Bio

PROF. ABUBAKAR LAILA UWESO

Professor Laila Abubakar has an academic and professional background in biochemistry and is currently an Associate Professor in the Department of Biochemistry. Her research interests include molecular basis of vector-parasite interactions and bio-prospecting in marine and fresh water environments.

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Publications


2012

Laila, A, Mwangi C, Uku J, Ndirangu S.  2012.  Afr. J. Pharmacol. Ther. 2012 . 1 (1): 19-23 A KeSoBAP Publication ©2012 . All rights reserved. 19 Antimicrobial activity of various extracts of the sea urchin Tripneustes gratilla (Echinoidea). AbstractWebsite

Background: Marine invertebrates rely solely on innate immune mechanisms, the cellular component of which is characterized by hemocytes that phagocytize microbe s and secrete soluble antimicrobial and cytotoxic s ubstances. In this regard, marine invertebrates are a potential s ource of promising antimicrobial compounds with nov el mechanisms of action. Objective: The objective of this study was to evaluate extrac ts of the gut, gonad, spines and mouth parts of the sea urchin Tripneustes gratilla for antimicrobial and haemolytic activities in vitro . Methods: Potentially bioactive metabolites were extracted u sing methanol and chloroform and tested for activit y against Salmonella typhi , Escherichia coli , Shigella sonnei , Pseudomonas aeruginosa and Penicillium spp. using the agar disc diffusion method. Toxicity was determined by a ssaying for hemolysis against human red blood cells . Results: Bioactivity against the tested bacteria was observ ed mainly with the methanol and chloroform extracts of the gonads and gut. Higher antibacterial activity was p resent in the methanol extracts compared to chlorof orm extracts. Activity against the Penicillium spp was detected only in the methanol extracts, while the chloroform extracts showed no activity. The various extracts of the sea urchin lacked any detectable hemolytic activity against h uman erythrocytes. Discussion: These research findings suggest that marine echino derms are a potential source of novel antimicrobial compounds.

Abubakar, LU.  2012.  Impact of genetic research on women in Africa, 12 December. International Conference on Muslim Women Scholars in Science & Technology Development. , Tehran, IRANabstract-african_women__genetics.pdf
Abubakar, LU, Mutie AM, Kenya EU, Muhoho A.  2012.  Characterization of algae oil (oilgae) and its potential as biofuel in Kenya. Journal of Applied Phytotechnology in Environmental Sanitation . 1 (4):147-153.abstract-apes.pdf
Abubakar, LU, Mwangi CN, Uku J, Ndirangu S.  2012.  Antimicrobial activity of various extracts of the sea urchin Tripneustes gratilla (Echinoidea). African Journal of Pharmacology and Therapeutics . 1(1):19-23.: Abubakar L.U. Abstractabstract-ajpt.pdfWebsite

Background:
Marine invertebrates rely solely on innate immune mechanisms, the cellular component of which is characterized by hemocytes that phagocytize microbes and secrete soluble antimicrobial and cytotoxic substances. In this regard, marine invertebrates are a potential source of promising antimicrobial compounds with novel mechanisms of action.
Objective:
The objective of this study was to evaluate extracts of the gut, gonad, spines and mouth parts of the sea urchin Tripneustes gratilla for antimicrobial and haemolytic activities in vitro.
Methods:
Potentially bioactive metabolites were extracted using methanol and chloroform and tested for activity against Salmonella typhi, Escherichia coli, Shigella sonnei, Pseudomonas aeruginosa and Penicillium spp. using the agar disc diffusion method. Toxicity was determined by assaying for hemolysis against human red blood cells.
Results:
Bioactivity against the tested bacteria was observed mainly with the methanol and chloroform extracts of the gonads and gut. Higher antibacterial activity was present in the methanol extracts compared to chloroform extracts. Activity against the Penicillium spp was detected only in the methanol extracts, while the chloroform extracts showed no activity. The various extracts of the sea urchin lacked any detectable hemolytic activity against human erythrocytes.
Discussion:
These research findings suggest that marine echinoderms are a potential source of novel antimicrobial compounds.
Key words:
Tripneustes gratilla, antimicrobial activity, marine invertebrates

UWESO, DRABUBAKARLAILA, Abubakar LU, Kyallo M, Pelle R.  2012.  Vector genomics and arthropod-borne diseases in Africa, 29 January 2012. Federation of African Societies of Biochemistry & Molecular Biology Congress. , Drakensberg, South Africa: 1. Abubakar L.U., Mwangi C. N., Uku J., Ndirangu S. Abstractabstract_fasbmb.pdf

