Nyctanthes arbor-tristis bioactive extract ameliorates LPS-induced inflammation through the inhibition of NF-κB signalling pathway

Nyctanthes arbor-tristis L. is a mythical plant used in traditional Indian medicinal systems for the treatment of inflammation, rheumatoid arthritis, and pain-related responses. However, its bioactive compounds and underlying mechanism of action have not been fully elucidated. This investigation aimed to study the anti-inflammatory and anti-nociceptive effects of the bioactive extract of N. arbor-tristis (NATE), both in vitro and in vivo, elucidate the possible mechanism of action, and determine its chemicals. We studied the anti-inflammatory and anti-nociceptive activities of NATE on lipopolysaccharide-stimulated RAW264.7 macrophages, paw-ear edema, and acetic acid-induced pain in rats and analysed its chemical components using Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometric (LC-ESI-MS). NATE efficiently reduced the production of various inflammatory mediators and factors, such as free radicals, lipid peroxidation, nitrous oxide (NO), reactive oxygen species (ROS), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-alpha (TNFα), interleukin-6 (IL-6), interleukin-1beta (IL-1β), and IL-10, as well as their corresponding mRNA expression in LPS-induced RAW264.7 cells (p < 0.001). Furthermore, NATE inhibited the activation of a key signaling pathway, nuclear factor-kappa B (NF-kB), as it caused a decrease in the degradation of inhibitor of kB alpha (IkBa). Administration of NATE significantly inhibited carrageenan-induced paw edema (p < 0.001), TPA-induced ear edema, and the production of inflammatory factors (p < 0.01). NATE revealed anti-nociceptive impacts in acetic acid-induced writhing and tail immersion experiments (p < 0.001) as well as no toxicity signs. A total of six compounds, namely iridoid glycoside (6,7-di-O-benzonylnyctanthoside), arborsides A, arborsides C, betulinic acid, kaempferol 3-O-glucoside, and kaempferol 3-O-rutinoside, were characterized through the examination of their mass spectra in correlation with those documented in a database of mass spectra. The present study furnishes scientific corroboration of the inhibitory potency of N. arbor-tristis as a promising herbal treatment for inflammation and pain responses without toxicity, offering a scientific basis for future drug development strategies aimed at ameliorating inflammatory diseases.