Rosmarinic acid exerts a neuroprotective effect in the kainate rat model of temporal lobe epilepsy: Underlying mechanisms

Abstract

Context: Temporal lobe epilepsy (TLE) is an intractable neurological disorder. Rosmarinic acid (RA) is a natural polyphenol with antioxidant, anti-apoptotic, and anti-inflammatory properties.

Objective: This study evaluates beneficial effect of RA in intrahippocampal kainate-induced model of TLE.

Materials and methods: Rats were divided into sham, RA-pretreated sham, kainate, and sodium valproate (VA) or RA-pretreated kainate groups. Rats received RA or VA p.o. at doses of 10 or 300?mg/kg/d, respectively, starting 1?week before the surgery. After 6?weeks, seizure intensity, apoptosis, and oxidative stress markers were evaluated in addition to determination of Timm index as an indicator of mossy fiber sprouting (MFS) and the number of Nissl-stained neurons.

Results: All rats in the kainate group had seizure and 24.3% of rats in the kainate?+?VA group and 36.7% of rats in the kainate?+?RA group showed seizure. The kainate group had a significant elevation of malondialdehyde (MDA) (p?<?0.05) and nitrite (p?<?0.01) and reduction of glutathione (GSH) and catalase activity (p?<?0.05) and pretreatment of kainate-lesioned rats with RA or VA significantly lowered MDA and nitrite content (p?<?0.05) and raised activity of catalase (p?<?0.05). The kainate group also had a significant reduction of neurons in CA1 and CA3 regions and an elevation of Timm index (p?<?0.05–0.001) and RA or VA significantly (p?<?0.05–0.01) prevented these changes.

Discussion and conclusion: RA could attenuate seizure, mitigates oxidative stress, augments the activity of defensive systems, and prevent hippocampal neuronal loss and MFS in the kainate model of TLE.     

The protective potential of metformin against acetaminophen-induced hepatotoxicity in BALB/C mice

Context: Acetaminophen overdose is regarded to a common cause of acute liver failure. The hepatotoxicity leads to mitochondrial oxidative stress and subsequent necrotic hepatocellular death.

Objective: This study examines the protective effect of metformin on acetaminophen-induced oxidative stress, inflammation and subsequent hepatotoxicity in mice.

Materials and methods: Male BALB/c mice were orally administered to acetaminophen (250?mg/kg/d) for a 7-day period. The mice received metformin (100 and 200?mg/kg/d, p.o.) for 21 days. To evaluate acetaminophen-induced oxidative stress, liver tissue level of malodialdehyde (MDA), end product of membrane lipid peroxidation, and activities of superoxide dismutase (SOD) and glutathione (GSH) were measured. Histological analysis and measurement of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) were performed. Moreover, tissue concentrations of proinflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), along with, C-reactive protein (CRP) were assessed.

Results: Acetaminophen caused focal hepatocyte necrosis, inflammation and fatty degeneration, as well as increased tissue levels of AST, ALT, ALP and MDA, and also decreased GSH and SOD activities. Moreover, IL-6, TNF-α and CRP levels were increased following acetaminophen hepatotoxicity. Metformin (200?mg/kg/d) significantly normalized MDA, SOD and GSH levels (p?<?0.001), and exerted a hepatoprotective effect by significant decreasing ALT, AST and ALP concentrations (p?<?0.001). The tissue levels of IL-6, TNF-α and CRP were markedly decreased by 21-day treatment with metformin (200?mg/kg/d) (p?<?0.001).

Discussion: The results suggest metformin protects hepatocytes against acute acetaminophen toxicity. Metformin is indicated to diminish oxidative stress, proinflammatory cytokines, and hepatocyte necrosis.     

Comparison of protective and curative potential of Daucus carota root extract on renal ischemia reperfusion injury in rats

Abstract

Context: Daucus carota Linn (Apiaceae), a useful vegetable, is traditionally used in treating kidney and hepatic dysfunctions.

Objective: To evaluate the protective and curative potential of D. carota root extract on renal ischemia reperfusion injury in rats.

Materials and methods: Wistar rats were selected with 8?+?8 groups (n?=?6). Renal pedicles of rats were occluded for 45?min and allowed for reperfusion period. In protective and curative studies, 14 days prior and 14 days after the induction of ischemia/reperfusion (I/R), rats received petroleum ether extract (PEE 250 and 500?mg/kg), fractional methanol extract (FME 250 and 500?mg/kg) and direct methanol extract (DME 250 and 500?mg/kg) of Daucus carota root, orally, once daily.

