Meshack Obonyo

Egerton University · Department of Biochemistry and Molecular Biology

Background and Objective: Mycotoxin contamination in maize and groundnuts has undermined Kenya's health care system for decades. This study aimed to determine the diversity of mycotoxin fungi in maize, groundnut and soils of Western Kenya and farmers' awareness of on-field mycotoxin mitigation measures. Materials and Methods: Infected maize, ground...

Background: Throughout the history, nature has provided mankind with most of their basic needs, which include food, shelter, medicine, clothes, flavours, scents as well as raw materials. Given that they are an integral part of cultural heritage, medicinal plants have played a significant role in human healthcare systems around the world. Investigat...

Background: The unmet demand for effective malaria transmission-blocking agents targeting the transmissible stages of Plasmodium necessitates intensive discovery efforts. In this study, a bioactive bisbenzylisoquinoline (BBIQ), isoliensinine, from Cissampelos pariera (Menispermaceae) rhizomes was identified and characterized for its anti-malarial...

Mycotoxigenic Aspergillus and Fusarium species that contaminate cereal crops with aflatoxins and fumonisins are a major threat to food security, human and animal health. Cases of mycotoxin contamination have been on the rise globally, with causes of such surges raising research interests. We conducted factorial experiments in the laboratory to test...

An integrated approach to innovatively counter the transmission of various arthropod-borne diseases to humans would benefit from strategies that sustainably limit onward passage of infective life cycle stages of pathogens and parasites to the insect vectors and vice versa. Aiming to accelerate the impetus towards a disease-free world amid the chall...

Stunting among children under five years old is still a problem in many developing countries including Kenya. However, there is little information linking stunting with mycotoxin contamination of complementary foods. The aim of this study was to assess knowledge about aflatoxin and fumonisin contamination in sorghum alongside postharvest handling a...

Intracellular effects exerted by phytochemicals eliciting insect growth-retarding responses during vector control intervention remain largely underexplored. We studied the effects of Zanthoxylum chalybeum Engl. (Rutaceae) (ZCE) root derivatives against malaria (Anopheles gambiae) and arbovirus vector (Aedes aegypti) larvae to decipher possible mole...

This article analyses the various historical phases in the evolution of theAfrican academic diaspora’s engagement to support the development ofhigher education in Africa. It examines the drivers and motivation for suchengagement and its implications for higher education development onthe continent. The data were derived from a critical review of se...

Background: Aflatoxins (AFs) are poisonous compounds produced by species of fungi belonging to the genus Aspergillus mainly A. flavus and A. parasiticus. However, there are some members of these species that do not produce toxins and have since become of interest for use in Biological Control programs. The species that produce AFs are believed to h...

Common methods of synthesizing metallic nanoparticles are chemical and physical. However, they are expensive and use toxic chemicals. Green synthesis is less costly and safer hence a potential alternative. Silver nanoparticles (Ag NPs) were synthesized using dichloromethane extract of Chrysanthemum cinerariaefolium and colour change from pale green...

In East Africa, passion fruit woodiness disease is caused by potyviruses, among which are Cowpea Aphid-Borne Mosaic Virus (CABMV) and Uganda Passiflora Virus (UPV). Previous studies suggest that synergistic interaction of viruses causes mild or severe outcomes of the disease. However, mixed infections of these viruses have not been documented. The...

Poultry is susceptible to mycotoxicoses caused by aflatoxins. Two experiments were carried out, where twenty-four, 28days old and 144 one-day-old broilers were assigned to six diets respectively. The diets were: diet1 (no aflatoxin and not fermented), diet2 (no aflatoxin and fermented without yeast), diet3 (no aflatoxin and fermented with yeast), d...

Background: Intracellular effects exerted by phytochemicals eliciting insect growth-reducing responses during vector control intervention remain largely underexplored. We studied the effects of Zanthoxylum chalybeum Engl. (Rutaceae) (ZCE) root derivatives against malaria (Anopheles gambiae) and arbovirus vector (Aedes aegypti) larvae to decipher po...

