Identification and characterization of anti-diabetic principle in Senna alata (Linn.) flower using alloxan-induced diabetic male Wistar rats.

ETHNO-PHARMACOLOGICAL RELEVANCE: The age-long folkloric use of Senna alata flower (SAF) was recently substantiated with scientific evidence. However, the study did not account for the anti-diabetic principle(s) in SAF. AIM OF THE STUDY: The study aimed to identify and characterize the bioactive principle(s) responsible for the anti-diabetic activity in SAF. MATERIALS AND METHODS: Ninety-one male Wistar rats were used for the two phases of this study. In phase 1, forty-two of these were allotted into six groups (A-F) of seven rats each. Animals in group A received distilled water while those in groups B-F were made diabetic by treatment with 150 mg/kg body weight (b.w.) of alloxan. Group B received 0.5 mL of distilled water; C, D and E were treated each with 75 mg/kg b.w. of ethyl acetate, n-butanol and aqueous residual fractions of SAF, while F received 2.5 mg/kg b.w. of glibenclamide. In the second phase, forty-nine rats were assigned into seven groups (A-G) of seven rats each. Group A received distilled water. Animals in Groups B-G were also made diabetic by alloxan treatment. B received 0.5 mL of distilled water; C, D, E and F were treated with 5.77, 25.96, 15.40, 27.87 mg/kg b.w (equivalent dose of 75 mg/kg b.w.) of sub-fractions obtained from the ethyl acetate fraction of SAF respectively whereas G received 2.5 mg/kg b.w. of glibenclamide. Fasting blood glucose (FBG), serum lipids, albumin, globulin, liver glycogen, urine ketone, hexokinase and glucose-6-phosphate dehydrogenase activities, α-glucosidase and α-amylase inhibitory activities and cardiac function indices were evaluated using standard methods. Compounds D, E and F isolated from ethyl acetate sub-fraction B were evaluated for in vitro anti-diabetic activity. The structure of the anti-diabetic compound was identified using FTIR, 1H-NMR, 1³C-NMR, HCOSY, HSQC and HMBC. Data were subjected to Analysis of Variance and Duncan Multiple Range Test at p < 0.05. RESULTS: Alloxan treatment increased the levels of FBG, total cholesterol, LDL-cholesterol, VLDL-cholesterol, urine ketone and cardiac function indices and reduced the levels of globulin, albumin, HDL-cholesterol, globulin, liver glycogen, hexokinase and glucose-6-phosphate dehydrogenase activities. Ethyl acetate fraction and sub-fraction B reversed the level and/or activities of these biochemical indices to levels and/or activities that compared favourably with the distilled water treated non-diabetic animals. Of the three compounds (D, E and F) that were obtained from the sub-fraction B, compound E which was Emodin (1, 3, 8-trihydroxy-6-methylanthraquinone) produced the highest α-glucosidase and α-amylase inhibitory activities. CONCLUSION: Emodin is one of the bioactive constituents present in Senna alata flower.

Nutritional performance and antioxidant activities of roasted and unroasted sprouted sorghum-based weaning diets in Wistar rats.

The nutritional performance and antioxidant profile of sprouted sorghum-based weaning diets were evaluated in weaning wistar rats. Rats were fed basal diet, unroasted germinated sorghum-based diet, roasted germinated sorghum-based diet, or a commercial weaning feed (nutrend) for 28 days. Energy, carbohydrate, crude protein, lipids, crude fiber, and ash contents of the sorghum-based diets compared significantly with FAO/WHO recommendations. Contrastingly, moisture content of the germinated sorghum-based diet was higher than the recommendation. Weight gain, feed efficiency ratio, protein efficiency ratio, net protein utilization, biological value, and digestibility of unroasted germinated sorghum-based diet-fed rats compared significantly with Nutrend. Roasted germinated sorghum-based diet produced differential effects on these indices. The unroasted germinated sorghum-based diet significantly raised the antioxidant enzymes in the rat liver and kidney. Overall, evidence from the study indicates that unroasted germinated sorghum-based diet improves the nutritional performance and the antioxidants of weaning rats compared to the roasted germinated sorghum-based diet. PRACTICAL APPLICATIONS: The provision of nutritionally adequate food from local sources during the weaning period of infants continues to be a major source of concern in developing countries. The formulated unroasted sprouted sorghum-based diet can be adapted and used as weaning food. Furthermore, the diet can be processed and developed into a weaning food.

Antidiabetic activity-guided isolation of gallic and protocatechuic acids from Hibiscus sabdariffa calyxes.

