ABSTRACT
BACKGROUND: Microangiopathy is a chronic diabetic complication resulting from metabolic derangements, oxidative stress, and increased pro-inflammatory cytokine production. Nigella sativa Linn. is used as an herbal medicine that exerts hypoglycemic, antilipidemic, anti-inflammatory, and antioxidant effects. OBJECTIVE: To examine the effects of N. sativa extract on cutaneous microvascular changes in diabetic rats. MATERIALS AND METHODS: Sprague-Dawley rats were randomly assigned into the following four groups: Untreated and N. sativa-treated normal controls and untreated and N. sativa-treated rats with streptozotocin-induced diabetes. A cold-pressed N. sativa extract was then orally administered (1000 mg/kg/day). After 8 weeks of treatment, the glucose, glycosylated hemoglobin (HbA1c), tumor necrosis factor-alpha (TNF-α), insulin levels, and lipid profile were determined in cardiac blood. Dermal capillary wall thickness was measured in tail skin sections stained with periodic acid-Schiff. Endothelial apoptosis was morphologically evaluated by hematoxylin and eosin staining. RESULTS: Diabetes significantly reduced the circulating insulin and low-density lipoprotein levels and caused elevations in the glucose, HbA1c, and triglyceride levels, accompanied by a slight increase in total cholesterol levels and no change in the high-density lipoprotein and TNF-α levels. Capillary basement membrane thickening and a decreased capillary luminal diameter despite no evidence of endothelial cell apoptosis were also observed. N. sativa treatment of diabetic rats reduced the mean HbA1c concentration by 1.4%, enlarged the capillary lumens, and tended to attenuate dermal capillary basement membrane thickening without affecting the lipid profile or TNF-α level. CONCLUSION: Our results indicate that N. sativa may be used to minimize the risk of diabetic microangiopathy, potentially due in part to its glycemic control activity. SUMMARY: Diabetes causes dermal capillary basement membrane thickening and a decreased capillary luminal diameterNigella sativa treatment of diabetic rats enlarged the capillary lumens and tended to attenuate dermal capillary basement membrane thickeningN. sativa treatment of diabetic rats reduced the mean glycosylated hemoglobin concentration by 1.4%, which exceeds the necessary reduction previously described to decrease the risk of diabetic microangiopathy, without affecting the lipid profile or tumor necrosis factor-alpha levelN. sativa improves rat diabetic microangiopathy, potentially due in part to its glycemic control activity. Abbreviations used: H and E: Hematoxylin and eosin, HbA1c: Glycosylated hemoglobin, HDL-C: High-density lipoprotein cholesterol, LDL-C: Low-density lipoprotein cholesterol, PAS: Periodic acid-Schiff, STZ: Streptozotocin.
ABSTRACT
Four Thai swamp buffaloes (SB) and four Murrah buffaloes (MB) fed a based diet of fresh ruzi grass (Bachiaria ruziziensis) with an increased proportion of fresh leucaena leaves. Intake of nutrients in animals increased when ruzi grass was mixed with leucaena. Digestibility of nutrients were the highest in SB and MB fed diets containing 25% and 50% of leucaena, respectively, and nitrogen (N) balances in both animal breeds were varied among diets. The regression equation coefficient of mimosine + DHP in the urine was twice as high in SB than in MB. Urinary purine derivatives excretion rate in SB was higher than that in MB. Plasma triiodothyronine and thyroxine declined in both animal breeds fed a diet containing >1 g mimosine intake/kg BW(0.75)/day. Plasma urea-N was the lowest in SB, but the highest in MB when fed a diet containing 84% of leucaena. Plasma ß-HBA in SB have declined when diets contained >50% of leucaena but that in MB was not affected by any diet. In conclusion, the effect of leucaena in diet upon buffalo breeds depends on the proportion of leucaena in the diet, mimosine contents and condensed tannins components.
