Larvicidal Effect of Essential Oil from Leaves of Lantana camara (Verbenaceae) Against Aedes aegypti (Diptera: Culicidae)

Essential oil of Lantana camara leaves were assayed in the laboratory against 3rd instars of Aedes aegypti larvae following standard World Health Organization insecticide susceptibility methodology. Seven concentrations (5, 10, 20, 40, 60, 80 and 100 mg/l) were used in the test and larval mortalities recorded after 12-,24, 36-, and 48 h treatment exposures. Results indicated dose-dependent relationship with larval mortalities commencing at 10mg/l dosage post 24 h exposure. A dosage of 60 mg/l caused 100% larval mortality at 48 h post-treatment exposure. Exposure time (F=256.0;df =0,10;

Effects of the Aqueous Root Extract of Vernonia amygdalina on the Haematological Profile of Rattus norvegicus

The effects of Vernonia amygdalina root extract on the haematological profile of 20 male albino rats (Wistar strain) were investigated for a period of 21 days. The rats were divided into three treatment groups A, B, and C and a control group D. The experimental groups A, B, and C were treated with 50mg.Kg-1, 150mg.Kg-1, and 300mg.Kg-1 body weight respectively while the control (group D) received equal volume of normal saline. The extracts were given to the animals orally for 21 days. Blood was collected through the orbital-plexus of rats to assay the effect of the extract on packed cell volume (PCV), white blood cell count (WBC), red blood cell count (RBC) and haemoglobin (Hb) level. The mean WBC, RBC, PVC and haemoglobin level ranged from 1560 ± 120 to 3200 ± 1200, 150.00 ± 40.00 to 276.00 ± 44.50, 38.00 ± 1.00 to 41.00 ± 3.00, and 16.00 ± 2.00 to 12.50 ± 0.50, respectively. There was no significant different (p>0.05) in the haematological profile of the treated groups when compared with the control. However, there was significant different (p<0.05) within each group from week one to week three except WBC in group D and PVC in all the groups. This suggested that the effect of the aqueous extract of V. amygdalina on the haematological profile of Rattus norvegicus was dependent on duration of consumption. Keywords: Vernonia amygdalina, Aqueous root extract, Haematological profile, Rattus norvegicu

Effect of Root Extracts of Lantana camara (Verbenaceae) on Larvae of Aedes aegypti (Diptera: Culicidae)

Larvicidal activity of three solvent root (bark and wood) extracts of Lantana camara Linn. was investigated against first and fourth instars of Aedes aegypti larvae after 24 and 48 h post-treatment exposure to serial concentrations (0.1, 0.05, 0.01, 0.005, 0.001 %) of aqueous, ethanolic and acetone crude extracts. All extracts showed varying degrees of larvicidal activity reported as LC50 and LC90 values. At 24 h post-treatment exposure of first instar larvae, larvicidal activities of acetone extract (LC50=0.011%; LC90=0.017%) was similar to the ethanolic extract (LC50=0.011%; LC90=0.023%) but differed from the aqueous extract (LC50=0.047%; LC90=0.056%). After 48 h treatment exposure of first instar larvae, acetone extracts (LC50=102 ppm or 0.0102%; LC90=162 ppm or 0.0162%) was significantly more toxic than either the ethanolic extract (LC50=107 ppm or 0.0107% ; LC90=216 ppm or 0.0216%) or aqueous extract (LC50=428 ppm or 0.0428%; LC90=548 ppm or 0.0548%). After 48 h treatment exposure of fourth instar larvae, acetone extracts (LC50=181 ppm or 0.0181%; LC90= 192 ppm or 0.0192%) exerted the most lethal effects, followed by ethanolic extract (LC50=225 ppm or 0.0225%) and aqueous extract (LC50=605 ppm or 0.0605% ; LC90= 710 ppm or 0.0710%). Sensitivity / susceptibility of larval instars to extracts appeared to be dose and developmental stage-dependent. Factorial analysis showed that extracts (F=0.044; df =2,36 ;

Human loa loa (Cobbold, 1864) (Filaroidea: Onchocercidae) morbidity distribution in northern Enugu State, Nigeria: implications for onchocerciasis control

