ß-patchoulene protects against non-alcoholic steatohepatitis via interrupting the vicious circle among oxidative stress, histanoxia and lipid accumulation in rats.

Non-alcoholic steatohepatitis (NASH), an extreme progressive subtype of metabolic associated fatty liver disease, is well characterized by hepatic steatosis, injury and inflammation. It causes irreversible hepatic damage and there are no approved interventions for it. ß-PAE, a representatively pharmacological active substance isolated from Pogostemon cablin, has been indicated to alleviate hepatic steatosis and injury through modulating lipid metabolism in rats with simple steatosis. However, its protection against NASH remains unclear. Here, this study explored the potential effect of ß-PAE against high-fat diet-induced NASH in rats. The results displayed that ß-PAE significantly reduced the gains of body weight and epididymal adipose tissue, liver index and attenuated liver histological damages in NASH rats. It also markedly alleviated hepatic inflammation by inhibiting NLRP3 inflammasome activation. In NASH, the active NLRP3 inflammasome is caused by hepatic lipid abnormal accumulation-induced oxidative stress. Excessive oxidative stress results in hepatic histanoxia, which exacerbates lipid metabolism disorders by elevating CD36 to suppress AMPK signalling pathways. Moreover, the lipid accumulation led by lipid metabolism dysfunction intensifies oxidative stress. A vicious circle is formed among oxidative stress, histanoxia and lipid accumulation, eventually, but ß-PAE effectively interrupted it. Interestingly, soluble CD36 (sCD36) was tightly associated not only with hepatic steatosis and injury but also with inflammation. Collectively, ß-PAE exerted a positive effect against NASH by interrupting the vicious circle among oxidative stress, histanoxia and lipid accumulation, and sCD36 may be a promising non-invasive tool for NASH diagnosis.

ß-patchoulene simultaneously ameliorated dextran sulfate sodium-induced colitis and secondary liver injury in mice via suppressing colonic leakage and flora imbalance.

Ulcerative colitis (UC) often occurs accompanied by colonic leakage and flora imbalance, resulting in secondary liver injury (SLI). SLI, in turn, aggravates UC, so the treatment of UC should not ignore it. ß-patchoulene (ß-PAE), a tricyclic sesquiterpene isolated from Pogostemon cablin, has been reported to exert a protective effect in gastrointestinal disease in our previous studies. However, its protection against UC and SLI remains unknown. Here we explored the protective effect and underlying mechanism of ß-PAE against dextran sulfate sodium-induced UC and SLI in mice. The results indicated that ß-PAE significantly reduced disease activity index, splenic index and attenuated the shortening of colonic length in UC mice. It alleviated colonic pathological changes and apoptosis through protecting tight junctions, reducing neutrophil aggregation, and inhibiting the release of pro-inflammatory cytokines and adhesion molecules. These effects of ß-PAE were associated with the inhibition of TLR4/MyD88/NF-κB and ROCK1/MLC2 signalling pathway. UC-induced colonic leakage caused abnormally high LPS levels to result in SLI, and ß-PAE markedly inhibited it. ß-PAE simultaneously ameliorated SLI with reduced biomarker levels of endotoxin exposure and hepatic inflammation. High levels of LPS were also associated with flora imbalance in UC mice. However, ß-PAE restored the diversity of gut microbiota and altered the relative abundance of characteristic flora of UC mice. Escherichia-dominated gut microbiota of UC mice was changed to Oscillospira-dominated after ß-PAE treatment. In conclusion, pharmacological effects of ß-PAE on UC and SLI were mainly contributed by suppressing colonic leakage and flora imbalance. The findings may have implications for UC treatment that not neglect the treatment of SLI.

Patchouli Essential Oil and Its Derived Compounds Revealed Prebiotic-Like Effects in C57BL/6J Mice.

Pogostemon cablin (Blanco) Benth (PC) is a Chinese medicinal plant traditionally used for the treatment of gastrointestinal symptoms. To investigate the prebiotic effect of patchouli essential oil (PEO) and its derived compounds through the modulation of gut microbiota (GM). C57BL/6J mice were treated with the PEO and three active components of PEO, i.e. patchouli alcohol (PA), pogostone (PO) and ß-patchoulene (ß-PAE) for 15 consecutive days. Fecal samples and mucosa were collected for GM biomarkers studies. PEO, PA, PO, and ß-PAE improve the gut epithelial barrier by altering the status of E-cadherin vs. N-cadherin expressions, and increasing the mucosal p-lysozyme and Muc 2. Moreover, the treatments also facilitate the polarization of M1 to M2 macrophage phenotypes, meanwhile, suppress the pro-inflammatory cytokines. Fecal microbial DNAs were analyzed and evaluated for GM composition by ERIC-PCR and 16S rRNA amplicon sequencing. The GM diversity was increased with the treated groups compared to the control. Further analysis showed that some known short chain fatty acids (SCFAs)-producing bacteria, e.g. Anaerostipes butyraticus, Butytivibrio fibrisolvens, Clostridium jejuense, Eubacterium uniforme, and Lactobacillus lactis were significantly enriched in the treated groups. In addition, the key SCFAs receptors, GPR 41, 43 and 109a, were significantly stimulated in the gut epithelial layer of the treated mice. By contract, the relative abundance of pathogens Sutterlla spp., Fusobacterium mortiferum, and Helicobacter spp. were distinctly reduced by the treatments with PEO and ß-PAE. Our findings provide insightful information that the microbiota/host dynamic interaction may play a key role for the pharmacological activities of PEO, PA, PO, and ß-PAE.

