Browsing by Author "Njue, Wilson N."
Now showing 1 - 11 of 11
Results Per Page
Sort Options
Item Anti-plasmodial Activity of Some Kenyan Medicinal Plant Extracts Singly and in Combination with Chloroquine(Wiley InterScience, 2004) Muregi, F.W.; Chhabra, S.C.; Njagi, Eliud N.; Lang’at, C.; Njue, Wilson N.; Orago, A.S.; Omar, S.A.; Ndiege, I.O.Sixty organic and aqueous extracts of eleven plants used for the control of malaria by local communities in Kisii District, Kenya were screened for in vitro anti-plasmodial activity. The plants selection was based on existing ethnobotanical information and interviews with local communities. The extracts were tested against chloroquine sensitive and resistant laboratory adapted strains of Plasmodium falciparum. The study revealed that 63.6% of the plants were active (IC50 ≤ 100 μg/mL). Extracts of four plants, Ekebergia capensis, Stephania abyssinica, Ajuga remota and Clerodendrum myricoides gave IC50 values below 30 μg/mL against both chloroquine sensitive and resistant P. falciparum strains. Combination of extracts of E. capensis and C. myricoides with chloroquine against the multi-drug resistant P. falciparum isolate (V1/S) revealed synergistic effect. The plants which showed activity may be useful as sources for novel anti-plasmodial compounds.Item Antiplamodial Activity of some Kenyan medicinal plant extracts singly and in combination with Chloroquine(2004) Muregi, F.W.; Chabbra, S.C.; Njue, Wilson N.; Njagi, Eliud N.; Langa’t, C.; Ndiege, I.O.Sixty organic and aqueous extracts of eleven plants used for the control of malaria by local communities in Kisii District, Kenya were screened for in vitro anti-plasmodial activity. The plants selection was based on existing ethnobotanical information and interviews with local communities. The extracts were tested against chloroquine sensitive and resistant laboratory adapted strains of Plasmodium falciparum. The study revealed that 63.6% of the plants were active (IC50 < or = 100 microg/mL). Extracts of four plants, Ekebergia capensis, Stephania abyssinica, Ajuga remota and Clerodendrum myricoides gave IC50 values below 30 microg/mL against both chloroquine sensitive and resistant P. falciparum strains. Combination of extracts of E. capensis and C. myricoides with chloroquine against the multi-drug resistant P. falciparum isolate (V1/S) revealed synergistic effect. The plants which showed activity may be useful as sources for novel anti-plasmodial compounds.Item Bioactive steroidal alkaloid glycosides from Selanum aculeastrum.(2002) Wanyonyi, Alphonse W.; Chhabra, S.C.; Mkoji, G.; Eilert, Udo; Njue, Wilson N.Solanum aculeastrum Dunal was investigated for the presence of molluscicidal compounds. This led to the isolation of solaculine A, from the root bark in addition to known steroidal alkaloids; solamargine and beta-solamarine from the berries. The structures were elucidated by spectroscopic techniques. Molluscicidal activity of the aqueous extracts of the berries and root bark, and the isolated compounds were investigated.Item Heavy Metals and Pesticides in Marine Sediment, Seawater, and Seaplants Along the Kenya-Mombasa Coastline(Taylor & Francis, 2003) Oyugi, Mildred P.; Chhabra, S.C.; Njue, Wilson N.; Kinyua, Anthony M.Marine sediment, seawater and several species of seaplants along the Kenya- Mombasa coastal region were analyzed to determine the levels of heavy metals by AAS and EDXRF and organochlorine pesticides (OCPs) by GLC-ECD. In marine sediments, there were high levels of manganese (1100 mg/L) at Vanga, compared to other study sites. In seawater, the heavy metals were detected in levels higher than those considered as natural in the ocean and the range was 0.01–0.30 mg/L. OCPs were detected in marine sediments and in seaplants. The trend of concentration of these pollutants in ascending order in seawater, marine sediment and seaplants was observed.Item Hypoglycemic Activity of Some Kenyan Plants Traditionally used to Manage Diabetes Mellitus in Eastern Province(2011) Piero, Ngugi M.; Joan, Murugi