Anti-nociceptive Effect of Euphorbia hirta Leaf Extract: Involvement of Adenosine, Cholinergic, and Opioid Receptors.

OBJECTIVE: The study was designed to investigate the anti-nociceptive activity of Euphorbia hirta leaf and its possible mechanism of action. METHODS: The extract of Euphorbia hirta obtained from the leaf was prepared as per standard procedures and evaluated at the three doses (300, 600, and 1200 mg/kg, i.p). The extract was screened for anti-nociceptive activity using heat-induced (tail-flick) and chemical-induced (acetic acid-induced writhing and formalin-induced paw lick) nociception models in mice. The possible mechanism of action of the extract was evaluated using antagonists of notable nociceptive pathways. RESULTS: Intraperitoneal administration of Euphorbia hirta extract at the doses of 600 and 1200 mg/kg significantly (p<0.05) reduced the formalin-induced paw licking in both neurogenic and inflammatory phases of the test. While administration of the extract at the dose of 300 mg/kg significantly inhibited the pain due to formalin in the inflammatory phase but not in the neurogenic phase. The anti-nociceptive effect of Euphorbia hirta extract increased the reaction time to thermal stimulus, also inhibited the acetic acid-induced writhing dose-dependently. The antinociceptive effect exhibited by Euphorbia hirta extract in the formalin test was reversed by the administration of naloxone, theophylline, and atropine. Glibenclamide, nifedipine, and yohimbine, however, did not significantly block the anti-nociceptive effect of the extract. Meanwhile, methylene blue administration enhanced the anti-nociceptive effect of the extract. CONCLUSION: The results indicated that Euphorbia hirta extract produces a dose-related antinociceptive effect in several models of chemical and thermal pain, through mechanisms that might involve interaction with adenosine, cholinergic, and opioid receptors.

Prevalence and associated factors of Plasmodium falciparum and soil transmitted helminth infections among pregnant women in Osun state, Nigeria.

BACKGROUND: Plasmodium falciparum and soil transmitted helminth (STHs) infection are widespread in sub-Sahara Africa, where co-infection is also common. This study assessed the prevalence of these infections and their risk factors among pregnant women in Osogbo, Nigeria. METHODS: A total of 200 pregnant women attending the antenatal clinic were recruited. Plasmodium falciparum was detected using thick and thin film methods, while formol ether concentration method was used for STHs detection. A questionnaire was used to investigate the possible risk factors associated with acquisition of malaria and helminth infections. RESULTS: The prevalence of P. falciparum, STHs and their co-infection was 29.5%, 12% and 5% respectively. P. falciparum, STHs and P. falciparum + STHs co-infection was significantly higher in primigravidae (52.5% vs 58.3% vs 80%) than in secongravidae (18.6% vs 25.0% vs 20%) and multigravidae (28.8% vs 16.7% vs 0%) (p=0.02). Prevalence associated factors identified for P. falciparum was age (p=0.0001) while gravidity (p=0.02) was identified for P. falciparum + STHs co-infection. CONCLUSION: High prevalence of P. falciparum and helminth infections was observed among the pregnant women with primigravidae being the most susceptible to co-infection. There is an urgent need to implement an effective malaria and STHs preventive method for this high risk population.

Co-endemicity of loiasis and onchocerciasis in rain forest communities in southwestern Nigeria.

