Dr Nyongesa Albert Wafula is a holder of PhD in Animal Physiology of the University of Nairobi. He is a lecturer at the Department of Veterinary Anatomy and Physiology, University of Nairobi, specializing in reproductive physiology and behavioral sciences. As a lecturer he is involved in teaching both at undergraduate and postgraduate level including supervision of Masters' and PhD students in relevant areas of research.

Dr. Albert Nyongesa




Makori, AO, Nyongesa AW, Odongo HO, Masai RJ.  2020.  Assessment of stress on serum estradiol and cortisol levels in female subordinate naked mole rats following isolation from natal colony. Journal of Biosciences and Medicines. 8:9-17.


Mutwedu, VB, Ayagirwe RBB, Bacigale SB, Mwema LM, Butseme S, Kashosi T, Mitima B, Manyawu GJ, Nyongesa AW.  2019.  Effect of dietary inclusion of small quantities of Mucuna pruriens seed meal on sexual behavior, semen characteristics, and biochemical parameters in rabbit bucks (Oryctolagus cuniculus)., 2019 Jun. Tropical animal health and production. 51(5):1195-1202. Abstract

The aim of this work was to investigate the effects of Mucuna pruriens seed meal (MSM) on sexual behavior, semen, and biochemical parameters in rabbit bucks. Twenty-four 12-week-old rabbit bucks weighing 1002 to 1156 g were randomly allocated to three experimental diets containing 0, 1.5, and 3% of MSM in a 3-month trial. Sexual behavior parameters such as mounting latency, mounting frequency, successful mounting frequency, intromission latency, and post ejaculatory interval were monitored at the end of the experiment by mating with receptive females. Thereafter, rabbits were weighed, stunned, and humanely sacrificed and testes, epididymis, and vas deferens were harvested for evaluation of organ weights and semen characteristics. Results indicate that supplementing rabbit diet with MSM induced a significant decrease (P < 0.05) in mounting latency (69.7%) and intromission latency (19.7%), while it significantly (P < 0.05) increased successful mounting frequency (60%) as well as relative weight of testis (33.3%) and vas deferens (54.5%). There was a dose-dependent increase (P < 0.05) in sperm motility (35.7%) and concentration (65.9%), serum albumin (19.1%) and protein concentration (9.9%), and a decrease in sperm morphological alterations (68.3%), serum cholesterol (13.4%), and urea (11.6%) in treatment groups where MSM was supplemented at 3% compared to controls. From the findings, it appears MSM is a potential enhancer of male reproductive performance that can be recommended to rabbit farmers for improving reproductive performance and quality of semen, hence a boon to reproduction and production in rabbit farming industry.

A.W, N, J.A O, D.O O, S C.  2019.  Khat (Catha edulis) Addiction, effects on general body health and interventional remedial measures. Drug Abuse: Addiction and Recovery Volume 1 Chapter 4. : Open access e-books


A.W, N, N.B P, E.O W, D.W O.  2017.  High khat dose and long-term exposure impairs spermatogenesis: experimental study using rabbit model. Journal of Morphological Sciences. 34:156-167.


Nyongesa, A, Oduma J, al'Absi M, Chirwa S.  2015.  Immunohistochemical localization of anterior pituitary cell types of vervet monkey (Chlorocebus aethiops) following sub-chronic cathinone exposure., 2015 Nov 04. Journal of ethnopharmacology. 174:168-77. Abstract

Khat (Catha edulis) contains cathinone, an active principal that is customarily used as a psychostimulant that wards off fatigue and to some extent used as an aphrodisiac.


Nyongesa, AW, Oduma JA, Nakajima M, Odongo HO, Adoyo A, al'Absi M.  2014.  Dose-response inhibitory effects of purified cathinone from khat (Catha edulis) on cortisol and prolactin release in vervet monkeys (Chlorocebus aethiops). Metabolic Brain Disease. 29(2):451-458.nyongesa_hormone_paper.pdf
Nyongesa, AW, Oduma JA, Nakajima M, Odongo HO, Adoyo A, al'Absi M.  2014.  Acute and sub-chronic effects of purified cathinone from khat (Catha edulis) on behavioural profiles in vervet monkeys (Chlorocebus aethiops). Metabolic Brain Disease. 29(2):441-449.abstract_behavior_paper.pdf



Nyongesa, AW, Onyango DW.  2010.  Khat (Catha edulis Forsk): A boon or bane to humanity. Recent Progress in Medicinal Plants. , Texas: Studium Press, LLCkhat_chapter.pdf


Nyongesa, AW, Patel NB, Onyango DW, Odongo HO, Wango EO.  2008.  Khat (Catha edulis) lowers plasma luteinizing hormone (LH) and testosterone secretion, but increases cortisol levels in male rabbits. Journal of Ethnopharmacology. 116:245-250.
Kimania, ST, Nyongesa AW.  2008.  Effects of single daily khat (Catha edulis) extract on spatial learning and memory. Abstract

This study investigated the effects of fresh khat extract on learning and memory in CBA mice. A total of 20 male CBA mice, weighing 20–30 g, 5–6 weeks old were administered intraperitoneally with a single daily dose of khat extract for 5 days. The animals were divided into four groups, each comprising five animals. The first three groups were administered three doses (40, 120 and 360 mg/kg body weight) of khat extract, respectively. The last group served as controls and was administered with 0.5 ml normal saline intraperitoneally. The animals were then subjected to Morris water maze (MWM) task performance. Moderate and high doses (120 and 360 mg/kg body weight) of khat extract significantly impaired (P < 0.05) while low dose (40 mg/kg body weight) of khat extract did not have a significant effect on CBA mice acquisition learning. The high dose of khat extract significantly (P < 0.05) improved while moderate and low doses impaired accuracy for spatial memory of the platform location. This study has shown that khat extract has selective effect on spatial learning and memory, with low dose having no effect on learning but impairing memory, whereas high dose impairs learning but improves memory.


Nyongesa, AW, Patel NB, Onyango DW, Wango EO, Odongo HO.  2007.  In vitro study of the effects of khat (Catha edulis Forsk) extract on isolated mouse interstitial cells. Journal of Ethnopharmacology. 110:401-405.

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