A cross-sectional epidemological investigation was conducted in Nsukka senatorial zone of Nigeriato evaluate the use of specific clinical signs/symptoms in the assessment of the endemicity, prevalence and morbidity of Loa loa infection in areas meso-endemic for onchocerciasis, and to evaluate the results in respect of the probability of occurrence of adverse reactons, post-treatmentwith ivermectin in areas presumed to be hypo-, meso-, and hyper endemic for Loa loa infection and morbidity. Standard questionnaire based on the key clinical manifesations of loiass were administered and the micofilaraemic levels of respondents determined at both community and individual levels. The results showed that the clinica symptoms/signs were known in all the studycommunities. Altogether 22.0% o respondents (n=1600) positively indicated having experienced either Loa loa infection and/ or Calabar swelling. Based on the questonnaire indices, an intercommunity prevalence of 21.9% (range 17.50 - 27.50%) was establshed An overall communiy medan microfaraemia (mf) prevalence of 19.4% (range 15.0 - 26.3%) was also recorded. A microfilaraemia prevalence >20% was however established in >35% of the study communities indicating the possibility of adverse reaction after ivermectin administration. More males (n=203, 12.7%) than females (n=109, 6.8%) were microfaraemic. Linear logistic regression indicated that Loa loa infection was significantly associated with age (adjusted odds rato: 1.12, 95% confidence interval: 1.00-1.14,

Preliminary studies on the efficacy of aloe vera (Aloe barbadensis) extracts on experimental Trypanosoma brucei brucei infection of mice

Extracts of Aloe vera were administered to experimentally infected mice with the Nigeria strain of Trypanosoma brucei brucei. The thirty-two (32) mice involved in the study were split into eight (8) groups of 4 mice each and treated intraperitoneally with the aqueous and ethanolic Aloe vera extracts of 40, 80, 20 mg/Kg body weight of aqueous extracts and 3.5mg/Kg (Berenil®). The untreated with 3.5mg/Kg (standard trypanocidal drug) achieved aparasitaemia of 3 days post treatment. The toxicity of the extract to the parasite was concentration-dependent. 80mg/Kg aqueous extract showed the most significant reduction in parasitaemia and effected the most dramatic post treatment reduction. This was followed by 40mg/Kg aqueous extract treatment regimen. The haematocrit value decreased with increasing concentration of both the aqueous and ethanolic extracts. Bio-Research Vol. 3(1) 2005: 21-2

Studies of the seasonal variations and prevalence of Helminth fauna on the black rat, Rattus rattus (Rodentia: Muridae) from different microhabitats in Nsukka, Nigeria

A twelve-month epizooic survey was conducted to evaluate the helminth fauna of the Ngerian strain of the black rat, Rattus rattus from six microecological habitats in Nsukka area of Nigeria andto assess the zoonotic and public health implications of the findings. Altogether 1458 rats (565 % males and 43.5 % females) were trapped and examined for helminths. A total of 1098 rats (55.7 % males and 44.3% females) harboured helminth parasites thus providing and overall prevalence o 75.3% and a mean worn burden of 1.3. The between-sex difference was statistically signiicant (x2 =2.64, P < 005) wth more males (53.2 %) than females (46.8 %) harbouring helmnhparasites. There was no marked variation in the infection pattern in the rat host from the different habitats, but the parasite prevalence and distrbution appeared to be season-dependent. Parasites (n = 1469) recovered were of 3 helminth groups (nematodes 72.4%, cestodes 27.5%, and trematodes 0.6%). Six nematode species identified were Nippostrongylus braziliensis (198%), Aspicularis tetrapera (17.5%), Syphacia muris 17.0 %), Angiostrongyus cantonensis 16.9%), Strongyloides ratti (16.0%) and Capiaria hepatca (12.8%). Also recovered from their rat hosts were the following six cestode species; Hymenolepis dimnua (22.7%), Taenia taeniaeformis (17.4%), T. muris (171%), T. hydatigera (166%), H. nana (164%) and Raillietina muris (9.8%). Trematodes(n=9) belonging to 3 species, Plagiochis muris, Platynosomoides muris and Corrigia muris were also recovered from five infected rats. A total of 103 rat hoss harboured single infections of nematodes, 818 (98.9%) had combined nematode/cestode infections, 5 (6.0%) haboured a combination of nematode/trematode whereas 4 (0.5%) showed concurrent cestode/trematode infections. The influence of seasonal fluctuations on the parasite-host relationship, le cycle patterns of the parasites and immunological potentials of the rat hosts are discussed.Keywords: Epizootic, helminth, Rattus rattus, Nematode, Cestode, Trematode, Seasonal fluctuatio

An Epidemio-Dermatological Assessment Of Onchocercal Skin Diseases In Awhum, Enugu State, Nigeria

A cross-sectional epidermiological and dermatological survey of onchocercal skin diseases (OSD) and the associated itching was conducted in Awhum, Enugu State, Nigeria. For quantitative data, compounds in each village were randomly selected and within the selected compound every individual in each household was systematically examined using the non-invasive nodule palpation technique. A nodular prevalence of 21.3% was recorded indicating the community was mesoendemic for onchocerciasis. No absolute control village was observed and the inter-village nodular prevalence was statistically significant (