Effect of three edible oils on the intestinal absorption of caffeic acid: An in vivo and in vitro study.

Polyphenolic antioxidants are mainly absorbed through passive paracellular permeation regulated by tight junctions. Some fatty acids are known to modulate tight junctions. Fatty acids resulting from the digestion of edible oils may improve the absorption of polyphenolic antioxidants. Therefore, we explored the effect of three edible oils on the intestinal absorption of caffeic acid. Rats were fed with soybean oil and caffeic acid dissolved in distilled water. Caffeic acid contents in the plasma collected up to 1 hr were quantified. The experiment was repeated with coconut oil and olive oil. Component fatty acids of the oils were individually tested in vitro for their effect on permeability of caffeic acid using Caco-2 cell monolayers. Highest absorption of caffeic acid was observed in animals fed with coconut oil. In vitro transport percentages of caffeic acid in 2.5 mmol/L solutions of fatty acids were 22.01±0.12 (lauric), 15.30 ± 0.25 (myristic acid), 13.59 ± 0.35 (linoleic acid), 3.70 ± 0.09 (oleic acid) and 0.10-2.0 (all other fatty acids). Lauric acid and myristic acid are the two major fatty acids present in coconut oil. Therefore, these fatty acids may contribute to the higher absorption of caffeic acid in the presence of coconut oil.

Anti-hyperglycaemic effects of herbal porridge made of Scoparia dulcis leaf extract in diabetics - a randomized crossover clinical trial.

BACKGROUND: Leaf extracts of Scoparia dulcis, is used as a herbal remedy by diabetics worldwide. Fresh Scoparia dulcis porridge elicited a low glycaemic index (GI) and anti-hyperglycaemic effects when fed to diabetic Wistar rats. Commercially produced Scoparia dulcis porridge (SDC) elicited medium GI. Present study was aimed at studying the anti-diabetic effects of consumption of commercially produced S. dulcis porridge. METHOD: A randomized crossover clinical trial with type 2 diabetic patients (n = 35) on medication, with mild and moderate diabetes [fasting blood glucose (FBG) 126-300 mg/dL, age 35-70 years] was conducted. Within the first three months (study period 1) group 1 was the test and group 2 was the control. Following a wash-out period, the two groups were crossed over (study period 2: group 1 - control; group 2 - test). Test group consumed commercially produced SDC for 3 days/week for three months and the control group any other food. At the onset and end of each study period glucose measurements [Fasting Blood Glucose (FBG), HbA1c], lipid measurements (total cholesterol, HDL-C, LDL-C, triglycerides, cholesterol ratios), toxicity parameters (liver enzymes, creatinine, CRP, eGFR) were analyzed by enzyme assay kit methods using a KONELAB 20XT auto analyzer. Significances between groups were analyzed by one way ANOVA (normal distribution) and Mann Whitney test (if the values were not normally distributed). Within group comparisons were carried out by Bonferroni post hoc test. RESULTS: During the crossover clinical trial HbA1c of group 1 decreased from 7.9 ± 0.5 to 6.5 ± 0.3 (p = 0.003) while HbA1c of group 2 decreased from 7.0 ± 0.3to 6.7 ± 0.3 while in the test group. Therefore, both test groups (1 and 2) elicited a decrease in HbA1c compared to respective control groups. Both test groups elicited a non significant decrease in FBG following the intervention (group 1 - from 174 ± 14 to 160 ± 10 mg/dL; group 2 - from 183 ± 13 to 160 ± 7 mg/dL). No significant differences (p >0.05) in insulin, cholesterol measurements (total cholesterol, LDL-C, HDL-C, triglycerides and cholesterol ratios) and atherogenic index between or within groups were observed. All other measurements (AST, ALT, ALP, creatinine, CRP, eGFR) were normal and not significantly different between or within groups. CONCLUSION: Porridge made with SDC leaf extract decreased FBG and HbA1c (p >0.05) of type 2 diabetic patients. The porridge had no effect on cholesterol measurements and no toxicity was observed at the dose tested. Therefore, the SDC porridge can be recommended as a suitable meal for diabetic patients.

Anti-diabetic properties of rice-based herbal porridges in diabetic Wistar rats.

The present study aims to investigate anti-hyperglycaemic, anti-hyperlipidaemic and toxic effects of long-term consumption of selected green leafy porridges in a streptozotocin-induced diabetic Wistar rat model. Porridges made with Asparagus racemosus Willd. (AR), Hemidesmus indicus (L) R. Br. W. T. Aiton (HI), Scoparia dulcis L. (SD) and coconut milk porridge (CM) were incorporated into diets of diabetic Wistar rats. Diabetic control (DM) and normal control groups (NC) were provided with standard rat diet. Fasting blood glucose (FBG), HbA1c , C reactive protein (CRP), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), liver enzymes and creatinine were measured. Feed and water intake among diabetic groups were significantly high when compared with those of NC (p < 0.05). All rats in SD (mean = 39 ± 19 g) and NC (mean = 114 ± 7 g) groups gained weight, whereas most rats in other diabetic groups lost weight. Among the diabetic groups, SD group had the lowest mean FBG, FBG increment percentage (45%) and HbA1c (5.8 ± 2.1). FBG increment percentage and HbA1c of SD group were not significantly different to those of NC (38%; 4.7 ± 0.7) (p > 0.05). Among the diabetic groups, lowest TC (119 ± 20.6 mg/dL) and highest HDL-C (33 ± 6.3 mg/dL) were also detected in SD group. Alanine transaminase and creatinine were not significantly different (p > 0.05) among diabetic groups but significant when compared with those of NC. When compared with those of NC, aspartate transaminase levels were significantly (p < 0.05) high in SD, CM and DM groups. Body weight : liver weight and body weight : pancreas weight ratios and CRP were not significantly different among all groups. The study proved that SD porridge reduced weight loss, elicited hypoglycaemic and hypolipidaemic properties, and caused no toxicity in diabetes-induced Wistar rats.

Green leafy porridges: how good are they in controlling glycaemic response?

Green leafy porridges made with leaf water extracts, rice and coconut milk are common Sri Lankan dietary remedies for diabetes. Though water and ethanolic extracts of most leaves elicit hypoglycaemic effects, data are not available on the efficacy when leaf extracts are incorporated into porridges. Thus, an effort was made to evaluate the proximate compositions and glycaemic index (GI) of some commonly consumed green leafy porridges. The GI of rice porridge and coconut milk porridge were measured to evaluate the effect of other ingredients other than the leaf extracts. Rice was the main contributor to carbohydrate (56-68% on dry weight) and water was the main component in porridges (89-93%). Fat and total dietary fibre contents ranged between 2.5-27% and 5-10%, respectively. The GI of all porridges was low (GI ≤ 55), except Cassia auriculata which had a high GI of 77 ± 12. The GIs of coconut milk, Aerva lanata, Hemidesmus indicus, Scoparia dulcis, Asparagus racemosus, Cephalandra indica, Cardiospermum halicacabum, Murraya koenigii and Aegle marmelos were 31 ± 5, 32 ± 5, 40 ± 8, 39 ± 8, 37 ± 4, 49 ± 8, 46 ± 8, 44 ± 8 and 50 ± 8, respectively. All porridges had a low or medium glycaemic loads ( ≤ 19). However, peak blood glucose reductions of ≥ 25% were observed in all leafy and coconut milk porridges, except in C. auriculata and Atlantia zeylanica, when compared with the glucose control. Therefore, green leafy porridges, except Cassia, can be recommended as breakfast meals for diabetics due to their low GI, peak blood glucose reduction and presence of other nutrients in green leaves.