Smith I. Jaja

Evaluation of the Antioxidant Activity and Lipid Peroxidation of the Leaves of Vernonia amygdalina

This study evaluated the in vitro antioxidant activity of water (VAWE) and ethanol (VAEE) extracts of the leaf of Vernonia amygdalina. The antioxidant activity of each extract was evaluated using various radicals or oxidation systems. The total phenolic or flavonoid contents and their correlation with total antioxidant activity were also evaluated. VAEE exhibited antioxidant scavenging potential comparable to butylated hydroxyanisole (BHA), but higher than butylated hydroxytoluene (BHT) or VAWE. The total antioxidant scavenging activity of the extracts measured as the millimolar (mM) equivalent of vitamin C gave VAEE a 10.09 ± 1.63, which is comparable to BHA with a 9.31 ± 1.17, but higher than VAWE with an 8.75 ± 1.28 or BHT with a 6.14 ± 2.01. Extracts inhibited bleaching of B-carotene, oxidation of linoleic acid and lipid peroxidation induced by Fe2+/ascorbate in a rat liver microsomal preparation. The total flavonoid and phenolic contents correlated positively with total antioxidant activity. The total flavonoid content also correlated well with total phenolic. Extracts of V. amygdalina contain natural antioxidants, have the potential to act as antioxidants against aqueous radicals and reactive species ions. The total phenolic content of the extracts is related to its total flavonoid, and it may be responsible for its total antioxidant activity.

l-Arginine supplementation enhances antioxidant activity and erythrocyte integrity in sickle cell anaemia subjects

The effect of oral, low-dose l-arginine supplementation (1g/day for 6 weeks) on antioxidant activity, haematological parameters and osmotic fragility of red blood cells was investigated in sickle cell disease sufferers. Twenty eight sickle cell anaemia subjects were recruited for the study. Five millilitres of blood was withdrawn from an ante-cubital vein for the estimation of plasma arginine concentration ([R]), total antioxidant enzymes (TAE) activity, malondialdehyde concentration ([MDA]), RBC count, [Hb], PCV, MCHC, MCV, MCH, percent irreversibly sickled cells (%ISC)) and osmotic fragility of red blood cells in the subjects. l-arginine supplementation increased [R] (p<0.001), TAE activity (p<0.05) and MCV (<0.05) but reduced plasma [MDA], MCHC, MCH and %ISC (p<0.001, respectively). Δ[R] correlated positively with ΔTAE (r=0.8) and negatively with Δ[MDA] (r=-0.7) and Δ%ISC (r=-0.5). Also ΔTAE activity correlated negatively with Δ[MDA] (r=-0.7) and Δ%ISC (r=-0.6). Supplementation shifted the osmotic fragiligram to the right and reduced the concentrations of NaCl at which initial and complete lyses of erythrocytes occurred. Study showed that low-dose, oral l-arginine increased antioxidant activity, red blood cell resistance to osmotic lysis but reduced red cell density in SCD.

Biochemical and histologic changes in rats after prolonged administration of the crude aqueous extract of the leaves of Vitex grandifolia.

Background: In recent times, many herbal remedies are used to treat variety of ailments. The leaves of Vitex grandifolia is claimed to be effective in the treatment of diabetes mellitus and as a diuretic in the treatment of high blood pressure. However, there are no scientific reports on the therapeutic benefits or toxicity of this plant. This study therefore investigated the effect of prolonged administration of the aqueous extract of the leaves of this plant in Sprague–Dawley rats. Methods: The plant leaves (No. FHI 107055) were dried at 40° C, powdered and extracted at room temperature in water (pH 5.72) by percolation. Extract was dried in vacuo to give a yield of 27.32 %w/v. The extract, 0.5–2 g/kg b. wt. was administered by gastric probe to rats for 14 days. The liver and kidney functions, blood chemistry, histopathologic alterations of vital organs and extract effect on rats b. wt. were investigated. Results: V. grandifolia caused significant increase in the serum electrolytes, creatinine, and liver function enzyme dose dependently compared with the control (P≤ 0.001). The extract had no effect on the heart; however, the architecture of the liver, kidney, and lungs were significantly altered in the treated groups compared with the control. The treated rats had significantly reduced body weight compared with the control (P≤ 0.001). Major clinical signs observed in the treated groups were polydipsia, polyuria, puffiness of hair, and calmness, which were consistent with increase in dose of the extract. Conclusion: It could be clearly concluded that prolonged administration of the aqueous leaf extract of V. grandifolia at the dose used in this study tends to be toxic to the rats. Its use in folkloric medicine should be with utmost care.

