Ethnobotanical survey, anthelmintic effects and cytotoxicity of plants used for treatment of helminthiasis in the Central and Kara regions of Togo

In vitro nematocidal potential of hydro-ethanolic and aqueous extracts of Calotropis procera (Aiton) W.T. Aiton, 1811 (Apocynaceae) and Faidherbia albida (Delile) A. Chev., 1934 (Fabacae) against Onchocerca ochengi and Caenorhabditiselegans

Onchocerciasis caused by Onchocerca volvulus Leuckart, 1893 is the second-world infection responsible for human blindness. Except Ivermectin which has as targets the microfilariae of that parasite, specific treatment for this disease does not exist and in developing countries, medicinal plants seem to remedy that health problem. For that, aqueous and hydro-ethanolic leaf, bark, and root extracts of Calotropis procera and Faidherbia albida were evaluated in vitro, against the most popular bovine model, Onchocerca ochengi and the free-resistant nematode Caenorhabditis elegans. O. ochengi microfilariae and adults extracted from the bovine nodules and skins as well as the free strains of C. elegans were exposed to the various concentrations of the plant parts extracts and Ivermectin. In results, all the plant parts extracts were rich in tannins, saponins, alkaloids, flavonoids, phenols, coumarins, and glycosides. Phenols (175.45 ± 0.01 mg EGA/g DM), flavonoids (158.98 ± 0.05 mg EC/g DM), and tannins (89.98 ± 2.56 mg ETA/g DM) contents were high in the bark hydro-ethanolic extract of F. albida. The leaf hydro-ethanolic extract of F. albida induced high activity against O. ochengi microfilariae (CL₅₀ = 0.13 mg/mL). The bark hydro-ethanolic extract of F. albida was also the most effective on O. ochengi adults and particularly on female adults (CL₅₀ = 0.18 mg/mL). Against the parasite strain resistant to Ivermectin, F. albida leaf hydro-ethanolic extract appeared more active with CL₅₀ = 0.13 mg/mL. Similarly, the bark hydro-ethanolic extract of F. albida was the most potent on the wild strain of C. elegans. Thus, this study validates the use of these plants by traditional healers in the management of onchocerciasis and suggests a new source of isolation of the potential plant compounds against Onchocerca.

Ethnobotanical knowledge on native Brazilian medicinal plants traditionally used as anthelmintic agents - A review

Intestinal helminthiasis is a neglected disease that affects a significant portion of the global population, specifically in developing countries, where medicinal plants are widely used for therapeutic purposes. With the purpose to identify the native species used in traditional Brazilian medicine for the management of helminthiasis, ethnopharmacological books edited in Brazil documenting the folk use of medicinal plants were analyzed. The native species cited in at least three studies were selected, and bibliographic research was performed using electronic databases to identify their scientifically validated anthelmintic properties. The search retrieved 133 native species belonging to 88 genera and 43 families from all six Brazilian biomes. Fabaceae (14 Genera and 25 Species) and Asteraceae (7 Genera and 8 Species) were the most frequently cited families. The most reported native species were Baccharis crispa Spreng., Hymenaea courbaril L., Senna occidentalis (L.) Link, Carapa guianensis Aubl., Stachytarpheta cayennensis (Rich.) Vahl, Annona glabra L., Hymenaea stigonocarpa Mart. ex Hayne, Spigelia anthelmia L., Simarouba versicolor A.St.-Hil. and Anacardium occidentale L. Bark (19%) and leaves (17%) were the most commonly used plant parts, and decoction (27%) was the most preferred method of preparation. Evidence of the anthelmintic properties of most species was confirmed using in vitro assays for key human and animal parasites, including Haemonchus contortus, Hymenolepis diminuta, Schistosoma mansoni and Trichostrongylus spp. The species S. alata, S. occidentalis, A. occidentale, and S. anthelmia have been the subject of many biological studies, supporting their use as vermicides. The overall results obtained in this review revealed that Brazil is rich in traditional herbal medicines used to manage helminthiasis; however pharmacological investigations are lacking to confirm their therapeutic properties. Thus, this study could serve as a baseline to validate their use and encourage further clinical investigation of their vermifuge potential.

