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Chronic wounds seriously affect the quality of life of the elderly, obese people, and diabetic patients. The excessive inflammatory response is a key driver of delayed chronic wound healing. Although lavender essential oil (EO [lav]) has been proven to have anti‐inflammatory and accelerate wound curative effects, the specific molecular mechanism involved is still ambiguous. The results showed that the wounds treated with lipopolysaccharide (LPS) not only had delayed healing, but also the expression levels of pro‐inflammatory cytokines, such as tumor necrosis factor‐α (TNF‐α), interleukin‐6 (IL‐6), interleukin‐1β (IL‐1β), and the inflammatory mediator protein, high‐mobility group box 1 protein (HMGB‐1), in the wound tissues were significantly increased. However, treatment of LPS‐induced chronic wounds with EO (lav) accelerated wound healing and decreased IL‐1β and HMGB‐1 expression levels. It was further found that LPS induced macrophage pyroptosis to produce IL‐1β. After treatment with EO (lav), the expression level of macrophage pyroptosis marker Gasdermin D (GSDMD) and pyroptosis‐related cytotoxic effects were significantly reduced. Immunofluorescence results also directly indicate that EO (lav) can protect macrophages from LPS‐induced pyroptosis. Moreover, EO (lav) can down‐regulate expression levels of IL‐1β, GSDMD, and nucleotide‐binding oligomerization domain‐like receptor protein 3 (NLRP3) in the caspase‐11‐related pyroptotic signaling pathway. This study demonstrates that EO (lav) can reduce proinflammatory factor production and ameliorate inflammatory response by inhibiting macrophage pyroptosis, which accelerates LPS‐induced chronic wound healing. [ABSTRACT FROM AUTHOR]

Abstract: The present study was performed to clarify the effects of high mobility group box-1 protein (HMGB1), a recently described late-acting pro-inflammatory cytokine, on apoptosis of macrophages. Treatment with HMGB1 (0.01, 0.1, 1, 10μg/ml for 24h, or 10μg/ml for 6, 12, 24, 48h) resulted in a dose- and time-dependent induction of apoptosis in mice macrophages, peaked at 24h after 10μg/ml HMGB1 stimulation. HMGB1 treatment enhanced the receptor for advanced glycation endproducts (RAGE) expression and caspase-3 activation in macrophages. Blockage of RAGE and caspase-3 activation could significantly reduce apoptosis of macrophages induced by HMGB1. The activity of NF-κB/p65 in macrophages was decreased after HMGB1 treatment. These results suggested that HMGB1-induced apoptosis of macrophages in a dose- and time-dependent manner. RAGE, together with caspase-3 activation and inhibition of NF-κB signaling pathways, might be involved in the pathogenesis of macrophage apoptosis induced by HMGB1. [Copyright &y& Elsevier]

• A positive feedback loop existed between NGP and TLR4 in response to multiple bacterial infection or LPS stimulation. • NGP played a critical role in the anti-inflammatory response by targeting the NF-κB signaling pathway and IL-10 secretion. • Endogenous NGP elevated IL-10 expression but exogenous NGP was not elevated. • NGP may be a novel anti-infectious agent by enhancing macrophage phagocytosis. Neutrophilic granule protein (NGP) belongs to the cystatin superfamily. Even though this superfamily is critically involved in cancer biology and adaptive immunity, the relationship of macrophage NGP to inflammation and phagocytosis remains poorly understood. In this study, we observed a significant increase of NGP in peritoneal macrophages (PMs) isolated from mice challenged with E. coli or lipopolysaccharide (LPS), as judged by NGP mRNA microarray. We also found changes in NGP to be mainly Toll-like receptor 4 (TLR4)-dependent. By western blot and electrophoretic mobility shift assay, we demonstrated NGP overexpression to reduce TNF-α and IL-1β production by LPS-induced RAW264.7 cells (RAW) via suppression of the NF-κB (p65 and p50) signalling pathway, rather than the JNK1/AP-1 (fos and jun) signalling pathway. NGP overexpression by LPS-induced RAW also induced IL-10, an anti-inflammatory cytokine, which was partially involved in the anti-inflammatory effect produced by NGP overexpression. Moreover, upregulated NGP enhanced the phagocytosis of E. coli by RAW. Taken together, these results demonstrated NGP to be an important host defense component that regulates inflammatory responses and phagocytosis by activated macrophages. As such, NGP may be useful for the treatment of inflammatory based disease. [ABSTRACT FROM AUTHOR]