Isaiah Oluwafemi Ademola

Anthelmintic Activity of Extracts of Spondias mombin Against Gastrointestinal Nematodes of Sheep: Studies In Vitro and In Vivo

This study was carried out to validate the efficacy ofSpondias mombin, used locally as an anthelmintic, and to standardize the effective dose of the plant extract required for worm control in livestock. In vitro andin vivo studies were conducted to determine the direct anthelmintic effect of ethanolic and aqueous extracts ofS. mombin towards different ovine gastrointestinal nematodes. A larval development assay (LDA) was used to investigate thein vitro effect of extracts on strongyle larvae. Another study was conductedin vivo to evaluate the therapeutic efficacy of the extracts administered orally at dose rates of 125, 250, 500 mg/kg to sheep naturally infected with gastrointestinal nematodes. Twenty sheep were selected on the basis of positive faecal egg counts (750 epg). The sheep were allocated randomly to a non-medicated control group (A) or to groups given 125 mg/kg (B), 250 mg/kg (C) or 500 mg/kg (D) of extract, respectively. Sheep in groups B–D were given extracts orally on two days. Individual faecal egg counts were performed on days 0, 3, 6, 9 and 12. The presence ofS. mombin extracts in in vitro cultures of larvae decreased the survival of L3 larvae. The LC50 of the aqueous extract ofS. mombin was 0.907 mg/ml, while the LC50 of the ethanolic extract was 0.456 mg/ml. This difference in LC50 was statistically significant (p>0.05). The mean percentage faecal egg reduction of sheep drenched with 500 mg/kgS. mombin extracts was 15.0%, 27.5%, 65.0%, 65.0%, 100.0% againstHaemonchus spp., Trichostrongylus spp., Oesophagostomum spp., Strongyloides spp. and Trichuris spp. respectively, on day 12. Extracts ofS. mombin could find application in the control of helminths in livestock.

Comparative Nematocidal Activity of Chromatographic Fractions of Leucaena leucocephala. Seed Against Gastrointestinal Sheep Nematodes

Abstract The anthelmintic effect of chromatographic fractions of leucaena leucocephala. (Lam.) de wit seed extract was investigated to determine the relative efficacy of the seed components as anthelmintic against gastrointestinal sheep nematodes. The fractions were obtained by thin-layer chromatographic (TLC) fingerprinting of eluates from gradient vacuum liquid chromatography (VLC) of the seed ethanol extract. These were evaluated for nematocidal activity by a larval development viability assay (LDVA) in vitro.. The effect of the test extracts on the transformation of L1 to L3 and the survival rate of infective larvae (L3), of strongyles of sheep, predominantly Haemonchus contortus. (Rudolphi), was used to determine relative bioactivity. Best-fit LC50 values were computed using global model of nonlinear regression curve-fitting. The composition of the fractions was identified by phytochemical screening. The extracts killed infective larvae of H. contortus. of sheep in a concentration-dependent manner. Best-fit LC50 values are 77.66, 65.56, 56.72, and 40.80 µg/ml for fractions A, B, C, and D, respectively (95% CI). The fractions are composed of alkaloids (A), alkaloids and tannins (B and C), and flavonoids and tannins (D). Fraction D was significantly more active than all the other fractions (p < 0.001, one-way ANOVA, Tukeys multiple comparison test). The most active fraction (D) contains polar polyphenols, thus providing a scientific justification for the use of aqueous extract in traditional practice. The polyphenol fraction of L. leucocephala. seed could find application in anthelmintic therapy in veterinary practice.

