Hypoglycemic and antioxidant effects of phenolic extracts and purified hydroxytyrosol from olive mill waste in vitro and in rats

Hamden, Khaled; Allouche, Noureddine; Damak, Mohamed; Elfeki, Abdelfattah

doi:10.1016/j.cbi.2009.04.002

Cited by 154 publications

(123 citation statements)

References 42 publications

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“…Table 2 Body and tissue weights of rats in the control group (C), the group consuming the non-supplemented cholesterol-rich diet (Chol) or the cholesterol-rich diet supplemented with hydroxytyrosol (HT), hydroxytyrosyl acetate (HT-Ac) and ethyl hydroxytyrosyl ether (HT-Et Considering an average daily food intake of 20 g and an average body weight of 300 g, the daily phenolic compound intake was 25 mg kg À1 body weight per day. This is a relatively low dose, comparable with doses used in other studies [8][9][10][11] and within a range proven to elicit no toxic effects in rats. Accordingly, no pathologic alterations or behaviours were observed in the animals during the study.…”

Section: Food Intake Body Weight Gain and Tissue Weightssupporting

confidence: 56%

“…These results are in line with previous human and animal studies showing that phenolic compounds present in virgin olive oil exert benecial cardiovascular effects, particularly improving the lipid prole. 8,10,31 In fact, the European Food Safety Authority has recently issued a positive opinion on the capacity of olive oil phenolic compounds to protect LDL cholesterol from oxidative damage. 32 Several markers show that rats in the present study suffered hepatic stress induced by the cholesterol-rich diet, which may have led to an incipient insulin resistance.…”

Section: Discussionmentioning

confidence: 99%

“…The renal protective effect of olive phenols reducing creatinine levels has already been described in diabetic rats. 8 The retroperitoneal/epididymal fat ratio provides information about adipose tissue distribution, being directly proportional to the abdominal fat accumulation. Both retroperitoneal and epididymal adipose depots are considered visceral fat associated with higher levels of inammation and lipolysis than subcutaneous fat, being related to insulin resistance.…”

Section: Discussionmentioning

confidence: 99%

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Comparative evaluation of the metabolic effects of hydroxytyrosol and its lipophilic derivatives (hydroxytyrosyl acetate and ethyl hydroxytyrosyl ether) in hypercholesterolemic rats

et al. 2014

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Hydroxytyrosol (HT), a virgin olive oil phenolic phytochemical with proven health benefits, has been used to generate new lipophilic antioxidants to preserve fats and oils against autoxidation. The aim of this work is to comparatively evaluate the physiological effects of HT and its lipophilic derivatives, hydroxytyrosyl acetate (HT-Ac) and ethyl hydroxytyrosyl ether (HT-Et), in high-cholesterol fed animals. Male Wistar rats (n ¼ 8)were fed a standard diet (C group), a cholesterol-rich diet (Chol group) or a cholesterol-rich diet supplemented with phenolic compounds (HT group, HT-Ac group and HT-Et group) for 8 weeks. Body and tissue weights, the lipid profile, redox status, and biochemical, hormonal, and inflammatory biomarkers were evaluated. Plasma levels of total cholesterol, LDL cholesterol, glucose, insulin and leptin, as well as malondialdehyde in serum increased in Chol compared to C (p < 0.05). Rats fed the test diets had improved glucose, insulin, leptin and MDA levels and antioxidant capacity status, with HT-Ac being the most effective compound. The studied phenolic compounds also modulated TNF-a and IL-1b plasma levels compared to Chol. HT-Ac and HT-Et improved adipose tissue distribution and adipokine production, decreasing MCP-1 and IL-1b levels. Our results confirm the metabolic effects of HT, which are maintained and even improved by hydrophobic derivatives, particularly HT-Ac.

