Screening of Indigofera lupatana Baker F. root extracts for antibacterial activities

Herbal remedies as cheap alternatives to conventionalmedicine have contributed significantly to rurallivelihoods. Apart from the traditional healerspracticing herbal medicine, many people are involved incollecting and trading medicinal plants. The WorldHealth Organization (WHO) estimates that 80% of theworld’s population depends on medicinal plants fortheir primary health care (Mothana et al, 2008; Ngoci etal, 2011). The use of traditional medicine has beenexplored globally and is widely used in developingcountries as an alternative or to complementconventional medicine (Rates, 2001; Gupta et al, 2010).Natural products, either as pure compounds or asstandardized plant extracts, provide exceptionalopportunities for new drug leads because of theunmatched chemical diversity of naturally derivedcompounds (Cowan, 1999; Parekh and Chanda, 2007;Mariita et al, 2010; Ngoci et al, 2011). Scientific interestin medicinal plants has burgeoned due to therecognized efficacy of plant derived drugs and everpresentconcerns about the side effects of modernmedicinal substances. This has fuelled the intensiveinvestigation of new molecular structures from theplant kingdom as potential medicinal compounds(Mariita et al, 2010). As a result, drugs derived fromunmodified natural products or semi-synthetic drugsobtained from natural sources accounted for 78% of thenew drugs approved by the United States Food andDrug Administration (FDA) between 1983 and 1994(Suffredini et al, 2006; Ngoci et al, 2011). Thisunderscores the importance of screening naturalproducts.Infectious diseases are a leading cause of human andanimal mortality. This is further aggravated by the rapiddevelopment of multi-drug resistance to available antimicrobialagents (Doughart and Okafor, 2007; Ngoci etal, 2011), their limited anti-microbial spectrum, theirside effects (Huie, 2002), and emergence and reemergenceof opportunistic infections. Therefore,studies aimed at identifying and characterizing of thesubstances that exhibit activity against infectious microorganisms,yet showing no cross resistance withexisting antibiotics, are required (Olila et al, 2001). Inrecent years, pharmaceutical companies have focusedon developing drugs from natural products thatpromises to counter the limitations of conventionalantibiotics (Doughart and Okafor, 2007).The bio-activity of natural products is due tophytochemicals, a group of secondary metabolites oftenelaborated for the plant defense against pests andherbivores or to gain an advantage over competingagents. These phytochemicals inadvertently also protecthumans against pathogens (Ngoci et al, 2011). Somephytochemicals are known to have antimicrobialproperties, immune-modulative properties, providenutrition for normal cell health and repairs, inhibitcarcinogens and act as antioxidants.Indigofera lupatana Baker F., locally called ‘mugiti’ bythe Mbeere community in Kenya, is a woody shrubfound in Acacia-Combretum ecological zones of Mbeere.It is widely used for its perceived medicinal value intreating coughs and diarrhea (Riley and Brokensha,1988; Ngoci et al, 2011), gonorrhea and pleurisy(Kokwaro, 1993; Ngoci et al, 2011).There is apparently no documented scientific report onanti-microbial properties of this plant. This lack ofscientific corroboration has often constituted a majorconstraint to the consideration of the use of herbalremedies in conjunction with or as an affordablealternative to conventional medical treatment (Okeke etal, 2001). Knowledge of the chemical constituents ofplants is desirable not only for the discovery oftherapeutic agents, but also because such informationmay be important in identifying new sources ofsubstances of economic value such as tannins, oils,gums, and precursors for the synthesis of complexchemical substances. In addition, the knowledge of thechemical constituents of plants would further bevaluable in discovering the actual value of folkloricremedies (Mojab et al, 2003).This study was therefore undertaken to determine theantibacterial properties of hexane, ethyl acetate anddichloromethane root extracts of I. lupatana Baker F

Linking Demand with Supply for Tropical Forage Genetic Resources to Reach Impact at Scale

Over the last decades a wealth of information on tropical forage genetic resources has been collated and is accessible to users ranging from farmers, development practitioners and researchers to decision makers and academia, e.g. through online tools such as Tropical Forages: An interactive selection tool (www.tropicalforages.info). However, while genetic diversity is being conserved by international gene banks, adoption of improved tropical forages is still far from reaching its full potential. Major bottlenecks in our view include lack of awareness of available forage genetic resources, confirmation of adaptation in a wide range of bio-physical, socio-economic, political and cultural contexts and functionality of financing, extension and seed supply systems. This paper discusses the potential for adoption of tropical forages in the context of new opportunities by market driven innovation, and presents early successes using as examples improved Urochloa spp., Megathyrsus maximus and other grass and legume germplasm, while describing possible pathways to go to scale with small and medium size livestock producers. We use examples of approaches from the tropical Americas, tropical Africa and tropical Asia, including partnerships with the private sector in diverse market environments (e.g. Africa and Latin America) and network approaches (Asia)