Results: PEE at a dose of 500?mg/kg significantly (p?<?0.001) reduced the levels of serum creatinine (0.853–3.090?mg/dl), uric acid (1.300–3.500?mg/dl) and urea (58.26–132.00?mg/dl) compared to disease control. FME at a dose of 500?mg/kg body weight significantly (p?<?0.001) reduced the levels of serum creatinine (0.960–3.090?mg/dl), uric acid (1.700–3.500?mg/dl) and urea (77.17–132.00?mg/dl) compared to disease control. DME at a dose of 500?mg/kg body weight significantly (p?<?0.001) reduced the levels of serum creatinine (1.173–3.090?mg/dl), uric acid (2.267–3.500?mg/dl) and urea (84.75–132.00?mg/dl) compared to disease control.

Discussion and conclusion: Findings demonstrate that postconditioning with the D. carota root extract significantly improves kidney function in I/R rats.     

Efficacy and safety of therapy with metformin plus pioglitazone in the treatment of patients with type 2 diabetes: a double-blind,placebo-controlled,clinical trial

ABSTRACT

Objective: To assess the efficacy and safety of combination therapy with pioglitazone and metformin in Japanese patients with type 2 diabetes.

Research design and methods: During a 12-week observation period 236 patients were treated with metformin 500 or 750?mg/day. 169 patients with a confirmed HbA_1c level ≥ 6.5% were randomized (stratified according to metformin dosage) to receive pioglitazone 15?mg/day for 12 weeks then increased to 30?mg/day for a further 16 weeks (n?=?83), or placebo (n?=?86). Outcome measures included HbA_1c, fasting blood glucose (FBG), percentage of patients achieving HbA_1c?<?6.5%, lipid profile, and other metabolic parameters.

Results: Mean HbA_1c was reduced by 0.67% in patients receiving pioglitazone plus metformin versus an increase of 0.25% in those receiving metformin alone (p?<?0.0001). After 8 weeks’ treatment and until the end of the study, HbA_1c was significantly lower with pioglitazone plus metformin and more patients in this group achieved an HbA_1c?<?6.5% (38.6% vs. 8.1%; p?<?0.0001). FBG was also reduced by a significantly greater amount in patients receiving pioglitazone plus metformin compared with metformin monotherapy (?20.5 vs. 1.9?mg/dl; p?<?0.0001). Combination therapy was associated with significantly increased HDL-cholesterol, total cholesterol, and adiponectin, and significantly decreased levels of fasting insulin, free fatty acids, and homeostasis model assessment insulin resistance (HOMA-R) compared with metformin monotherapy. Overall, combination therapy and monotherapy were equally well tolerated and the incidence of adverse effects ‘possibly’ related to therapy was 15.7% and 11.6% (p?=?0.505), respectively. Edema occurred slightly more often in the combination group (6.0 vs. 1.2%).

Conclusion: Pioglitazone plus metformin significantly improved glycemic control (HbA_1c and FBG), and markers associated with increased insulin resistance and cardiovascular risk compared with metformin monotherapy.

Clinical trial registration number: UMIN 000001110.     

The beneficial effects on blood pressure,dyslipidemia and oxidative stress of Sambucus nigra extract associated with renin inhibitors

Context: The health effects of Sambucus nigra L. (Caprifoliaceae) could be due to polyphenols whose modes of action differ from the traditional one proposed for exogenous antioxidants.

Objective: The study emphasizes the effects of the association between the renin inhibitor and the polyphenolic extract on biochemical parameters and systolic (TAS) and diastolic (TAD) blood pressure within an L NAME-induced experimental model of arterial hypertension (AHT).

Materials and methods: The polyphenols are extracted with ethanol from isolated and purified vegetable material represented by the mature fruit of the S. nigra with a dosage of 0.046?g/kg body weight (PS), every 2 days, for 8 weeks. The dose represents 1/20 of LD₅₀. The Wistar white rat blood pressure values were recorded using a CODA? system, which uses a non-invasive blood pressure measuring method.

Results and discussion: The total antioxidant capacity levels were significantly decreased (p?<?0.001) in AHT group as compared to the rats in the AHT?+?PS group. A combination of a renin inhibitor (Aliskiren) and polyphenolic extract generated a superior antioxidant effect compared to administering the two separately. Both TAS and TAD in rats with drug-induced hypertension were reduced by polyphenolic extract. The homogeneous values of TAS record a significant decrease (p?<?0.001) of the average values in AHT?+?PS group or AHT?+?Aliskiren group.

Conclusion: The combination of two different classes of substances, namely, renin inhibitors and natural polyphenol extracts, reduces arterial pressure and also might reduce the side effects of the major classes of antihypertensive agents and improve the quality of live.     

