Polar and apolar extra virgin olive oil and leaf extracts as a promising anti-inflammatory natural treatment for osteoarthritis

Osteoarthritis (OA) is a common joint disease with important socio-economic impact. Looking for a novel natural treatment represents an important challenge and a public health objective. A wide range of previous studies highlighted the antioxidant and anti-inflammatory properties especially of phenolic compounds present in olive oil. Therefore, the aim of this study was to investigate the anti-inflammatory activity of Tunisian Extra Virgin Olive Oil (EVOO) extracts in an in vitro OA model. To this aim we evaluated the polar and apolar olive oil fractions and olive leaf extract. The antioxidant capacity of these extracts was determined by using DPPH and FRAP assays. For the in vitro study, the human OA chondrocytes were exposed to lipopolysaccharide (LPS) to induce inflammatory response. The inducible isoform of nitric oxide syntheses (iNOS) and collagen type II expressions were evaluated by immunocytochemistry and western blot analysis. Principal outcome showed that the extracts had important anti-inflammatory potential by decreasing iNOS synthesis in OA chondrocytes. The anti-inflammatory effect was dependent on the extract composition and the used dose. An insignificant effect was seen on collagen type II expression. These results show that nutritional components contained in Tunisian EVOO influence the cellular metabolism, suggesting their potential therapeutic use in patients with inflammatory joint diseases.