Characterization of the natural products in cocoyam (Colocasia esculenta) using GC-MS.

CONTEXT: There is paucity of information in literature on the natural products in cocoyam [Colocasia esculenta Linn (Araceae)] that confer it with biological properties. OBJECTIVES: This study investigated the antioxidant properties of C. esculenta and also reported for the first time the natural products in C. esculenta that justify its biological properties. MATERIALS AND METHODS: The antioxidant activity of the methanol extract (50-250 µg/mL) of C. esculenta was determined using the 2,2-diphenyl-1-picryl hydrazyl (DPPH) radical and reducing power assays. Characterization of the natural products in C. esculenta was done using the gas chromatographic-mass spectrometric (GC-MS) technique. The experiment lasted for 3 months. RESULTS: GC-MS analysis of methanol/chloroform extract of the flour of C. esculenta indicated the presence of eight compounds, namely hexadecanoic acid methyl ester (0.43%), octadecanoic acid (20.91%), 9,12-octadecadienoyl chloride (0.77%), 11-octadecenoic acid methyl ester (2.12%), 9-octadecenoic acid (64.37%), 3-hexadecyloxycarbonyl-5-(2-hydroxylethyl)-4-methylimidazolium(1.36%), hexanedioic acid, bis(2-ethylhexyl)ester (1.36%) and 3,5-di-t-butyl phenol (3.27%). The total phenolic content of C. esculenta was 15.15 ± 0.35 mg Gallic Acid Equivalence/g and it was significantly higher (p < 0.05) than the total flavonoid (8.50 ± 0.42 mg Quercetin Equivalence/g) and condensed tannin (4.40 ± 0.14 mg Catechin Equivalence/g) contents, respectively. C. esculenta possessed strong antioxidant capacity though it was lower than that of standard quercetin. DISCUSSION AND CONCLUSION: Results showed that C. esculenta possesses strong antioxidant activity and also contains some important bioactive compounds that justify its medicinal properties as used in ethno-medicine.

Quality evaluation of commercially sold table water samples in Michael Okpara University of Agriculture, Umudike, Nigeria and surrounding environments.

In Michael Okpara University of Agriculture, Umudike, Nigeria (MOUAU) and surrounding environments, table water of different brands is commercially hawked by vendors. To the best of our knowledge, there is no scientific documentation on the quality of these water samples. Hence this study which evaluated the quality of different brands of water samples commercially sold in MOUAU and surrounding environments. The physicochemical properties (pH, total dissolved solids (TDS), biochemical oxygen demand (BOD), total hardness, dissolved oxygen, Cl, NO3, ammonium nitrogen (NH3N), turbidity, total suspended solids (TSS), Ca, Mg, Na and K) of the water samples as indices of their quality were carried out using standard techniques. Results obtained from this study indicated that most of the chemical constituents of these table water samples commercially sold in Umudike environment conformed to the standards given by the Nigerian Industrial Standard (NIS), World Health Organization (WHO) and American Public Health Association (APHA), respectively, while values obtained for ammonium nitrogen in these water samples calls for serious checks on methods of their production and delivery to the end users.

Effect of livingstonepotato (Plectranthus esculenthus N.E.Br) on hyperglycemia, antioxidant activity and lipid metabolism of streptozotocin induced diabetic rats.

The effect of livingstone potato (Plectranthus esculenthus N.E.Br) on serum glucose, glycated hemoglobin (HbA1C), serum triglyceride, total cholesterol, high density lipoprotein (HDL), low density lipoprotein (LDL), very low density lipoprotein (VLDL), hepatic malic enzyme (ME), isocitrate dehydrogenase (IDH) and catalase activities of Streptozotocin induced diabetic rats were investigated using standard techniques. The atherogenic index (AI) and coronary risk index (CRI) of the rats were calculated as the ratios of LDL to HDL and total cholesterol to HDL, respectively. The serum glucose of the non-diabetic, diabetic control and diabetic rats given livingstone potato incorporated feeds (test feed) were 92.58 ± 3.97, 352.30 ± 4.88 and 165.50 ± 7.88 mg/dl, respectively. Intake of the test feed by the diabetic rats of group 3, resulted in significant (P < 0.05) decrease of their serum glucose, HbA1c, triglyceride, cholesterol, LDL, VLDL, AI and CRI but significant increase (P < 0.05) of hepatic levels of ME, IDH, catalase and serum HDL compared with the diabetic control rats that had significant alteration of these parameters (P < 0.05) compared with the non-diabetic rats. The feed intakes of the non-diabetic, diabetic control and diabetic rats given the test feed were 133.34 ± 1.32, 137.84 ± 5.77 and 146.38 ± 4.33 g/rat/week by the last week of experimentation. The diabetic control rats recorded significant loss of weight (P < 0.05) compared with the non diabetic rats despite increased feed intake. Chemical analysis of the standard and test feeds showed that the standard rat feed contained 15.00 ± 0.78% protein, 7.24 ± 1.20% fat, 31.55 ± 2.62% carbohydrates, energy value of 290.65 ± 4.77 kcal/100 g, 10% crude fiber and 0.12 ± 0.04 mg Gallic Acid Equivalent while the test feed contained 40.10 ± 0.16% carbohydrates, 17.22 ± 0.40% protein, 22.16 ± 0.34% fat, energy value of 428.70 ± 2.12 kcal/100 g, 8.51 ± 0.16% crude fiber, 1.3 ± 0.2 mg Gallic Acid Equivalent/g of sample and strong antioxidant activity comparable to standard quercetin. The study shows the potentials of livingstone potato in the management of diabetes and hyperlipidemia.