N.; Kibiti, Cromwell M.; Ngeranwa, Joseph; Njue, Wilson N.; Maina, Daniel N.; Gathumbi, Peter; Njagi, Eliud N.In this study five aqueous extracts; Bidens pilosa, Strychnos henningsii, Aspilia pluriseta, Catha edulis and Erythrina abyssinica were screened for anti-diabetic activity and their in vivo safety evaluated. The anti-diabetic activity was assessed by intraperitoneally injecting varying doses of aqueous extracts of the five plants into alloxanised mice. Toxicity was determined by injecting normal mice with 450mg of the plant extract / kg body weight and observing the effects of the extracts on histology of various organs. All the extracts showed hypoglycaemic activity. At high doses, some plants proved to be highly toxic, mildly toxic and others were safe. This study has established that the five bioactive plants can be safely used in the management of diabetes.Item Hypoglycemic effect of Helichrysum odoratissimum in alloxan induced diabetic mice(2015) Njagi, J.M.; Ngugi, Mathew P.; Kibiti, Cromwell M.; Ngeranwa, Joseph; Njue, Wilson N.; Gathumbi, Peter; Njagi, Eliud N.Diabetes mellitus is a disease of antiquity with worrying global incidence and prevalence. Conventional management and/or treatment interventions have been hampered by drawbacks like high costs, inaccessibility, likelihood of potential adverse and toxic effects among others. Use of antidiabetic phytodrugs has been on the rise, particularly in the developing countries, perhaps due to cost implications and accessibility advantages. In this study, an aqueous leaf extract of the medicinal plant Helichrysum odoratissimum was bioscreened for their hypoglycemic potential in alloxan-induced diabetic mice. Three dose ranges were used viz; 50 mg/kgbwt, 100 mg/kgbwt and 150 mg/kgbwt. Results indicate that the extract appreciably lowered blood glucose level in the diabetic mice. The glucose lowering potency of this extract was dose dependent. Preliminary in vivo toxicity assessment revealed that the plant has no discernible toxicity on the major organs of the study animals. The study results confirm the folklore reports from traditional medical practitioners that the extract has safe bioactivity against diabetes mellitus. It avails an impetus for further bioscreening efforts with a view to the development of more hypoglycemic agents in future.Item In vitro antiplasmodial activity of some plants used in Kisii, Kenya against Malaria and their chloroquine potentiative effects.(2003) Muregi, F.W.; Chhabra, S.C.; Njagi, Eliud N.; Lang’at-Thoruwa, C.; Njue, Wilson N.; Ndiege, I.O.Fifty-five organic and aqueous extracts of 11 plants used in malaria therapy in Kisii District, Kenya were tested in vitro against chloroquine (CQ)-sensitive and resistant strains of Plasmodium falciparum. Of the plants tested, 73% were active (IC(50) < 100 microg/ml). Three plants, Vernonia lasiopus, Rhamnus prinoides and Ficus sur afforded extracts with IC(50) values ranging less than 30 microg/ml against both CQ-sensitive and resistant strains. Combination of some extracts with CQ against the multi-drug resistant P. falciparum isolate V1/S revealed some synergistic effect. The plant extracts with low IC(50) values may be used as sources for novel antimalarial compounds to be used alone or in combination with CQ.Item molluscicidal and antimicrobial activity of solanum aculeastrum(2003) Wanyonyi, Alphonse W.; Chhabra, S.C.; Mkojo, G.; Njue, Wilson N.; Tarus, Paul K.The methanolic extract of the fresh root bark and berries of Solanum aculeastrum showed significant activity against host snails of schistosomiasis. The berries extract was more potent with 100% snail kill at 50 ppm. Fractionation increased activity with 100% mortality at 20 ppm. The aqueous and methanolic extracts of the berries showed moderate antimicrobial activity, increasing by fractionation.Item Organo-chlorine residues in tissues of marine fauna along the coast of Kenya Mombasa Island(2007) Bor, S.K.; Simbauni, J.A.; Oyugi, Mildred P.; Njue, Wilson N.; Chhabra, S.C.Soft tissues of species of marine fauna; crabs (Crust acea ), oysters ( Pelecypoda, Bivalvia), sea stars ( Asterroidea ), sea urchin (Echinoidea) and bony fishes (Osteichtyes) sampled along the Kenya - Mombasa coastal region were analyzed to determine the levels of organochlorine pesticides (OCPs). Analysis was done using gas chromatography with an electron capture detector. This study showed that marine fauna accumulated some OCPs in their tissues, 1,2,3,4,5,6 - hexachlorocyclohexane (BHC) being the most common of the OCPs. These findings highlight evidence of pollution of marine fauna at the Kenyan coastal sites. It is necessary to have thorough waste management programs as a strategy to minimize marine pollutionItem Photolabelling of Prostaglandin E2 receptor in cardiac sarcolemmnal vesicles(1990) Njue, Wilson N.; Liu, H.J.; Olley, P.N.A [3H]azidophenacyl ester of PGE2 ([3H]azido-PGE2) was synthesized and used to photoaffinity label the protein component of the high affinity PGE2 binding site in cardiac sarcolemma membrane. Photolysis of the isolated cardiac sarcolemmal vesicles in the presence of [3H]azido-PGE2 resulted in the covalent labelling of a protein component that migrated on sodium dodecyl sulfate-polyacrylamide gels with an apparent molecular weight of 100,000. Incorporation of the [3H]azido-PGE2 did not occur in the absence of photolysis. The photolabelling of the 100-kDa protein by [3H]azido-PGE2 was inhibited by excess unlabelled PGE2 and azido-PGE2. Specific binding of [3H]azido-PGE2 was displaced by excess unlabelled PGE2 or azido-PGE2, but not PGF2 alpha, 6-keto-PGF1 alpha or PGD2. These results indicate that the 100-kDa photoaffinity labelled [3H]azido-PGE2 binding protein contains the binding site for PGE2 in isolated cardiac sarcolemma membranes.Item Use of human nails as bio-indicators of heavy metals environmental exposure among school age children in Kenya(2008-04) Hussein, Were F.; Njue, Wilson N.; Murungi, J.; Wanjau, R.Metal pollution and its health effects present a challenge currently facing the developing countries. Metal poisoning is usually difficult and expensive to assess or screen in these countries due to limited resources, which means that policies, guidelines, regulations and institutional managements are limited. Hair and nail as biopsy materials were suggested as more attractive biomarkers in assessing heavy metals environmental exposure. This paper deals with quantitative determination of lead (Pb), cadmium (Cd), calcium (Ca), zinc (Zn), and iron (Fe) in fingernails of children (n=200) in urban and rural areas using atomic absorption spectrometry. Factors that were suspected to influence the accumulation of Pb and Cd in children were obtained through a questionnaire. The mean levels of heavy metals in children in urban areas were found to be higher (27.5+/-1.8 microg/g Pb and 0.73+/-0.08 microg/g Cd) than in rural areas (19.7+/-0.9 microg/g Pb and 0.44+/-0.06 microg/g Cd). The difference was significant (P<0.05; DF=168, t-test). Other factors that were found to have significant influence were socioeconomic background, health conditions, dietary habits and environmental risk exposure. The results also showed that the school location has more influence on the heavy metals level than the area of residence. The children in a school near the highway were found to have a mean of 34.4+/-3.5 microg/g Pb as compared to those who lived near the highway (31.6+/-2.8 microg/g Pb), however the difference was not significant (P>0.05), suggesting a common source of contaminants in the areas. The correlation results also indicated that a high level of Pb in the nail influenced negatively Zn and Fe but not Ca levels (R=-0.256 Zn; -0.188 Fe) while high levels of Cd had a negative relationship with Fe only (R=-0.241). The association of toxic metals in the nails of children with environmental exposure, and nutritional status implies that policies and actions to reduce heavy metal levels must be implemented and reinforced to address the health issues affecting children and by extension the general public in this country.