Bioseparation and activity of Khaya senegalensis fractions against infective larvae of Haemonchus contortus

The anthelmintic constituents of Khaya senegalensis (Deser.) A. Juss (Meliaceae) bark extract, previously demonstrated to show both in vitro and in vivo activity against gastrointestinal nematodes of sheep was investigated by chromatographic separation of the crude extract and bioassay of fractions. Bioseparation of the crude ethanol (95%) extract was carried out by gradient vacuum liquid chromatographic analysis and thin layer chromatography fingerprinting of eluates. The activity of the fractions was tested by a larval development assay in vitro. The survival rate of infective larvae L3 of sheep nematodes, predominantly Haemonchus contortus, was used to assess relative bioactivity. A secondary fraction obtained from further purification by preparative thin layer chromatography of a primary active fraction was also assessed for bioactivity. The compositions of the fractions were determined by qualitative chemical tests. The extracts killed infective larvae of H. contortus in a concentration-dependent manner. Best-fit LC50 values were 80.81, 63.73, 44.03 and 63.90 microg/ml for fractions A, B, C, and D, respectively (95% CI). The fractions are composed of saponins (A), saponins and alkaloids (B), saponins, terpenoids, flavonoids, condensed tannins (C), and saponins and tannins (D). Fraction C shows the highest activity of all the fractions, however, the difference is not statistically significant (p>0.05, Kruskal-Wallis test). The secondary fraction, C1A obtained from fraction C gave best-fit LC50 value of 5.09 microg/ml (95% CI) and was identified to be condensed tannin. The anthelminthic activity of K. senegalensis appears to involve synergism between various secondary metabolites found in the extract rather than a particular group of compounds.

Anthelmintic efficacy of cashew (Anarcadium occidentale L.) on in vitro susceptibility of the ova and larvae of Haemonchus contortus

The use of plants for the treatment of human and animal diseases continues to rise although there are few studies providing proof of these effects. Among them is the Anacardium occidentale L., popularly known as cashew. In vitro egg hatch and larval development and viability assays was conducted to determine possible direct anthelmintic effect of acetone extract and fractions of A. occidentale against nematode of sheep, predominantly, Haemonchus contortus . The effect of the extracts on hatching of eggs and development and survival of infective larvae (L 3) was assessed. The best-fit LC 50 values were computed by global model of non-linear regression curve fitting (95% confidence interval). The presence of A. occidentale extracts in the cultures decreased the hatchability of eggs and survival of L 3 larvae in a concentration dependent manner. The LC 50 values of acetone extract was 0.311 and 1.72 mg/ml for egg hatch and larval viability test, respectively. The fractions of A. occidentale were more active, demonstrating a lower LC 50 compare with the acetone extract. The activities of the fractions were not significantly different against the eggs and larvae of H. contortus (p > 0.05). Further studies are required to identify the compound(s) responsible for activity and more clearly comprehend the anthelmintic mechanism detected in this study.

Ovicidal and larvicidal activity of Cassia alata leaf acetone extract and fractions on Haemonchus contortus: in vitro studies.

Context: The failure of modern anthelmintics to control nematode parasites of sheep and goats is a reality on many farms in the tropical/subtropical regions of the world. This necessitates chemotherapeutic control alternatives and plant secondary metabolite with activity is one of those potential solutions. Objective: This study was design to evaluate the efficacy of solvent: solvent fractions of Cassia alata Gelenggang Besar (Leguminosae) leaf acetone extract against Heamonchus contortus Rudolphi (Trichostrongylidae). Materials and methods: C. alata leaf was extracted with 70% acetone and fractions were obtained by solvent: solvent group separation procedures. The acetone extract and the fractions were tested by egg hatch assay (EHA) and larval development and viability assay to assess relative bioactivity against H. contortus eggs and larvae. Results: The extracts inhibited egg hatchability and killed infective larvae of H. contortus in a concentration-dependent manner. The best-fit LC50 values were 0.562, 0.243, 0.490, 0.314, and 0.119 mg/mL for the acetone extract, chloroform, hexane, butanol and 35% water in methanol fractions, respectively, when tested against nematode eggs. The best-fit LC50 values were 0.191, 0.505, 1.444, 0.306, and 0.040 mg/mL for acetone extract, chloroform, hexane, butanol and 35% water in methanol fractions, respectively, when tested against larvae. The 35% water in methanol fraction was the most active against the larvae and eggs of H. contortus demonstrating the lowest LC50 values Discussion and conclusion: This study demonstrates that the leaf extracts of C. alata have anthelmintic activity; therefore it could find application in the control of helminths in livestock.