We isolated and identified gallic and protocatechuic acids as the antidiabetic principles in Hibiscus sabdariffa using solvent extraction, column chromatographic fractionation, and nuclear magnetic resonance (NMR) spectroscopy. Ethylacetate fraction of the aqueous extract of H. sabdariffa inhibited α-amylase and α-glucosidase with IC50 of 411.73 and 433.93 µg/ml, respectively. Furthermore, fractions I and II obtained from column chromatography inhibited α-amylase with IC50 of 27.03 and 20.12 µg/ml, and α-glucosidase with IC50 of 24.30 and 22.29 µg/ml, respectively. In addition, the principles reduced the serum glucose and lipid peroxide levels of diabetic rats and with an improvement in the rat lipid profiles and antioxidant defenses. Fractions I and II were identified as protocatechuic acid and gallic acid, respectively, using 1 H and 13 C NMR. Protein-ligand docking showed that these compounds form multiple favorable interactions with the active-site residues of the two glycosidases. Overall, protocatechuic and gallic acids emerge as natural antidiabetic agents. PRACTICAL APPLICATIONS: Hibiscus sabdariffa (Zoborodo) is a refreshment drink for ceremonial gatherings in Nigeria. Also, its pharmacological use includes diabetes, hypertension, hyperlipidemia, metabolic syndrome, and hepatoprotection. The consumption of this food drink could improve diabetes, hypertension, dyslipidemia, metabolic syndrome, and liver disease. Furthermore, the inhibition of α-amylase and α-glucosidase could prevent diabetic complications associated with postprandial glucose. Developing the extract of H. sabdariffa calyx as food supplement could be used in managing diabetes and its associated complications such as dyslipidemia, hypertension, and metabolic syndrome.

Lophirones B and C prevent aflatoxin B1-induced oxidative stress and DNA fragmentation in rat hepatocytes.

Context Despite the reported anticarcinogenic activity of lophirones B and C, no scientific information exists for its activity in rat hepatocytes. Objective Effect of lophirones B and C on aflatoxin B1 (AFB1)-induced oxidative stress, and DNA fragmentation in rat hepatocytes was investigated. Materials and methods Wistar rat hepatocytes were incubated with lophirones B and C (1 mg/mL) or sylimarin (1 mg/mL) in the presence or absence of AFB1. For an in vivo study, rats were orally administered with lophirones B and C, and/or AFB1 (20 µg/d) for 9 weeks. Results Lophirones B and C lowered AFB1-mediated increase in nitric oxide, superoxide anion radicals, caspase-3 and fragmented DNA. Lophirones B and C attenuated AFB1-mediated decrease in superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and reduced glutathione. Also, lophirones B and C attenuated AFB1-mediated increase in conjugated dienes, lipid hydroperoxides and malondialdehyde in rat hepatocytes. Furthermore, AFB1-mediated alterations in alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, albumin, total bilirubin and globulin in rat serum were significantly annulled in lophirones B and C-treated rats. Conclusion This study revealed that lophirones B and C prevented AFB1-induced oxidative damage in rat hepatocytes.

Diethylnitrosamine-induced redox imbalance in rat microsomes: protective role of polyphenolic-rich extract from Sorghum bicolor grains.

BACKGROUND: This study investigates the protective role of polyphenolic-rich extract from Sorghum bicolor against diethylnitrosamine (DEN)-induced redox imbalance in rat microsomes. METHODS: Reactive oxygen species (ROS) scavenging potentials of the polyphenolic extract from S. bicolor (0.2-1.0 mg/mL) was investigated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, superoxide ion, hydrogen peroxide, hydroxyl radical, and ferric ion reducing system. The detoxification of ROS was evaluated in DEN-induced redox imbalance in rat microsomes. RESULTS: Sorghum bicolor polyphenolic extract at 1.0 mg/mL scavenged the DPPH, superoxide ion, hydrogen peroxide, and hydroxyl radical at 75%, 76%, 79%, and 81%, respectively; it also reduced ferric ion significantly. The polyphenolic extract significantly (p<0.05) attenuated DEN-mediated decrease in the activities of ROS detoxifying enzymes (superoxide dismutase, catalase, glutathione peroxidase and reductase, and glucose-6-phosphate dehydrogenase). The concentrations of malondialdehyde, conjugated dienes, lipid hydroperoxide, protein carbonyl, and percentage DNA fragmentation in DEN-treated microsomes were significantly reduced by the polyphenolic extract. CONCLUSIONS: The results of the present study indicated that S. bicolor polyphenolic extract possessed in vitro antioxidant activity and protected microsomes from DEN-mediated oxidative stress by scavenging free radicals and ROS scavenger and inducer of ROS detoxifying enzymes.

Redox status of the liver and kidney of 2,2-dichlorovinyl dimethyl phosphate (DDVP) treated rats.

The effect of 2,2-dichlorovinyl dimethyl phosphate on redox homeostasis in male rats was investigated. Rats were grouped into four: A, B, C and D where A (the control) received orally 1 ml of distilled water; B, C and D (test groups) received orally 2.5, 5 and 10mg/kg body weight of DDVP respectively for 28 days. DDVP administration significantly reduced (P<0.05) the alkaline phosphatase activity in the liver and kidney with corresponding increases in the serum. Acid phosphatase activity increased significantly (P<0.05) in liver and kidney, while there was no significant change (P>0.05) in the serum acid phosphatase activity. There was also a significant decrease (P<0.05) in the activities of superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase in the liver and kidney. Liver and kidney levels of GSH, vitamins C and E were also significantly reduced (P<0.05). Serum malonidialdehyde and lipid hydroperoxide also increased significantly (P<0.05) in all DDVP treated groups. The available data from this study revealed that DDVP brings about its toxicity through depletion of the antioxidant systems and thus exposing the cells and cellular macromolecules to oxidative attacks by reactive oxygen species generated either from its metabolites or other in vivo means.