No abstract

Oleuropein is one of the primary phenolic compounds present in olive leaf. In this study, the anti-inflammatory effect of oleuropein was investigated using lipopolysaccharide (LPS)-stimulated RAW 264.7 and a zebrafish model. The inhibitory effect of oleuropein on LPS-induced NO production in macrophages was supported by the suppression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). In addition, our enzyme immunoassay showed that oleuropein suppressed the release of pro-inflammatory cytokines such as interleukin-1β (IL-1β) and interleukin-6 (IL-6). Oleuropein inhibited the translocation of p65 by suppressing phosphorylation of inhibitory kappa B-α (IκB-α). Oleuropein also decreased activation of ERK1/2 and JNK, which are associated with LPS-induced inflammation, and its downstream gene of AP-1. Furthermore, oleuropein inhibited LPS-stimulated NO generation in a zebrafish model. Taken together, our results demonstrated that oleuropein could reduce inflammatory responses by inhibiting TLR and MAPK signaling, and may be used as an anti-inflammatory agent.

No abstract

Compound K, a major metabolite of ginsenosides Rb1, which is produced by human intestinal bacteria after oral administration, is one of the main pharmacologic compounds found in ginseng. In our previous study, we demonstrated that compound K inhibited the production of nitric oxide (NO) and prostaglandin E2 in lipopolysaccharide (LPS)-treated RAW264.7 cells. However, the mechanisms by which compound K may be effective against inflammation remain unknown. In the present study, compound K significantly inhibited LPS-induced NO production by suppression of inducible NO synthase (iNOS) in LPS-treated RAW264.7 cells. Compound K also inhibited LPS-induced cyclooxygenase-2 (COX-2) expression at both the mRNA and protein levels. It effectively suppressed both the release and mRNA expression levels of pro-inflammatory cytokines such as interleukin-1β (IL-1β) and IL-6. The anti-inflammatory effects of compound K appeared to occur via inhibition of LPS-induced phosphorylation of mitogen-activated protein kinases (MAPKs) and inhibition of NF-κB translocation from the cytosol to the nucleus by suppressing phosphorylation of inhibitory kappa B-α (IκB-α). Furthermore, we showed that compound K inhibited LPS-induced NO generation in an experimental zebrafish model. Considering these results, compound K could potentially be developed as a natural anti-inflammatory agent.

Gelidium elegans extract (GEE) is derived from a red alga from the Asia–Pacific region, which has antioxidant, anti-adipogenic, and anti-hyperglycemic effects. However, detailed studies of the toxicology of GEE have not been performed. We evaluated the single oral dose toxicity of GEE in male and female Sprague-Dawley (CD) rats. GEE did not cause deaths or have toxic effects at dosages of 5000 mg/kg/day, although compound-colored stools and diarrhea were observed in both sexes, which lasted <2 days. Therefore, the LD50 of GEE is likely to be >5000 mg/kg. We next evaluated the repeated oral dose toxicity of GEE in CD rats over 14 days and 13 weeks. GEE did not induce any significant toxicological changes in either sex at 2000 mg/kg/day. Repeated oral dose toxicity studies showed no adverse effects, in terms of clinical signs, mortality, body mass, food consumption, ophthalmic examination, urinalysis, hematology, serum biochemistry, necropsy, organ masses, or histopathology, at dosages of 500, 1000, or 2000 mg/kg/day. The no observed adverse effect level (NOAEL) for GEE is thus likely to be >2000 mg/kg/day, and no pathology was identified in potential target organs. Therefore, this study indicates that repeated oral dosing with GEE is safe in CD rats.

No abstract

The obesity‐induced inflammatory response in adipocyte is characterized by an induced migration of macrophages. MCP‐1 and TNF‐α are important modulators of a lipid accumulation and obesity‐induced inflammation. 6‐gingerol has been known to inhibit pro‐inflammatory cytokines secretion from macrophages and abnormal lipid accumulation in adipocytes. Here we show that 6‐gingerol significantly decreased the mRNA expression levels of TNF‐α, aP2, C/EBPα and PPARγ in 3T3‐L1 adipocytes. Also, 6‐gingerol treatment of co‐cultured 3T3‐L1 adipocytes and RAW264.7 macrophages resulted in a decrease in NO production and cytokine expression of MCP‐1, TNF‐α, Interleukin 6 (IL‐6), interleukin‐1 beta (IL‐1β) which is related to inflammation, regulated upon activation interleukin 10 (IL‐10) which is related to anti‐inflammation. We expect that the 6‐gingerol may provide useful applications to reduce the lipid accumulation and obesity related chronic inflammatory properties.

No abstract