A meta-analysis of the prevalence of African animal trypanosomiasis in Nigeria from 1960 to 2017

BackgroundAfrican animal trypanosomiasis is an economically significant disease that affects the livestock industry in Nigeria. It is caused by several parasites of the genus Trypanosoma. National estimates of the disease prevalence in livestock and tsetse flies are lacking, therefore a systematic review and meta-analysis were performed to understand the trend of the disease prevalence over the years.MethodsPublications were screened in Web of Science, Ovid MEDLINE, Global Health, EMBASE and PubMed databases. Using four-stage (identification, screening, eligibility and inclusion) process in the PRIMSA checklist, only studies that met the inclusion criteria for AAT and tsetse infections were analysed. Point estimates prevalence and subgroup analyses based on diagnostic techniques in livestock were evaluated at 95% confidence interval (CI).ResultsA total of 74 eligible studies published between 1960 and 2017 were selected for meta-analysis. This covers the six geopolitical zones, involving a total of 53,924 animals. The overall prevalence of AAT was 16.1% (95% CI: 12.3–20.3%). Based on diagnostic techniques, the prevalence of AAT in cattle was highest in PCR followed by serology and microscopy while the highest prevalence in pigs was observed with serology. Out of 12,552 tsetse flies examined from 14 eligible studies, an overall prevalence of 17.3% (95% CI: 4.5–36.0%) and subgroup prevalence of 49.7% (95% CI: 30.7–68.8%), 11.5% (95% CI: 6.1–18.5) and 4.5% (95% CI: 1.8–8.8%) in G. morsitans, G. tachinoides and G. palpalis, respectively, were observed using the random effects-model.ConclusionsThe prevalence of trypanosomes in both vectors and animal hosts was high in Nigeria. Therefore, further research on risk factors, seasonal and transhumance effects, vectoral capacity and competence are warranted for an effective control of AAT in Nigeria.

Novel trypanocide from an extract of Pleurotus sajor-caju against Trypanosoma congolense

Abstract Context: Control of African trypanosomiasis relies on chemotherapy, but the development of resistance and the problem of drug residues require research for alternatives. Triterpenes and phenolics, the major constituents of Pleurotus sajor-caju (Fr.) Singer (Pleurotaceae), are reported to be effective against trypanosomiasis. Objective: Trypanocidal effect of whole Pleurotus sajor-caju aqueous extract was investigated in vivo against Trypanosoma congolense. Materials and methods: Mice (25–32 g) were divided into seven groups of six animals. Mice in groups A–F received 2.5 × 104 trypanosomes, while group G was uninfected. Extracts (100–250 mg/kg) were administered intraperitoneally for 5 days to groups A–D while diminazine aceturate (group E) and normal saline (group F) served as positive and negative controls, respectively. Parasitemia, survival time, body weight and haematological parameters were monitored for 60 days post-treatment. Results: Parasitemia decreased significantly (p < 0.01) post-treatment with 200 and 250 mg/kg of the extract and became undetectable by day 16 and 12 post-infection, respectively; the ED50 was 221.5 mg/kg. The packed cell volume (PCV) and the weight of mice treated with 250 mg/kg extract were 46.20 ± 2.6% and 32.05 ± 3.63 g, respectively, which is higher than the group treated with diminazine aceturate. The mean survival time of animals in groups D and E was >60 days, while that of group F was <4 days. Differential leucocyte count on day 68 post-infection in groups C, D and E were not significantly different. Conclusion: Pleurotus sajor-caju therefore could be a potential source of new trypanocidal drugs.

Absence of detectable benzimidazole-resistance associated alleles in Haemonchus placei in cattle in Nigeria revealed by pyrosequencing of β-tubulin isotype 1.