Impact of Vitamins C and E supplement on anti-oxidant enzymes (catalase, superoxide dismutase, and glutathione peroxidase) and lipid peroxidation product (malondialdehyde levels) in sickle subjects

Aim: This study sought to investigate the effect of combined supplements of Vitamins C and E glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) malondialdehyde (MDA) levels in sickle cell and non-sickle cell patients. Materials and Methods: A total of 27 subjects (16 controls and 11 test subjects) were used for this study. The sickle cell subjects (test) were obtained among the sickle cell patients who visited the out-patient clinic of the Lagos University Teaching Hospital (LUTH) for check-up, their ages ranged from 18 to 27 years. Venous blood samples of the subjects were carefully withdrawn using disposable syringes and needles at the sickle cell anemia (SCA) clinic, LUTH, Nigeria. Vitamins C and E supplementation commenced on the 1 st day of blood collection and lasted for 6 weeks. All the subjects received Vitamin E (1000 IU) in soft gelatinous capsule once daily and 200 mg of Vitamin C orally per day for 42 days. Blood was collected from each subject under aseptic procedure and MDA was determined to assess lipid peroxidation enzyme activity while GPx, SOD, and CAT were estimated for antioxidant enzymes′ activity. Results: Results revealed significantly (P < 0.01) lower basal levels of SOD, GPx, and MDA in sickle (SCA) compared with non-sickle anemia (NSCA). After 42 days of Vitamins C and E supplementation, SOD, GPx, and MDA increased significantly in both groups, but the increase was more in SCA compared with NSCA subjects (P < 0.01). Conclusion: Hence, it was found that Vitamins C and E supplementation did not reduce lipid peroxidation enzymes (MDA) activity in SCA subjects despite the increase in scavenging enzymes′ (SOD and GPx) activities in SCA.

Supplementation with l-arginine stabilizes plasma arginine and nitric oxide metabolites, suppresses elevated liver enzymes and peroxidation in sickle cell anaemia

The effect of l-arginine on liver function in SCD has received little or no attention. The effect of a chronic, oral, low-dose supplementation with l-arginine (1gm/day for 6 weeks) on some liver enzymes, lipid peroxidation and nitric oxide metabolites was studied in 20 normal (non-sickle cell anaemia; NSCA) subjects and 20 sickle cell anaemia (SCA) subjects. Ten milliliters of blood was withdrawn from an ante-cubital vein for the estimation of plasma arginine concentration ([R]), alanine aminotransaminase (ALT), aspartate aminotransaminase (AST) and alkaline phosphatase (ALP), plasma total bilirubin concentration [TB], malondialdehyde concentration [MDA] and nitric oxide metabolites concentration [NOx]. Before supplementation, ALT, AST, ALP (p<0.05 respectively) and TB (p<0.001) were higher in SCA subjects than in NSCA subjects. [R] and [NOx] were higher in NSCA subjects (p<0.001 and p<0.05 respectively). Supplementation caused greater percent increases in [R], and [NOX] in SCA than in NSCA subjects (p<0.001 in each case). l-Arginine caused greater percent reductions in ALT and AST in SCA subjects but greater percent reduction in ALP in NSCA subjects (p<0.001 in each case). Changes in [MDA] and [TB] in the two groups were similar. Study shows that chronic, oral, low-dose supplementation with l-arginine improved liver function, oxidative stress, plasma arginine concentration and nitric oxide metabolites levels in NSCA and SCA subjects. Responses in SCA subjects to l-arginine were more sensitive than in NSCA subjects.

Epithelial sodium channel blockade and new β-ENaC polymorphisms among normotensive and hypertensive adult Nigerians

ABSTRACT We sought to determine the effect of amiloride on blood pressure (BP) and the presence of polymorphisms of the β-subunit of the epithelial sodium channel (ENaC) among normotensive (NT) and hypertensive (HT) Nigerians. Healthy volunteers—47 NT and 53 age-matched HT were recruited after giving informed consent. Subjects were salt-loaded with 200 mmol of NaCl daily for 5 days. Following a week washout period, salt-loading was repeated in addition to the administration of 5 mg amiloride daily for five days. Blood pressure, plasma and urine electrolytes were measured at baseline, after salt-loading and after salt-loading plus amiloride. PCR amplicons were sequenced for β-ENaC polymorphisms. Salt-loading led to a significant increase (p < 0.05) in SBP among NT and HT and in DBP (p < 0.001) only among HT. Amiloride reduced SBP and DBP to below baseline levels in NT (p < 0.05) and HT (p < 0.001) subjects. Five of the subjects had the β-T594M polymorphism, HT 3/53; NT 2/47 (p = 0.75). Four previously unreported β-ENaC mutations were recorded: E632V and E636V, respectively, among two HT subjects, D638Y in another HT and L628Q in one NT subject. We showed the presence of β-ENaC polymorphisms among our populace and the possible usefulness of amiloride as a single antihypertensive among Nigerians.

Effects of Ascorbic Acid Intake on the Intima-Media Thickness and Blood Flow Velocities of the Carotid Artery in Patients With Sickle Cell Anemia

This study aims to investigate and compare the effects of six-week oral vitamin C supplementation on blood velocities, intima-media thickness, and cross-sectional diameter (CSD) of the common carotid artery of sickle cell anemia (SCA) and non–sickle cell anemia (NSCA) subjects using sonography. Results showed that the CSD and end-diastolic velocity were significantly higher (P < .002 and P < .001, respectively) in the SCA subjects than in the NSCA subjects in the presupplementation phase. Calculated resistivity index (RI) was significantly lower in the SCA subjects (P < .003). Vitamin C supplementation had a slight effect on all the measured parameters in the NSCA subjects but caused a significant increase in peak systolic velocity (PSV) (P < .02) and RI (P < .01) in SCA. A comparison of change in each measured variable between the groups showed significant differences. Oral supplementation with vitamin C should be encouraged in patients with SCA as prophylaxis against endothelial damage, thereby preventing vaso-occlusive crises and their associated morbidity.