The effects of Melissa officinalis (lemon balm) pretreatment on the resistance of the heart to myocardial injury

Context: The antihyperlipidemic, antiarrhythmic, neuroprotective and hepatoprotective effects of Melissa officinalis L. (Lamiaceae) have been reported. However, no study has examined its effects on the resistance of the heart to stressful conditions.

Objective: The objective of this study is to evaluate the effects of aqueous extract of M. officinalis aerial parts on Wistar rat heart with/without cardiac injury.

Materials and methods: Animals were grouped as control, isoproterenol (ISO), M. officinalis without (M50, M100, and M200) and with isoproterenol (M50?+?ISO, M100?+?ISO, and M200?+?ISO). The aqueous extract of M. officinalis was orally administered at dosages of 50, 100, and 200?mg/kg/d, respectively, for 7 consecutive days. On the 6th and 7th day, ISO, M50?+?ISO, M100?+?ISO, and M200?+?ISO groups received 85?mg/kg of isoproterenol for myocardial injury induction. On day 8, hemodynamic parameters were recorded and samplings were done.

Results: The extract (50, 100, and 200?mg/kg) significantly reduced the heart rate (264?±?5, 259?±?5 and 281?±?3 versus 377?±?13 in control group, p?<?0.01). Blood pressure was significantly decreased in M50?+?ISO (75?±?5) versus M50 (110?±?6) and M100?+?ISO (72?±?6) versus M100 (105?±?5?mmHg, p?<?0.01). The malondialdehyde levels of the injured hearts were lower in M50?+?ISO and M100?+?ISO groups than in the ISO group (p?<?0.05). Serum cardiac troponin I was higher in the M200?+?ISO group (5.1?±?1.7) than in the ISO group (2.7?±?0.7?ng/ml, p?<?0.05).

Conclusion: The lower dose of extract, by improving the balance of the redox system and by reducing the heart rate, may increase the heart resistance to injury. However, the higher doses of extract may intensify the injury of ischemic heart.     

Effectiveness of localized ultrasound-targeted microbubble destruction with doxorubicin liposomes in H22 mouse hepatocellular carcinoma model

Objective: In order to increase local drug concentration and reduce systemic side effects of liver cancer chemotherapy, it is desirable to develop novel non-invasive technologies for drug targeting, such as ultrasound-targeted microbubble destruction (UTMD).

Methods: H22 hepatocellular carcinoma (HCC) xenograft transplantation model was generated in UTMD study. BALB/c mice were randomly divided into six groups: doxorubicin HCl liposomal injection (DOX), DOX?+?US, UTMD, DOX?+?UTMD, H22 liver tumor control (CH control) and blank control group. The therapeutic schedule started on day 4 after tumor inoculation.

Results: Average survival time of the animal model was approximately 18?d. The UTMD therapy parameters were optimized in the H22 mouse model to be: microbubble (MB) diameter, 2.30?±?0.25?μm; MB density, 4.0?×?10⁹ bubbles/ml; treatment dose, 0.2?ml per 20?g mouse body weight; sonication frequency, 1.3?MHz; and sonication power, 2.06?W/cm². Mice treated with DOX?+?UTMD had the smallest tumor volume and weight (p?<?0.001), and the highest tumor inhibition rate (p?<?0.01), intratumoral DOX concentration (p?<?0.001) and survival rate among all tumor-burden groups (p?<?0.001). Cell viability in different treatment groups was also assessed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.

Conclusion: An improved antitumor effect was observed with the combination therapy of DOX and UTMD, as compared with treatment with DOX, DOX?+?US or UTMD, which implicates a novel approach for HCC treatment.     

Effects of the hydroalcoholic extract of Rosa damascena on learning and memory in male rats consuming a high-fat diet

Context: High-fat diet (HFD) can cause deficits in learning and memory through oxidative stress and increase Alzheimer disease risk. Rosa damascena Mill. (Rosaceae) extract possesses potent antioxidant properties.

Objective: This study investigated the effects of the hydroalcoholic extracts of petals of R. damascena on learning and memory in male rats consuming an HFD.

Materials and methods: Forty male Wistar rats (200–250?g) were randomly assigned to four groups: control, R. damascena extract, HFD and HFD?+?extract. The extract (1?g/kg bw daily) was administered by oral gavage for 1?month. Animals were allowed free access to high-fat chow for 3?months. The Morris water maze and the passive avoidance learning tests were used to assess learning and memory.

