First ethnobotanical inventory and phytochemical analysis of plant species used by indigenous people living in the Maromizaha forest, Madagascar

Dysphania ambrosioides (L.) Mosyakin and Clemants: bridging traditional knowledge, photochemistry, preclinical investigations, and toxicological validation for health benefits

Dysphania ambrosioides L. (Chenopodiaceae) is a Moroccan medicinal plant known locally as "M'Khinza." It is widely used in traditional medicine to treat numerous ailments, such as diabetes, digestive disorders, fever, fertility problems, immune disorders, hypertension, bronchitis, respiratory conditions, pharyngitis, cough, and flu. As part of this review, comprehensive preclinical investigations, including in vitro, in vivo, and in silico studies, were conducted to better understand the mechanisms of action of D. ambrosioides. Additionally, the phytochemical profile of the plant was examined, highlighting the presence of certain bioactive secondary metabolites. The information was gathered from electronic data sources such as Web of Science, PubMed, Science Direct, Scopus, Springer Link, and Google Scholars. Numerous studies have mentioned the pharmacological properties of D. ambrosioides, including its antioxidant, anti-inflammatory, antiparasitic, antiviral, antibacterial, and antifungal activities. Furthermore, research has also suggested its potential as an anticancer, antidiabetic, and vasorelaxant agent. Phytochemical characterization of D. ambrosioides has revealed the presence of over 96 major bioactive compounds, including terpenoids, polyphenols, flavonoids, alkaloids, and fatty acids. As for the toxicity of this plant, it is dose-dependent. Furthermore, more in-depth pharmacological studies are needed to establish the mechanisms of action of this plant more accurately before considering clinical trials. In conclusion, this review highlights the traditional use of D. ambrosioides in Moroccan medicine and emphasizes its potential pharmacological properties. However, to fully harness its therapeutic potential, further research, both in terms of chemistry and pharmacology, is necessary. These future studies could help identify new active compounds and provide a better understanding of the mechanisms of action of this plant, thus opening new prospects for its pharmaceutical application.

Fungal Patterns from Soils in Madagascar: an Insight from Maromizaha Forest (Evergreen Humid Forest) to Outside (Deciduous Forest)

Soil fungal diversity was studied by next-generation sequencing and compared in two different Malagasy ecosystems, the first a New Protected Area (Maromizaha NAP) that is a rich humid evergreen forest and the second a degraded and declined deciduous forest (Andaravina) whose area has been also eroded. Both areas, however, have comparable annual rainfalls and soil pH values. So it was of interest to examine the soil fungal diversity in each system and compare them. We detected 1,817,658 reads representing Ascomycota, which were dominant in both habitats (55.9%), followed by unidentified fungi (21.5%), Basidiomycota (12.7%) and Mortierellomycota (6.7%), with Mucoromycota, Chytridiomycota, Glomeromycota and other phyla accounting for less than 5% in total. In detail, 1,142 OTUs out of 1,368 constitute the common core shared by both sampling areas, which are characterized by tropical climate, whereas 185 are Maromizaha specific and 41 Andaravina specific. The most represented guilds involve fungi related to saprotrophic behaviour, with a greater tendency towards pathotrophic mode. A significant variability in terms of richness and abundance is present within Maromizaha, which is a heterogeneous environment for fungi but also for plant composition, as it emerged from the vegetational survey of the investigated sites. A few fungal sequences match taxa from Madagascar, highlighting the scarce representativeness of fungi from this island in the fungal databases and their still low knowledge. Enlarging studies in Madagascar will help not only to unravel its largely unknown fungal biodiversity but also to give a contribution for studies on the reconstruction of the diversity of soil fungi worldwide.

Antiviral Effect of Stenocline ericoides DC. and Stenocline inuloides DC., Two Flavonoid-Rich Endemic Plants from Madagascar, against Dengue and Zika Viruses

