Bio

PROF. GRACE N. THOITHI

Grace Thoithi is a holder of Doctor of Philosophy and Masters of Pharmaceutical Sciences degrees from Katholieke University Leuven, and a Bachelor of Pharmacy from the University of Nairobi. She is a Professor of Pharmaceutical Chemistry,the immediate former Dean of School of Pharmacy and has held many administrative duties at the University of Nairobi.

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Publications


2011

Njogu, PM, Thoithi GN, Mwangi JW, Kibwage IO, Kamau FN, Kariuki ST, Yenesew A, Mugo HN, Mwalukumbi JM.  2011.  Phytochemical and Antimicrobial Investigation of Girardinia diversifolia (Link) Friis (Urticaceae). East and Central African Journal of Pharmaceutical Sciences. 14(3):89-94.phytochemical_and_antimicrobial_investigation_of_girardinia_diversifolia_link_friis_urticaceae.pdf

2010

Dambolena, JS, Zunino MP, Lopez AG, Rubinstein HR, Zygadlo JA, Mwangi JW, Thoithi GN, Kibwage IO, Mwangi JM, Mwalukumbi JM, Kariuki ST.  2010.  Essential oils composition of Ocimum basilicum L. and Ocimum gratissimum L. From Kenya and their inhibitory effects on growth and fumonisin production by Fusarium verticillioides. Innovative Food Science and Emerging Technologies. 11:410-414.

2009

Ongarora, DSB, Thoithi GN, Kamau FN, Abuga KO, Mwangi JW, Kibwage IO.  2009.  Triterpenoids From the Stem Bark of Blighia unijugata Bak. (Sapindaceae). Abstract

Two pentacyclic triterpenoids were isolated, for the first time, from the stem bark of Blighia unijugata Bak. The structures of the two compounds were elucidated on the basis of their spectral data as friedelin and epifriedelinol.

Thoithi, GN;, Faith A.  2009.  Country case study: Kenya.
Mwangi, JW, Thoithi GN, Kibwage IO.  2009.  Essential oil bearing plants from Kenya: Chemistry, biological activity and applications. In H.R. Juliani, J.E. Simon and C.T. Ho (eds).. African Natural Plant Products: Discoveries and Challenges in Quality Control. :495-526.., Washington, D.C.: American Chemical Society Symposium Series 1021,American Chemical Society

2008

Maima, AO, Thoithi GN, Ndwigah SN, Kamau FN, Kibwage IO.  2008.  Phytosterols from the stem bark of Combretum fragrans F. Hoffm.. East Cent. Afr. J. Pharm. Sc.. 11:52-54.

2007

Kibwage, IO, Mwangi JW, Thoithi GN.  2007.  Quality control of herbal medicines. Abstract

The use of traditional and herbal medicines is gaining recognition globally. To safeguard the patient, there are legitimate demands that all medicines be safe, efficacious and of good quality. The required parameters for their quality evaluation include assessment for inorganic matter(dust),absence of adulteration microbial load, identification and profile of contents and where possible quantitation of the active compound or marker compounds. Also of importance are heavy metals, pesticides and product stability. The mixture of portions of herbs in traditional medicines complicates the quality control tests of these preparations. The content profile becomes difficult to replicate from batch to batch, while quantification of the active compound(s) in such multi-component products would require prior processing to isolate and identify the chemical compounds

and R. S. Malele, Mwangi JW, Thoithi GN, Kibwage IO, López ML, Zunino MP, López AG, Zygadlo JA, Oliva MM, Demo MS.  2007.  Essential oil of Cymbopogon winterianus Jowitt from Tanzania: Composition and antimicrobial activity. J. Essential Oil Bearing Plants. 10:83-87.

2006

Amugune, BK, Thoithi GN, Kibwage IO.  2006.  Liquid chromatographic analysis of phenobarbitone, ethosuximide, phenytoin and carbamazepine on a polystyrenedivinylbenzene column.. East Cent. Afr. J. Pharm. Sc.. 9:19-25.

2005

Thoithi, GN, Amugune BK.  2005.  Screening of some plants used traditionally for antifungal activity in Vihiga district, Western Kenya. AICAD Research Mini-reviews. (4):72-75.
Ndwigah, SN, Thoithi GN, Mwangi JW, Kibwage IO.  2005.  Constituents of the stem bark of Dombeya rotundifolia. East Cent. Afr. J. Pharm. Sc.. 8:40-42.
Kibwage, IO, Mwangi JW, Thoithi GN.  2005.  Quality Control of Herbal Medicines. East Cent. Afr. J. Pharm. Sc.. 8:27-31.
Mwangi, JW, Mungai NN, Thoithi GN, Kibwage IO.  2005.  Traditional/Herbal Medicine in National Healthcare in Kenya. East Cent. Afr. J. Pharm. Sc.. 8:22-26.
Mwangi, JW, Thoithi GN, Kibwage IO, Demo MS, Oliva MM, Zunino MP, Zygadlo JA.  2005.  Essential oil of Rhynchosia minima from Kenya: Composition and antibacterial properties. J. Essential Oil Research. 17:230-231.

