Differential responses to blood pressure and oxidative stress in streptozotocin-induced diabetic Wistar-Kyoto rats and spontaneously hypertensive rats: effects of antioxidant (honey) treatment

Oxidative stress is implicated in the pathogenesis and/or complications of hypertension and/or diabetes mellitus. A combination of these disorders increases the risk of developing cardiovascular events. This study investigated the effects of streptozotocin (60 mg/kg; ip)-induced diabetes on blood pressure, oxidative stress and effects of honey on these parameters in the kidneys of streptozotocin-induced diabetic Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). Diabetic WKY and SHR were randomized into four groups and received distilled water (0.5 mL) and honey (1.0 g/kg) orally once daily for three weeks. Control SHR had reduced malondialdehyde (MDA) and increased systolic blood pressure (SBP), catalase (CAT) activity, and total antioxidant status (TAS). SBP, activities of glutathione peroxidase (GPx) and glutathione reductase (GR) were elevated while TAS was reduced in diabetic WKY. In contrast, SBP, TAS, activities of GPx and GR were reduced in diabetic SHR. Antioxidant (honey) treatment further reduced SBP in diabetic SHR but not in diabetic WKY. It also increased TAS, GSH, reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio, activities of GPx and GR in diabetic SHR. These data suggest that differences in types, severity, and complications of diseases as well as strains may influence responses to blood pressure and oxidative stress.

Glibenclamide or metformin combined with honey improves glycemic control in streptozotocin-induced diabetic rats

Diabetes mellitus is associated with deterioration of glycemic control and progressive metabolic derangements. This study investigated the effect of honey as an adjunct to glibenclamide or metformin on glycemic control in streptozotocin-induced diabetic rats. Diabetes was induced in rats by streptozotocin. The diabetic rats were randomized into six groups and administered distilled water, honey, glibenclamide, glibenclamide and honey, metformin or metformin and honey. The animals were treated orally once daily for four weeks. The diabetic control rats showed hypoinsulinemia (0.27 ± 0.01 ng/ml), hyperglycemia (22.4 ± 1.0 mmol/L) and increased fructosamine (360.0 ± 15.6 µmol/L). Honey significantly increased insulin (0.41 ± 0.06 ng/ml), decreased hyperglycemia (12.3 ± 3.1 mmol/L) and fructosamine (304.5 ± 10.1 µmol/L). Although glibenclamide or metformin alone significantly (p < 0.05) reduced hyperglycemia, glibenclamide or metformin combined with honey produced significantly much lower blood glucose (8.8 ± 2.9 or 9.9 ± 3.3 mmol/L, respectively) compared to glibenclamide or metformin alone (13.9 ± 3.4 or 13.2 ± 2.9 mmol/L, respectively). Similarly, glibenclamide or metformin combined with honey produced significantly (p < 0.05) lower fructosamine levels (301.3 ± 19.5 or 285.8 ± 22.6 µmol/L, respectively) whereas glibenclamide or metformin alone did not decrease fructosamine (330.0 ± 29.9 or 314.6 ± 17.9 µmol/L, respectively). Besides, these drugs or their combination with honey increased insulin levels. Glibenclamide or metformin combined with honey also significantly reduced the elevated levels of creatinine, bilirubin, triglycerides, and VLDL cholesterol. These results indicate that combination of glibenclamide or metformin with honey improves glycemic control, and provides additional metabolic benefits, not achieved with either glibenclamide or metformin alone.

The association between pre-morbid conditions and respiratory tract manifestations amongst Malaysian Hajj pilgrims

In a very closed and overcrowding environment, influenza transmission during Hajj season is almost inevitable. The aim of this study was to determine the association between pre-morbid conditions and influenza-like illness (ILI) amongst Hajj pilgrims. A cross-sectional study was conducted amongst Malaysian Hajj pilgrims in year 2007. Survey forms were distributed at Madinatul-Hujjaj, Jeddah and Tabung Haji Clinic, Medina, Saudi Arabia where pilgrims stay on transit before returning to Malaysia. Allergic rhinitis was significantly associated with sore throat (p=0.047), longer duration of cough (p=0.017) and runny nose (p=0.016). Pilgrims who suffered from chronic obstructive pulmonary diseases (COPD) had significant association with longer duration of cough (p=0.041) and those with diabetes mellitus had significant association with longer duration of sore throat (p=0.048). Underlying asthma was significantly associated with severe influenza like illness requiring admission to hospital for further treatment of respiratory symptoms (p=0.016). Based on these findings, we suggest those with underlying asthma should be discouraged from participating in the hajj and they should seek early treatment if they develop respiratory symptoms.

