The biological activities of essential oils from three plants grown in Cameroon: Ocimum basilicum, Ocimum canum, and Cymbopogon citratus were tested against Plasmodium falciparum and mature-stage larvae of Anopheles funestus. Gas chromatography and gas chromatography – mass spectrometry analyses showed that the main compounds are geranial, 1,8-cineole and linalool in C. citratus, O. canum and O. basilicum, respectively. Larvicidal tests carried out according to the protocol recommended by the World Health Organization showed that the essential oil of leaves of C. citratus is the most active against larvae of An. funestus (LC50 values = 35.5 ppm and 34.6 ppm, respectively, for larval stages III and IV after 6 h of exposure). Besides, the in vitro anti-plasmodial activity evaluated by the radioisotopic method showed that the C. citratus oil is the most active against P. falciparum, with an IC50 value of 4.2 ± 0.5 μg/mL compared with O. canum (20.6 ± 3.4 μg/mL) and O. basilicum (21 ± 4.6 μg/mL). These essential oils can be recommended for the development of natural biocides for fighting the larvae of malaria vectors and for the isolation of natural products with anti-malarial activity.

Malaria vectors control is essentially based on the use of insecticides against adult mosquitoes. However because of the development of resistance to insecticides, there is now a renewed interest in the management of larval sources. The aim of the present study was to map and characterize the breeding sites of Anopheles coluzzii in the Wouri river estuary in Cameroon. Larval surveys were carried out between December 2013 and August 2014 in rural areas on the island of Manoka and urban area in Youpwe at Douala. Culicidae breeding sites identified were georeferenced and mapped. Their larval productivity was evaluated by the method of "dipping" and their physicochemical parameters measured by spectrophotometry and oximetry. Culicidae collected larvae were reared in the insectarium to the adult stage. Adult mosquitoes were subjected to morphological identification and those belonging to the Anopheles gambiae complex have subsequently been subjected to molecular identification by the PCR-RFLP technique. A total of 240 breeding sites were geo-referenced in the two sites, including 10 types. Abandoned containers and pools were the most frequent breeding sites respectively in Manoka and in Youpwe. After morphological and molecular identification, eleven mosquito species have been identified. Anopheles coluzzii and Culex quinquefasciatus were the most frequent species respectively in Manoka and in Youpwe. Mosquito density was higher in managed gutters and canoes respectively in Manoka and in Youpwe. Culex and Aedes genus were more frequent in the hollow palm and water wells respectively in Manoka and Youpwe. The productivity of breeding sites varied according to the physicochemical parameters. Species richness varied according to the type of breeding site. Anopheles coluzzii was observed for the first time in Cameroon in water storage containers, tires, discarded containers and canoes. This study highlighted diversity in the type of breeding site of An. coluzzii in the Wouri estuary, suggesting the adaptation of this species in its environment. These results could be used to develop an antilarval control strategy in Manoka and in Youpwe.

Since the outbreak in December 2019, in Wuhan (China) of COVID-19, approved drugs are still lacking and the world is seeking effective treatment. The purpose of this article is to review the medicinal plants with potential to be used as complementary therapies against COVID-19. Bibliographic information was searched in several databases (Google Scholar, PubMed, Scopus, ScienceDirect, PROTA, ResearchGate and GLOBEinMED), to retrieve relevant papers on (1) plants used to manage common symptoms of COVID-19, (2) plant secondary metabolites with confirmed inhibitory effects on COVID-19 and (3) plants exhibiting pharmacological activities of relevance for COVID-19 management. A total of 230 species was recorded as potential source of ingredients for the fight against the 2019 novel corona virus. Of these species, 30 contain confirmed antiCOVID-19 secondary metabolites, 90 are used traditionally to manage at least 3 common symptoms of COVID-19, 10 have immunostimulant activity, 52 have anti-inflamatory activity, 14 have antiviral properties and 78 species are documented as used to treat malaria. A PCA analysis showing cluster formatting among the recorded species indicates 4 groups of species and an array of possibility of using individual species or a combination of species for their complementary effects. The authors argue that Cameroonian medicinal plants can be of potential contribution to the fight against COVID-19. Further applied research is needed to provide more scientific evidence for their efficacy, to establish standard formulations and clinical studies as part of efforts to develop therapies for COVID-19.

Introduction: Schistosomiasis is a neglected tropical disease with endemic foci in Cameroon. Epidemiological data on schistosomiasis in pregnancy are scarce in the country. This study describes the prevalence, diversity and factors associated with schistosomiasis in pregnant women in Njombe-Penja where schistosomiasis was first reported in 1968. Methodology: Two hundred and eighty-two (282) pregnant women were enrolled at first antenatal consultation between April and December 2016. A questionnaire was used to document socio-economic and obstetric information. Stool and terminal urine samples were collected and analysed using Kato-Katz/Formol-Ether concentration techniques and centrifugation methods respectively. Haemoglobin concentration was measured from finger prick blood, using an URIT®-12 electronic haemoglobinometer. Bivariate and logistic regression were used for statistical analyses with Epi-Info version 7.2.1.0. Statistical significance level was set at 0.05. Results: The overall prevalence of schistosomiasis was 31.91%. Schistosoma guineensis, S. haematobium and S. mansoni infections were found in 0.35% (n = 1), 4.96% (n = 14) and 28.01% (n = 79) of participants, respectively. Co-infection with two species of Schistosoma was found in 4.44% of these women. The prevalence of this disease was significantly higher in younger women (≤ 20 years old) and among residents of Njombe. All S. haematobium infected women were anemic and infection was associated with significantly lower haemoglobin levels (p = 0.02). Conclusion: The prevalence of schistosomiasis is high among pregnant women in Njombe-Penja, with some adverse effects on blood levels. Three Schistosoma species were found. Female of childbearing age should be considered for mass drug administration.

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