Inhibitory effects of phenolic compounds fromArtocarpus styracifoliuson respiratory burst of rat neutrophils

Abstract

Materials and methods:The anti-respiratory burst activities of eight phenolics (20 mM) were assessed by determining luminol-dependent chemiluminiscence in rat PMNs. Cytotoxicity of active compounds (1-1000 mM) was assayed by Trypan blue dye exclusion method. Cell-free models were employed to evaluate scavenging capacity of active compounds (20 mM) against reactive oxygen species.Results: The PMA-induced respiratory burst was significantly inhibited (p50.05) by six isoprenylated phenolics (AS1-6) at the concentration of 20 mM (below the toxic concentration) with the inhibition rate ranging from 25.0 to 99.6%. The inhibitory potency estimated by IC 50 was in the order of AS1 (3.1 mM) 4AS6 (5.9 mM) 4AS2 (9.1 mM) 4AS3 (10.0 mM) 4AS5 (29.7 mM) 4AS4 (57.7 mM). AS1-4, four isoprenylated flavones, potently quenched superoxide anion, hydroxyl radical, and hydrogen peroxide at the concentration of 20 mM with their scavenging rates in the range of 30.1-78.1%, 35.4-69.7%, and 65.5-86.3%, respectively. In contrast, AS5-6, two isoprenylated 2-arylbenzofurans, showed less effect than that exhibited by AS1-4. Conclusion and discussion: The isoprenylated phenolics from A. styracifolius can potently inhibit PMA-induced respiratory burst in rat neutrophils without showing cytotoxicity. The inhibitory effects of these isoprenylated phenolics on the respiratory burst might depend on their different types of structure.

Flavonoids ofArtocarpus heterophyllusLam. heartwood inhibit the innate immune responses of human phagocytes

“…According to a previous study, artocarpanone had a potent antioxidant activity with an IC 50 value of 135.8 μ m . The anti‐respiratory burst effect of this flavonoid is in accordance with previous study on the effect of flavonoid in inhibiting respiratory burst of rat neutrophil …”

“…[33] The antirespiratory burst effect of this flavonoid is in accordance with previous study on the effect of flavonoid in inhibiting respiratory burst of rat neutrophil. [34] Myeloperoxidase is a haemic enzyme which expressed in PMNs. Upon stimulation by phorbol myristate acetate (PMA), PMNs will release MPO which catalyse the production of hypochlorous acid (HClO), as an important microbicidal agent.…”

Inhibitory effect of plant phenolics on fMLP-induced intracellular calcium rise and chemiluminescence of human polymorphonuclear leukocytes and their chemotactic activityin vitro

“…increase in [Ca 2+ ] i ) and/or unspecific scavenging of ROS generated by blood phagocytes in response to fMLP stimulation. In a study on rat PMNs, certain phenolics were unequally potent in suppressing chemiluminsecence of stimulated cells and scavenging radicals in cell-free models, which also suggests more than one mechanism of action (Ren et al, 2014).…”

Unusual Prenylated Stilbene Derivatives with PTP1B Inhibitory Activity from Artocarpus styracifolius

“…The roots of this plant are documented to have various therapeutic effects and are used as a folk medicine to treat rheumatism, psoatic strain, rheumatic heart disease, diabetes, and hemiplegic paralysis [12]. Like other members of the genus Artocarpus, A. styracifolius was previously reported to contain prenylated flavonoids, stilbenes, and 2-arylbenzofurans with various bioactivities, such as anti-plasmodial, anti-trypanosomal, anti-respiratory burst, and cathepsin K inhibitory effects [13][14][15][16]. In a search for PTP1B inhibitors from natural products, a chloroform-soluble extract from the roots of A. styracifolius was found to inhibit PTP1B activity (90 % inhibition at a concentration of 50 µg/mL).…”