Assessment of the possible ameliorative effects of beta-caryophyllene oxide either alone or in combination with methotrexate in complete Freund's adjuvant-induced arthritis in Wistar rats

Abstract Background β-Caryophyllene oxide (BCPO) has wooden odor so widely used as cosmetic and food additives. It is naturally found in various spice and food plant such as basil, black pepper, clove, salvia, and indian bay leaf. It is traditionally used to treat arthritis. The present study anticipated to appraise the anti-inflammatory and anti-arthritic potential of BCPO alone and in combination with methotrexate. Results Data from in vitro assays showed that BCPO exerted the highest percentage inhibition at 1600 μg/ml. Complete Freund’s Adjuvant-induced arthritis in Wistar rats treated with BCPO and its combination with methotrexate (MTX) revealed a notable restoration of body weight and reduced pain, arthritic score, oxidative stress, and hematological alterations in contrast to disease control. The histopathological examination showed that BCPO therapy decreased joint inflammation, pannus formation, and bone erosion. Biochemical studies revealed that BCPO alone and in combination not only downregulated the mRNA expression of TNF-α, IL-1β, NF-kB, and COX-2 but also increased the expression of IL-4, and IL-10. Conclusion It can be inferred from the finding that BCPO in combination with MTX can be effectively used to manage polyarthritis due to notable anti-inflammatory, antioxidant, and anti-nociceptive activities than monotherapy. Graphical abstract