Results: In the passive avoidance learning test, the step-through latencies in the retention test (STLr) of the extract (147.4?±?23.3) and HFD (150.3?±?25.2) groups were significantly lower than those of the control group (270.4?±?10.5) (respectively, p?p?p?p?Discussion and conclusion: Our results indicate that, while HFD or R. damascena extract alone leads to memory deficits, R. damascena extract exerted a positive effect on HFD-induced memory deficits. We hypothesize that the observed effects of R. damascena extract are likely due to its strong antioxidant properties.     

Therapeutic role of quercetin on oxidative damage induced by acrylamide in rat brain

Context Quercetin (QE), a bioflavonoid present abundantly in fruits and vegetables, has been reported to possess antioxidant properties. Acrylamide (ACR) is formed in foods during cooking and is known to be neurotoxic.

Objective The present study was designed to evaluate the protective effect of QE against neurotoxicity induced by ACR.

Materials and methods Four groups of Wistar rats consisting of six rats each: (i) control group; (ii) acrylamide treated group (50?mg/kg body weight as single dose); (iii) quercetin group: rats were treated intraperitoneally (i.p.) with QE (10?mg/kg body weight alone every day for 5 d); (iv) quercetin?+?acrylamide group: quercetin (10?mg/kg bw) was given i.p. every day for 5 d followed by acrylamide i.p. injection (50?mg/kg bw) on fifth day (single dose). Rats were killed after 48?h.

Results Administration of ACR (50?mg/kg bw) in Wistar rats resulted in significant increase of dopamine, interferon-γ and 8-hydroxyguanosine with concomitant decrease of serotonin (p?<?0.001) in the rat brain. Treatment of rats with QE intraperitonealy (10?mg/kg body weight) before ACR assault resulted in the diminution of ACR-mediated neurotoxicity as evident from decreased levels of dopamine, interferon-γ (p?<?0.001) and 8-hydroxyguanosine with concomitant restoration of serotonin levels (p?<?0.001).

Discussion and conclusion On the basis of the above results, the present study suggests that quercetin may be a potential therapeutic agent for restoration of oxidative damage to neurons.     

Effects of vildagliptin versus saxagliptin on daily acute glucose fluctuations in Chinese patients with T2DM inadequately controlled with a combination of metformin and sulfonylurea

Objective The present study aimed to compare the effects of the dipeptidyl peptidase-4 (DPP-4) inhibitors vildagliptin and saxagliptin on 24?hour acute glucose fluctuations in Chinese patients with type 2 diabetes mellitus (T2DM) inadequately controlled with a combination of metformin and sulfonylurea.

Research design and methods This was a 24 week, prospective, randomized, open-label, active-controlled study. Patients (N?=?73) with T2DM who had inadequate glycemic control (HbA1c 7.0%–10.0%) with a stable dosage of metformin plus gliclazide for more than 3 months were randomized to receive either vildagliptin 50?mg twice daily (BID, n?=?37) or saxagliptin 5?mg once daily (QD, n?=?36). Change in mean amplitude of glycemic excursions (MAGE) was assessed at the end of 24 weeks.

Results At baseline, the mean (±SD) age was 62.9?±?6.55 years, disease duration was 7.0?±?2.33 years, and HbA1c was 8.4?±?0.68%. After 24 weeks of treatment, the MAGE decreased from 5.81?±?1.16?mmol/L to 4.06?±?0.86?mmol/L (p<0.001) in the vildagliptin group and from 5.66?±?1.14?mmol/L to 4.79?±?1.25?mmol/L (p?=?0.003) in the saxagliptin group. The mean change in MAGE in the vildagliptin group was significantly greater than that in the saxagliptin group (1.74?±?0.48?mmol/L vs. 0.87?±?0.40?mmol/L, p<0.001). The mean change in HbA1c, from baseline to the study endpoint, in the vildagliptin and saxagliptin groups, was 1.22?±?0.40% and 1.07?±?0.36%, respectively, with no significant difference between the groups (p?=?0.091). The overall safety and tolerability of vildagliptin and saxagliptin were similar. The limitations of the study were a small number of patients and open-label administration of the study drug.

Conclusion Vildagliptin produced a significantly greater reduction in acute glucose fluctuations compared with saxagliptin when added to a dual combination of metformin and sulfonylurea in Chinese patients with T2DM.

Chinese clinical trial registration number ChiCTR-TRC-13003858.     

