 0.480 ± 0.018 mg mL-1 and revealed excellent anti-inflammatory activity by dose-dependently inhibiting the heat-induced denaturation of the egg albumin (IC50 = 0.676 ± 0.000 mg mL-1). In general, ZnO NPs showed a positive antibacterial activity towards the selected microbes. The present study revealed that the active phytochemicals present in the green synthesized ZnO NPs pave the way to its effective application in biomedical and nano-drug delivery systems.