2004

Ndwigah, SN, Thoithi GN, Kibwage IO.  2004.  Phytochemical Investigation and Anthelmintic Activity of Dombeya rotundifolia, Hochst. M.Pharm. Abstract

Dombeya rotundifolia (Hochst) is a shrub (or tree) and grows in woodland, wooded grassland and rocky mountain slopes from Ethiopia southwards to Kwazulu Natal, South Africa. It is widespread in Kenya and has many traditional uses. Roots are boiled and the soup used to treat rheumatism. Roots are pounded, soaked in water and the macerate given to children with diarrhea. Its stems and roots are used as an anthelmintic and to treat syphilis. It is also used to treat heart problems, nausea in pregnant women, headaches, haemorrhoids, dyspepsia, regulate the menses, to hasten the onset of labour and as an abortifacient. Dried entire plant is used in South Africa for treatment of diarrhea and in Tanzania for intestinal upset and to rid evil effects of witchcraft. It is also used to treat abdominal pains, intestinal ulceration, headaches, haemorrhage and as a tonic. Phytochemical studies were carried out on the methanol, chloroform, hot water and cold water extracts of Dombeya rotundifolia. All the extracts contained cardiac glycosides. The methanol, hot water and could water extracts contained saponins. None of the extracts contained alkaloids and anthraquinones. Fractionation of the chloroform extract yielded two compounds which were identified as lupeol and -sitosterol by spectroscopic methods. The extracts delayed the normal hatching of strongyle eggs while killing the eggs at high concentration. Many of the un-hatched eggs below the concentration of 5000 g/ml had developed and the larvae could be seen inside the shell but some were dead showing that the extracts retarded development of the eggs. The calculated LD50 for egg hatch assay was 2570 g/ml, 500.9 g/ml, 2709.4 g/ml and 1762.9 g/ml for the hot water, cold water, methanol and chloroform extracts, respectively. The calculated LD50 for the larvae mortality assay was 635.9 g/ml, 657.0 g/ml, 96.9 g/ml and 4195 g/ml for the hot water, cold water, methanol and chloroform extracts, respectively. The extracts killed the hatched larvae at high concentrations. The calculated LD50 for the larvae development assay was 1689.6 g/ml, 765.4 g/ml, 4909.8 g/ml and 3062 g/ml for the hot water, cold water, methanol and chloroform extracts, respectively. This showed that the extracts prevented the normal development of the larvae from Larvae1 to Larvae3 (adult stage). The most active extract in egg hatch and larvae development assay was the cold water extract, while methanol extract was the most active in larvae mortality assay. The hot water and could water extracts relaxed the isolated rabbit ileum, an effect similar to that of adrenaline, supporting the use of this plant to treat diarrhea. The methanol and chloroform extracts had no effects on the isolated rabbit ileum up to a dose of 40 mg (2 mg/ml). No extract had activity on guinea pig ileum. All the extracts had broncho-constrictive effect on guinea pig trachea. The chloroform extract had a marked negative chlorotropic and inotropic effects on the isolated rabbit heart. The methanol and the water extracts had no effects on the heart up to a dose of 20 mg. Starting with a tissue bath concentration of 0.5 mg/ml, both methanol and hot water extracts caused contraction of isolated rat uterus with activity at a concentration of 2 mg/ml being comparable to the effect of oxytocin 0.1 i.u/ml and acetylcholine 0.5 g/ml. Both chloroform and cold water extracts had no noticeable effect on the uterus upto a dose of 2 mg/ml. The oxytocin-like contractions of isolated rat uterus caused by methanol and hot water extracts supports the use of this plant decoction as an abortifacient. The extracts had high activity against Artemia salina showing they may have good pestcidal and cytotoxic activity. The LD50 of methanol, chloroform, hot water and cold water extracts were 470.7, 323.3, 30.2 and 38.5 g/ml, respectively. The LD50 of lupeol and -sitosterol was 116.2 and 95.9 g/ml, respectively. In this work, the isolation of any compound from Dombeya rotundifolia is reported for the first time. The compounds lupeol and -sitosterol were isolated from the stem bark. The present work shows there is a scientific basis for the traditional use of the plant Dombeya rotundifolia as anthelmintic, antidiarrhoeal and abortifacient.

