ETHNOPHARMACOLOGICAL RELEVANCEPrunella vulgaris L.(PV) and Tussilago farfara (TF) are perennial herbs rich in flavonoids and phenolic compounds with immense medicinal value. PV extract (PV-E) possesses potent antipyretic, anti-inflammtory, antioxidant, antiseptic, anti-cancer and immune stimulatory properties and have been traditionally known for the treatment of wounds, ulcers and sores. TF extract (TF-E) has been known for antibacterial, antioxidant, anti-inflammatory, anti-viral, anti-diabetic, anti-cancer, anti-obesity and wound healing effects. Additionally, TF-E infusions have been used for asthma, cough, and bronchopneumonia treatments.AIM OF THE STUDYThe therapeutic efficacy of transplanted human adipose stem cells (hASCs) is abrogated under the deteriorating effects of heat stress offered by burn wounds. Earlier researches has documented antioxidant priming as an effective strategy to enhance stem cell performance. As both PV-E and TF-E are known for their potent antioxidant effects. The present study aims to examine the cryoprotective effects of PV-E and TF-E priming on hASCs against in-vitro heat-induced thermal stress. Moreover, we determined the anti-inflammatory potential of both PV-E and TF-E on rabbits.METHODSAntioxidant capacity of both PV-E and TF-E is examined via DPPH assay and anti-inflammatory activity is assessed in rabbits using carrageen-induced paw edema model of inflammation. Next, we investigate the efficacy of different doses (1.25-100μg/ml) of PV-E and TF-E on hASCs; MTT, LDH, calcein AM staining, and wound scratch assay were used to assess cell viability, cytotoxicity, proliferation ability and cell migration potential in the cells. Then, hASCs were pretreated for 24 h with optimum doses of PV-E and TF-E determined from MTT assay results and were subsequently exposed to in-vitro thermal injury (51 °C,10 min). The cytoprotective effects of both PV-E and TF-E priming under thermal stress were investigated via MTT, LDH, annexin-V staining and gene expression analysis.RESULTSBoth PV-E and TF-E extracts demonstrated potent antioxidant and effective anti-inflammatory activities, with a clear reduction in inflammation. Study on hASCs exhibited improved cell viabilities, enhanced cell proliferation and migration abilities of both extracts. While heat stress data revealed that PV-E (2.5μg/ml) and TF-E (5μg/ml) pretreatment significantly ameliorated effects of thermal-injuries in hASCs as depicted by significantly enhanced cell viabilities, low LDH release profile, and lower annexin-V expression and regulated gene expression of the pretreated cells.CONCLUSIONPV-E and TF-E priming effectively enabled hASCs to combat thermal injury by significantly promoting cell survival than untreated cells. Hence, these findings suggest that PV-E and TF-E priming could be used to attain improved cellular responses and enhanced therapeutic efficacy in burnt tissue.