The prevalence of acute respiratory symptoms and role of protective measures among Malaysian hajj pilgrims

BACKGROUND

Respiratory symptoms including cough, runny nose, sore throat, and fever are the most common clinical manifestations faced by hajj pilgrims in Mecca. The aim of the study was to determine the prevalence of respiratory symptoms among Malaysian hajj pilgrims and the effect of a few protective measures taken by hajj pilgrims to reduce respiratory symptoms.

METHODS

A cross-sectional study was conducted by distributing survey forms to Malaysian hajj pilgrims at transit center before flying back to Malaysia. The recruitment of respondents to the survey was on a voluntary basis.

RESULTS

A total of 387 survey forms were available for analysis. The mean age was 50.4 +/- 11.0 years. The common respiratory symptoms among Malaysian hajj pilgrims were: cough 91.5%, runny nose 79.3%, fever 59.2%, and sore throat 57.1%. The prevalence of hajj pilgrims with triad of cough, subjective fever, and sore throat were 40.1%. The symptoms lasted less than 2 weeks in the majority of cases. Only 3.6% did not suffer from any of these symptoms. Seventy-two percent of hajj pilgrims received influenza vaccination before departure and 72.9% wore facemasks. Influenza vaccination was not associated with any of respiratory symptoms but it was significantly associated with longer duration of sore throat. Wearing masks was significantly associated with sore throat and longer duration of sore throat and fever.

CONCLUSIONS

The prevalence of respiratory symptoms was high among Malaysian hajj pilgrims and the current protective measures seemed inadequate to reduce it. Beside standardization of the term used in hajj studies, more collaborative effort should be taken to reduce respiratory symptoms. The hajj authority should prepare for the challenge of pandemic influenza by providing more healthcare facilities and implementation of more strict measures to reduce the transmission of pandemic influenza strain among hajj pilgrims.

Hypoglycemic and Antioxidant Effects of Honey Supplementation in Streptozotocin-induced Diabetic Rats

Objectives: Oxidative stress plays a crucial role in the development of diabetic complications. The aims of this study were to investigate whether honey could reduce hyperglycemia and ameliorate oxidative stress in kidneys of streptozotocin-induced diabetic rats. Methods: Diabetes was induced by a single dose of STZ (60 mg/kg; i. p.). Diabetic rats were randomly grouped and administered distilled water (0.5 mL/day) and honey (0.2 g/kg/day, 1.2 g/kg/day and 2.4 g/kg/day) by oral gavage for four weeks. Each group consisted of six rats. Results: Total antioxidant status (TAS), activities of catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione-S-transferase (GST) were significantly reduced, while superoxide dismutase (SOD) activity was up-regulated in kidneys of diabetic rats. Lipid peroxidation (TBARS) and fasting plasma glucose (FPG) were significantly elevated while body weight was reduced in diabetic rats. Honey significantly increased body weight, TAS, activities of CAT, GPx, GR, and GST in diabetic rats. It significantly restored SOD activity, and reduced FPG and TBARS levels in diabetic rats. Histopathological examinations of the kidneys revealed that mesangial matrix expansion and thickening of glomerular basement membrane were reduced in the honey-treated diabetic rats. Conclusions: Honey exerts a hypoglycemic effect and ameliorates oxidative stress in kidneys of streptozotocin-induced diabetic rats.

Tolerability and pharmacokinetics of non-fixed and fixed combinations of artesunate and amodiaquine in Malaysian healthy normal volunteers

Objective

There is limited pharmacokinetic data available for the combination artesunate + amodiaquine, which is used widely to treat uncomplicated malaria. This study examines the bioavailability and tolerability of a fixed (200 mg artesunate + 540 mg amodiaquine) and loose (200 mg + 612 mg) combination with a 2×2 cross-over design in 24 healthy volunteers.

Methods

Parent compounds and metabolites [dihydroartemisinin (DHA) and desethylamodiaquine (DEAQ)] were measured by high-performance liquid chromatography–electrochemical detection, and the area under the curve (AUC)_0-t and C_max were compared by an analysis of variance (ANOVA) based on geometric least square means using the Schuirmann two one-sided test.

Results

The AUC_0-t for total DHA and DEAQ were 1522 ± 633 and 30021 ± 14211 ng h/ml for the fixed products and 1688 ± 767 and 40261 ± 19824 ng h/ml (mean ± standard deviation) for the loose products. The ANOVA showed no statistical differences except for sequence effect for DHA. The values obtained with the fixed product were within the 125% bioequivalent limits but extend below the 80% bioequivalence limits.

Conclusion

Both combinations were well tolerated and had comparable pharmacokinetic profiles; differences are unlikely to be clinically relevant.

Electronic supplementary material

The online version of this article (doi:10.1007/s00228-009-0656-1) contains supplementary material, which is available to authorized users.