Evaluation of hepatorenal impairments in Wistar rats coexposed to low-dose lead,cadmium and manganese: insights into oxidative stress mechanism

The study aims to evaluate effects of chronic low-dose coexposure to lead (Pb), cadmium (Cd) and manganese (Mn) on hepatorenal toxicity and oxidative stress. Young male Wistar rats were treated with Pb acetate (1.4?mg/kg BW), Cd chloride (0.01?mg/kg BW), Mn chloride (0.14?mg/kg BW) and their combination (Pb?+?Cd?+?Mn) by oral gavage, for 15 weeks. Liver enzymes, albumin (Alb), globulin (Glb), total protein, creatinine, urea and electrolyte concentrations were measured in the serum. Hepatic and renal malondialdehyde (MDA), glutathione peroxidase-1 (GPx1) and metallothionein-1 (MT1) concentrations were measured by enzyme immunoassay technique. Chronic exposure to the metals significantly (p?<?.05) increased serum Glb concentration and decreased Alb/Glb ratio, compared to the controls. Serum creatinine concentration significantly (p?<?.05) decreased in the Pb, Cd and Pb?+?Cd?+?Mn groups, but elevated in the Mn group. Hepatic MDAs rose significantly (p?<?.05) in the Pb group, while hepatic GPx1 activities increased significantly (p?<?.05) in the Cd, Mn and Pb?+?Cd?+?Mn groups. Hepatic and renal MT1 concentration decreased (p?<?.05) in the Mn group only. Biochemical alterations were confirmed by light microscopy of the liver and kidneys, which showed degenerative changes. It is concluded that prolonged coexposure to environmentally relevant levels of Pb, Cd and Mn impairs liver and kidney functions via the induction of oxidative stress, and it underlines the importance of studying toxicants in combination.     

Effectiveness and safety of vildagliptin and vildagliptin add-on to metformin in real-world settings in Egypt – results from the GUARD study

Objective: The GUARD study evaluated the effectiveness, safety, and tolerability of vildagliptin treatment with or without metformin in patients with type 2 diabetes mellitus (T2DM) in real-life settings. Here we present the results of the GUARD study for the patient subset from Egypt.

Research design and methods: This was a 24?±?6 weeks, prospective, non-interventional study that enrolled adult patients with T2DM receiving vildagliptin or vildagliptin?+?metformin combination therapy as per local prescribing information.

Main outcome measures: The primary effectiveness endpoint was change in HbA1c levels from baseline to week 24?±?6 endpoint. Safety was assessed by reporting of adverse events and serious adverse events (SAEs).

Results: Of 2786 patients enrolled from Egypt, 655 received vildagliptin and 2131 received vildagliptin?+?metformin. Overall, at baseline, mean (± standard deviation [SD]) age was 49.5?±?9.49 years, BMI was 31.5?±?4.85?kg/m², HbA1c was 8.4?±?0.86%, and duration of T2DM was 2.3?±?3.78 years. At week 24, significant reductions in mean (±SD) HbA1c were observed in the vildagliptin (?1.47?±?0.79%) and vildagliptin?+?metformin (?1.62?±?0.82%) groups (both p?Conclusion: In a real-world setting, vildagliptin, with or without metformin, resulted in significant reductions in HbA1c and was well tolerated in patients with T2DM from Egypt. Limitations of the study include non-randomization and the open-label, observational nature of the study.     

雷公藤甲素通过调节cAMP/PKA/BDNF信号通路促进脑缺血再灌注损伤神经元可塑性

目的 研究雷公藤甲素(triptolide,TP)对脑缺血再灌注(ischemia-reperfution,I/R)损伤大鼠的疗效评价及其发挥效能的机制。方法 大脑中动脉线栓法手术复制大鼠脑I/R损伤模型,治疗组给予TP(0.1,0.2 mg·kg^?1),同时设假手术组。Longa评分法测评鼠神经功能,尼氏染色呈现大鼠缺血侧脑组织神经元形态,免疫荧光法检测缺血侧脑组织中MAP2和Syn的表达水平。Western blotting 法检测cAMP、PKA、BDNF、Syn、PSD-95的表达水平。结果 与模型组比较,TP治疗组神经学评分明显下降(P<0.01或P<0.001),对损伤神经元有保护作用,且TP治疗组cAMP、PKA、BDNF、PSD-95、Syn的表达均显著上调。结论 TP治疗能显著改善I/R损伤,其机制可能与激活cAMP/PKA/BDNF信号通路有关。     

Evaluation of effects of repeated sevoflurane exposure on rat testicular tissue and reproductive hormones

Abstract

Context: Evaluation of inhalation anesthetics on sperm and reproductive hormones are extremely important.

Objective: Investigation of the effects of sevoflurane used as an inhalation anesthetic on sperm morphology and reproductive hormones in rat testes.

