Anti-Arthritis and Biosafety Properties of Green Synthesized Zinc Oxide Nanoparticles Loaded with Cedrus libani...

This research was conducted to develop an easy and safe method for synthesizing zinc oxide nanoparticles (ZnO NPs) with the aim of enhancing the efficacy and biosafety of ethanolic Cedrus libani (CL) extract and its aqueous fraction (ACL), as a potential preclinical candidate for anti-arthritis applications.

UV-visible spectrophotometry, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy analysis, dynamic light scattering, and zeta potential were used to characterize the synthesized ZnO NPs. The optimal synthesis conditions were determined by evaluating the effects of reaction parameters. The anti-arthritis effect was investigated in vitro using albumin denaturation and human red blood cells (HRBCs) membrane stabilization tests. Additionally, Franz cells were used to determine the ex vivo permeability; carrageenan-induced paw edema, C-reactive protein measurement, and erythrocyte sedimentation rate were used to study the in vivo anti-arthritis effect. Biosafety was assessed through acute and subacute dermal toxicity tests.

Both CL and ACL could synthesize ZnO NPs with 71 and 44 nm diameters, respectively. In vitro, synthesized ZnO NPs showed superior anti-arthritis effects compared to sodium diclofenac and plant extracts, with the IC₅₀ values for the albumin denaturation test being10.84 and 11.93 µg/mL for CL-ZnO NPs and ACL-ZnO NPs, respectively. The IC₅₀ values for the HRBCs membrane stabilization assay were 9.74 and 14.8 µg/mL for CL-ZnO NPs and ACL-ZnO NPs, respectively. The ex vivo permeability study showed high permeability (946.8 µg/h/cm²). In vivo, both synthesized ZnO NPs demonstrated significant inhibition of carrageenan-induced edema, and performed better than sodium diclofenac and plant extracts, with maximum inhibition of 85.96±14.21% (CL-ZnO NPs) and 92.97±6.43% (ACL-ZnO NPs). Acute and subacute toxicity evaluations revealed no adverse effects.

The green synthesized ZnO NPs from both CL and ACL had high permeability, superior efficacy, and biosafe which make them a promising natural product for managing arthritis conditions.