Encapsulation of Ginger Extract in Nanoemulsions: Preparation, Characterization and in vivo Evaluation in Rheumatoid Arthritis

Ginger is an anti-inflammatory and antioxidant natural substance, however, its effectiveness is limited pri-marily due to insufficient solubility and low oral bioavailability. This study aimed to formulate ginger extract into nanoemulsion (NE) to enhance therapeutic benefits against rheumatoid arthritis (RA). Hence, ginger extract-loaded NEs were prepared by the spontaneous emulsification method. The NE that passed the ther-modynamic stability analyses showed no phase changes or appearance of turbidity. They had an average droplet diameter of 76 +/- 45 nm with a zeta potential of -35 +/- 12 mV. Besides, the high antioxidant activities (IC50 = 53.89 mg/mL), about ten times increment of the skin permeability, and no sign of skin irritancy were observed from the ginger-loaded NE. The anti-arthritic evaluations of RA-induced rats treated with ginger-loaded NE showed a significant decline in arthritic symptoms and the highest rate of paw edema inhibition (27.7 %). In addition, the level of involved inflammatory cytokines in the serum of rats was significantly reduced (p < 0.05) compared to the negative control, so that histopathological manifestations also approved the reduction of inflammation indications. Thus, the topical delivery of ginger-loaded NE can be an efficient approach for reducing inflammation and inhibit of RA symptoms.(c) 2023 American Pharmacists Association. Published by Elsevier Inc. All rights reserved.

Automated summary

This study formulated ginger extract into nanoemulsion to enhance its therapeutic benefits against rheumatoid arthritis. The ginger-loaded nanoemulsion demonstrated high antioxidant activities and increased skin permeability. In anti-arthritic evaluations, it showed significant improvement in arthritic symptoms, including a decline in paw edema and reduction of inflammatory cytokines.