Lead poisoning is an emerging worldwide public health concern, especially in the developing countries. Occupational tasks such as spray painting and welding in informal automobile repair enterprises present risks of exposures to lead generally through inhalation and ingestion. The artisans therefore risk high blood lead (BPb) levels, which is criti...

Aflatoxins contaminate foodstuff posing a severe threat to human health because chronic exposure is linked to liver cancer while acute exposure may cause death. Therefore, it is of interest to reduce the contamination of crops by aflatoxins in the field and post-harvest. Among the current technologies being developed is the deployment of non-aflato...

Chronic, high-level lead exposure is known to be a risk factor for kidney and liver diseases. The health effect of low-level occupational exposure to lead is less well known, particularly among informal automobile repair artisans, a population that is at risk of occupational lead exposures due to their predisposing occupational tasks. The study ass...

Aflatoxins contaminate foodstuff posing a severe threat to human health because chronic exposure is linked to liver cancer while acute exposure may cause death. Therefore, it is of interest to reduce the contamination of crops by aflatoxins in the field and post-harvest. Among the current technologies being developed is the deployment of non-aflato...

Abstract: Artisans in the informal automobile sector are involved in diverse occupational activities that could predispose them to health risks associated with lead exposure. A comparative cross-sectional study was conducted to assess the risk of having high blood lead levels among the artisans. Data were collected using structured questionnaire an...

Background: Aflatoxin contamination of grain is a major constraint to sustained quality cereal production. The causative fungi, Aspergillus species infect crops in the field and continue to do so post-harvest where they produce toxins in store. The current study aimed at establishing seasonal variation in levels and types of aflatoxins in maize fr...

Maize lethal necrosis is one of the most devastating diseases of maize causing yield losses reaching up to 90% in sub-Saharan Africa. The disease is caused by a combination of maize chlorotic mottle virus (MCMV) and any one of cereal viruses in the Potyviridae group such as sugarcane mosaic virus. MCMV has been reported to be transmitted mainly by...

Insect damage is one of the major predisposing factors to ear rot and mycotoxins. With climate- smart push-pull technology, the common insect pests of maize in Eastern Africa, Busseola fusca and Chilo partellus are control. This results to reduction of ear rots and mycotoxins.

It is imperative to establish the distribution and density of soil fungal communities as a requisite for formulating strategies for management of ear rot infections and mycotoxin contamination. In a two seasons study, short (SR) and long rainy (LR) seasons, we investigated the distribution of Aspergillus and Fusarium fungi causing ear rots and prod...

Pilobolus are abundant in herbivore dung. Although they are non-pathogenic to herbivores, they are vectors to lungworms present in the dung that cause bronchitis if ingested. Thus, determining the presence of Pilobolus in the field might prove useful to assess a link between Pilobolus and lungworm infections, as well as the areas where they occur....

The potential role of anti-herbivory mechanisms used by plants and their synergistic responses to grazing and interactive effects on herbivores are poorly understood. The aim of this study was to quantify the influence of grazing intensity on cyanogenic glycosides in Lake Bogoria, Baringo County Kenya. Field experiments were carried out in ten 50×1...

Sweet potato is a major source of dietary carbohydrate and a key food security crop in Kenya. Production of orange-fleshed sweetpotato (OFSP) in Kenya is constrained by sweetpotato virus diseases whose synergistic interaction between two virus families, sweetpotato feathery mottle virus (SPFMV) and sweetpotato chlorotic stunt virus (SPCSV). The abs...

Background and purpose: Medicinal plants including the prickly pear cactus have been reported to modulate blood sugar levels. Extracts of prickly pear cactus have been used in various parts of the world to manage diabetes mellitus. However the cactus is viewed as a weed in Kenya. The current study therefore aimed at evaluating the efficacy of prick...

Background/Aim: Clerodendrum myricoides is a Kenyan herbal plant used in management of respiratory diseases. In the current study, we investigated in-vitro antimicrobial activity, cytotoxicity and phytochemical screening of Clerodendrum myricoides. Materials and methods: Antimicrobial activities of C. myricoides organic fractions against array of m...

