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Articles by R.A. Umar
Total Records ( 7 ) for R.A. Umar
  S.W. Hassan , R.A. Umar , H.M. Maishanu , I.K. Matazu , U.Z. Faruk and A.A. Sani
  The effect of solar, sun and oven drying on the nutrients and non-nutrients composition of leaves of Gynandropsis gynandra was determined. Ash content of sun (3.14±0.09%), solar (3.16±0.03%) and oven (3.30±0.08%) dried samples were significantly (p<0.05) increased compared to fresh samples. All the drying methods were found to significantly (p<0.05) lower moisture, carbohydrates and protein. However, crude fibre content was significantly (p<0.05) increased with drying method. Drying method, with exception of oven drying, did not significantly (p>0.05) lower lipid content. Significant (p<0.05) increases of mineral elements upon drying with exception of sodium were observed. Alkaloids, tannins, saponins, saponins glycosides, flavonoids and volatile oils were detected in fresh and dried samples. These phytochemicals detected were found to decrease upon drying to trace amounts. Solar and oven drying were found to significantly reduce acid value from 3.91±0.31 to 1.66±0.06 and 2.69±0.33%, respectively. Solar drying may be the preferred method of drying the leaves of Gynandropsis gynandra as it is faster, more hygienic and preserves the nutrients better.
  S.W. Hassan , R.A. Umar , M. Lawal , L.S. Bilbis , B.Y. Muhammad , U.Z. Faruk and A.A. Ebbo
  The alkaloidal composition, histopathological and toxicity studies of alkaloid and aqueous ethanol extracts of Boscia angustifolia on biochemical indices of kidney and liver functions in rats were studied. The amount of alkaloids detected in 50 g powdered root extract of the plant was 11.44% (w/v). Renal and liver indices were significantly (p<0.05) altered at higher doses of 703.60, 1125.70 (alkaloidal extract), 839.30 and 1342.80 mg kg-1 body weight (aqueous ethanol extract). The aqueous ethanol and alkaloidal root extracts produced histopathological lesions of the liver and kidney at higher doses. These lesions include perivascular cuffs, protein cast, infiltration (kidney) and slight infiltration and perivascular cuffs (liver). There was a significant (p<0.05) dose dependent decrease in weight in the rats given higher doses of the aqueous ethanol and alkaloidal root extracts of Boscia angustifolia. The use of this plant is associated with some levels of organ toxicity.
  R.A. Umar , S.W. Hassan , M.J. Ladan , I.K. Matazu , M. Nma Jiya and H.O. Usman
  Retrospective analysis of the results of haemoglobin genotyping of 1033 cases was conducted at the Haemoglobin Genotyping Laboratory in Sokoto, Nigeria. Haemoglobin genotype determination was performed by cellulose acetate electrophoresis. The results show that 666 (64.5%) were Hb AA, 241 (23.3%) Hb AS, 117 (11.3%) Hb SS, 5.0 (0.48%) Hb AC 2.0 (0.19%) and Hb SC 2.0 (0.19%). We conclude that the prevalence of genes for these haemoglobin variants could be explained on the basis of selection due to evolutionary pressure imposed by malaria in line with malaria theory and theory of balanced polymorphism. The implication of our findings on health care provision and planning in the region is discussed.
  S.W. Hassan , R.A. Umar , M.J. Ladan , P. Nyemike , R.S.U. Wasagu , M. Lawal and A.A. Ebbo
  This study was aimed to assess the nutritive value, phytochemical constituents and antifungal activity of leaf, root and stem extracts of Pergularia tomentosa. Chemical composition of leaf, stem and root extracts of the plant were determined using standard methods. Aqueous and organic solvents extracts of the plant parts were screened for antifungal activity using agar dilution method. Phytochemicals detected in the leaf and stem extracts were alkaloids, cardiac glycosides, cyanogenic glycosides, saponins, flavonoids, tannins and anthraquinones. The roots contain trace amounts of cyanogenic glycosides, cardiac glycosides, saponins, tannins and anthraquinones. Mineral element composition of the plant showed higher amount of phosphorus and potassium in the root and stem and sodium, magnesium and calcium in the leaf extracts. All the plant parts used contain high percentages of carbohydrates and crude fibre ranging from 53.27±1.75 to 61.31±2.84% and 16.33±0.29 to 23.17±0.58%, respectively. Lipids (6.83±0.76%), ash (17.17±1.04%) and crude protein contents (6.39±0.17%) were higher in the leaf extracts while the stem was of higher moisture (10.67±0.76%) content. Hexane (HX), Petroleum Ether (PE) and chloroform (CHL) leaf, stem and root extracts were active against all the isolates tested with percentage inhibitions ranging from 41.90±5.63 to 97.52±0.28%. The organic solvent extracts demonstrated near complete inhibitions of the fungal isolates at 8.00 mg mL-1 while the aqueous (AQ) extracts of the plant parts inhibited the growth of the isolates at 27.17±7.79 to 97.45±0.21% with near complete inhibition of the tested isolates also at 8.00 mg mL-1. The results showed that the leaf, root and stem extracts of Pergularia tomentosa have potential nutritional and antifungal uses.