Ameliorative potentials of cocoyam (Colocasia esculenta L.) and unripe plantain (Musa paradisiaca L.) on the relative tissue weights of streptozotocin-induced diabetic rats.

AIM: To investigate the ameliorating potentials of cocoyam (Colocasia esculenta L.) and unripe plantain (Musa paradisiaca L.) incorporated feeds on the renal and liver growths of diabetic rats, induced with 55 and 65 mg/kg body weight of Streptozotocin. METHOD: The blood glucose level of the rats was measured with a glucometer, the protein and glucose and specific gravity (SPGR) in the urine samples of the rats were measured using urine assay strips and urinometer respectively. The chemical composition and antioxidant screening of the test feeds were carried out using standard techniques. RESULTS: Administration of the test feeds for 21 days to the diabetic rats of groups 4 and 5, resulted in 58.75% and 38.13% decreases in hyperglycemia and amelioration of their elevated urinary protein, glucose, SPGR, and relative kidney weights. The diabetic rats administered cocoyam incorporated feeds, had 2.71% and 19.52% increases in weight and growth rates, the diabetic rats administered unripe plantain incorporated feeds had 5.12% and 29.52% decreases in weight and growth rates while the diabetic control rats had 28.69%, 29.46%, 248.9% and 250.14% decreases in weights and growth rates. The cocoyam incorporated feeds contained higher antioxidants, minerals and phytochemicals except alkaloids than unripe plantain feed. CONCLUSION: Cocoyam and unripe plantain could be useful in the management of diabetic nephropathy.

Ameliorative Potentials of Ginger (Z. officinale Roscoe) on Relative Organ Weights in Streptozotocin induced Diabetic Rats.

The ameliorating potentials of ginger incorporated feed (10%) on the relative organ weights of Streptozotocin (STZ) induced diabetic rats was investigated. The experiment lasted for three weeks. Results show that administration of 10% ginger feed to the diabetic rats of group 3, resulted in a 29.81% decrease in their resulting hyperglycemia with a corresponding amelioration of elevated urinary protein, sugars, specific gravity as well as renal growth. In addition, administration of the ginger incorporated feeds to the diabetic rats of group 3, resulted in 9.88% increase in body weight with a corresponding 60.24% increase in growth compared with the non-diabetic rats administered standard rat pellets that had 6.21% increase in weight with a corresponding 60.14% increase in growth unlike the diabetic control rats that recorded 28.62% decrease in body weight with a corresponding 239.9% decrease in growth rates. Analysis of the chemical composition of the flour of the ginger incorporated feed indicated that it contained moderate amounts of moisture, crude fibre, alkaloids, saponins, tannins, Fe and Zn but considerable amounts of proteins, lipids, carbohydrates, ash, flavonoids, calcium, magnesium, potassium, phosphorous and energy value. There was no significant difference (P>0.05) in the liver and relative liver weights of the diabetic control rats and the diabetic -ginger treated rats. In addition, there were no significant differences in the kidney weights of the non-diabetic, diabetic control and diabetic treated rats (P>0.05) while there were significant differences in the relative kidney weights of the non-diabetic rats and the diabetic rats treated with ginger feeds (P<0.05). Results show that the use of ginger in the dietary management of diabetes mellitus could be a breakthrough in the search for novel plants that could prevent the development of diabetic glomerular hypertrophy.