Dr.okalebo Faith Apolot


Dr.okalebo Faith Apolot

Academic Qualifications:

B. Pharm., M.Pharm. (UoN), Ph.D. (UCT)

Areas of Specialization:

Pharmacology

Curriculum Vitae:

Click here to Download CV


Publications (8 Records)

  • Wanyama P. Juma, Hoseah M. Akala, Fredrick L. Eyase, Lois L. Muiva, Matthias Heydenreich, Faith A. Okalebo, Martin Peter, Douglas Walsh, Mabel Imbuga, Abiy Yenesew. Terpurinflavone: an antiplasmodial flavone from the stem of Tephrosia purpurea. Phytochemistry Letters. Manuscript number PHYTOL-D-00140R1 Terpurinflavone: An antiplasmodial flavone from the stem of Tephrosia Purpurea Wanyama P. Juma a, Hoseah M. Akala b, Fredrick L. Eyase b,c, Lois M. Muiva a, Matthias Heydenreich d, Faith A. Okalebo e, Peter M. Gitu a, Martin G. Peter d, Douglas S. Walsh b, Mabel Imbuga c, Abiy Yenesew a,* a Department of Chemistry,University of Nairobi, P.O. Box 30197-00100, Nairobi, Kenya b United States Army Medical Research Unit-Kenya, MRU 64109, APO, AE 09831-4109, USA c Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000, Nairobi, Kenya d Institut fu¨r Chemie, Universita¨t Potsdam, P.O. Box 60 15 53, D-14415 Potsdam, Germany e School of Pharmacy, University of Nairobi, P. O. Box 30197-0011, Nairobi, Kenya - 2011

    1. Introduction

    Tephrosia Pers (Leguminosae-Papilionoideae) is a large tropical and sub-tropical genus estimated to contain about three hundred species (Waterman and Khalid, 1980; Abou-Douh et al., 2005) out of which thirty species are found in Kenya (Tarus et al., 2002). The extracts of some Tephrosia species have shown various biological activities including antiplasmodial (Muiva et al., 2009), antibacterial (Abou-Douh et al., 2005) anticancer (Santram et al., 2006) and insecticidal activities (Delfel et al., 1970). The taxon T. purpurea is among the most widely used Tephrosia species in traditional medicine (Damre et al., 2003). Various biological activities including antibacterial (Hegazy et al., 2009; Chinniah et al., 2009), antidiabetic and antioxidant (Pavana et al., 2009), immunomodulatory (Damre et al., 2003), anti-inflammatory (Damre et al., 2003) and cancer chemopreventive activities (Chang et al., 2000) have been reported for extracts and pure compounds from this plant. T. purpurea. is rich in prenylated flavonoids including flavones (Hegazy et al., 2009; Pelter et al., 1981), flavanones (Pelter et al., 1981; Gupta et al., 1980), chalcones (Chang et al., 2000; Pelter et al., 1981) and rotenoids (Ahmad et al., 1999). In the search for compounds with antiplasmodial activity from Kenyan plants, the stem of T. purpurea has been investigated. This report is on the isolation and characterization of a new prenylated flavone, named terpurinflavone (1), with antiplasmodial activity along with three known flavonoids.

    The stem extract of Tephrosia purpurea showed antiplasmodial activity against the D6 (chloroquinesensitive) and W2 (chloroquine-resistant) strains of Plasmodium falciparum with IC50 values of 10.47  2.22 mg/ml and 12.06 2.54 mg/ml, respectively. A new prenylated flavone, named terpurinflavone, along with the known compounds lanceolatin A, -semiglabrin and lanceolatin B have been isolated from this extract. The new compound, terpurinflavone, showed the highest antiplasmodial activity with IC50 values of 3.12  0.28 mM (D6) and 6.26  2.66 mM (W2). The structures were determined on the basis of spectroscopic evidence.

       Manuscript number PHYTOL-D-00140R1

  • Oscar Mayunzu, D. Shitanda, F. Okalebo and L. Simiyu. Evaluation of the Antimicrobial and Antioxidant properties of Extracts of Mondia whytei roots. Pakistan Journal of Nutrition 9 (X): XX-XX, 2010. Pakistan Journal of Nutrition 9 (x): xx-xx, 2010 ISBN 1680-5194 © Asian Network for Scientific Information, 2010 Corresponding Author: O. Mayunzu, BEED, Jomo Kenyatta University of Agriculture and Technology, Kenya 1 Evaluation of the Antimicrobial and Antioxidant Properties of Extracts of Mondia whytei Roots O. Mayunzu1, D. Shitanda1, F. Okalebo2 and L. Simiyu1 1BEED, Jomo Kenyatta University of Agriculture and Technology, Kenya 2School of Pharmacy, University of Nairobi, Nairobi, Kenya - 2011

