Bio-augmentation and bio-stimulation with kenaf core enhanced bacterial enzyme activities during bio-degradation of petroleum hydrocarbon in polluted soil.

Indigenous micro-organisms often possess the ability to degrade petroleum hydrocarbon (PHC) in polluted soil. However, this process can be improved by supplementing with nutrients or the addition of more potent microbes. In this study, the ability of kenaf-core to stimulate the PHC degradation capability of microbial isolates from PHC polluted soil samples was evaluated. The standard experimental methods used in this study include: the digestion and analysis of the physico-chemical properties of petroleum hydrocarbon contaminated and non-contaminated soil samples; evaluation of petroleum hydrocarbon biodegradation using bio-augmentation and bio-stimulation (with kenaf-core) treatments; and, determination of soil microbial enzyme activities. Results from this study show that K, Na, total nitrogen, organic carbon, exchangeable cations, and heavy metals were found to be significantly (P < 0.05) higher in the polluted soil than in the non-polluted soil. Also, the polluted samples had pH values ranging from 5.5 to 6.0 while the non-polluted samples had a pH of 7.6. The microbial enzyme activities were comparatively lower in the polluted soils as compared to the non-polluted soil. The percentage degradation in the kenaf-core treated samples (AZ1T2-78.38; BN3T2-70.69; OL1T2-71.06; OT1T2-70.10) were significantly (P < 0.05) higher than those of the untreated (AZ1T1-13.50; BN3T1-12.50; OL1T1-10.55; OT1T1-9.50). The degradation of petroleum hydrocarbon in the bio-augmented and bio-stimulated treatments increased with increasing time of incubation, and were higher than that of the untreated sample. Comparatively, the treatment with a combination of kenaf-core and rhamnolipid exhibited a significantly (P < 0.05) higher degradation rate than that of the treatment with only kenaf core or rhamnolipid. While, the bio-stimulated and bio-augmented treatments had appreciable microbial counts that are higher than that of the untreated. In conclusion, the nutrient-supplement with kenaf-core significantly enhanced microbial growth and activities in the soil, thus improving their ability to biodegrade petroleum hydrocarbons in the polluted soils. Thus, supplementing with Kenaf core to encourage microbiological degradation of petroleum hydrocarbon is recommended.

Drying temperature affects the hypolipidemic, antioxidant, and antihypertensive potential of Hibiscus sabdariffa calyx in rats induced with L-NAME.

The effects of different drying temperatures on the hypolipidemic, antioxidant, and antihypertensive potential of Hibiscus sabdariffa calyx was evaluated. The calyx were dried under different temperature conditions (- 58 °C, 30 °C, 40 °C, and 50 °C), and extracted with a solvent mixture of ethanol and water (1:4 % w/v). To induce hypertension, the rats were administered with 40 mg/kg body weight dose of N-nitro L-arginine methyl-ester (L-NAME), via the intra-gastric route. H. sabdariffa extract was administered orally, at varying doses (250, 500, and 1000 mg/kg) to the rats. Afterwards, the hypolipidemic, antioxidant, and antihypertensive potentials of the extracts were evaluated using standard validated methods. Induction with L-NAME significantly (p < 0.05) increased the total cholesterol, triglyceride, and LDL levels, significantly decreased the HDL levels; significantly (p < 0.05) increased the levels of LPO/MDA, H2O2, and decreased GPx, and SOD activities; significantly (p < 0.05) increased the pressures (diastolic and systolic); significantly (p < 0.05) increased ACE and arginase activities, glucose level, and significantly decreased nitric oxide activity. Treatment with H. sabdariffa extract significantly (p < 0.05) reversed these trends in the hypertensive experimental rats. The hypolipidemic, antioxidant, and antihypertensive properties of the extract from the calyx of H. sabdariffa, which varies with the drying temperatures of the calyx, portends its potential as a curative agent in the treatment of hypertensive conditions, and other cardiovascular diseases.