BACKGROUND: Loiasis is currently receiving attention as a disease of public health importance because of the possibility of increased risk of developing neurologic serious adverse event following mass ivermectin treatment against onchocerciasis in individual co-infected with Onchocerca volvulus and Loa loa. METHODOLOGY/PRINCIPAL FINDINGS: Rapid assessment procedure for loiasis (RAPLOA) was conducted in 12 communities covering the 3 senatorial districts of Osun State, Nigeria. A total of 960 people were interviewed for history of eye worm using the WHO guidelines for rapid assessment. The survey confirmed the presence of loiasis in all the 12 communities with 4 in Osun East/Ife south senatorial district being at high risk with a prevalence of over 40%. Based on the RAPLOA results, communities within Osun East/Ife south senatorial district were selected for microfilaraemic assessment of L. loa and O. volvulus. A total of 1115 and 1091 individuals were screened for L. loa and O. volvulus microfilaria worms respectively. 160 (14.3%) had L. loa microfilaria detected in their blood with 8 (5.0%) individuals having L. loa loads above 8000 mf/ml. 166 (15.2%) subjects had O. volvulus microfilaria (range 4-504 mf/ml) detected in their skin snip. 30 (2.69%) subjects were co-infected with both L. loa and O. volvulus. There was a significant variation in the prevalence (2.1% to 33.3%) of onchocerciasis in the communities studied (p = 0.001). Five (41.7%) of the studied communities had a prevalence that is equal to or greater than 20%. CONCLUSIONS/SIGNIFICANCE: Low prevalence of onchocerciasis and loiasis co-infection in this study suggests that loiasis may not pose a serious epidemiological threat to the continuous distribution and sustainability of ivermectin for the treatment of onchocerciasis. Evaluation of the interruption of onchocerciasis transmissions in this region using all the indicators set forth by WHO is therefore suggested.

Prevalence of Plasmodium falciparum Parasitaemia and Its Correlation with Haematological Parameters among HIV-Positive Individuals in Nigeria.

Malaria and HIV are the two most important health challenges of our time. Haematologic abnormalities are features in Plasmodium falciparum infection, and anaemia is a well-known outcome. The prevalence and haematological impact of P. falciparum parasitaemia were determined among HIV-infected individuals in Nigeria. Parasite detection was carried out using microscopy and Polymerase Chain Reaction (PCR). Haemoglobin concentration was determined using an automated machine while CD4+ T-cells count was analyzed using flow cytometer. Thirty-seven (18.5%) out of the 200 HIV individuals enrolled had malaria parasites detected in their blood. All the positive cases were detected by PCR while only 20 (10%) were detected by thick blood microscopy. The mean haemoglobin concentration and packed cell volume (PCV) of HIV individuals with malaria parasitaemia were lower compared to those without malaria parasitaemia but the difference was not statistically significant. Also no significant difference was observed in malaria positivity in respect to sex and mean CD4+ cell count. The study highlights the effects of P. falciparum parasitaemia on the haematologic and immune components of HIV individuals.

Assessment of Clinical Diagnosis, Microscopy, Rapid Diagnostic Tests, and Polymerase Chain Reaction in the Diagnosis of Plasmodium falciparum in Nigeria.

This study compares the performance of clinical diagnosis and three laboratory diagnostic methods (thick film microscopy (TFM), rapid diagnostic test (RDT), and polymerase chain reaction (PCR)) for the diagnosis of Plasmodium falciparum in Nigeria. Using clinical criteria, 217 children were recruited into the study out of which 106 (48.8%) were positive by TFM, 84 (38.7%) by RDT, and 125 (57.6%) by PCR. Using a composite reference method generated from the three diagnostic methods, 71 (32.7%) patients were found to be truly infected and 90 (41.5%) truly uninfected, while 56 (25.8%) were misidentified as infected or noninfected. When each of the 3 diagnostic methods was compared with the composite reference, PCR had sensitivity of 97.3%, specificity of 62.5%, positive predictive value (PPV) of 56.8%, and negative predictive value (NPV) of 97.8%; microscopy had sensitivity of 77.2%, specificity of 72%, PPV of 66.9%, and NPV of 81.1%, while RDT had sensitivity of 62.3%, specificity of 87.4%, PPV of 67.7%, and NPV of 84.5%. PCR test performed best among the three methods followed by TFM and RDT in that order. The result of this study shows that clinical diagnosis cannot be relied upon for accurate diagnosis of P. falciparum in endemic areas.