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ABSTRACT: Olive leaf extract (OLE) has antioxidant and antiinflammatory actions. However, the role of OLE in mechanical inflammatory arthritis (osteoarthritis, OA) is unclear. This study investigated the effect of OLE on the development of kaolin and carrageenan-induced arthritis, a murine model of OA. Administration of OLE significantly ameliorated paw swelling, the paw Evans blue content and the histopathological scores. In the human monocyte cell line, THP-1, the OLE reduced the LPS-induced TNF-α production and was dose dependent. Croton oil-induced ear edema in mice also revealed that treatment with OLE suppressed ear edema, myeloperoxidase (MPO) production and was dose dependent. These results indicated that OLE is an effective antiarthritis agent through an antiinflammation mechanism. Also OLE may be beneficial for the treatment of OA in humans.
Phytotherapy Research 07/2011; 26(3):397-402. · 2.09 Impact Factor
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ABSTRACT: Hydroxytyrosol (HT) is a simple phenol compound extracted from olive leaves. The content of HT in the studied preparation was about 20%, and the preparation was called hydroxytyrosol-20 (HT-20). HT has antioxidant and antiinflammatory activities. There has been no report so far on the efficacy of HT-20 in carrageenan-induced acute inflammation and hyperalgesia in rats. Therefore, the aim of this study was to assess the inhibitory role of HT-20 on carrageenan-induced swelling and hyperalgesia of rat paw. Paw inflammation was assessed by the increase in paw volume and hyperalgesia. The rat paws were cut out under ether anesthesia at 270 min after administration of carrageenan. The tissue of the right paw was isolated separately from the individual rat. The levels of the tumor necrosis factor-alpha (TNF-alpha), interleukin 1beta (IL-1beta) and interleukin 10 (IL-10) mRNA in the tissue were estimated by reverse transcription-polymerase chain reaction (RT-PCR). The results showed that the paw pressure thresholds of rats orally administered HT-20 significantly increased at 210, 240 and 270 min after administration of carrageenan, compared with corresponding basal paw pressure thresholds; the degree of swelling of the right hind paw showed a statistically significant reduction, compared with rats in the carrageenan-treated control. In this model, HT-20 appears to decrease pro-inflammatory cytokines IL-1beta and TNF-alpha and not to increase the antiinflammatory cytokine mRNA expression of IL-10.
Phytotherapy Research 01/2009; 23(5):646-50. · 2.09 Impact Factor
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ABSTRACT: The chemoprotective effect of hydroxytyrosol (HT), a strong antioxidant compound from extra virgin olive oil, against acrylamide (AA)-induced genotoxicity was investigated in a human hepatoma cell line, HepG2. The micronucleus test (MNT) assay was used to monitor genotoxicity. In MNT, we found that HT at all tested concentrations (12.5-50 microM) significantly reduced the micronuclei frequencies in a concentration-dependent manner caused by AA. In order to clarify the underlying mechanisms we measured the intracellular reactive oxygen species (ROS) formation using 2,7-dichlorofluorescein diacetate (DCFH-DA) as a fluorescent probe. Intracellular glutathione (GSH) level was estimated by fluorometric methods. The rate-limiting enzyme in GSH synthesis is gamma-glutamylcysteine synthetase (gamma-GCS) and gamma-GCS was measured using Western blotting. The results showed that HT significantly concentration-dependent reduced the genotoxicity caused by AA. Furthermore, HT was able to reduce intracellular ROS formation and attenuate GSH depletion caused by AA in a concentration-dependent manner. It was also found that HT enhanced the expression of gamma-GCS in HepG2 cells treated with 10 mM AA using immunoblotting in a concentration-dependent manner. The results showed that HT reduced the AA-induced genotoxicity by decreasing the ROS level and increasing the GSH level. The data strongly suggest that HT have significant protective ability against AA-induced genotoxicity in vitro.
Chemico-biological interactions 09/2008; 176(2-3):173-8. · 2.46 Impact Factor
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ABSTRACT: The anti-atherogenic effect of olive leaf extract is supposed to be related to its activities of anti-oxidation and anti-inflammation.
To prove the effect of anti-atherosclerosis by olive leaf extract (OLE) and to elucidate the mechanism behind.
Twenty-four rabbits were assigned to the control, high lipid diet (HLD) and OLE group that were fed with standard diet, HLD and HLD supplemented with OLE, respectively. Serum levels of atherosclerosis related markers, triglyceride (TG), total cholesterol (T-CHO), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) and malondialdehyde (MDA) were detected at the ends of week 2, 4 and 6. Surface lesions and thickness of intimas were measured at the end of week6. The protein and/or mRNA expressions of inflammation factors, monocyte chemoattractant protein (MCP)-1, vascular cell adhesion molecule (VCAM)-1, nuclear factor-kappa B (NF-kappaB) and tumor necrosis factor alpha (TNF-alpha) were investigated by immunohistochemistry and RT-PCR.
Atherosclerotic lesions were found in the HLD and OLE groups but not in the control group. In comparison with that in the HLD group, reduced size and thickness of intima (0.31 +/- 0.26 in the HLD group versus 0.10 +/- 0.03 mm in the OLE group) were found in the OLE group. The MDA level, an indicator of antioxidant status, was 35.27 +/- 15.37 in the HLD group and 20.63 +/- 11.52 nmol/ml in the OLE group. The level of CHO, TG and LDL-C were 104.46 +/- 30.34, 2.48 +/- 1.11, 82.83 +/- 28.44 mmol/l in the HLD group versus 83.03 +/- 27.23, 1.84 +/- 0.44, 59.51 +/- 23.72 mmol/l in the OLE group. Down-regulated expressions of MCP-1, VCAM-1, NF-kappaB and TNF-alpha at both protein and mRNA level (P < 0.05) were also found with the administration of OLE.
This study proved the effect of OLE on inhibition of atherosclerosis, which is related to the suppressed inflammatory response.
European Journal of Nutrition 08/2008; 47(5):235-43. · 2.75 Impact Factor
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ABSTRACT: The chemoprotective effect of hydroxytyrosol (HT) against Sudan I-induced genotoxicity was investigated in a human hepatoma cell line, HepG2. The comet assay and micronucleus (MN) assay were used to monitor genotoxicity. Intracellular reactive oxygen species (ROS) formation was measured using a fluorescent probe, 2,7-dichlorofluorescein diacetate (DCFH-DA). The levels of oxidative DNA damage and lipid peroxidation were estimated by immunocytochemistry analysis of 8-hydroxydeoxyguanosine (8-OHdG) and by measuring levels of thiobarbituric acid-reactive substances (TBARS), respectively. Intracellular glutathione (GSH) level was estimated by fluorometric methods. The results showed that HT significantly reduced the genotoxicity caused by Sudan I. Furthermore, HT ameliorated lipid pexidation as demonstrated by a reduction in TBARS formation and attenuated GSH depletion in a concentration-dependent manner. It was also found that HT reduced intracellular ROS formation and 8-OHdG level caused by Sudan I. These results strongly suggest that HT has significant protective ability against Sudan I-induced genotoxicity.
Free Radical Research 03/2008; 42(2):189-95. · 2.88 Impact Factor
