Anti-inflammatory and anti-rheumatic effects of Phoenix dactylifera L. (date palm) seed by controlling cytokines and inhibiting JAK1/STAT3 pathway on CFA-induced arthritis rat and its phytochemical profiling.

ETHNOPHARMACOLOGICAL RELEVANCE:Phoenix dactylifera L. (date palm) seed is widely used in Arabian traditional medicine to alleviate several health problems including inflammatory conditions. The herbal tea of date palm seed has been consumed by rheumatoid patients to relief their symptoms. AIM OF THE STUDY:The purpose of this study was to investigate the claimed beneficial use of P. dactylifera L. (Sewy variety) seed (PDS) in the treatment of rheumatoid arthritis (RA) and its mechanism of action as well as to study its phytoconstituents. MATERIALS AND METHODS:The anti-inflammatory and anti-oxidative properties of the non-polar and the polar extracts of PDS were studied using Complete Freund's adjuvant (CFA)-induced arthritis rat model. Paw edema, body weight, total nitrate/nitrite NOX content and cytokine markers were evaluated to monitor the progress of arthritis. Also, histological examination and thermal analysis were conducted. The phytoconstituent profiles of non-polar and polar extracts of PDS were investigated using liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). The multiple reactions monitoring mode (MRM) of liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) was used to quantify phenolic phytoconstituents in both extracts. RESULTS:According to the findings, the polar and non-polar PDS extracts kept body weight comparable to those of healthy individuals while considerably lowering paw swelling, edema, and neutrophil infiltration. It also reduced the levels of Nuclear Factor Kappa B (NF-κB), Tumor Necrosis Factor Alpha (TNF-α), Interleukin 22, Interleukin 23, Interferon (IFN), Interleukin 17, Interleukin 1β, Interleukin 6, Interleukin 36, Janus Kinase 1 (JAK1), and Signal Transducer and Activator of Transcription 3 (STAT3). They also reduced the degenerative alterations caused by RA. Thermal research gave additional support for these findings. 83 phytoconstituents were identified in the non-polar PDS extract and 86 phytoconstituents were identified in the polar PDS extract. 74 of the identified phytoconstituents were common in both extracts. 33 phytoconstituents were identified here from P. dactylifera for the first time as far as we know. In MRM-LC-ESI-MS/MS analysis, the major phenolics in both extracts were chlorogenic acid, naringenin, and vanillin. Catechin was only detected in the non-polar PDS extract. On the other hand, apigenin, kaempferol, and hesperetin were only detected in the polar PDS extract. Generally, the polar PDS extract showed higher concentrations of the identified phenolics than the non-polar extract. CONCLUSIONS:The PDS extracts especially the non-polar extract showed significant anti-inflammatory and anti-oxidative properties in the CFA-induced arthritis rat model. PDS might be used to produce RA medicines.