Mixed methods research in complementary and alternative medicine: a scoping review

OBJECTIVE

To update the current characteristics about the scope and quality of mixed methods research (MMR) in complementary and alternative medicine (CAM) after nearly 10 years.

METHODS

A 5-stage approach for conducting a scoping review was adopted. Articles published on the top 10 journals in CAM with the highest impact factor in 2020 were screened for MMR. Information of included articles were extracted, and then synthesized to illustrate the current state. Methodological quality was evaluated according to the Mixed Method Appraisal Tool (MMAT) 2018 version.

RESULTS

A total of 55 (55/2991, 2%) articles using mixed methods were retrieved, including 17 medical studies and 38 ethnobotanical studies. We performed an in-depth analysis on the 17 medical studies, which studied cancer, stress, pain, fatigue, exercises, mindfulness intervention, herbal medicine use, art and acupuncture. Thirteen pilot studies applied MMR to evaluate the feasibility of interventions or programs (13/17, 76%); phenomenology was inferred as the most common philosophical assumptions (13/17, 76%); the most applied type of MMR was convergent design (16/17, 94%); integration often took place at integration (12/17, 71%). Among the 16 eligible studies for quality appraisal, majority were rated as good (14/16, 88%), whereas two studies were rated as poorly described. Primarily, a poor rating was due to incomplete reporting of data analysis and citations in qualitative components; lack of confounder controlling and the sampling strategy in quantitative components; poor description of integration and justification for mixed methods. Comparing with the previous review, fewer MMR were published in 2020 in CAM, but the proportion of studies that clearly reported MMR has increased by 4 times (4%→15%).

CONCLUSION

CAM researchers need to realize the benefits that MMR can have on conducting further health care research. Our findings highlight that applying MMR will be helpful to understand the complex dynamics and interdisciplinary nature of complex intervention. In addition, addressing a standardized reporting criteria for MMR is recommended.

Anti-Th17 and anti-Th2 responses effects of hydro-ethanolic extracts of Aframomum melegueta, Khaya senegalensis and Xylopia aethiopica in hyperreactive onchocerciasis individuals’ peripheral blood mononuclear cells

Hyperreactive onchocerciasis (HO) is characterized by a severe skin inflammation with elevated Th17-Th2 combined responses. We previously demonstrated the anthelminthic activity of Aframomum melegueta (AM), Xylopia aethiopica (XA) and Khaya senegalensis (KS) used by traditional healers to treat helminthiasis in the endemic area of Togo. However, their effect on severe onchocerciasis is poorly investigated. The present study aimed to investigate the anti-Th17 and anti-Th2 effects of hydro-ethanolic extracts of AM, XA and KS during HO. Onchocerca volvulus-infected individuals were recruited in the Central region of Togo in 2018. Isolated peripheral blood mononuclear cells (PBMCs) from both generalized onchocerciasis (GEO) and HO forms were activated with anti-CD3 and anti-CD28 monoclonal antibodies in the presence or absence of the hydro-ethanolic extracts of AM, XA and KS as well as their delipidated, deproteinized and deglycosylated fractions. After 72 hours, cytokines were assayed from cell culture supernatants. Then, flow cytometry was used to investigate the effects of the extracts on cell activation, proliferation, intracellular cytokines and T cells transcription factors. The production of both Th17 and Th2 cytokines IL-17A and IL-5 were significantly inhibited upon T-cell receptor (TCR) activation in the presence of the hydro-ethanolic extracts of AM, XA and KS in HO individuals’ PBMCs in vitro. AM and XA inhibited CD4⁺RORC2⁺IL-17A⁺ and CD4⁺GATA3⁺IL-4⁺ cell populations induction. This inhibition was not Th1 nor Treg-dependent since both IFN-γ and IL-10 were also inhibited by the extracts. AM and XA did not interfere with T cell activation and proliferation for their inhibitory pathways. Lipid and protein compounds from AM and XA were associated with the inhibition of IL-17A. This study showed that in addition to their anthelminthic effects, hydro-ethanolic extracts of Aframomum melegueta, Xylopia aethiopica and Khaya senegalensis could downregulate both Th17 and Th2 responses and prevent the severe skin disorder observed.

