Human onchocerciasis is caused by the filarial worm. Onchocerca volvulus is a parasite that forms nodules under the skin. The aim of this work was to assess the nematicidal activities of Aloe vera on Onchocerca ochengi and Caenorahbditis elegans and to determine the phytochemical compounds. Nodules were collected from the umbilical region of infected cattle, dissected and male worms were cultured in RPMI-1640. Worms were incubated with different concentrations of A. vera extracts in RPMI-1640 and M9-buffer. Polyphenol, tannin and flavonoid contents of extract were determined by using gallic acid and rutin as standards. The anthelmintic effect of A. vera extract against O. ochengi was concentration dependent with LC50 of 20.71 µg/mL and 11.75 µg/mL after 48 and 72 h respectively. A. vera extract exerted concentration dependent lethal effects (LC50 = 2747 and LC50 = 31,937 µg/mL) against C. elegans (Wild Type). Methanolic-methylene chloride (MeOH–CH2Cl2) of A. vera extract exhibited high DPPH activity with an IC50 value of 15 µg/mL and 9 µg/mL for ascorbic acid. The highest activity in adult worms was observed with the MeOH (100: 0) and AcOEtMeOH fractions with LC50 values of 12.82 and 15.50 µg/mL respectively. EcOEtMeOH (8:2 v/v) was more effective (LC50 = 250 µg/mL) on WT of C. elegans. A. vera contains polyphenols (1015.05 and AcOEtMeOH = 893.60), flavonoids (25.35 and MeOH = 225.76) and tannins (401.37 and Hex = 788.89). A. vera showed in vitro nematicidal activity against O. ochengi and C. elegans. A. vera could be used as an alternative anthelmintic for onchocerciasis treatment.

Background Human onchocerciasis caused by the filarial worm, Onchocerca volvulus is a parasitic that forms nodules under the skin. In the developing countries, it has been estimated that more than 80% of the population rely on traditional medicines for their primary healthcare needs. The aim of this work was to assess the nematicidal activities of Aloe vera on Onchocerca ochengi and Caenorahbditis elegans and to determine the phytochemical compounds. Methods Nodules were collected from the umbilical region of infected cattle, dissected and male worms were cultured in RPMI-1640. Worms were incubated for 48 h and 72 h with different concentrations of A. vera extracts in RPMI-1640 and M9-buffer. Polyphenol, tannin and flavonoid contents of extract were determined by using gallic acid and rutin as standards. The antioxidant activity was evaluated by DPPH radical scavenging method. Results The anthelmintic effect of A. vera extract against O. ochengi was concentration dependent with LC 50 of 20.71 µg/mL and 11.75 µg/mL after 48 and 72h respectively. A. vera extract exerted concentration dependent lethal effects (LC 50 = 2747 and LC 50 = 1937 µg/mL) against C. elegans (WT). MeOH-CH 2 Cl 2 of A. vera extract exhibited high DPPH activity with an IC 50 value of 15 µg/mL and 9 µg/mL for ascorbic acid. The highest activity in adult worms was observed with the MeOH (100: 0) and AcOEtMeOH fractions with LC 50 values of 12.82 and 15.50 µg/mL respectively. EcOEtMeOH (8:2 v/v) was more effective (LC 50 = 250 µg/mL) on WT C. elegans. A. vera contains polyphenols (1015.05 and AcOEtMeOH = 893.60), flavonoids (25.35 and MeOH = 225.76) and tannins (401.37 and Hex = 788.89). Conclusions A. vera showed in vitro nematicidal activity against O. ochengi and C. elegans . Aloe vera could be used as alternative anthelmintic for onchocerciasis treatment.