Materials and methods: Forty Wistar-Albino male rats were divided into five groups of eight rats each. The control group received 2?L/min oxygen for seven days, 2?h/day while sevoflurane treatment S1 received 1 minimal alveolar concentration (MAC) sevoflurane?+?2?L/min oxygen for seven days, 2?h/day, and sevoflurane S2 received 1 MAC sevoflurane?+?2?L/min oxygen for seven days, 2?h/day followed by seven days of no treatment. Sevoflurane treatment S3 received 1 MAC sevoflurane?+?2?L/min oxygen for 14 days, 2?h/day and sevoflurane treatment S4 received 1 MAC sevoflurane?+?2?L/min oxygen for 14 days, 2?h/day, with no treatment for the following seven days. All rats were examined histologically after experimental procedures. Rat luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone (T), and inhibin levels were measured.

Results: Histological injury scores were significantly higher in S2, S3, and S4 receiving sevoflurane in comparison to the control group (p?=?0.001, <0.001, and 0.001, respectively). Sperm motility and concentration decreased in S3 and S4 compared to the control group (p?=?0.03 and 0.02, respectively). Significant differences were detected among all groups for serum LH, FSH, T, and inhibin serum concentrations (p?<?0.05).

Conclusion: Testicular and sperm morphology, and reproductive hormones were affected by chronic exposure to sevoflurane. However, more randomized, controlled, and well-designed clinical studies with larger population are needed to confirm of these results.     

Comparison of the Therapeutic Efficacy of 4-Methylpyrazole and N-Acetylcysteine on Acetaminophen (Paracetamol) Hepatotoxicity in Rats

Summary

Obtaining effective analgesia with a minimal erosive effect on gastric mucosal tissue has increased the consumption of acetaminophen (paracetamol), especially among the elderly. However, the hepatotoxic effects of acetaminophen have also increased. We aimed to compare the effects of 4-methylpyrazole (4-MP), N-acetylcysteine (NAC) and their combined use on the hepatotoxicity of acetaminophen in a rat model. Male Wistar Albino rats were divided into six groups. Groups 1–5 received 2000?mg/kg acetaminophen by gavage while the control group was group 6. Group 2 animals were given NAC (loading dose 140?mg/kg followed by seven doses at 4?h intervals); group 3 received 50?mg/kg 4-MP; group 4 received 200?mg/kg 4-MP; and group 5 received NAC as in group 2 plus 200?mg/kg 4-MP. Blood samples were taken for measurements of serum AST and ALT levels. The livers of the rats were removed for microscopic examination and grading of hepatic necrosis. AST and ALT levels in groups 2–5 were lower than that of group 1 (p?<?0.001), although no significant difference was noted between groups 2–5 (p?>?0.05). Higher levels of ALT were found in group 5 than in group 2 (p?<?0.05), and higher levels of AST were found in group 5 than in group 3 (p?<?0.01). Median necrosis scores were 3.36 for rats receiving acetaminophen alone (p?<?0.001, compared with groups 2–6), 1.45–1.81 for groups 2–5 (p?>?0.05, compared with each other), and 0.18 for control rats (p?<?0.001, compared with groups 1–5). In conclusion, the administration of 4-MP and/or NAC after 4?h of administering toxic dose of acetaminophen, inhibits hepatotoxicity in rats. There was no difference between the 4-MP and NAC-treated groups as reflected by comparable levels of serum transaminases and the degree of hepatic necrosis. Combining of 4-MP and NAC offers no benefit.     

Metabolic effect of repaglinide or acarbose when added to a double oral antidiabetic treatment with sulphonylureas and metformin: a double-blind,cross-over,clinical trial

ABSTRACT

Objective: To compare the metabolic effects of acarbose and repaglinide in type 2 diabetic patients who are being treated with a sulphonylurea–metformin combination therapy. The primary endpoint of the study was to evaluate which add-on treatment between acarbose and repaglinide is more efficacious in reducing PPG. The second endpoint was to evaluate which of these two treatment is more efficacious in the global management of glucose homeostasis in the enrolled patients.

Research design and methods: After a 4-week run-in period with a suplonylurea–metformin combination, 103 patients were randomised to receive in addition either repaglinide, up to 6?mg/day (2?mg three times a day) or acarbose, up to 300?mg/day (100?mg three times a day) with forced titration (independently of their glycaemic control, unless side-effects developed due to the drug dosage) for 15 weeks. The treatment was then crossed-over for further 12 weeks until the 27th week. We assessed body mass index (BMI), glycosylated haemoglobin (HbA_1c), fasting plasma glucoe (FPG), postprandial plasma glucose (PPG), fasting plasma insulin (FPI), postprandial plasma insulin (PPI), homeostatic model assesssment (HOMA) index, systolic blood pressure (SBP), diastolic blood pressure (DBP), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides (Tg), at baseline and at 1, 2, 15 and 27 weeks of treatment.