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Section: Food Intake Body Weight Gain and Tissue Weightssupporting

confidence: 56%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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Comparative evaluation of the metabolic effects of hydroxytyrosol and its lipophilic derivatives (hydroxytyrosyl acetate and ethyl hydroxytyrosyl ether) in hypercholesterolemic rats

et al. 2014

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“…3 and 4 show that MnSOD activity regulates HT-induced extension of CLS. HT has been shown recently to increase superoxide dismutase, catalase, and glutathione peroxidase activity in the liver and kidney of diabetic rats (Hamden et al 2009). Indeed, a significant increase in MnSOD activity, protein, and mRNA levels was observed in HT-treated quiescent cultures of NHFs (Fig.…”

Section: Discussionmentioning

confidence: 99%

“…Several studies report the antioxidant properties of HT in biological systems (Cornwell and Ma 2008;D'Angelo et al 2005;Hamden et al 2009;Jemai et al 2009;Manna et al 1999;O'Dowd et al 2004;Visioli et al 1998). However, the mechanisms leading to the antioxidant properties of HT are not completely understood.…”

Section: Discussionmentioning

confidence: 99%

MnSOD activity regulates hydroxytyrosol-induced extension of chronological lifespan

Sarsour

Kumar

Kalen

et al. 2011

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Chronological lifespan (CLS) is defined as the duration of quiescence in which normal cells retain the capacity to reenter the proliferative cycle. This study investigates whether hydroxytyrosol (HT), a naturally occurring polyphenol found in olives, extends CLS in normal human fibroblasts (NHFs). Quiescent NHFs cultured for a long duration (30-60 days) lose their capacity to repopulate. Approximately 60% of these cells exit the cell cycle permanently; a significant increase in the doubling time of the cell population was observed. CLS was extended in quiescent NHFs that were cultured in the presence of HT for 30-60 days. HT-induced extension of CLS was associated with an approximately 3-fold increase in manganese superoxide dismutase (MnSOD) activity while there was no change in copper-zinc superoxide dismutase, catalase, or glutathione peroxidase protein levels. Quiescent NHFs overexpressing a dominant-negative mutant form of MnSOD failed to extend CLS. HT suppressed ageassociated increase in mitochondrial ROS levels. Results from spectroscopy assays indicate that HT in the presence of peroxidases can undergo catechol-semiquinone-quinone redox cycling generating superoxide, which in a cellular context can activate the antioxidant system, e.g., MnSOD expression. These results demonstrate that HT extends CLS by increasing MnSOD activity and decreasing age-associated mitochondrial reactive oxygen species accumulation.

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Assessment of the antidiabetic and antilipidemic properties of bacillus subtilis spb1 biosurfactant in alloxan‐induced diabetic rats

et al. 2015

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The present study aimed to scrutinize the potential of Bacillus subtilis SPB1biosurfactant, orally administered, for preventing diabetic complications in rats. The findings revealed that, Bacillus subtilis biosurfactant was an effective reducer of α-amylase activity in the plasma. Moreover, this supplement helped protect the β-cells from death and damage. Both the inhibitory action of SPB1 biosurfactant on α-amylase and the protection of the pancreas' β-cells lead to a decrease of the blood glucose levels, consequently antihyperglycemic effect. Interestingly, this lipopeptide biosurfactant modulated key enzyme related to hyperlipidemia as lipase; which leads to the regulation of the lipid profile in serum by the delay in the absorption of LDL-cholesterol and triglycerides, and a significant increase in HDL-cholesterol. Histological analyses also showed that it exerted a protective action on the pancreases and efficiently preserved the liver-kidney functions of diabetic rats, evidenced by significant decreases in aspartate transaminase, alanine transaminase, gamma-glytamyl transpeptidase and lactate deshydrogenase activities in the plasma, as well as in the creatinine and urea contents. Overall, the present study demonstrated that the hypoglycemic and antilipidemic activities exhibited by Bacillus subtilis biosurfactant were effective enough to alleviate induced diabetes in experimental rats. Therefore, SPB1biosurfactant could be considered as a potential strong candidate for the treatment and prevention of diabetes.

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Hypoglycemic and antioxidant effects of phenolic extracts and purified hydroxytyrosol from olive mill waste in vitro and in rats

Cited by 154 publications

References 42 publications

Comparative evaluation of the metabolic effects of hydroxytyrosol and its lipophilic derivatives (hydroxytyrosyl acetate and ethyl hydroxytyrosyl ether) in hypercholesterolemic rats

Comparative evaluation of the metabolic effects of hydroxytyrosol and its lipophilic derivatives (hydroxytyrosyl acetate and ethyl hydroxytyrosyl ether) in hypercholesterolemic rats

MnSOD activity regulates hydroxytyrosol-induced extension of chronological lifespan

Assessment of the antidiabetic and antilipidemic properties of bacillus subtilis spb1 biosurfactant in alloxan‐induced diabetic rats

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