Background:
Marine invertebrates rely solely on innate immune mechanisms, the cellular component of which is characterized by hemocytes that phagocytize microbes and secrete soluble antimicrobial and cytotoxic substances. In this regard, marine invertebrates are a potential source of promising antimicrobial compounds with novel mechanisms of action.
Objective:
The objective of this study was to evaluate extracts of the gut, gonad, spines and mouth parts of the sea urchin Tripneustes gratilla for antimicrobial and haemolytic activities in vitro.
Methods:
Potentially bioactive metabolites were extracted using methanol and chloroform and tested for activity against Salmonella typhi, Escherichia coli, Shigella sonnei, Pseudomonas aeruginosa and Penicillium spp. using the agar disc diffusion method. Toxicity was determined by assaying for hemolysis against human red blood cells.
Results:
Bioactivity against the tested bacteria was observed mainly with the methanol and chloroform extracts of the gonads and gut. Higher antibacterial activity was present in the methanol extracts compared to chloroform extracts. Activity against the Penicillium spp was detected only in the methanol extracts, while the chloroform extracts showed no activity. The various extracts of the sea urchin lacked any detectable hemolytic activity against human erythrocytes.
Discussion:
These research findings suggest that marine echinoderms are a potential source of novel antimicrobial compounds.
Key words:
Tripneustes gratilla, antimicrobial activity, marine invertebrates

2011

UWESO, DRABUBAKARLAILA, Abubakar LU, Kenya EU, Muhoho A.  2011.  Microalgae species biodiversity and abundance and their potential for biofuel in Kenya. 4th National Council of Science & Technology National Conference. :155-158., Nairobi, KENYA Abstractabstract-ncst.pdf

Background:
Marine invertebrates rely solely on innate immune mechanisms, the cellular component of which is characterized by hemocytes that phagocytize microbes and secrete soluble antimicrobial and cytotoxic substances. In this regard, marine invertebrates are a potential source of promising antimicrobial compounds with novel mechanisms of action.
Objective:
The objective of this study was to evaluate extracts of the gut, gonad, spines and mouth parts of the sea urchin Tripneustes gratilla for antimicrobial and haemolytic activities in vitro.
Methods:
Potentially bioactive metabolites were extracted using methanol and chloroform and tested for activity against Salmonella typhi, Escherichia coli, Shigella sonnei, Pseudomonas aeruginosa and Penicillium spp. using the agar disc diffusion method. Toxicity was determined by assaying for hemolysis against human red blood cells.
Results:
Bioactivity against the tested bacteria was observed mainly with the methanol and chloroform extracts of the gonads and gut. Higher antibacterial activity was present in the methanol extracts compared to chloroform extracts.
Activity against the Penicillium spp was detected only in the methanol extracts, while the chloroform extracts showed no activity. The various extracts of the sea urchin lacked any detectable hemolytic activity against human erythrocytes.

Discussion:
These research findings suggest that marine echinoderms are a potential source of novel antimicrobial compounds.
Key words:
Tripneustes gratilla, antimicrobial activity, marine invertebrates

2008

UWESO, DRABUBAKARLAILA.  2008.  Burugu, M. W., Mbatia, B. N., Osir, E. O., Kenya, E. U., Abubakar, L. U. . International Journal of Tropical Insect Science. : International Journal of Tropical Insect Science Abstract
Rural aquaculture in Lake Victoria basin is a fast increasing nontraditional farming activity which if not appropriately practised will lead to degradation of the wetlands. As part of a study to develop appropriate guidelines and model systems for wetlands-based rural aquaculture in the basin a survey was conducted to assess the status and the ecological and socioeconomic impact of rural aquaculture on wetlands and wetlands communities. Aquaculture practice was found to be common but not as a major activity. Aquaculture in the wetlands can be described as a low input-low output production activity and subsistence based on ponds under 400 m2 using free seed from public agencies with hardly any supplementary feeding. Men owned most of the ponds and women only contributed to the management of the fishponds by feeding the fish. Poorly constructed ponds and loss during harvesting have led to the escape of cultured species into the wild. Introduction of nonnative species in the basin has already led to wide ranging ecological, environmental and socioeconomic changes whose impact and usefulness are still very much contentious. Repeat of such scenarios can be avoided if appropriate and science-based models for rural aquaculture farming are developed, tested and disseminated to the communities