Management of Napier stunting disease

A poster prepared on stunt disease management in Keny

In search of a new tool for phenotyping tick resistance in cattle

Ticks and tick borne diseases cause significant loss in livestock production with about 80% world's cattle at risk. The cost of chemical control is high and there is an ever increasing tick resistance to chemicals. Genetic selection as alternative long term control strategy is constrained by laborious phenotyping using tick counts or scores. This study explores the use of host volatile semiochemicals that may be attractants or repellents to ticks as a novel phenotype with potential to be used as a proxy in selection programmes. About a 100 young cattle composed of Bos indicus and Bos taurus were artificially infested with 2,500 R. decoloratus larvae with daily female ticks (4.5 mm) counts taken from day 20 post infection. Volatile compounds we sampled before and after tick infestation. We identified three pre-infestation volatile compounds that were associated with tick resistance (P-value<0.01) and one post infestation (P-value<0.05) using 6 day repeated measure analysis. The high correlation coefficients (r=0.66) between repeated records with all volatile compounds support the potential predictive value for volatile compounds in selective breeding programmes for tick resistance in cattle

Clinical and pathological findings in piglets infected with Trypoanosoma simiae tsavo

No Abstract. BAHPA Vol. 54 (3) 2006: pp. 176-18

The Orma Boran - ten years of field observations

Presents the Orma Boran field observations carried out under tsetse fly challenge on Galana ranch in Kenya since 1980. Their response to trypanosomiasis has been compared to that of the ranch bred Kenya (Galana) Boran. The mean monthly prevalence of trypanosomiasis observed in Orma steers over five years was 17 percent compared with 31 percent in the Galana Borans. Mean annual mortality over five years was 35 percent in untreated Orma steers compared with 71 percent in untreated Galana steers. The primary difference appeared to be in their response to Trypanosoma vivax challenge. Their ability to acquire resistance has also been investigated under field conditions and both acquired and innate resistance appear to play a role. Steers monitored weekly over two years and treated with diminazene aceturate immediately on detection of infection showed some evidence of improved control of anaemia. In contrast, steers treated only when the PCV fell to 15 percent showed little evidence of improved anaemia control over two years. There was strong evidence for an innate component and the repeatabilities of PCV and infection rate were significant between the two years. Orma calves born on Galana ranch and herded together with their Galana counterparts were detected parasitaemic less often and the pre-weaning mortality was 7 percent compared with 17 percent for the Galana calves. The trypanosome prevalence in both groups of calves was lower than that observed over the same period in their dams and the vivax ratio was higher. Orma calves, however, had significantly lower birth & weaning weights than their Galana counterparts

Clinical and pathological findings in piglets infected with Trypoanosoma simiae tsavo

No Abstract. BAHPA Vol. 54 (3) 2006: pp. 176-18

The potential for use of haematological and anti-IgE humoral responses as phenotypic markers for tick resistance in cattle

Approximately 80% of the global cattle population is at risk of infestation and infection by ticks and tick-borne diseases (TTBDs). The economic losses from animal mortality, reduced production, vector control costs and animal treatment are very substantial, hence there is an urgent need to develop and deploy alternative vector control strategies. Breeding for host tick resistance has the potential for sustainable large-scale TTBD control especially in cattle. The gold standard method for phenotyping tick resistance in cattle is by counting ticks on the body but is very laborious and subjective. Better methods for phenotyping tick resistance more objectively, faster and at scale, are essential for selecting host genetic resistance to ticks. This study investigated the correlation between haematological cellular profiles and immunological responses (immunoglobulin E, IgE) and full body tick counts in herds of Bos indicus and Bos taurus following artificial tick challenge with Rhipicephalus decoloratus larvae. Fifty-four Friesian and Ayrshire (Bos taurus) and 52 East African Zebu (Bos indicus) calves were each infested with ∼2500 larvae. Near-replete adult female ticks (≥4.5 mm) were counted daily from day 20–25. Blood and serum samples were obtained from each animal on days 0 and 23 for cellular blood and IgE titre analysis, respectively. The indicine cattle were refractory to R. decoloratus infestation in comparison with the taurine breed (P < 0.0001). Repeated measurements of blood components pre-infestation revealed a significant (P < 0.05) association with tick count in IgE and red blood cells, heamatocrit, and haemoglobin post-infestation. There was also a strong positive correlation between the tick counts and red blood cell numbers, haemoglobin, haematocrit, and IgE concentration (P < 0.0001) following tick challenge. The application of this approach to phenotype host resistance needs to be assessed using higher cattle numbers and with different tick species or genera