Therapeutic Effect of Carvacrol-loaded Albumin Nanoparticles on Arthritic Rats

Rheumatoid arthritis (RA) is one of the most common autoimmune diseases. Carvacrol,an important natural terpenoid product in aromatic plants such as thyme, has shown antiinflammatoryeffects in animal models of arthritis. However, its poor water solubility andhigh volatility have limited its application. In the present study in order to overcome thisproblem, we encapsulated carvacrol in the bovine serum albumin (BSA) nanoparticles andexamined its therapeutic and immunomodulatory effects in adjuvant-induced arthritis (AIA).Carvacrol-loaded BSA nanoparticles were prepared by desolvation method. Nanoparticleshad encapsulation efficiency (EE) of 67.7 ± 6.9% and loading capacity (LC) of 26.6 ± 2%.The size of particles was 148 ± 25 nm and they had monomodal distribution. After arthritisinduction, the rats were treated intraperitoneally with nanoparticle for every 3 days until day28. The treatment of the rats with 375 mg/mL carvacrol-loaded BSA nanoparticle significantlydecreased clinical severity score (27.5 ± 9.8%, p = 0.008), erythrocyte sedimentation rate(33.4 ± 10%, p = 0.02), nitric oxide production (82.3 ± 2.6%, p = 0.004) and interleukin (IL)-17 gene expression (55.1 ± 8.2%, p = 0.003) compared to the untreated arthritic group. Ahigher reduction in inflammation severity in arthritic rats treated with carvacrol-loaded BSA incomparison to those treated with carvacrol alone was observed. In conclusion, encapsulationof carvacrol in nanoparticles reduced arthritis signs and release of NO and IL-17 inflammatorycytokine and therefore is suggested to be considered as a good approach for improving thetherapeutic applications of carvacrol in RA.