Results: Seven patients did not complete the study, comprising one patient who was lost to follow-up and a further six through side-effects (two in week 1, one in week 15 and three after cross-over) Side-effects were classified as nausea (one in acarbose group), gastrointestinal events (four in acarbose group), and hypoglycaemia (one in repaglinide group). After 15 weeks of therapy, the repaglinide-treated patients experienced a significant decrease in HbA_1c (?1.1%, p?<?0.05), FPG (?9.5%, p?<?0.05), and PPG (?14.9%, p?<?0.05), when compared to the baseline values. However, the same treatment was associated with a significant increase in body weight (+2.3%, p?<?0.05), BMI (+3.3%, p?<?0.05) and FPI (+22.5%, p?<?0.05); The increase was reversed during the cross-over phase. After 15 weeks of therapy, the acarbose-treated patients experienced a significant decrease in body weight (?1.9%, p?<?0.05), BMI (?4.1%, p?<?0.05), HbA_1c (?1.4%, p?<?0.05), FPG (?10.7%, p?<?0.05), PPG (?16.2%, p?<?0.05), FPI (?16.1%, p?<?0.05), PPI (?26.9%, p?<?0.05), HOMA index (?30.1%, p?<?0.05), when compared to the baseline values. All these changes were reversed during the cross-over study phase, except those relating to HbA_1c, FPG and PPG. The only changes that significantly differed when directly comparing acarbose- and repaglinide-treated patients were those relating to FPI (?16.1% vs. +22.5%, respectively, p?<?0.05) and HOMA index (?30.1% vs. +2.7%, p?<?0.05).

Conclusion: In addition from having a similar effect to repaglinide on PPG, acarbose appeared to have a more comprehensive positive effect on glucose metabolism compared to repaglinide in this relatively small sample of type 2 diabetic patients when used as add-on therapy to sulphonylureas and metformin.     

Antihyperlipidemic activity of adenosine triphosphate in rabbits fed a high-fat diet and hyperlipidemic patients

Context Recently, adenosine triphosphate (ATP) was occasionally found to decrease the triglyceride (TG) levels in several hyperlipidemic patients in our clinical practice.

Objective The study investigates the anti-hyperlipidemic effects of ATP in a high-fat fed rabbit model and hyperlipidemic patients.

Materials and methods Twenty-four rabbits were randomly divided into three groups of eight animals each as follows: normal diet, high-fat diet and high-fat diet?+?ATP group. ATP supplementation (40?mg/day) was started at the 20th day and lasted for 10 days. Serum concentrations of total cholesterol (TC), TG, LDL-C, HDL-C were measured on the 20th day and 30th day. Heart, liver and aorta were subjected histopathological examination. Twenty outpatients diagnosed primary hyperlipidemia took ATP at a dose of 60?mg twice a day for 1 week.

Results Feeding rabbits with a high-fat diet resulted in a significant elevation of lipid parameters including TC, TG, LDL-C, VLDL-C compared to the normal diet group (p?<?0.01). ATP treatment significantly decreased serum TG level (p?<?0.01), whilst other parameters remained statistically unaltered. Meanwhile, ATP significantly reduced the thickness of fat layer in cardiac epicardium (p?<?0.05) and pathological gradation of ballooning degeneration in hepatocytes (p?<?0.05). After taking ATP for 1 week, hyperlipidemia patients exhibited a significant decrease of TG (p?<?0.01), but other lipid parameters had no significant change.

Discussion and conclusion The study indicates that ATP selectively decreases serum TG levels in high-fat diet rabbits and hyperlipidemic patients. Therefore, ATP supplementation may provide an effective approach to control TG level.     

Evaluation of SAMe-TT2R2 score and other clinical factors influencing the quality of anticoagulation therapy in non-valvular atrial fibrillation: a nationwide study in Spain

