Naproxen-Derived New Compound Inhibits the NF-κB, MAPK and PI3K/Akt Signaling Pathways Synergistically with Resveratrol in RAW264.7 Cells.

Naproxen is widely used for anti-inflammatory treatment but it can lead to serious side effects. To improve the anti-inflammatory activity and safety, a novel naproxen derivative containing cinnamic acid (NDC) was synthesized and used in combination with resveratrol. The results showed that the combination of NDC and resveratrol at different ratios have a synergistic anti-inflammatory efficacy in RAW264.7 macrophage cells. It was indicated that the combination of NDC and resveratrol at a ratio of 2:1 significantly inhibited the expression of carbon monoxide (NO), tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), induced nitric oxide synthase (iNOS), cyclooxygenase 2 (COX-2) and reactive oxygen species (ROS) without detectable side effects on cell viability. Further studies revealed that these anti-inflammatory effects were mediated by the activation of nuclear factor kappa-B (NF-κB), mitogen-activated protein kinase (MAPK) and phosphoinositide-3 kinase (PI3K)/protein kinase B (Akt) signaling pathways, respectively. Taken together, these results highlighted the synergistic NDC and resveratrol anti-inflammatory activity that could be further explored as a strategy for the treatment of inflammatory disease with an improved safety profile.

Inhibitory effect of plant essential oils on α-glucosidase.

Diabetes mellitus, associated with α-glucosidase, has been considered as a chronic metabolic disorder, seriously affecting human health. Thus, searching natural α-glucosidase inhibitors and investigating their inhibition mechanism are urgently important. In this study, sixty-two essential oils (EOs), derived from aromatic plants, were found to exert different inhibition on α-glucosidase. The further study revealed that the most potent EOs against α-glucosidase were chuan-xiong, fructus cnidii, sacha inchi, aloe, ganoderma lucidum spore and ginger with IC50 values of 3.02, 2.88, 7.37, 5.06, 5.32 and 7.40 µg/mL. Moreover, the inhibitory mechanism and kinetics studies found that chuan-xiong and sacha inchi were reversible and mixed-type inhibitors. Fructus cnidii, aloe, ganoderma lucidum spore and ginger were reversible and uncompetitive-type inhibitors. It is suggested that EOs, being of natural origin, would be promising anti-α-glucosidase agents.

Inhibition of plant essential oils and their interaction in binary combinations against tyrosinase.

Background: Essential oils (EOs), derived from aromatic plants, exhibit properties beneficial to health, such as anti-inflammatory, anti-oxidative, antidiabetic, and antiaging effects. However, the effect of EOs and their interaction in binary combinations against tyrosinase is not yet known. Objective: To evaluate the underlying mechanisms of EOs and their interaction in binary combinations against tyrosinas. Design: We explored to investigate the inhibitory effect of 65 EOs and the interaction among cinnamon, bay, and magnolia officinalis in their binary combinations against tyrosinase. In addition, the main constituents of cinnamon, bay, and magnolia officinalis were analyzed by gas chromatography-mass spectrometry (GC-MS). Results: The results showed that the most potent EOs against tyrosinase were cinnamon, bay, and magnolia officinalis with IC50 values of 25.7, 30.8, and 61.9 µg/mL, respectively. Moreover, the inhibitory mechanism and kinetics studies revealed that cinnamon and bay were reversible and competitive-type inhibitors, and magnolia officinalis was a reversible and mixed-type inhibitor. In addition, these results, assessed in mixtures of three binary combinations, indicated that the combination of cinnamon with bay at different dose and at dose ratio had a strong antagonistic effect against tyrosinase. Magnolia officinalis combined with cinnamon or bay experienced both antagonistic and synergistic effect in anti-tyrosinase activity. Conclusion: It is revealed that natural EOs would be promising to be effective anti-tyrosinase agents, and binary combinations of cinnamon, bay, and magnolia officinalis might not have synergistic effects on tyrosinase under certain condition.