2007

UWESO, DRABUBAKARLAILA, Mwanja WW, Akol MA, Bugenyi FW, Mwanja MT, Banga JM, Msuku BS.  2007.  Status of rural aquaculture in the Lake Victoria Basin. African Journal of Ecology 45: 165-174. : African Journal of Ecology Abstract

Rural aquaculture in Lake Victoria basin is a fast increasing nontraditional farming activity which if not appropriately practised will lead to degradation of the wetlands. As part of a study to develop appropriate guidelines and model systems for wetlands-based rural aquaculture in the basin a survey was conducted to assess the status and the ecological and socioeconomic impact of rural aquaculture on wetlands and wetlands communities. Aquaculture practice was found to be common but not as a major activity. Aquaculture in the wetlands can be described as a low input-low output production activity and subsistence based on ponds under 400 m2 using free seed from public agencies with hardly any supplementary feeding. Men owned most of the ponds and women only contributed to the management of the fishponds by feeding the fish. Poorly constructed ponds and loss during harvesting have led to the escape of cultured species into the wild. Introduction of nonnative species in the basin has already led to wide ranging ecological, environmental and socioeconomic changes whose impact and usefulness are still very much contentious. Repeat of such scenarios can be avoided if appropriate and science-based models for rural aquaculture farming are developed, tested and disseminated to the communities

2006

Kenya, EU, Okun DO, Gachuche DN, Abdulahi A, U. AL, Manohar R.  2006.  Detection and presumptive identification of Clostridium perfrigens in drinking water. Aquaculture. 7(1):27-36.: Aquaculture Abstractabstract.pdfWebsite

Rural aquaculture in Lake Victoria basin is a fast increasing nontraditional farming activity which if not appropriately practised will lead to degradation of the wetlands. As part of a study to develop appropriate guidelines and model systems for wetlands-based rural aquaculture in the basin a survey was conducted to assess the status and the ecological and socioeconomic impact of rural aquaculture on wetlands and wetlands communities. Aquaculture practice was found to be common but not as a major activity. Aquaculture in the wetlands can be described as a low input-low output production activity and subsistence based on ponds under 400 m2 using free seed from public agencies with hardly any supplementary feeding. Men owned most of the ponds and women only contributed to the management of the fishponds by feeding the fish. Poorly constructed ponds and loss during harvesting have led to the escape of cultured species into the wild. Introduction of nonnative species in the basin has already led to wide ranging ecological, environmental and socioeconomic changes whose impact and usefulness are still very much contentious. Repeat of such scenarios can be avoided if appropriate and science-based models for rural aquaculture farming are developed, tested and disseminated to the communities

2003

UWESO, DRABUBAKARLAILA.  2003.  Abubakar L. U., Zimba G., Wells C., Mulaa F., Osir E. O. . International Journal of Tropical Insect Science. : Abubakar L.U Abstract
Background: Marine invertebrates rely solely on innate immune mechanisms, the cellular component of which is characterized by hemocytes that phagocytize microbes and secrete soluble antimicrobial and cytotoxic substances. In this regard, marine invertebrates are a potential source of promising antimicrobial compounds with novel mechanisms of action. Objective: The objective of this study was to evaluate extracts of the gut, gonad, spines and mouth parts of the sea urchin Tripneustes gratilla for antimicrobial and haemolytic activities in vitro. Methods: Potentially bioactive metabolites were extracted using methanol and chloroform and tested for activity against Salmonella typhi, Escherichia coli, Shigella sonnei, Pseudomonas aeruginosa and Penicillium spp. using the agar disc diffusion method. Toxicity was determined by assaying for hemolysis against human red blood cells. Results: Bioactivity against the tested bacteria was observed mainly with the methanol and chloroform extracts of the gonads and gut. Higher antibacterial activity was present in the methanol extracts compared to chloroform extracts. Activity against the Penicillium spp was detected only in the methanol extracts, while the chloroform extracts showed no activity. The various extracts of the sea urchin lacked any detectable hemolytic activity against human erythrocytes. Discussion: These research findings suggest that marine echinoderms are a potential source of novel antimicrobial compounds. Key words: Tripneustes gratilla, antimicrobial activity, marine invertebrates