2003

Gathumbi, PK;, Thoithi GN;, Mwangi JW;, Kibwage IO;, Maingi N;, Pelle R;, Wando J.  2003.  Evaluation Of Effects Of Plant Extracts On Trypanosomes.
M. M. Oliva, Demo MS, Malele RS, Mutayabarwa CK, Mwangi JW, Thoithi GN, Kibwage IO, Faillaci SM, Scrivanti RL, Lopez AG, Zygadlo JA.  2003.  Essential Oil of Brachylaena hutchinsii Hutch from Tanzania: Composition and Antimicrobial Activity and composition. East Cent. Afr. J. Pharm. Sc.. 6:61-63.
F. K. Kamau, Thoithi GN, J. K. Ngugi, Kingondu OK, Kibwage IO.  2003.  Quality of amoxycillin preparations in the Kenyan market. East Cent. Afr. J. Pharm. Sc.. 6:57-60.
Abuga, KO, Mwagiru PM, Thoithi GN, Nguyo JM, Ngugi JK, Kingondu OK, Mugo HN, Kibwage IO.  2003.  Quality of antiretroviral drugs analyzed in the Drug Analysis Research Unit during 2000-2003. East Cent. Afr. J. Pharm. Sc.. 6:20-23.
Malele, S, Mutayabarwa CK, Mwangi JW, Thoithi GN, Lopez AG, Lucini EI, Zygadlo JA.  2003.  Microbial activity and composition of Hyptis suaveolens (L.) Poit. Essential oil from Tanzania.. J. Essential Oil Research. 5:438-440.
Malele, S, Mutayabarwa CK, Mwangi JW, Thoithi GN, Lopez AG, Lucini EI, Zygadlo JA.  2003.  Microbial activity and composition of Hyptis suaveolens (L.) Poit. Essential oil from Tanzania.. J. Essential Oil Research. 5:438-440.

2002

Thoithi, GN, Maingi N, Karume D, Gathumbi PK, Mwangi JW, Kibwage IO.  2002.  Anthelmintic and other pharmacological activities of the root bark extracts of Albizia anthelmintica Brongn. East Cent. Afr. J. Pharm. Sc.. 5:60-66.
Thoithi, GN, Abuga KO, Nguyo JM, Mukindia G, Kingondu O, Ngugi JK, Kibwage IO.  2002.  Drug quality control work in Drug Analysis and Research Unit: Observation during 1996-2000. East Cent. Afr. J. Pharm. Sc.. 5:28-32.
Thoithi, G, Kibwage IO, Kingondu O, Roets E, Hoogmartens J.  2002.  Liquid chromatographic separation of isoniazid, pyrazinamide and rifampicin on a reversed-phase silica column.. East Cent. Afr. J. Pharm. Sc.. 5:8-14.

2001

Mwangi, JW, Thoithi GN, Kibwage IO, Zygadlo JA, Lopez ML, Olivia MM, Demo MS, and TM, Chalchat J-C.  2001.  Constituents of the essential oil of Cymbopogon afronardus Stapf. East Cent. Afr. J. Pharm. Sc.. 4:43-47.
Kamau, FN, Thoithi GN, Kibwage. IO.  2001.  Quality of ampicillin preparations on the Kenyan market. East Cent. Afr. J. Pharm. Sc.. 4:25-29.
Mwangi, JW, Thoithi GN,(Jr.) JHR, Zygadlo JA.  2001.  Composition of the essential oil of Microglossa pyrrhopappa var. pyrrhopappa. J. Essential Oil Research. 13:228-330.
Mwangi, JW, P. K. Gathumbi, Kibwage IO, Thoithi GN, Oketch-Rabah HA.  2001.  Alternative medicines and prostate enlargement-Prunus africana emphasis.. Pharm. J. Kenya. (March):26-31.

2000

Thoithi, G, Schepdael AV, R. Busson, Janssen G, Roets E, Hoogmartens J.  2000.  Investigation of the kinetics of degradation of hexopyranosylated cytosine nucleosides using liquid chromatography.. Nucleosides and Nucleotides. 19:189-203.

1999

Mwangi, JW, Thoithi GN, Lwande W, Hassanali H.  1999.  Aromatic plants of Kenya II: Volatile constituents of leaf oil of Psiadia punculata (D.C.) Vatke. J. BiochemiPhysics. 8:32-33.
Mwangi, JW, Masengo W, Thoithi GN, Kibwage IO.  1999.  Screening of some Kenyan medicinal plants using the Brine Shrimp Lethality Test. East Cent. Afr. J. Pharm. Sc.. 2:63-71.
Mwangi, JW, Thoithi GN, Addae-Mensah I, Achenbach H, undefined, Hassanali H.  1999.  Aromatic plants of Kenya IV: Volatile and some non-volatile constituents of the stem bark of Synadenium compactum NE Br. Var. compactum. East Cent. Afr. J. Pharm. Sc.. 1(1):5-7.

1998

Mwangi, JW, Thoithi GN, Addae-Mensah I, Achenbach H, Lwande W, Hassanali. H.  1998.  Aromatic plants of Kenya III: Volatile and some non-volatile constituents of Croton sylvaticus.. H. Hassanali.. 1:41-43.

1997

Thoithi, G, Schepdael VA, Herdewijn P, Roets E, Hoogmartens J.  1997.  Liquid chromatographic separation of hexopyranosylated cytosine nucleosides from their degradation products. J. Pharm. Biomed. Anal.. 16:533-540.

1995

Thoithi, G, Schepdael VA, Herdewijn P, Roets E, Hoogmartens J.  1995.  Liquid chromatographic separation of diamino analogues of 2'- or 3'-deoxyadenosine from adenine on a poly(styrene-divinylbenzene) polymer column. J. Chromatogr. A. 689:247-254.

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