Meloidogyne represent a genus of plant-parasitic nematode. This nematode is serious crop pests, including tomatoes and is widespread in almost all regions of the world. Very little attention has been paid to these parasites in Cameroon and none in the agro-ecological zone of the Guinean high savannah. We therefore undertook this study to identify and assess the density of this nematode in this area. For this study, a total of 30 root samples were collected in tomatoes production areas from 4 districts and females Meloidogyne were isolated and counted. Specific identification was done by Polymerase Chain Reaction (PCR) using the markers C2F3/1108 and COX1. The genus Meloidogyne was thus identified in the 30 production basin sites of this zone. High densities of Meloidogyne were observed in 18 sites, with an average density of between 21-50 females per gram of fresh root. In contrast, low densities were noted at 12 sites with values between 6 and 19 females per gram of root. However, this distribution is function of the cropping period, soil texture, pH, organic matter content, soil saturation rate, and cropping practices (host or non-host plants and fallow practice). Electrophoretic profiles of Deoxyribonucleic Acid (DNA) amplified with C2F3/1108 and COX1 primers showed corresponding migrations at 1700 bp, 1100 bp and 421 bp characteristic of the presence of M. incognita/M. javanica, M. arenaria and M. incognita/M. hapla in this agro-ecological zone. In view of these results, which provide information on the distribution of Meloidogyne in this area, it seems necessary for producers to develop management strategies by improving preventive techniques and by piloting technical and cultural itineraries for the control of this plant pest.

The anthelmintic activity of ethanolic, methanolic and methanolic/methylene chloride extracts of leaves stem bark and root bark of Ficus sycomorus was assessed in vitro by using the cattle parasite nematode Onchocerca ochengi and Caenorhabditis elegans. Extracts were diluted to different concentrations in 0,5 % DMSO in the presence of parasites and incubated at 37 ° C. The anthelminthic activity was observed in terms of number of live worms after 72 h of incubation. The methanolic/methylene chloride and methanolic extracts of leaves and roots bark showed higher activity on O. ochengi with LC50 values 0,45 µg/ml, 0,65 µg/ml and 0,22 µg/ml; 0,62 µg/ml, 0,55 µg/ml, 0,40 µg/ml respectively. Lower activity was observed with ethanolic extract of stem bark. LC50 values were 17,5 µg/ml, 12,5 µg/ml and 30 µg/ml respectively for leaves, roots bark and stem barks after 72 h of incubation. The wild strain WT of Caenorhabditis elegans was sensitive with the methanolic extracts of the leaves of Ficus sycomorus and CB3474 (ben-1 (e1880) was not sensitive in the presence of the methanolic extracts of the stem bark of Ficus sycomorus with the LC50 values 239.16 µg/ml and 872.13 µg/ml respectively.Tests with ivermectin have shown high effeciency on Onchocerca ochengi with LC50 value of 1 µg/ml. These results confirmed the efficiency and the use of Ficus sycomorus against nematode infections by traditional healers, herdsmen and pastoralists. According to our data, extracts of plant could be used as an alternative to fight Human and Bovine onchocerciasis.

Onchocerciasis is a filarial disease caused by Onchocerca volvulus and transmitted through the bite of a blackfly of the genus Simulium. The microfilaricidal drug ivermectin has long been relied on to treat onchocerciasis. Nowadays, the focus is on the complete elimination of the disease through the development of macrofilaricidal drugs. In this study, a hydro-alcoholic extract from Annona senegalensis leaves was screened for micro- and macrofilaricidal activities against the cattle parasitic nematode Onchocerca ochengi and the freeliving nematode Caenorhabditis elegans, both model organisms. Worms were assessed by in vitro motility/ mortality assay studies and incubated with the various natural products and their effects on mortality were monitored after 48 h. The crude extract showed high activity with LC50 = 1450.2 mg/mL on the young adult of C. elegans wild type and 19.63 mg/mL on adult males of O. ochengi after 48 h post-exposure. The compounds, Quercetin-3-O-glucoside, (+)-Catechin, (-)-Epicatechin, Rutin and AS14.5, displayed LC50 of 179.3, 840.5, 1270.3, 118.2 and 129.7 mg/mL on C. elegans wild type (young adult), respectively, and 7.3, 17.5, 12.6, 6.6 and 11.5 mu g/mL on O. ochengi (adult males), respectively, after 48 h. These data support the use of Annona senegalensis for the treatment of infections caused by Onchocerca volvulus. (C) 2020 SAAB. Published by Elsevier B.V. All rights reserved.

