Office: SW156

Extension: 2628

Email: andrew.siwela@nust.ac.zw

Qualifications
AssocDipAppBiol, BAppSc (RMIT); MPhil (UZ); PhD (NUST)

Research
Metabolism, toxicity, carcinogenicity and prevalence of aflatoxins; Environmental toxicology; pesticide and heavy metal contamination of aquatic flora and fauna; study of antioxidant enzymes as a function of pollution and parasitic infections; Bioconversion of B-carotene to vitamin A in vivo and in vitro and Composition and levels of amino acids in local foodstuffs and feeds.

Publications by Prof. Andrew H. Siwela

Siwela, A.H. (1985). Quantitative amino acid analysis of  extracted soyabean meal hydrolysates by Ion Exchange  Chromatography. Zimbabwe Agricultural Journal, 82 :161-163

Hasler, J.A., Siwela, A.H., Nyathi, C.B. and Chetsanga, C.J.  (1986). The effect of schistosomiasis on the activation of  aflatoxin B1.  Research Communications in Chemical Pathology and Pharmacology, (USA) 51: 421 - 423.

Siwela, A.H. and Caley, A.D. (1989).  Aflatoxin contamination  of stored groundnuts in Zimbabwe. In Summary and Recommendations of the International Workshop on aflatoxin control of groundnut, 6 - 9 Oct. 1987, ICRISAT Centre,  India. pp 9.  (Abstract Only)4) 4)Siwela, A.H. and Caley, A.D. (1989).  Aflatoxin contamination  of stored groundnuts in Zimbabwe. In: Aflatoxin  contamination of groundnut. Proceedings of the International  Workshop, 6-9 Oct. 1987, ICRISAT Centre,Patancheru, AP 502324,   India. pp 59-63.

Siwela, A.H. (1989). The effect of schistosomiasis on the activation of Aflatoxin B1. M.Phil thesis, University of Zimbabwe, Harare, Zimbabwe. p 113.

Siwela, A.H., Nyathi, C.B., Chetsanga, C.J. and Hasler, J.A. (1990). The effect of schistosomiasis on the covalent  binding of 2-acetylaminofluorene to mouse liver macromolecules in vivo and in vitro. Biochemical Pharmacology, (U.K.) 40: 379-382.

Siwela, A.H., (1996).  Combined use of Phenyl-Bonded Phase Cleanup and HPLC for the determination of aflatoxins. Tropical Science, (U.K.) 36:197-200.

Siwela, A.H., Marufu, G. and Mhlanga, A.T. (1996). A  Comparison of Organochlorine Pesticides in Upper Ncema and Lower Umguza Dams, Zimbabwe.  Journal of Applied Science in Southern Africa, (Zimbabwe) 2: 23-30.

Siwela, A.H. and Nziramasanga, N. (1999). Regulatory aspects of aflatoxin control in Zimbabwe: A review. Journal of Applied Science in Southern Africa, (Zimbabwe)  5:141-147.

Siwela, A.H., Shonhai, A., Foggin, C.M. and Brigitte, Revol (2000) Establishment of baseline values of copper, zinc and manganese in ostriches in Zimbabwe: A preliminary study. Zimbabwe Veterinary Journal, 31:57-64.

Dube, S., Siwela, A.H., Masanganise, K.E. and Dube, C. (2002).  Prevalence of Paramhphistones  in Mashonaland West, Central and East and Midlands Provinces, Zimbabwe. Acta  Zoologica Taiwanica, 13:31-52.

Siwela, A.H., Siwela, M.  Matindi, G. Dube. S. and Nziramasanga, N.(2005). Decontamination of aflatoxin -contaminated  maize by dehulling. Journal of the Science  of Food and Agriculture, (UK) 85:2535-2538.

Dube, S., Siwela, A.H.,  Dlamini, N.R. and Masanganise, K.E. (2005) Paramphistomes species infecting cattle in Matebeleland North Province in Zimbabwe. UNZA Journal of  Science and Technology  (Zambia) 9: 21-29.

Siwela, A.H, Matsaure, F., Ncube, T., Olonitola, O.S. and Best, G.R. 2007. A comparison of antibiotic resistance in microorganisms isolated from chicken and ostritch faeces in Bulawayo, Zimbabwe. International Journal of Biological and Chemical Sciences  (Cameroon). 1:158-164.

Siwela, A.H. 2007 Some ecotoxicolgical aspects of selected freshwater bodies around Bulawayo. PhD thesis, National University of Science and Technology, Bulawayo,  Zimbabwe. p 167.

Siwela A.H., Nyathi C.B, and Naik Y.S. 2009 Metal accumulation and antioxidant enzyme activity in C. gariepinus, Catfish, and O. mossambicus, Tilapia, collected from  Lower Mguza and Wright Dams, Zimbabwe. Bulletin of Environemental Contamination  and Toxicology (UK) 83:648-651.

Siwela A.H., Chiedza.Isabel Mambvura, K.E. Masanganise and S. Dube 2010 Oxidative stress associated with nematode infections in sheep: A preliminary study. International Journal of Biological and Chemical Sciences (Cameron). 4: 235-240.

Siwela A.H., Nyathi C.B, and Naik Y.S. 2010. A comparison of metal levels and antioxidant enzymes in freshwater snails, Lymnaea natalensis, exposed to sediment and water collected from Wright Dam and Lower Mguza Dam, Bulawayo,Zimbabwe. Ecotoxicology and Environmental Safety (USA) 73:1728-1732. doi:10.1016/jecoenv.2010.08.001

Siwela A.H., Mukaro K.J., Nziramasanga, N. 2011. Aflatoxin carryover during large       scale peanut butter production. Food and Nutrition Sciences (USA) 2: 105-108. doi:10.4236/fns.2011.22014

Muzhingi, T., Gadaga, H.T., Siwela, A.H., Grusak, M.A., Russel, R.M. and Tang, G.2011. Yellow maize with high β-carotene is an effective source of vitamin A in healthy Zimbabwean men. American Journal of Clinical Nutrition 94:510-519. doi: 10.3945/ajcn.110.006486

Siwela A.H. Motsi, L. and Dube, S. 2013. Alteration of some hepatic enzyme activities  by gastrointestinal helminth parasites in domesticated ostriches. Advances in  Bioresearch (India) 4: 145-150.

Dangwa, N., Mwenje, E., Dhlamini, Z. and Siwela, A.H. 2014. Molecular characterization of aflatoxigenic Aspergillus species in dried traditional foods in Zimbabwe. Advances in Bioresearch (India) 5:29-36

Muzhingi, T., Tang, G., Yeum, K.J., Bermudez, O. and Siwela, A.H. 2014. Peanut butter increases kale β-carotene absorption  and conversion to Vit A in pre-school children.The FASEB  Journal (USA) 28 (1 Supplement), LB417