Hibiscus sabdariffa calyx protect against oxidative stress and aluminium chloride-induced neurotoxicity in the brain of experimental rats.

We evaluated the antioxidant and neuroprotective potentials of extracts of Hibiscus sabdariffa calyx in Wistar albino male rats injected intraperitoneally with aluminium chloride at a dose of 7 mg/kg/day. Phytochemical screening of H. sabdariffa calyx show that coumarin glycosides and steroid were absent after drying at 50 oC. At 30 oC, there were significant (p < 0.05) highest amounts of phenols, flavonoids, alkaloids, tannin, and saponin. The extracts showed significantly (p < 0.05) high dose-dependent antioxidant activities. MDA significantly (p < 0.05) increased, while GSH, GPX, SOD, CAT activities significantly (p < 0.05) decreased in the brain of the experimental rats induced with AlCl3, while treatment with the extracts reversed these effects to a relatively normal level. At doses of 500 and 1000 mg/kg body weight, the extracts of the calyx dried at 30 oC exhibited the highest capacity to increase the activities of GSH and GPx. Also, AlCl3 caused significant increases (p < 0.05) in the percentage inhibition of acetylcholinesterase and butyrylcholinesterase activities, and a significantly (p < 0.05) lower protein levels in the brain of the test rats, while treatment with the extracts, at low and high doses, significantly (p < 0.05) reversed these effects in the rat brain to near normal.H. sabdariffa exhibited a good potential to protect against oxidative stress and neurotoxicity.

Tolerance, taxonomic and phylogenetic studies of some bacterial isolates involved in bioremediation of crude oil polluted soil in the southern region of Nigeria.

Indigenous bacteria play vital roles in the bioremediation of crude oil polluted soils. The effectiveness of the bioremediation process depends on the tolerance, characteristics and biodiversity of the bacteria isolates. Bacteria strains were isolated from crude-oil polluted sites in different locations in the southern region of Nigeria namely: Azikoro and Otukpoti (Bayelsa state); Ologbo and Benin (Edo State) and non-polluted soil was collected from Ibadan (Oyo state). Tolerance study was conducted for 96 h s. Isolation and characterization of the most effective isolate from each location was done using cultural, physico-chemical and molecular methods. The tolerance level of the isolates from the different oil-polluted soils and their comparative growth performance on crude oil supplemented media decreases in the order: Azikoro - Ologbo - Otukpoti - Benin. MATS analysis showed that cell surfaces of Azikoro, Ologbo and Otukpoti strains exhibited 58-63 % adhesion to n-hexadecane and are hydrophobic strains while Benin strain possess 38% adhesion to n-hexadecane and are hydrophilic. The cell surfaces of isolates from Azikoro, Ologbo and Otukpoti are highly Lewis-acidic while that from Benin is highly Lewis-basic. Isolates from Benin-3, Ologbo-1, and Otukpoti-1 were shown to be gram positive while that from Azikoro was gram negative. 16S rDNA fingerprinting confirmed the identities of the isolates as follows: Paenalcaligenes suwonesis with accession numbers NR-133804.1 from Azikoro spillage site (93.77%); Lactobacillus nagelii with accession number NR-158108.1 (91.30%) from Benin spillage site; Lactobacillus fermentum with accession number NR-104927.1 (96.70%) from Ologbo and Otukpoti spillage sites. Phylogenetic analysis putatively categorized the isolates from Otukpoti and Ologbo in close association belonging to same homology while Benin isolate is a subgroup. The characteristics and biodiversity of all the isolated bacteria from the regions possibly justifies their involvement in the bioremediation of petroleum hydrocarbons.

Carbohydrate digestive enzyme inhibition, hepatoprotective, antioxidant and antidiabetic benefits of Persea americana.