  S.W. Hassan , M.J. Ladan , R.A. Dogondaji , R.A. Umar , L.S. Bilbis , L.G. Hassan , A.A. Ebbo and I.K. Matazu
  The leaves of Erythrophleum africanum is known in the arid land of tropical Africa to posses toxicological properties. Phytochemical, acute and sub-acute evaluation of the possible toxicity risk of E. africanum aqueous leaves extracts were investigated in this study. Phytochemical constituents detected in the leaves extracts were saponins (1.16% w/v), cardiac glycosides, tannins (0.17 true tannins and 0.23% w/v pseudotannins), flavonoid glycosides, free flavonoids and alkaloids (4.34% w/v). The Lethal Dose (LD50) of the aqueous leaves extracts was greater than 3000 mg kg-1 per os (orally) in albino rats. Sub-acute administration of the extract for 28 days resulted in significant (p<0.05) changes in some renal and liver indices at 3000 and 2000-3000 mg kg-1 body weight, respectively. Histopathological lesions of the kidney and liver in form of moderate and marked infiltration with necrosis and perivascular lymphocytic cuff were observed. The observed lesions could be due to roles played by liver and kidneys in metabolism of xenobiotics and their elimination from the body. These investigations thus seem to indicate the toxic effects of the aqueous leaves extracts of E. africanum at 2000-3000 mg kg-1. These could be attributed to the combined toxicity of the phytochemical constituents such as tannins, saponins, glycosides and alkaloids.
  S.W. Hassan , F.L. Bilbis , M.J. Ladan , R.A. Umar , S.M.Dangoggo , Y. Saidu , M.K. Abubakar and U.Z. Faruk
  The aqueous and organic solvents extracts of leaves, stem barks and roots of Calotropis procera were screened for antifungal (agar dilution method) and phytochemical properties. Organic solvents extracts of the stem bark significantly (p<0.05) inhibited growth of Trichophyton rubrum and Microsporum gypseum. The petroleum ether (PE) extract however was significantly (p<0.05) active on only Trichophyton rubrum at concentrations ranging from 0.66 to 5.33 mg mL-1. All the leave extract fractions completely inhibited the growth of the tested organisms. The roots fractions of hexane (HX) and PE extracts showed significant (p<0.05) growth inhibitions of Microsporum gypseum and Aspergillus niger. All the aqueous extract fractions of the plant parts showed complete growth inhibition of all the tested organisms. Alkaloids, flavonoids, tannins, steroids, triterpenoids, saponins and saponin glycosides were detected in the leaves and roots extract fractions, with only flavonoids, triterpenoids and saponins in the stem bark extracts. The results obtained lend scientific credence for the use of the plant against fungal diseases.
  R.A. Umar , N.M.Jiya , S.W. Hassan , K. Abdullahi , J.M. Ahmed and U. Nata`ala
  Three cases of uncomplicated Plasmodium falciparum malaria in Sokoto, Nigeria, between June and July 2006, apparently failed treatment with artesunate monotherapy. Two of the cases fulfilled the World Health Organization’s criteria for low grade resistance level while one case fulfilled the criteria for high grade resistance. Use of artesunate monotherapy and improper use among the population may likely quicken the pace of the emerging resistance to the drug amongst the local strains of the parasites.
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