Dengue and Zika viruses are identified as the most medically important arthropod-borne viral pathogens. Over the past 20 years, the global dengue incidence has dramatically increased with epidemics of severe dengue where the case fatality rate can reach up to 20% in untreated patients. The association between Zika virus infection and severe congenital anomalies was first reported in 2015. Today no specific antiviral therapies are available for dengue and Zika virus infections, accentuating the need of adapted antiviral strategies based on medicinal plant drug discovery. Plants are a potential source of antiviral phytocompounds which act primarily by blocking virus entry in the host-cell. In the present study, we evaluated whether crude extracts from Stenocline ericoides DC. and Stenocline inuloides DC., two endemic plants from Madagascar, may have antiviral effects against dengue and Zika viruses. We showed that S. ericoides has virucidal action whereas S. inuloides inhibits the early steps of virus infection with a non-cytotoxic effect in human cells. The administration of S. ericoides and S. inuloides extracts in zebrafish had no effect on the behavior of animals at the active doses against dengue and Zika viruses, suggesting the absence of adverse effects at these doses. LC-HRMS² and molecular networking analyses revealed the richness of these two plants in polyphenols and flavonoid with the presence of clusters of phytocompounds specific to each Stenocline species. Consequently, S. ericoides and S. inuloides represent potential sources for natural and safe antiviral phytocompounds against flaviviruses of medical concern.

Finding food in the hunger season: A mixed methods approach to understanding wild plant foods in relation to food security and dietary diversity in southeastern Madagascar

In many rural farming societies, wild plant foods (WPFs) continue to play an important role in everyday diets as well as in coping with hunger during food shortages. However, WPF collection and consumption may pose challenges to biodiversity conservation efforts (e.g., in protected areas), and some “famine foods,” foods not typically eaten under normal conditions, may have deleterious health impacts. Using data from a cross-sectional survey of 328 smallholder farmers and fisherfolk living in 15 villages surrounding Manombo Special Reserve on the southeastern coast of Madagascar, we examine the relationship between food security, dietary diversity, and consumption of WPFs, specifically giant aquatic arrowhead or via (Typhonodorum lindleyanum) and Polynesian arrowroot or tavolo (Tacca leontopetaloides), during the region's main lean season. We complement survey findings with focus group interviews to document traditional ecological knowledge and perceptions of these WPFs, including how tavolo and via are rendered edible, as well as human health effects from collecting, preparing, and eating them. Using multilevel logistic regression modeling, we found that consumption of these WPFs were significantly associated with inadequate nutrition among farmers. Wealthier households were less likely to consume these WPFs as a coping strategy during food insecure periods, while larger and more food insecure households were more likely to consume them. These findings reaffirm the importance of access to natural areas and support the design of protected area conservation strategies that honor local foodways and consider WPFs that serve as food safety nets for more vulnerable populations.

Structural Investigation of the Interaction Mechanism between Chlorogenic Acid and AMPA Receptor via In Silico Approaches

Chlorogenic acid (CGA), an important metabolite in natural plant medicines such as honeysuckle and eucommia, has been shown to have potent antinociceptive effects. Nevertheless, the mechanism by which CGA relieves chronic pain remains unclear. α-amino-3-hydroxy-5-methyl-4-isooxazolpropionic acid receptor (AMPAR) is a major ionotropic glutamate receptor that mediates rapid excitatory synaptic transmission and its glutamate ionotropic receptor AMPA type subunit 1 (GluA1) plays a key role in nociceptive transmission. In this study, we used Western blot, surface plasmon resonance (SPR) assay, and the molecular simulation technologies to investigate the mechanism of interaction between CGA and AMPAR to relieve chronic pain. Our results indicate that the protein expression level of GluA1 showed a dependent decrease as the concentration of CGA increased (0, 50, 100, and 200 μM). The SPR assay demonstrates that CGA can directly bind to GluA1 (K_D = 496 μM). Furthermore, CGA forms a stable binding interaction with GluA1, which is validated by molecular dynamics (MD) simulation. The binding free energy between CGA and GluA1 is -39.803 ± 14.772 kJ/mol, where van der Waals interaction and electrostatic interaction are the major contributors to the GluA1-CGA binding, and the key residues are identified (Val-32, Glu-33, Ala-36, Glu-37, Leu-48), which play a crucial role in the binding interaction. This study first reveals the structural basis of the stable interaction between CGA and GluA1 to form a binding complex for the relief of chronic pain. The research provides the structural basis to understand the treatment of chronic pain and is valuable to the design of novel drug molecules in the future.