Tuberculosis is a serious chronic infectious disease affecting large global population. While efforts to control tuberculosis have intensified, they are challenged by rapid drug resistance development. For this reason, prospecting for compounds with potential antituberculous activity have been stepped up. The current study was done in a participato...

Schistosoma mansoni parasites cause schistosomiasis (bilharzia), an infectious disease of worldwide significance. Reactive Oxygen Species (ROS) generated during parasite tissue-specific invasion, replication-mediated cellular injuries and host immune-mediated cytotoxic reactions encompass this disease. Though host endogenous oxidant systems play a...

World Health Organization studies have demonstrated that 80% of the world’s population depends on medicinal plants for their primary health care. This has prompted increased efforts to the adoption and integration of herbal practices in health systems. This study soughts to answer the question whether Piliostigma thonningii has antitubercular, anti...

Research Article that reports the antischistosomal effects of various antioxidant plant extracts in Swiss albino mice

Aim: Schistosoma mansoni is a parasite of medical importance because it is the causative agent of intestinal schistosomiasis. The present study was designed to assess the in vivo antischistosomal effects of methanolic extracts of three food plants: Apple (Malus domestica), Lemon (Citrus limon) and Onion (Allium cepa) on Swiss Albino mice infected w...

Management of mosquito vectors by current classes of mosquitocides is relatively ineffective and necessitates prospecting for novel insecticides with different modes of action. Larvicidal activities of 15 crude extracts from three geographically isolated Aloe ngongensis (Christian), Aloe turkanensis (Christian), and Aloe fibrosa (Lavranos & L.E.New...

doi:10.3390/insects5040885 insects ISSN 2075-4450 www.mdpi.com/journal/insects/ Article Abstract: Tetraspanins are important conserved integral membrane proteins expressed in many organisms. Although there is limited knowledge about the full repertoire, evolution and structural characteristics of individual members in various organisms, data obtain...

Schistosoma mansoni is a parasite of medical importance as the causative agent of Schistosomiasis- a serious tropical disease affecting over 200 million people worldwide. Schistosomes survive and evade host defense mechanisms by utilizing antioxidant pathways. Challenging antioxidant pathways with different inhibitors of the central antioxidant enz...

Farmers in Kenya continue to raise concerns of difficulty in managing Tetranychus evansi, the most widespread pest species of tomato applying the most commonly used acaricides. This invasive pest species is not only found in Kenya, but in Eastern and Southern Africa, as well as parts of Europe and Asia. In the current study, populations of T. evans...

http://aobpla.oxfordjournals.org/content/early/2013/03/27/aobpla.plt022.full.pdf+html

Napier grass is an important forage crop for dairy production in the tropics; as such, its existing genetic diversity needs to be assessed for conservation. The current study assessed the genetic variation of Napier grass collections from selected regions in Eastern Africa and the International Livestock Research Institute Forage Germplasm-Ethiopia...

The ability of the congeneric braconid parasitoids Cotesia sesamiae (Cameron) and Cotesia flavipes Cameron to discriminate between stemborer larval cues upon contact was studied using their natural hosts, namely the noctuid Busseola fusca (Fuller) and the crambid Chilo partellus (Swinhoe), respectively, and the pyralid non-host Eldana saccharina (W...

The host recognition and acceptance behaviour of two braconid larval parasitoids (Cotesia sesamiae and C. flavipes) were studied using natural stemborer hosts (i.e., the noctuid Busseola fusca for C. sesamiae, and the crambid Chilo partellus for C. flavipes) and a non-host (the pyralid Eldana saccharina). A single larva was introduced into an arena...

Maize fields in Africa are usually surrounded by land occupied by wild plants many of which harbor lepidopteran stemborer species not found on crops. It is not known if the exotic braconid parasitoid Cotesia flavipes, which was released in Kenya in 1993 against the invasive crambid Chilo partellus, searches for and attacks these borers in their nat...