Modulation of TRPV1 function by Citrus reticulata (tangerine) fruit extract for the treatment of sensitive skin.

BACKGROUND: Sensitive skin (SS) is a clinical syndrome defined by the occurrence of unpleasant sensations (such as stinging, burning, pain, pruritus, and tingling) in response to stimuli that normally should not provoke them. According to growing evidence, transient receptor potential vanilloid subtype 1 (TRPV1) has elevated expression in individuals with SS and is linked with the severity of SS symptoms. However, its pathogenesis is still unknown. OBJECTIVE: Herein, Citrus reticulata (Tangerine) fruit extract (CR) was obtained and examined for its effect on SS with a focus on TRPV1 stimulation and expression. METHODS: A recombinant hTRPV1 over-expression cell line (HaCaT-TRPV1-OE cell) was constructed to screen substances and extracts from several plants. Intracellular calcium mobilization was monitored by Flexstation 3 and a fluorescence microscope using Fluo 8 AM fluorophore. Next, immunofluorescence was used to detect the TRPV1 expression under different stimulants treated for 24 h. To investigate the relief and increased tolerance of CR to lactic acid-induced skin discomfort, clinical tests were carried out on the nasolabial folds or cheek areas. RESULTS: According to the obtained results, compared to HaCaT cells, HaCaT-TRPV1-OE cells showed a higher expression of TRPV1. Neuronal hyperresponsiveness in SS triggered by capsaicin (CAP), lactic acid, phenoxyethanol or nicotinamide may be through activation of TRPV1 and increased TRPV1 expression. CAP activates TRPV1 in HaCaT-TRPV1-OE cells, and more than 100 plants or chemicals were tested for their inhibitory effects before being screened for CR. CR (1%-4%) inhibited TRPV1 activation induced by CAP or phenoxyethanol or nicotinamide. Meanwhile, CR (0.25%) suppressed TRPV1 protein expression induced by phenoxyethanol or lactic acid. In vivo results showed that CR not only instantly relieved lactic acid-induced skin discomfort under 5 min but also enhanced skin tolerance to lactic acid after 7 days of continuous use. CONCLUSIONS: Topical application of CR showed an instant and long-lasting improvement in SS by modulating the activation and expression of TRPV1. Moreover, it has been suggested that CR might act as a TRPV1 inhibitor to reduce skin irritation or sensitivity.

Protective effect of tanshinone II A on lipopolysaccharide-induced lung injury in rats.

OBJECTIVE: To explore the protective effect of tanshinone II A on lipopolysaccharide (LPS)-induced lung injury in rats, and possible mechanism. METHODS: LPS (O(111): B4) was used to produce a rat model of acute lung injury. Sprague-Dawley rats were randomly divided into 3 groups (8 in each group): the control group, the model group (ALI group), and the tanshinone II A treatment group. Expression of adhesion molecule CD18 on the surface of polymorphonuclear neutrophil (PMNCD18) in venous white blood cells (WBC), and changes in coagulation-anticoagulant indexes were measured 6 h after injection of LPS or normal saline. Changes in malondialdehyde (MDA) content, wet and dry weight (W/D) ratio and morphometry of pulmonary tissue as well as PMN sequestration in the lung were also measured. RESULTS: (1) When compared with the control group, expression of PMNCD18 and MDA content were enhanced in the ALI group with a hypercoagulable state (all P<0.01) and an increased W/D ratio (P<0.05). Histopathological morphometry in the lung tissue showed higher PMN sequestration, wider alveolar septa; and lower alveolar volume density (V(V)) and alveolar surface density (S(V)), showing significant difference (P<0.01). (2) When compared with the ALI group, the expression of PMN-CD18, MDA content, and W/D ratio were all lower in Tanshinone II A treatment group (P<0.05) with ameliorated coagulation abnormality (P<0.01). Histopathological morphometry in the lung tissue showed a decrease in the PMN sequestration and the width of alveolar septa (both P<0.01), and an increase in the V(V) and S(V) (P<0.05, P<0.01). CONCLUSION: Tan II A plays a protective role in LPS-induced lung injury in rats through improving hypercoagulating state, decreasing PMN-CD18 expression and alleviating migration, reducing lipid peroxidation and alleviating pathological changes.