Biofactors - Volume 23, issue 1

Authors: Terao, Junji | Hiwada, Mio | Taguchi, Keiko | Takahara, Keigo | Mohri, Satoshi

Article Type: Research Article

Abstract: Vegetables are generally recognized as rich sources of dietary antioxidants for inhibiting lipid peroxidation. Here we investigated lipid hydroperoxide (LOOH)-reducing activity of several vegetables to estimate their role on the prevention of lipid peroxidation in food and the digestive tract. By using HPLC analysis, we screened vegetables possessing the ability to convert 13-hydroperoxyoctadecadienoic acid (13-HPODE) to its reduced derivative, 13-hydroxyoctadecadienoic acid (13-HODE). Welsh onion (Allium fistulosum L.) was found to be highly …active in the reduction of 13-HPODE among tested vegetables. There was no relationship between 13-HPODE reducing activity and GSH peroxidase (GPX) activity in the tested vegetables. 13-HPODE-reducing activity of welsh onion was enhanced by the addition of sulfhydryl compounds including glutathione (GSH). Neither GPX inhibitor nor heat treatment suppressed 13-HPODE-reducing activity effectively. These results suggest that welsh onion and other vegetables contain GPX mimics responsible for the reduction of LOOH. GPX mimics may be helpful in the attenuation of harmful effect of LOOH from food. Show more

Keywords: glutathione peroxidase, lipid peroxidation, preventive antioxidant, welsh onion, hydroperoxide-reducing activity

Citation: BioFactors, vol. 23, no. 1, pp. 1-6, 2005

Authors: Cicero, A.F.G. | Derosa, G. | Miconi, A. | Laghi, L. | Nascetti, S. | Gaddi, A.

Article Type: Research Article

Abstract: Objective: to describe the effect of CoQ10 (added to either a fibrate, or PUFA or association of both) in patients affected by massive hypertriglyceridemia (MHTG) resistant to fibrates and PUFA. Design: Open, sequential, comparative intervention study. Setting: Specialised centres for dyslipidemia management. Subjects: 15 subjects (mean age: 45.1 ± 12.5 years) affected by MHTG and hyporesponsive to either fibrates, or PUFA, or fibrates-PUFA association, and 15 age-matched subjects regularly responders to PUFA and …fenofibrate treatment. Interventions: Treatment for periods of 6 weeks each with the following consecutive treatments: CoQ10 150 mg/day, PUFA 3000 mg/day, fenofibrate 200 mg/day, PUFA 3000 mg/day + fenofibrate 200 mg/day, PUFA 3000 mg/day + CoQ10 150 mg/day, fenofibrate 200 mg/day + CoQ10 150 mg/day, and finally, fenofibrate 200 mg/day + PUFA 3000 mg/day + CoQ10 150 mg/day. Results: CoQ10 supplementation improved, in the control group, systolic and diastolic blood pressure, creatinine and Lp(a) plasma levels, both during fenofibrate and/or PUFA treatment. In MHTG group, CoQ10 supplementation significantly improved TG, TC, Lp(a), uric acid and blood pressure during fenofibrate treatment, but only Lp(a) and blood pressure during PUFA treatment. Fenofibrate appeared to have better effect on hsCRP and γ-GT plasma levels than PUFA. No significant change was observed in any group and under any treatment in regards to homocysteinemia, PAI-1, or t-PA. Conclusion: Even though the mechanism of action through which the effects were obtained is yet to be elucidated, adding CoQ10 to fenofibrate could improve the drug's efficacy in MHTG patients not responding to fenofibrate alone. Show more

Keywords: massive hypertriglyceridemia, therapy, fenofibrate, coenzyme Q10, polyunsaturated fatty acids

Citation: BioFactors, vol. 23, no. 1, pp. 7-14, 2005

Authors: Yamasaki, Keiichi | Takemura, Shigekazu | Minamiyama, Yukiko | Hai, Seikan | Yamamoto, Satoshi | Kodai, Shintaro | Hirohashi, Kazuhiro | Suehiro, Shigefumi

Article Type: Research Article

Abstract: A large number of studies have reported the action of K_{ATP} channel openers in accelerating the proliferation of hepatocytes and many other cell types in vitro. Few studies, however, have examined the proliferative effect of K_{ATP} channel openers in vivo. The aim of this study was to determine whether the K_{ATP} channel opener minoxidil accelerates liver regeneration after partial hepatectomy (PH) in vivo. Male Wistar rats …underwent a 70% partial hepatectomy (PH) after receiving a subcutaneous injection of minoxidil (0.01 mg/kg or 0.03 mg/kg). Some of the rats were intravenously treated with 5-hydroxydecanoic acid (5-HD, 10 mg/kg) just before the minoxidil injection. Seventy-two hours after PH, DNA synthesis was immunohistochemically assessed by bromodeoxyuridine (BrdU) incorporation into the nuclei. Minoxidil induced significant and dose-dependent increase in the BrdU labeling index after PH, and 5-HD reversed this minoxidil-induced change. Minoxidil did not significantly affect the changes in liver weight and liver function after PH. The hepatic levels of prealbumin decreased by about 60% after PH and minoxidil inhibited the decrease. In conclusion, the K_{ATP} channel opener minoxidil enhanced DNA synthesis after PH without affecting the liver function. Show more

