Sphagneticola trilobata (L.) Pruski-derived kaurenoic acid prevents ovalbumin-induced asthma in mice: Effect on Th2 cytokines, STAT6/GATA-3 signaling, NFκB/Nrf2 redox sensitive pathways, and regulatory T cell phenotype markers.

ETHNOPHARMACOLOGICAL RELEVANCE: Sphagneticola trilobata (L.) Pruski is used in traditional medicine in Brazil for inflammatory diseases treatment including asthma. The diterpene kaurenoic acid (KA) is one of its active compounds, but whether KA activity could explain the traditional use of S. trilobata in asthma is unknown. AIM: Investigate KA effect and mechanisms in asthma. METHODS: Experimental asthma was induced by ovalbumin immunization and challenge in male Swiss mice. KA (0.1-10 mg/kg, gavage) was administered 1 h before the ovalbumin challenge. Total leukocytes, eosinophil, and mast cell were counted in bronchoalveolar lavage fluid (BALF), and lung histopathology was performed. Lung mRNA expression of Th2 and regulatory T cells markers, and BALF type 2 cytokine production were quantitated. NFκB activation and oxidative stress-related components in pulmonary tissue were measured. RESULTS: KA inhibited the migration of total leukocytes and eosinophils to BALF, reduced lung histopathology (inflammatory cells and mast cells), mRNA expression of IL-33/ST2, STAT6/GATA-3 and NFκB activation in the lung, and reduced IL-33, IL-4, IL-5 production in the BALF. KA also reduced the mRNA expression of iNOS and gp91phox, and superoxide anion production accompanied by the induction of Nrf2, HO-1 and NQO1 mRNA expression, thus, exerting an antioxidant effect. Finally, KA induced nTreg-like and Tr1-like, but not Th3-like markers of suppressive T cell phenotypes in the lung tissue. CONCLUSION: KA prevents antigen-induced asthma by down-regulating Th2 and NFκB/cytokine-related pathways, and up-regulating Nrf2 and regulatory T cells' markers. Thus, explaining the ethnopharmacological use of S. trilobata for the treatment of lung inflammatory diseases.

The citrus flavanone naringenin attenuates zymosan-induced mouse joint inflammation: induction of Nrf2 expression in recruited CD45+ hematopoietic cells.

BACKGROUND: Naringenin is a biologically active analgesic, anti-inflammatory, and antioxidant flavonoid. Naringenin targets in inflammation-induced articular pain remain poorly explored. METHODS: The present study investigated the cellular and molecular mechanisms involved in the analgesic/anti-inflammatory effects of naringenin in zymosan-induced arthritis. Mice were pre-treated orally with naringenin (16.7-150 mg/kg), followed by intra-articular injection of zymosan. Articular mechanical hyperalgesia and oedema, leucocyte recruitment to synovial cavity, histopathology, expression/production of pro- and anti-inflammatory mediators and NFκB activation, inflammasome component expression, and oxidative stress were evaluated. RESULTS: Naringenin inhibited articular pain and oedema in a dose-dependent manner. The dose of 50 mg/kg inhibited leucocyte recruitment, histopathological alterations, NFκB activation, and NFκB-dependent pro-inflammatory cytokines (TNF-α, IL-1ß, and IL-33), and preproET-1 mRNA expression, but increased anti-inflammatory IL-10. Naringenin also inhibited inflammasome upregulation (reduced Nlrp3, ASC, caspase-1, and pro-IL-1ß mRNA expression) and oxidative stress (reduced gp91phox mRNA expression and superoxide anion production, increased GSH levels, induced Nrf2 protein in CD45+ hematopoietic recruited cells, and induced Nrf2 and HO-1 mRNA expression). CONCLUSIONS: Naringenin presents analgesic and anti-inflammatory effects in zymosan-induced arthritis by targeting its main physiopathological mechanisms. These data highlight this flavonoid as an interesting therapeutic compound to treat joint inflammation, deserving additional pre-clinical and clinical studies.

Antinociceptive Effect of Tephrosia sinapou Extract in the Acetic Acid, Phenyl-p-benzoquinone, Formalin, and Complete Freund's Adjuvant Models of Overt Pain-Like Behavior in Mice.

Tephrosia toxicaria, which is currently known as Tephrosia sinapou (Buc'hoz) A. Chev. (Fabaceae), is a source of compounds such as flavonoids. T. sinapou has been used in Amazonian countries traditional medicine to alleviate pain and inflammation. The purpose of this study was to evaluate the analgesic effects of T. sinapou ethyl acetate extract in overt pain-like behavior models in mice by using writhing response and flinching/licking tests. We demonstrated in this study that T. sinapou extract inhibited, in a dose (1-100 mg/kg) dependent manner, acetic acid- and phenyl-p-benzoquinone- (PBQ-) induced writhing response. Furthermore, it was active via intraperitoneal, subcutaneous, and peroral routes of administration. T. sinapou extract also inhibited formalin- and complete Freund's adjuvant- (CFA-) induced flinching/licking at 100 mg/kg dose. In conclusion, these findings demonstrate that T. sinapou ethyl acetate extract reduces inflammatory pain in the acetic acid, PBQ, formalin, and CFA models of overt pain-like behavior. Therefore, the potential of analgesic activity of T. sinapou indicates that it deserves further investigation.