The front line molecules from filarial worms and other nematodes or helminthes are their Excretory-Secretory (ES) products. Their interaction with the host cells, proteins and immune system accounts for the skin and eye pathology or hyposensitivity observed in human onchocerciasis. ES products and adult worms’ crude extracts from Onchocerca ochengi, a filarial nematode that infects the African zebu cattle, were utilized in the present study as a model for studying Onchocerca volvulus that causes river blindness in man.

One of the strategies for developing novel pharmaceutical drugs is to use natural sources such as plants for therapeutic treatment. Plant extracts are a cocktail of compounds which act synergically and can improve treatment effectiveness, reduce therapeutic duration and resistance. The ethanolic extracts of leaves and seeds of Cucurbita pepo ovifera var ovifera from Sudano-Guinean and Sudano-Sahelian zones of Cameroon were evaluated on the cattle parasite nematode Onchocerca ochengi. Worms were incubated with different concentrations of the plant extracts in RPMI-1640 supplemented with streptomycin and gentamicin. Mortality at 37 degrees C was monitored after 24, 48 and 72 h. Ivermectin was used as positive control and DMSO as negative. Plant extracts from the two ecological zones showed anthelminthic activities on O. ochengi after 72 h with LC50 varying from 20 to 1090 mu g /mL. The highest antifilarial activity in Sudano-Guinean zone was obtained with leave extract of C. pepo ovifera (LC50 of 20 mu g/mL), while highest antifilarial activity in Sudano-Sahelian zone was obtained with seed extracts of the plant with LC50 value of 17 mu g/mL after 72 h. These results show that anthelmintic activity depends on the part of the plant and the ecological zones. Additionally, the plant is not toxic. These results on the ethanolic extracts of leaves and seeds of C. pepo ovifera var ovifera confirmed the use of this plant in traditional medicine in Cameroon to treat disease due to nematodes. The plants could be used as alternative anthelmintic to fight against Human and Bovine onchocerciasis.

Acacia nilotica fruits with high tannin content are used in the northern parts of Cameroon as anti-filarial remedies by traditional healers. In this study, the hydro-alcoholic fruit extract (crude extract (CE)) and, one of the main constituents in its most active fractions, (+)-catechin-3-O-gallate (CG), as well as four related proanthocyanidins, (−)-epicatechin-3-O-gallate (ECG), (+)-gallocatechin (GC), (−)-epigallocatechin (EGC) and (−)-epigallocatechin-3-O-gallate (EGCG), were assessed for their potential in vitro anthelmintic properties against the free-living model organism Caenorhabditis elegans and against the cattle filarial parasite Onchocerca ochengi. Worms were incubated in the presence of different concentrations of fruit extract, fractions and pure compounds. The effects on mortality were monitored after 48 h. The plant extract and all of the pure tested compounds were active against O. ochengi (LC50 ranging from 1.2 to 11.5 µg/mL on males) and C. elegans (LC50 ranging from 33.8 to 350 µg/mL on wild type). While high LC50 were required for the effects of the compounds on C. elegans, very low LC50 were required against O. ochengi. Importantly, tests for acute oral toxicity (lowest dose: 10 mg/kg) in Wistar rats demonstrated that crude extract and pure compounds were non-toxic and safe to use. Additionally, the results of cytotoxicity tests with the Caco-2 cell line (CC50 ranging from 47.1 to 93.2 µg/mL) confirmed the absence of significant toxicity of the crude extract and pure compounds. These results are in good accordance with the use of A. nilotica against nematode infections by traditional healers, herdsmen and pastoralists in Cameroon.

Onchocerciasis is one of the tropical neglected diseases (NTDs) caused by the nematode Onchocerca volvulus. Control strategies currently in use rely on mass administration of ivermectin, which has marked activity against microfilariae. Furthermore, the development of resistance to ivermectin was observed. Since vaccine and safe macrofilaricidal treatment against onchocerciasis are still lacking, there is an urgent need to discover novel drugs. This study was undertaken to investigate the anthelmintic activity of Lophira lanceolata on the cattle parasite Onchocerca ochengi and the anthelmintic drug resistant strains of the free living nematode Caenorhabditis elegans and to determine the phytochemical profiles of the extracts and fractions of the plants.