Keywords: K_{ATP} channel opener, minoxidil, DNA synthesis, partial hepatectomy, rats

Citation: BioFactors, vol. 23, no. 1, pp. 15-23, 2005

Authors: Basini, Giuseppina | Bianco, Federico | Grasselli, Francesca

Article Type: Research Article

Abstract: Vascular Endothelial Growth Factor (VEGF) plays a pivotal role in the physiological ovarian angiogenic process: its production appears to be stimulated by the hypoxic environment which takes place during follicle development. Recently, epigallocatechin-3-gallate (EGCG) from green tea has been used in livestock nutrition as an alternative to antibiotics. However, despite many potential benefits of EGCG consumption, it is also important to get an insight on the possible reproductive-related consequences of feeding supplementation: …in fact this substance has been found to inhibit angiogenesis, a process fundamental for follicle development. Therefore, we evaluated the effect of EGCG (5 and 50 μg/ml) on the production of the main angiogenetic factor, VEGF, by swine granulosa cells cultured in normoxia (19% O_{2} ), partial (5% O_{2} ) or total hypoxia (1% O_{2} ). In addition, we studied the effect of the catechin on cell proliferation. Our data demontrate that both partial and total hypoxia stimulated VEGF production. EGCG reduced VEGF production independently of the O_{2} condition: 50 μM was the most effective doses. Granulosa cell proliferation was inhibited by EGCG even if only by the highest concentration. This effect might possibly be due to the decrease induced in VEGF production. Therefore feeding supplementation with EGCG should be carefully considered. Show more

Keywords: EGCG, VEGF, granulosa cells, hypoxia, angiogenesis

Citation: BioFactors, vol. 23, no. 1, pp. 25-33, 2005

Authors: Deiana, Monica | Rosa, Antonella | Corona, Giulia | Collu, Stefania | Ennas, Maria Grazia | Dessì, Maria Assunta

Article Type: Research Article

Abstract: Intraperitoneal injection of the iron chelate ferric-nitrilotriacetate (Fe-NTA) induces in rodents renal and hepatic suffering, associated with oxidative damage. We investigated the oxidation pattern in plasma of treated rats in relation to liver and kidney, monitoring the variation of the lipid components more susceptible to oxidation, unsaturated fatty acids (UFA) and α-tocopherol, as biomarkers of the oxidative damage. A sublethal dose of Fe-NTA induced a strong and extremely significant decrease of UFA …levels at 1 h after injection in the plasma compartment and at 3 h in the kidney, with reductions up to 40–50% of the control values, together with an increase of conjugated dienes fatty acids hydroperoxides and a consumption of α-tocopherol. The same modifications were observed in the liver, but to a lesser extent. Histological observation proved that biochemical changes in the lipid fraction were a direct consequence of an ongoing membrane lipid peroxidation process. Our data show that oxidative damage to the lipid fraction is initially evident in the plasma compartment, where Fe-NTA toxicity is assumed to be caused by the elevation of serum free iron concentration, and proceeds with different speed and severity in the kidney and liver. Show more

Keywords: ferric nitrilotriacetate, lipid peroxidation, oxidative stress, polyunsaturated fatty acids, plasma

Citation: BioFactors, vol. 23, no. 1, pp. 35-44, 2005

Authors: Margaritis, Irène | Rousseau, Anne-Sophie | Hininger, Isabelle | Palazzetti, Stéphane | Arnaud, Josiane | Roussel, Anne-Marie

Article Type: Research Article

Abstract: Selenium requirements in athletes are supposed to be increased with energy expenditure (EE) to preserve selenium status and an optimal antioxidant balance. The question of whether selenium intakes are related to EE and whether plasma selenium status induces up-regulation in erythrocyte endogenous antioxidant defense and decreases plasma oxidative damage markers in athletes was addressed. 118 well-trained athletes completed 7 d food and activities records in a cross-sectional study. Blood was sampled on day 8. Among the …athletes, 23% of the males and 66% of the females had selenium intakes below two-third of the French RDA. Plasma selenium concentrations in most of less trained athletes were lower than the postulated concentration to be required to maximize erythrocyte GSH-Px activity. Athletes with the highest daily EE had the highest selenium intakes, percentage of vegetal protein intakes and plasma selenium concentrations. Only 2.6% of the athletes exhibited low plasma selenium concentrations (< 0.75 μmol/l). The relation between plasma selenium and EE was polynomial (r = 0.50; P < 0.005). Erythrocyte GSH-Px activity in athletes was not linked to selenium status. Selenium requirements are increased in athletes without being linearly related to EE. Show more

Keywords: lipid peroxidation, glutathione reductase, glutathione peroxidase, thiols, oxidative stress, superoxide dismutase

Citation: BioFactors, vol. 23, no. 1, pp. 45-55, 2005