Objective: To assess the major clinical factors affecting the quality of anticoagulation and evaluate the predictive value of the SAMe-TT₂R₂ score to identify patients who will achieve a high average time in therapeutic range (T.T.R.) with vitamin K antagonist (V.K.A.) treatment. Research design and methods: This observational, cross-sectional, retrospective and nationwide multicenter study included 1524 patients from the primary care setting with non-valvular atrial fibrillation receiving V.K.A. (≥12 months). We performed a bivariate analysis to identify factors individually associated with the T.T.R. and a multiple regression analysis to identify the independent predictive factors. For the validation of the SAMe-TT₂R₂ score, the receiver operating characteristic (R.O.C.) curve was calculated and the Hosmer–Lemeshow test was used to test calibration. Results: A total of 94.8% of patients received acenocumarol (4.8% warfarin). A progressive decrease in mean T.T.R. was found when the SAMe-TT₂R₂ score increased from 0 points (72.1?±?17.1%) to 4 points (64.1?±?23.2%), p?<?0.001. Other risk scores (CHADS₂ and CHA₂DS₂-VASc, HAS-BLED) were also associated with the mean T.T.R. We found a significant association between low T.T.R. and the following clinical factors: female sex, three or more comorbidities, amiodarone treatment, dietary habits, bleeding history and the intake of ≥7 tablets per day besides V.K.A. (p?<?0.01). Regarding SAMe-TT₂R₂ score validation, the R.O.C. curve showed significant capability, although not high, of discriminating good anticoagulation control (T.T.R. ≥65%) with an area under the curve of 0.562 (95% C.I. 0.533–0.592, p?<?0.001) which increased, remaining modest, to 0.594 (95% C.I. 0.564–0.624, p?<?0.001) when the factors not included in SAMe-TT₂R₂ score were added. Conclusion: In this cohort, the SAMe-TT₂R₂ score had a significant, although modest, ability to assess the likelihood of good international normalized ration (I.N.R.) control, and its predictive value might slightly improve by adding other simple clinical factors. Further research is needed to refine the predictive scales.     

Importance of LDL/HDL cholesterol ratio as a predictor for coronary heart disease events in patients with heterozygous familial hypercholesterolaemia: a 15-year follow-up (1987-2002)

SUMMARY

This study evaluated the prognostic significance of several risk factors on the outcome of coronary heart disease (CHD) in 639 cardiovascular disease-free subjects with heterozygous familial hypercholesterolaemia (FH). During the 15-year follow-up, 53 (18%) men and 34 (9.8%) women had a CHD event (men vs women, p?<?0.001). The age-adjusted 15-year event rate was 3% (87 events/2915 person-years). Smoking increased the CHD risk (hazard ratio?=?2.45, p?<?0.001), women had a 74% lower risk of a vascular event, compared to men, after controlling for the post-menopausal status (hazard ratio?=?0.26, p?<?0.001). A one-unit difference in low density lipoprotein (LDL)/high density lipoprotein cholesterol (HDL) cholesterol ratio was associated with a 17% higher risk (hazard ratio?=?1.17, p?<?0.05); hypertension increased the risk for an adverse event (hazard ratio?=?3.02, p?<?0.05) and a 1?mg/dl increase in plasma fibrinogen level was associated with a 4% higher CHD risk (hazard ratio?=?1.04, p?<?0.05).

With the power of the 15 years of prospective evaluation, the study shows that increased smoking, hypertension and LDL cholesterol levels eight times more than HDL cholesterol predicts an adverse CHD event, in patients with FH.     

Hepatoprotective effect of withanolide-rich fraction in acetaminophen-intoxicated rat: decisive role of TNF-α, IL-1β, COX-II and iNOS

Context: Overdose of acetaminophen (APAP) is common in humans and is often associated with hepatic damage. Withania somnifera (L.) Dunal (Solanaceae) shows multiple pharmacological activities including antioxidant and anti-inflammatory potential.

Objective: To evaluate the possible mechanism of hepatoprotective activity of withanolide-rich fraction (WRF) isolated from a methanolic extract of Withania somnifera roots.

Materials and methods: Hepatotoxicity was induced by oral administration of APAP (750?mg/kg, p.o.) for 14 d. The control group received the vehicle. APAP-treated animals were given either silymarin (25?mg/kg) or graded doses of WRF (50, 100 and 200mg/kg) 2?h prior to APAP administration. Animals were killed on 15th day and blood and liver tissue samples were collected for the further analysis.

Results: In WRF-treated group, there was significant and dose-dependent (p?<?0.01 and p?<?0.001) decrease in serum bilirubin, ALP, AST and ALT levels with significant and dose-dependent (p?<?0.01 and p?<?0.001) increase in hepatic SOD, GSH and total antioxidant capacity. The level of MDA and NO decreased significantly (p?<?0.01) by WRF treatment. Up-regulated mRNA expression of TNF-α, IL-1β, COX-II and iNOS was significantly down-regulated (p?<?0.001) by WRF. Histological alternations induced by APAP in liver were restored to near normality by WRF pretreatment.

Conclusion: WRF may exert its hepatoprotective action by alleviating inflammatory and oxido-nitrosative stress via inhibition of TNF-α, IL-1β, COX-II and iNOS.