    Abstract: Aqueous, ethanol and methanol extracts of Mondia whytei (M. whytei) root barks were screened for their inhibitory effects on some fungal and bacterial strains. Staphylococcus aureus (S. aureus) (ATCC25923), Escherichia coli (E. coli) 0157:H7 (PSSCMI 0032), Bacillus subtillus, Candida albicans and Asparagus niger were used as test organisms. The water extract lacked significant activity against all organisms except Staphylococcus. aureus where the water extract exhibited the highest activity. However,

    the ethanol extract had significant activity against Candida albicans and Asperigillus niger with minimuminhibitory values of 58.59 and 14.65 μg/ml respectively. Methanol had high Minimum Inhibitory Concentration (MIC) values of less than 14.65 and 14.7 μg/ml for Asperigillus niger and E. coli respectively. From the results it was concluded that activity varied with the solvent used. Contrary to previous reports, the plant seems to lack significant antibacterial activity except against E. coli. The popularity of a herbal recipe is not always a measure for its potency. However, M. whytei had antifungal activity since the ethanol and methanol extracts showed significant activity against the tested strains of fungi. The antioxidant activity of the extracts was also evaluated using the DPPH free radical scavenging assay. M. whytei exhibited substantial inhibition of the DPPH activity with EC50 of 413 mg/l for the crude extracts. The results suggest that M. whytei has significant antioxidant activity as demonstrated by the DPPH assay. This antioxidant activity of the crude extracts can be attributed to the presence of 2-Hydroxy-4-Methoxybenzaldehyde that is a known antioxidant in the root extracts.

     Key words: Aqueous, ethanol extract, methanol extract

       Pakistan Journal of Nutrition 9 (x): xx-xx, 2010

  • test - 2010

  • M. W. Karara, F. A. Okalebo, M. N. Oluka, J. Ombega, A. N. Guantai and G. O. Osanjo (2010). Comparative tolerability and efficacy of stavudine 30 mg versus stavudine 40 mg in patients on combination antiretroviral therapy in Kenya. Journal of AIDS and HIV Research, vol 2 (2) pages 024-031. - 2010

    This study compared the efficacy and tolerability of stavudine at the two dose levels in patients attending HIV Comprehensive Care Centre, in the largest public hospital in Kenya. Data on CD4 cell counts, drug adverse events and opportunistic infections were collected retrospectively from the records of 810 adult patients distributed in three study groups: patients weighing ≥ 60 kg receiving 40 mg BD stavudine; patients weighing ≥ 60 kg receiving 30 mg BD stavudine; and patients weighing < 60 kg receiving 30 mg BD stavudine. Fewer stavudine related adverse effects were seen in patients weighing ≥ 60 kg treated with 30 mg stavudine compared to those who received 40 mg stavudine in the same weight category (4.2 % vs 16.7 %, p < 0.001). Patients weighing < 60 kg were more likely to experience drug toxicity than those ≥ 60 kg when given 30 mg stavudine (12.8% vs 4.2 %, p<0.001). Occurrence of any adverse drug reactions was also significantly associated with age greater than 45 years (HR = 2.16, CI:1.41-3.31, p<0.001), co-morbidities (HR = 2.16, CI:1.06-4.38, p < 0.001), treatment with isoniazid (HR = 2.07, CI:1.09-3.96, p<0.001) and severe (WHO stage IV) immunosuppression (HR=1.45,CI:0.86-2.45, p<0.001). The onset of drug related toxicities, for all study arms, was principally in the first year of commencing therapy, for example 76 % of all cases of peripheral neuropathy were diagnosed within 12 months of treatment. The study demonstrated similar immunologic outcomes in the treatment groups given either 30 or 40 mg stavudine, with median CD4 cell counts after 12 months of treatment more than doubling for patients in all the study cohorts. The findings support the use of combination antiretroviral therapy regimens containing low dose stavudine in Kenya.

    Key words

    Low-dose stavudine, combination antiretroviral therapy, HIV, stavudine tolerability

       Vol 2 (2) pages 024-031

  • F. A. Okalebo, A. N. Guantai, C. K. Maitai, I. O. Kibwage. Pharmacological screening of extracts of Clematis brachiata Thunberg (Ranunculaceae). East African Journal of Botany. 2 (1): 279 – 289, 2010. - 2010

    The leaves and old stems of Cletmatis brachiata Thunberg (Ranunculaceae) are chewed in Kenya for the management of toothache and sore throat. An infusion of the leaf is drunk for the management of headaches and abdominal disorders.  The study was done to determine the scientific rationale for the use of the plant as an analgesic and for the management of abdominal disorders.  Extracts of the plant were subjected to the hot plate and tail pressure tests for antinociceptive activity and guinea pig wheal test for local anesthetic activity.  The effects of the extracts on the isolated rabbit jejunum were also studied.  The extracts of the leaf and stem were found to have significant local anesthetic and antinociceptive activity. The extracts had spasmolytic effects on the isolated rabbit jejunum.  These findings support the traditional uses of the plant which could be subjected to bioactivity guided isolation for analgesic, local anaesthetic and spasmolytic compounds.
     

    Key words: Clematis; Ranunculaceae; plant extracts; antinociceptive; local anesthesia; spasmolytic

       East African Journal of Botany. 2 (1): 279 – 289, 2010.

[First Page] [Prev] Showing page 1 of 2 pages [Next] [Last Page]