Trichostrongyles are gastrointestinal parasites that occur globally and can cause subclinical to severe, sometimes life-threatening, infections in ruminants, particularly young animals. Benzimidazoles (BZ) are commonly used for the treatment of gastrointestinal parasites in ruminants. Increasing spread of worm populations with anthelmintics resistance has been reported and is considered a consequence of highly frequent and longstanding use of anthelmintics. To obtain initial information regarding the occurrence of putatively BZ-resistant Nigerian Haemonchus populations, screening based on the molecular analysis of BZ-resistance-associated β-tubulin isotype 1 gene sequence polymorphisms was undertaken. Genomic DNA was isolated from pooled adult Haemonchus sp. from 35 animals from each of the six states of southwestern Nigeria. Sequencing of internal transcribed spacer 2 (ITS-2) and external transcribed spacer (ETS) regions was used to determine the Haemonchus species. Pyrosequencing assays were used for detection of single-nucleotide polymorphisms (SNPs) in the β-tubulin isotype 1 genes of the worms at codons 200 and 167 (TTC/TAC) or 198 (GAA/GCA). Exclusively, Haemonchus placei was detected and allele frequencies obtained at all three positions showed no evidence for the presence of resistance-related alleles. For Lagos State, pools of 10 worms from 30 different animals were analyzed separately for the codon 200 SNP, successfully excluding the presence of resistance-associated SNPs in very low frequencies. These positive findings, showing absence of elevated frequencies of BZ-resistance-associated β-tubulin alleles, have considerable significance since it suggests that farmers can still rely on the efficacy of this important drug class when used for controlling trichostrongyle infections in cattle in Nigeria.

Anticoccidial effects of Morinda lucida acetone extracts on broiler chickens naturally infected with Eimeria species

Abstract Context: The development of drug resistance to Eimeria species in poultry is a reality on farms. This necessitates chemotherapeutic control alternatives, and plant secondary metabolities with activity is one of those potential solutions. Objective: This study was designed to evaluate the efficacy of acetone leaf extract of Morinda lucida Benth. (Rubiaceae) against coccidiosis in broiler chickens. Materials and methods: Acute toxicity of the plant was investigated using 30 one-day-old broiler chicks. Anticoccidial activity investigations were carried out in birds drenched with 2.0, 3.0, 4.0, 5.0 and 6.0 g/kg body weight (BW) of acetone extract of M. lucida leaves once a day for five days, with toltrazuril® and untreated controls. The activity was evaluated by means of oocyst inhibition in feces, fecal score, weight gain, mortality and hematological parameters. Results: No sign of toxicity was observed during the acute toxicity test. Fecal oocyst counts decreased steadily in all the treatment groups with time. The anticoocidial efficacy of birds treated with 2.0, 3.0, 4.0, 5.0 and 6.0 g/kg BW of the extract was 91.2, 95.2, 98.7, 99 and 99.5%, respectively. The packed cell volumes, red blood cell counts and white blood cell of the treated birds were not significantly different (p > 0.05) from the untreated control. However, haemoglobin concentration and weight gain of the treated birds were significantly different (p < 0.05) from the untreated control. Conclusion: This study is the first to demonstrate the anticoccidial effect of M. lucida on Eimeria parasites. Morinda lucida leaves could therefore find application in anticoccidial therapy.

Co-infection with Plasmodium berghei and Trypanosoma brucei increases severity of malaria and trypanosomiasis in mice

Individuals in natural populations may be infected with multiple different parasites at a time. These parasites may interact with each other or act independently in the host, and this may result to varying outcomes on host health and survival. This study therefore aimed at investigating the health impact of co-infection of mice with Plasmodium berghei and Trypanosoma brucei. Forty Swiss albino mice (14-17g) were divided into four groups of ten. Mice in groups A and B received 10(6)P. berghei and groups B and C 10(5)T. brucei, while group D were uninfected. The co-infected mice had higher P. berghei and T. brucei parasitaemia, compared with the mono-infected mice. The co-infected mice had significantly (p<0.05) lower survival rate compared with the mono-infected mice. Co-infection of mice with P. berghei and T. brucei resulted in rapid P. berghei and T. brucei development and increased parasitaemia. The leukocyte numbers significantly (p<0.05) reduced on days 12 and 15 post infection among P. berghei infected mice, in the presence or absence of T. brucei. Anaemia and hypoglycaemia was more severe in the co-infected mice. Therefore, co-infection of mice with P. berghei and T. brucei may increase pathologic impact to the host by increasing parasitaemia.