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Context: Syzygium aromaticum (L.) Merr. & Perry (Myrtaceae), commonly known as clove, originally found in the Muluku Islands in East Indonesia, is widely used as a spice and has numerous medicinal properties., Objective: This study investigated the antioxidant potential of S. aromaticum aqueous extract (SAAE) in vitro and its protective effects on lipopolysaccharide (LPS)-induced lung inflammation in mice., Material and Methods: Neutrophils were isolated from healthy donors and reactive oxygen species (ROS) generation was measured by luminol-amplified chemiluminescence. Superoxide anion generation was detected by cytochrome c reduction assay. H 2 O 2 was detected by DCFH fluorescence assay. Myeloperoxidase (MPO) activity was mesured by tetramethyl benzidine oxidation method. To study the anti-inflammatory activity of SAAE, lung inflammation was induced in mice (BALB/c) by intra-tracheal instillation of lypopolysaccharide (5 µg/mouse), and SAAE (200 mg/kg body weight) was injected intraperitoneally prior to LPS administration. Bronchoalveolar lavage and lung tissue were collected to assess inflammatory cells count and total protein content. Metalloproteinases activity was detected by zymography technique., Results: SAAE inhibited luminol-amplified chemiluminescence of resting neutrophils and N-formyl-methionyl-leucyl-phenylalanine- or phorbol myristate acetate-stimulated neutrophils, with an inhibitory effect starting at a concentration as low as 0.5 µg/mL. Moreover, SAAE reduced significantly MPO activity and it exhibits a dose-dependent action (IC 50 = 0.5 µg/mL). In vivo results showed that SAAE decreased markedly neutrophil count (From 61% to 15%) and proteins leakage into bronchoalveolar lavage fluid. Gelatin zymography assay showed that S. aromaticum inhibited MMP-2 (15%) and MMP-9 (18%) activity in lung homogenates., Discussion and Conclusion: Our results suggest that the anti-inflammatory activity of SAAE, in vivo, is due to the inhibition of ROS production and metalloproteinases activity via its action on MPO. According to these findings, SAAE could be a potential source of new compounds with anti-inflammatory activity.

Punica granatum peel aqueous extract (PGE) is widely used to treat disorders such as inflammation, ulcers and infections, but its pharmacological target is not known. In this study we investigated the effect of PGE on human neutrophil reactive oxygen species (ROS) production in vitro and on LPS-induced lung inflammation in vivo in mice. Neutrophils were isolated and ROS generation was measured by luminol-amplified chemiluminescence. Superoxide anion generation was detected by the cytochrome c reduction assay. H(2)O(2) was detected by DCFH fluorescence assay. Myeloperoxidase (MPO) activity was measured by the tetramethyl benzidine oxidation method. Lung inflammation was induced in mice by LPS instillation. PGE inhibited luminol-amplified chemiluminescence of resting neutrophils and N-formyl-methionyl-leucyl-phenylalanine (fMLF)- or phorbol myristate acetate (PMA)-stimulated neutrophils, in a concentration-dependent manner. PGE had no effect on superoxide anion generation, suggesting that it does not directly inhibit NADPH oxidase activity or activation pathways, or scavenge superoxide anions. PGE did not scavenge H(2)O(2) but directly inhibited myeloperoxidase activity in vitro. In vivo studies showed that PGE also attenuated LPS-induced lung inflammation in mice. So this study reveals that PGE inhibits neutrophil MPO activity and attenuates LPS-induced lung inflammation in mice. Inhibition of MPO activity by PGE could explain its anti-inflammatory action., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Eugenol (Eug) is a polyphenol extracted from the essential oil of Syzygium aromaticum (L.) Merr. and Perry (Myrtaceae). The health benefits of eugenol in human diseases were proved in several studies. This work aims to evaluate the effect of eugenol on lung inflammatory disorders. For this, using human neutrophils, the antioxidant activity of eugenol was investigated in vitro. Furthermore, a model of LPS-induced lung injury in mice was used to study the anti-inflammatory effect of eugenol in vivo. Results showed that eugenol inhibits luminol-amplified chemiluminescence of resting neutrophils and after stimulation with N-formyl-methionyl-leucyl-phenylalanine (fMLF) peptide or phorbol myristate acetate (PMA). This effect was dose dependent and was significant from a low concentration of 0.1 µg/mL. Furthermore, eugenol inhibited myeloperoxidase (MPO) activity without affecting its degranulation. Eugenol has no scavenging effect on hydrogen peroxide (H2O2) and superoxide anion (O2−). Pretreatment of mice with eugenol prior to the administration of intra-tracheal LPS significantly reduced neutrophil accumulation in the bronchoalveolar lavage fluid (BALF) and decreased total proteins concentration. Moreover, eugenol clearly inhibited the activity of matrix metalloproteinases MMP-2 (21%) and MMP-9 (28%), stimulated by LPS administration. These results suggest that the anti-inflammatory effect of eugenol against the LPS-induced lung inflammation could be exerted via inhibiting myeloperoxidase and metalloproteinases activity. Thus, eugenol could be a promising molecule for the treatment of lung inflammatory diseases. [ABSTRACT FROM AUTHOR]

Aim: Plants used in traditional medicine produce diverse active metabolites exhibiting various medicinal properties. For several centuries Citrillus colocynthis and Punica granatum have been used to treat inflammation, cancer, edema, bacterial infections and diabetes. The objectives of this work were to study the effect of C. colocynthis and P. granatum peel aqueous extracts, on activity of metalloproteinases, enzymes implicated in chronic inflammatory diseases such Chronic Obstructive Pulmonary Disease (COPD) and emphysema. Materials and Methods: Lung inflammation was induced in the mice (Strain BALB/c) by intra-tracheal instillation of lipopolysaccharide (5 µg/mouse) and P. granatum peel extract (PGE) or C. colocynthis peel extract (CCPAE) (200 mg/Kg body weight) was injected intraperitoneally prior to LPS administration. Bronchoalveolar lavage and lung tissue were collected to assess inflammatory cells count and total protein content. Metalloproteinases activity and expression was detected by RT-PCT and zymography techniques, respectively. Results: Results showed that PGE and CCPE decreased markedly neutrophils count and proteins leakage into Bronchoalveolar Lavage Fluid (BALF). Gelatin zymography assay showed that PGE inhibited MMP-2 and MMP-9 activity in BALF and in lung homogenates. However, CCPE inhibited MMP-2 and MMP-9 in lung homogenates but only MMP-2 in BALF. Furthermore, both PGE and CCPAE inhibit MMP-2 and -9, expression in the lung. Conclusion: Our results showed that PGE and CCPAE exhibit anti-inflammatory and, antimetalloproteinases especially MMP-2 and -9, activities. According to these findings, these natural products could be used as a potential source of new compounds with anti-inflammatory and anti-metalloproteinases activity. [ABSTRACT FROM AUTHOR]