Severe form of human onchocerciasis also called hyperreactive onchocerciasis (HO) is characterized by skin disorders such as dermatitis. Our previous study showed that concomitant Th2 and Th17 responses play a role in the pathophysiology of the disease. In Onchocerca volvulus endemic areas such as Togo, traditional healers (TH) used to treat this disease with medicinal plants such as Aframomum melegueta (AM), Xylopia aethiopica (XA) and Khaya senegalensis (KS). Mass drug administration including ivermectin and albendazole has been used over the past decade to control and eradicate helminths infections. Despite its successes, resistance to ivermectin has been reported and therefore, alternative drugs are urgently needed. We previously confirmed in vitro the anthelminthic effects of Aframomum melegueta (AM), Xylopia aethiopica (XA) and Khaya senegalensis (KS). However, their effect on severe onchocerciasis has not been demonstrated. Here, the anti-Th17 and anti-Th2 effects of hydro-ethanolic extracts of AM, XA and KS during HO were investigated. The data showed that in addition to their helminth-killing effects, plant-derived molecules AM, XA and KS downregulated Th2 and Th17 profiles and therefore, could be candidates for the development of new drugs not only for the treatment of helminth-induced inflammatory pathologies but also auto-immune Th2/Th17-dependent inflammatory diseases in general.

Ethnopharmacological evaluation of antioxidant, anti-angiogenic, and anti-inflammatory activity of some traditional medicinal plants used for treatment of cancer in Togo/Africa

ETHNOPHARMACOLOGICAL RELEVANCE

Cancer is a multistep disease and its management is exceedingly expensive. Nowadays medicinal plants are gaining more attention in drug discovery and approximately 70% of anticancer drugs were developed from natural products or plants. A strong candidate from medicinal plant with anticancer potential should have four major properties: antioxidant, anti-inflammatory, anti-angiogenic, and cytotoxic activities.

AIM OF THE STUDY

In order to assess Togolese traditional healer's claims about the anticancer potential of medicinal plants and obtain candidate plants for anticancer drug discovery, some species were selected from surveys and evaluated for their antioxidant, anti-inflammatory, anti-angiogenic and cytotoxic activities.

METHODS

Four species, Cochlospermum planchonii (CP), Piliostigma thonningii (PT), Paullinia pinnata (PP), and Securidaca longipedunculata (SL) were selected and analyzed to detect the phytochemical components. The mentioned bioactivities were evaluated using in vitro, ex vivo and in vivo assays.

RESULTS

Relative to SL extract, CP and PT have shown significantly high polyphenols and flavonoids content. The DPPH, FRAP, and TAC of the extracts revealed that CP, PT, and PP have a potent antioxidant effect compared to SL. MDA analysis revealed the same antioxidant activity as CP, PT and PP showed a minor MDA level. The egg albumin denaturation assay showed that IC50 of CP and PP was significantly higher than control (P < 0.05). In contrast, the Bovine Serum Albumin (BSA) results showed a nonsignificant effect (P > 0.05). Notably, SL extract was nonsignificant to control in both Egg Albumin and BSA. Furthermore, angiogenesis assay showed that SL at 50 μg/ml and PP at 100 μg/ml effectively reduced the number of blood vessels than control and showed a potent anti-angiogenic effect (2.7-fold and 2.5-fold, respectively, P < 0.05). No cytotoxicity on PBMC was reported for CP, PP, and PT up to 1000 μg/ml, whereas SL at 1000 μg/ml exhibit benign cytotoxicity (P < 0.0001).

CONCLUSION

This study provided in vitro evidence supporting further evaluation on cancer cell lines and tumors in vivo.