Protective role of ß-patchoulene from Pogostemon cablin against indomethacin-induced gastric ulcer in rats: Involvement of anti-inflammation and angiogenesis.

BACKGROUND: Non-steroidal anti-inflammatory drugs (NSAIDs) are most widely used as effective anti-inflammatory agents. However, their clinical application brings about inevasible gastrointestinal side effects. Pogostemon cablin is a traditional herbal medicine used for the treatment of gastrointestinal diseases in China. One of its representative components, the tricyclic triterpenoid ß-patchoulone (ß-PAE) has demonstrated great anti-inflammatory activity and gastroprotective effect against ethanol-induced gastric injury, but its protective effect against gastric ulcer induced by indomethacin is still unknown. PURPOSE: To assess the protective effect of ß-PAE against ulcer produced by indomethacin and reveal the underlying pharmacological mechanism. STUDY DESIGN: We used an indomethacin-induced gastric ulcer model of rats in vivo. METHODS: Gastroprotective activity of ß-PAE (10, 20, 40 mg/kg, i.g.) was estimated via indomethacin-induced gastric ulcer model in rats. Histopathological and histochemical assessment of ulcerated tissues were performed. Protein and mRNA expression were determined by Elisa, Western blotting and qRT-PCR. RESULTS: ß-PAE could inhibit ulcer formation. Histopathological and histochemical assessment macroscopically demonstrated that ß-PAE alleviates indomethacin-induced gastric ulceration in dose-dependent manner. After administration of ß-PAE, elevated tumor necrosis factor -α level was significantly decreased and the phosphorylation of JNK and IκB was markedly inhibited. ß-PAE suppressed the levels of E-selectin, P-selectin, intercellular adhesion molecule-1, vascular cell adhesion molecule and monocyte chemoattractant protein 1, as well as myeloperoxidase. Meanwhile, ß-PAE increased cyclooxygenase enzyme activities (COX-1 and COX-2) to enhance the production of prostaglandin E2. Proangiogenic protein, vascular endothelial growth factor and its receptor fms-like tyrosine kinase-1 mRNA expression were promoted while anti-angiogenic protein, endostatin-1 and its receptor ETAR mRNA expression were decreased. CONCLUSION: ß-PAE may provide gastroprotection in indomethacin-induced gastric ulcer in rats by reducing inflammatory response and improving angiogenesis.

ß-Patchoulene from patchouli oil protects against LPS-induced acute lung injury via suppressing NF-κB and activating Nrf2 pathways.

ß-Patchoulene (ß-PAE), a tricyclic sesquiterpene isolated from the essential oil of the leaves and stems of Pogostemon cablin (Blanco) Benth., has been reported to have potent anti-inflammatory activity. The aim of this study was to evaluate the potential protective effect of ß-PAE on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice and to illuminate the underlying mechanisms. ALI was induced by intracheal instillation of LPS into lung, and dexamethasone (DEX) was used as a positive control. Results indicated that pretreatment with ß-PAE significantly decreased the mortality rate of mice and lung W/D weight ratio, ameliorated lung pathological changes as compared to model group. Meanwhile, ß-PAE pretreatment markedly inhibited the increase of TNF-α, IL-6 and IL-1ß secretions in the bronchoalveolar lavage fluid, and prevented LPS-induced elevations of MPO activity and MDA level in the lung. Additionally, ß-PAE pretreatment significantly elevated miR-146a expression and suppressed the LPS-induced activation of NF-κB and expression of its mediated genes (TNF-α, IL-6 and IL-1ß). ß-PAE was also observed to markedly upregulate the Nrf2 and HO-1 expression and activate the antioxidant genes (NQO-1, GCLC and HO-1). Taken together, ß-PAE possessed protective effect against LPS-induced ALI, which might be associated with its differential regulation of NF-κB and Nrf2 activities and up-regulation of expression of miR-146a. The results rendered ß-PAE a promising anti-inflammatory agent worthy of further development into a pharmaceutical drug for the treatment of ALI.

Anti-inflammatory activity of ß-patchoulene isolated from patchouli oil in mice.

ß-Patchoulene (ß-PAE) is a tricyclic sesquiterpene isolated from the oil of Pogostemon cablin (patchouli oil), which has been widely used in traditional Chinese medicine for the treatment of inflammatory diseases. However, as one of the major principle of patchouli oil, the biological activity of ß-PAE has not been explored so far. In the present study, the anti-inflammatory activity in vivo, and the underlying mechanism, of ß-PAE was investigated on experimental mice models of acute inflammation, i.e. xylene-induced ear edema, acetic acid-induced vascular permeability and carrageenan-induced paw edema. The results showed that ß-PAE evoked a significant dose-dependent inhibition of ear edema induced by xylene, paw edema induced by carrageenan and suppressed the increase of vascular permeability elicited by acetic acid. Histopathological analysis indicated that ß-PAE could markedly decrease the cellular infiltration in paw tissue. ß-PAE was also shown to significantly decrease the malondialdehyde (MDA) level and myeloperoxidase (MPO) activity in edema paw. In addition, carrageenan-induced production of some pro-inflammatory cytokines: tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), prostaglandin E2 (PGE2) and nitric oxide (NO), were suppressed in a dose-dependent manner in mice subjected to ß-PAE pretreatment, and it also significantly down-regulated the protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Further analysis revealed that ß-PAE also inhibited the translocation of nuclear factor-κB (NF-κB) from the cytoplasm to the nucleus and stabilize the conversion of nuclear factor-κBα (IκBα) level. These results provided additional chemical and pharmacological basis for the traditional application of P. cablin in inflammatory disorders.