The present study aimed to examine the anti-inflammatory actions of oleoylethanolamide (OEA) in lipopolysaccharide (LPS)-induced THP-1 cells. The cells were stimulated with LPS (1 μg/ml) in the presence or absence of OEA (10, 20 and 40 μM). The pro-inflammatory cytokines were evaluated by qRT-PCR and ELISA. The THP-1 cells were transiently transfected with PPARα small-interfering RNA, and TLR4 activity was determined with a blocking test using anti-TLR4 antibody. Additionally, a special inhibitor was used to analyse the intracellular signaling pathway. OEA exerted a potent anti-inflammatory effect by reducing the production of pro-inflammatory cytokines and TLR4 expression, and by enhancing PPARα expression. The modulatory effects of OEA on LPS-induced inflammation depended on PPARα and TLR4. Importantly, OEA inhibited LPS-induced NF-κB activation, IκBα degradation, expression of AP-1, and the phosphorylation of ERK1/2 and STAT3. In summary, our results demonstrated that OEA exerts anti-inflammatory effects by enhancing PPARα signaling, inhibiting the TLR4-mediated NF-κB signaling pathway, and interfering with the ERK1/2-dependent signaling cascade (TLR4/ERK1/2/AP-1/STAT3), which suggests that OEA may be a therapeutic agent for inflammatory diseases.

The extract of Moringa oleifera seeds has been shown to possess various pharmacological properties. In the present study, we assessed the neuropharmacological effects of 70% ethanolic M. oleifera seed extract (MSE) on cognitive impairment caused by scopolamine injection in mice using the passive avoidance and Morris water maze (MWM) tests. MSE (250 or 500 mg/kg) was administered to mice by oral gavage for 7 or 14 days, and cognitive impairment was induced by intraperitoneal injection of scopolamine (4 mg/kg) for 1 or 6 days. Mice that received scopolamine alone showed impaired learning and memory retention and considerably decreased cholinergic system reactivity and neurogenesis in the hippocampus. MSE pretreatment significantly ameliorated scopolamine-induced cognitive impairment and enhanced cholinergic system reactivity and neurogenesis in the hippocampus. Additionally, the protein expressions of phosphorylated Akt, ERK1/2, and CREB in the hippocampus were significantly decreased by scopolamine, but these decreases were reversed by MSE treatment. These results suggest that MSE-induced ameliorative cognitive effects are mediated by enhancement of the cholinergic neurotransmission system and neurogenesis via activation of the Akt, ERK1/2, and CREB signaling pathways. These findings suggest that MSE could be a potent neuropharmacological drug against amnesia, and its mechanism might be modulation of cholinergic activity via the Akt, ERK1/2, and CREB signaling pathways.

Inflammation plays a pivotal role in the pathogenesis of atherosclerosis. Peroxisome proliferator-activated receptor-alpha (PPAR-α) and cannabinoid receptor 2 (CB₂) crucially impact the modulation of inflammation. N-Oleoylethanolamine (OEA), a natural agonist of PPAR-α, can also up-regulate the expression of CB₂ in human umbilical vein endothelial cells (HUVECs) and further shows an antiatherosclerotic effect. Our study was designed to determinate whether OEA could inhibit inflammation in HUVECs induced by tumor necrosis factor-α (TNF-α) and to identify the mechanism of OEA function. Interleukin-6 (IL-6), interleukin-8 (IL-8), vascular adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1) levels were detected in HUVECs exposed to tumor necrosis factor-α in the presence of OEA. The results showed that OEA suppressed the expression of interleukin-6, interleukin-8, vascular adhesion molecule-1, and intercellular adhesion molecule-1 in a dose-dependent manner. OEA also enhanced CB₂ and PPAR-α receptor expression, which contributed to its anti-inflammatory effect. OEA inhibited the nuclear factor-κB (NF-κB) pathway, and the effect of OEA on nuclear factor-κB was partly abolished when HUVECs were pretreated with either CB₂ or PPAR-α antagonist. OEA attenuated tumor necrosis factor-α-induced inflammation in HUVECs by up-regulating the expression of CB₂ and PPAR-α receptors. Furthermore, OEA suppresses the nuclear factor-κB pathway. These results suggest that OEA exerts anti-inflammatory and anti-adhesive effects on HUVECs.

Hyperlipidemia and many other metabolic diseases are related to oxidative stress.Centella asiaticais a traditional Chinese medicine whose antioxidant effect in vitro has been reported. We are interested in whether it possesses this effect in vivo and hence modulates lipid metabolism. Therefore, experiments were carried out on mice and golden hamsters regarding its antioxidant and hypolipidemic effect. We observed that a fraction (CAF3) of the ethanol extract (CAE) ofCentella asiaticahad a cholesterol decrease of 79% and a triglyceride decrease of 95% in acute mice model, so CAF3 was further investigated in high-fat-fed hamster model. It was shown that CAF3 increased SOD and GSH-Px activities and decreased MDA level, and it also improved TC, TG, LDL-C, HDL-C, AST, and ALT levels. L-CAT and SR-BI gene expression in hamsters were increased. Taken together, our data suggest that the CAF3 fraction ofCentella asiaticahas antioxidant and hypolipidemic properties.