1999

UWESO, DRABUBAKARLAILA.  1999.  Osir E. O., Abubakar L.U., Abakar, M. . 25th Meeting of the International Scientific Council for Trypanosomiasis Research & Control (ISCTRC) Mombasa, KENYA. : ISCTRC Abstract
Background: Marine invertebrates rely solely on innate immune mechanisms, the cellular component of which is characterized by hemocytes that phagocytize microbes and secrete soluble antimicrobial and cytotoxic substances. In this regard, marine invertebrates are a potential source of promising antimicrobial compounds with novel mechanisms of action. Objective: The objective of this study was to evaluate extracts of the gut, gonad, spines and mouth parts of the sea urchin Tripneustes gratilla for antimicrobial and haemolytic activities in vitro. Methods: Potentially bioactive metabolites were extracted using methanol and chloroform and tested for activity against Salmonella typhi, Escherichia coli, Shigella sonnei, Pseudomonas aeruginosa and Penicillium spp. using the agar disc diffusion method. Toxicity was determined by assaying for hemolysis against human red blood cells. Results: Bioactivity against the tested bacteria was observed mainly with the methanol and chloroform extracts of the gonads and gut. Higher antibacterial activity was present in the methanol extracts compared to chloroform extracts. Activity against the Penicillium spp was detected only in the methanol extracts, while the chloroform extracts showed no activity. The various extracts of the sea urchin lacked any detectable hemolytic activity against human erythrocytes. Discussion: These research findings suggest that marine echinoderms are a potential source of novel antimicrobial compounds. Key words: Tripneustes gratilla, antimicrobial activity, marine invertebrates

1995

Abubakar, L, Osir EO, Imbuga MO.  1995.  Properties of a blood-meal-induced midgut lectin from the tsetse fly Glossina morsitans. Abstract

The properties of a blood-meal-induced lectin (agglutinin) from the midgut of Glossina morsitans capable of agglutinating Trypanosoma brucei were studied in vitro. The midgut homogenate from flies that had been fed twice had the highest agglutination activity, followed by that from the once-fed flies and that from the unfed insects. As compared with the bloodstream-form trypanosomes, a much lower concentration of the midgut homogenate was required for agglutination of the procyclic parasites. Furthermore, the agglutination process was specifically inhibited by D-glucosamine. Soybean trypsin inhibitor abrogated agglutination of the bloodstream-form parasites, whereas the procyclics were unaffected. The agglutination process was temperature-sensitive, with little activity being evident between 4 degrees and 15 degrees C. Similarly, heating the midguts to 60 degrees-100 degrees C led to loss of activity. When the midgut homogenate was separated by anion-exchange chromatography, the agglutination activity co-eluted with trypsin activity at approximately 50% NaCl. These results suggest a very close relationship between midgut trypsin-like enzyme and the agglutinin. Since successful agglutination of bloodstream-form trypanosomes requires protease activity, it may be that the enzyme cleaves off some surface molecules on the parasite surface, thus exposing the lectin-binding sites

Osir, EO, Abubakar L, Imbuga MO.  1995.  Purification and characterization of a midgut lectin-trypsin complex from the tsetse fly Glossina longipennis. Abstract

A blood-meal-induced lectin (agglutinin) with proteolytic activity was isolated from midgut extracts of Glossina longipennis by a two-step procedure involving anion-exchange chromatography. It is a glycoprotein [native molecular weight (M(r) 61,000 +/- 3000 da) composed of two noncovalently-linked subunits designated alpha (M(r), approximately 27,000 da) and beta (M(r), approximately 33,000 da). The trypsin activity and the glycosyl residues were present on the alpha- and beta-subunits, respectively. The native protein was capable of agglutinating both bloodstream-form and procyclic trypanosomes as well as rabbit red blood cells. This activity was strongly inhibited by D-glucosamine and weakly inhibited by N-acetyl-D-glucosamine. Similarly, soybean trypsin inhibitor abrogated agglutination of bloodstream-form parasites, whereas the procyclics were unaffected. The agglutination activity was sensitive to temperatures above 40 degrees C but was unaffected by chelators of metal ions. Antibodies raised against the protein were used in immunoblotting experiments to show the presence of a similar protein in several members of the Glossina species. However, no cross-reactivity was detected with midgut extracts prepared from sandflies, mosquitoes, or stable flies. It is proposed that this molecule might play an important role in differentiation of bloodstream-form trypanosomes into procyclic (midgut) forms.

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