The medicinal use of Persea americana in the treatment of some diseases like hypertension, diabetes, is often with dearth of supporting scientific proof. Thus, we evaluated its ethnomedicinal benefits for possible scientific justification. Thirty healthy Wistar rats were randomly grouped in fives. Alloxan was used to induce diabetes in the rats in groups II to VI. The diabetic rats in group II were treated with glibenclamide, while those in group III were not treated. Also, the diabetic rats in groups IV to VI were treated with the ethanol extracts of the stem bark, leaf, and root of P. americana respectively. The parts of P. americana comparatively possess highest amounts of phenols (250.50 ± 0.68-bark), saponin (436.80 ± 3.76-leaf), flavonoid (382.80 ± 0.67-leaf) and tannins (58.34 ± 0.09-root). The extracts exhibited high reducing property (FRAP and total reducing), as well as high ABTS and DPPH free radical scavenging ability. The enzyme (alpha-glycosidase and alpha-amylase) inhibitory activity of P. americana increases with increasing concentration of the extracts. Administration of methanol extracts of P. americana bark, leaf and root to alloxan-induced diabetic rats resulted in significant (P < 0.05) decreases in AST, ALP, ALT, Total bilirubin, LPO, plasma glucose and significant (P < 0.05) increases in GSH, CAT and SOD. These effects were like that of glibenclamide. The enzyme inhibitory, hepatoprotective, antioxidant and antidiabetic properties of P. americana are some of the benefits derived from its consumption and ethnomedicinal use.

Synclisia scabrida protects against oxidative stress, hepatotoxicity and hyperglycaemia in alloxan-induced diabetic rats.

Background: Synclisia scabrida is commonly used in traditional medical practices for the management of diseases like diabetes and its complications. This study seeks to establish a scientific rationale for this practice. Methods: Thirty Wistar rats were randomly and equally grouped into six. Alloxan was used to induce diabetes in the rats in groups 2 to 6. The diabetic rats in group 2 were treated with glibenclamide, while those in group 3 were not treated. Also, the diabetic rats in groups 4, 5 and 6 were, respectively, treated with the ethanol extracts of the stem, root and leaf of S. scabrida. After 28 days of treatment, blood and organ samples were collected for biochemical studies. Results: S. scabrida possesses high amounts of useful phytochemicals. It also exhibits high total reducing capacity, FRAP activity, DPPH and ABTS scavenging ability. The inhibition of the α-glucosidase and α-amylase activities by the methanol extracts of S. scabrida stem, leaf and root were significantly (p < 0.05) higher than that of glibenclamide. Administration of S. scabrida extracts to the alloxan-induced diabetic rats caused significant (p < 0.05) decreases in the blood glucose, total bilirubin, AST, ALT, and ALP of the treated groups as compared to that of the untreated group. Treatment with the extracts also resulted in significantly (p < 0.05) lower LPO and significantly (p < 0.05) higher levels of GSH, SOD and CAT. Conclusion: S. scabrida extracts exhibited antioxidative, hepatoprotective and hypoglycaemic properties which are similar to that of the standard drug, glibenclamide.

Effect of germination on the phytase activity, phytate and total phosphorus contents of rice (Oryza sativa), maize (Zea mays), millet (Panicum miliaceum), sorghum (Sorghum bicolor) and wheat (Triticum aestivum).

The effect of germination on the level of phytase activity and the contents of phytates and phosphorus of five Nigeria grown cereal grains was studied. The cereals screened were rice (Oryza sativa), maize (Zea mays), millet (Panicum miliaceum), sorghum (Sorghum bicolor) and wheat (Triticum aestivum). Phytase activity was high (0.21-0.67 U g(-1)) in all samples. Phytate content ranged between 5.6 and 6.2 mg g(-1) while total phosphorus content ranged between 3.3 and 4.3 mg g(-1). During germination, the level of phytase activity increased and reached its maximal value after seven (16-fold), six (5-fold), five (7-fold), seven (3-fold) and eight (6-fold) days of germination for rice, maize, millet, sorghum and wheat respectively. After this initial increase, phytase activity declined slightly (P < 0.05). The increase in phytase activity during germination was accompanied by a significant reduction in phytate (P < 0.05) and a small but significant increase in total phosphorus.