The In Vitro Effects of Aqueous and Ethanolic Extracts of the Leaves of Ageratum conyzoides (Asteraceae) on Three Life Cycle Stages of the Parasitic Nematode Heligmosomoides bakeri (Nematoda: Heligmosomatidae)

A comparative in vitro study was carried out to determine the ovicidal and larvicidal activity of aqueous and ethanolic extracts of Ageratum conyzoides (Asteraceae) leaves on the eggs (unembryonated and embryonated), first and second larval stages of Heligmosomoides bakeri. Four different concentrations (0.625, 1.25, 2.5, and 3.75 mg·mL−1) of both aqueous and ethanolic extracts were tested. Distilled water and 5% tween were used as negative controls in the bioassay. In fact, they did not affect development of eggs, hatching, and larval survival. The extract activities were dose dependent. The ethanolic extract was more potent against embryonation (39.6 ± 2.9%) than the aqueous extract (53.3 ± 10.9%) at the highest concentration (3.75 mg·ml−1). Both types of extracts killed larvae. Mebendazole proved more lethal (EC50 of 0.745 and 0.323 mg·mL−1, resp., for L1 and L2 larvae). The aqueous extracts were the least lethal (EC50 of 4.76 and 2.29 mg·mL−1, resp., for L1 and L2 larvae). The ethanolic extracts showed intermediate activity (EC50 of 1.323 and 1.511 mg·mL−1, resp., for L1 and L2 larvae). It is concluded that the ovicidal and larvicidal properties of aqueous and ethanolic extracts of Ageratum conyzoides leaves are demonstrated in this work

In Vitro Sensitivity of Plasmodium falciparum Field Isolates to Methanolic and Aqueous Extracts of Cassia alata (Fabaceae)

International audienc

In vitro comparative effect of extracts of the seeds of Embelia rowlandii (Myrsinaceae) on the eggs and L1 and L2 larval stages of the parasitic nematode Heligmosomoides bakeri (Nematoda; Heligmosomatidae)

In vitro ovicidal and larvicidal activities of extracts of the seeds of Embelia rowlandii were investigated on unembryonated and embryonated eggs, first and second stage larvae of Heligmosomoides bakeri. Three different extracts were prepared with distilled water (DW) and 95% ethanol. The organic extract was first diluted with 3% Tween and then distilled water added to obtain five different concentrations (625, 1250, 2500, 3750 and 5000 μg/ml). These concentrations were put in contact with eggs and larvae of H. bakeri. One milliliter of each extract at different concentrations and controls were added to 1 ml solution containing 30 to 40 eggs or 10 to 15 larvae (L<sub>1</sub> and L<sub>2</sub> larvae) and distributed in different Petri dishes. Both eggs and larvae were incubated at 24°C and exposure time was 48 h for fresh (unembryonated) eggs, 6 h for embryonated eggs, 24 h for L<sub>1</sub> and L<sub>2</sub> larvae, respectively. Distilled water and 3% Tween were used as negative controls in the bioassay. These placebos neither affected egg development, hatching nor larval survival. A significant effect was obtained with cold water extract (CWE), hot water extract (HWE) and ethanolic extract (EtE) and differences were observed depending on the parasitic stage. CWE, HWE and EtE inhibited embryonic development (60.5, 82.5 and 46.9%) and hatching (85.8, 74.1 and 41.0%), respectively at 5000 μg/ml. All the three extracts killed both L<sub>1</sub> larvae (84.5, 86.0 and 61.2%) and L<sub>2</sub> larvae (65.2, 83.7 and 33.3%) respectively at 5000 μg/ml. These in vitro results suggest that extracts of E. rowlandii possess ovicidal and larvicidal properties.Keywords: Embelia rowlandii, Heligmosomoides bakeri, plant extractsAfrican Journal of Biotechnology Vol. 12(2), pp. 205-21

Impact of Plasmodial Parasitaemia on the Quality of Erythrocyte Concentrates Distributed at the Blood Transfusion Center of the Regional Hospital of Bafoussam-Cameroon

Background: Blood transfusion is a potential route for transmission of Plasmodium, which lives mainly in erythrocytes and can survive low temperatures. Therefore, this study was undertaken in order to determine the plasmodial  parasitaemia in labile blood products for the evaluation of the quality of erythrocyte concentrates (EC) distributed at the Blood Transfusion Center of the Bafoussam Regional Hospital. Material and methods: This was an analytical cross-sectional study carried out between March 15 and May 31, 2021 on 101 EC. The data collection was done on one hand by using a questionnaire and the technical sheet for the evaluation of the quality of the EC compared to the Cameroonian reference and on the other hand, by the analysis of the blood taken from the donors. This analysis was made through the examinations of RDT malaria, Thick blood smear, Thin blood smear, measurement of the hemoglobin level thanks to the HemoCue and hemogram using the Urit 3000 automaton. Data analysis was done using Epi info and SPSS software. Results: The prevalence of malaria among donors of the Bafoussam Regional Hospital Blood Bank was 4.41%. By considering the three parameters simultaneously, a compliance rate of 34.65% was obtained. A positive, although non-significant, correlation was established between plasmodial parasitaemia and EC quality. Conclusion: The importance of quality control of ECs is essential, sofar as the parasitaemia of plasmodial is not negligible with one bag of erythrocyte concentrate out of three non-compliant