Inhibition of proinflammatory pathways by bioactive fraction of Tinospora cordifolia

Tinospora cordifolia (Willd.) Miers ex Hook. f. & Thomson, a known immunomodulatory agent extensively used in ayurveda, has not been effectively validated for the mechanisms involved in immunomodulation and the identification of the active principles. The bioactive fraction of T. cordifolia (TBF) in methanol was used for nitric oxide (NO) radical scavenging activity, lipoxygenase (LOX) and cyclooxygenase (COX) dual inhibition and cytotoxicity studies. Production of the proinflammatory cytokines, tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in dendritic cell (DC) suspensions treated with lipopolysaccharide (LPS) was also studied. The bioactive principles involved were identified with ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometric (UPLC-Q-ToF MS/MS) system. The results indicate significantly higher potency of TBF as compared to positive standards for LOX/COX inhibition with moderate NO radical scavenging activity and the fraction was also found to be non-cytotoxic to monocyte cells. A significant inhibition was also observed in TNF-α and IL-1β production in LPS-treated DC suspensions as compared to standards, rolipram and dexamethasone, respectively. 11 compounds were identified from TBF by MS/MS system. The potent inhibition of LOX and COX enzymes with moderate NO scavenging was indicative of a free radical scavenging-independent mechanism of immunomodulation. Further investigations into the active principles identified would result in the development of lead candidates with potent therapeutic implications.