Ethnopharmacological Study of Medicinal Plants Used for the Treatment of Cardiovascular Diseases and Their Associated Risk Factors in sub-Saharan Africa

Cardiovascular diseases (CVDs) are the leading cause of global mortality, including deaths arising from non-communicable diseases in sub-Saharan Africa (SSA). Consequently, this study aimed to provide details of medicinal plants (MPs) employed in SSA for the treatment of CVDs and their related risk factors to open new avenues for the discovery of novel drugs. The extensive ethnopharmacological literature survey of these MPs in 41 SSA countries was based on studies from 1982 to 2021. It revealed 1,085 MPs belonging to 218 botanical families, with Fabaceae (9.61%), Asteraceae (6.77%), Apocynaceae (3.93%), Lamiaceae (3.75%), and Rubiaceae (3.66%) being the most represented. Meanwhile, Allium sativum L., Persea americana Mill., Moringa oleifera Lam., Mangifera indica L., and Allium cepa L. are the five most utilised plant species. The preferred plant parts include the leaves (36%), roots (21%), barks (14%), fruits (7%), and seeds (5%), which are mostly prepared by decoction. Benin, Mauritius, Nigeria, South Africa, and Togo had the highest reported use while most of the investigations were on diabetes and hypertension. Despite the nutraceutical advantages of some of these MPs, their general toxicity potential calls for caution in their human long-term use. Overall, the study established the need for governments of SSA countries to validate the efficacy/safety of these MPs as well as provide affordable, accessible, and improved modern healthcare services.

The relevance of quantitative ethnobotanical indices for ethnopharmacology and ethnobotany

ETHNOPHARMACOLOGICAL RELEVANCE

As an interdisciplinary field of research ethnopharmacology draws on methodologies and methods from a variety of disciplines. A range of ethnobotanical indices are frequently used to transform primary data obtained through field studies into statistical measures. These indices are claimed to serve as a proxy for efficacy or drug discovery (Fidelity Level 'FL') and to show the importance of botanical drugs and plants used as medicines (Relative Importance 'RI', Use Value 'UV' or Cultural Importance Index 'CI', Cultural Value Index 'CV', Relative Frequency of Citation 'RFC'). This is, however, doubtful, as these indices have not been developed by statisticians, nor by pharmacologists while a proof of concept is lacking. Moreover, the question whether a simple number can summarize the cultural value or importance of plants is not only mathematical but also epistemological.

MATERIAL AND METHODS

The FL, RI, UV/CI, CV and the RFC are shortly reviewed. Their statistical rigour is explained and the relevance for ethnobotany, ethnopharmacology and drug discovery discussed.

RESULTS

The effect of the sample size on the dispersal of data and the differential probability of botanical drugs being used for the different categories of use are not being considered by these indices. They lack statistical rigour and are simple percentage calculations. Moreover, important factors influencing plant use, such as the availability of pharmaceutical drugs, or the severity of diseases covered by the use-categories, are not accounted for.

CONCLUSION

Especially unexperienced and young researchers may be ensnared by using ethnobotanical indices to describe their field data. However, the cultural value and importance of plants in general, and more specifically, of medicinal plants and botanical drugs cannot be summed up by numbers. The discussed indices encrypt parts of the primary data but fail to show the value or importance of plant use because the reasons for which plants are valued or important to people are far more complex than what the formulations of these indices suggest. The indices also lack the power to pinpoint plant species or botanical drugs for drug discovery that contextualized primary data has. Botanical drugs may be useful for a range of disorders or only for specific indications, according to their pharmacologic properties. Therefore, the exclusiveness of therapeutical applications (FL) does not serve as a proxy for effectiveness. The solution is to use and understand the contextualized primary data.

Ethnomedical uses, chemical constituents, and evidence-based pharmacological properties of Chenopodium ambrosioides L.: extensive overview

Background

The Chenopodium genus is a plant family widely spread worldwide that includes various plant species reputed to possess several medicinal virtues in folk medicines. Chenopodium ambrosioides L. is among the most used plants in traditional medicines worldwide. This review aimed to highlight ethnomedicinal uses, phytochemical status, and pharmacological properties of C. ambrosioides L.

Main body of the abstract

The analysis of relevant data highlights various ethnomedicinal uses against human and veterinary diseases in forty countries. Most indications consisted of gastrointestinal tract dysfunctioning troubles and worms parasitemia. Around 330 chemical compounds have been identified in different plant parts, especially in its essential oil fractions (59.84%). However, only a few compounds—mainly monoterpenes and glycosides—have been isolated and characterized. Experimental pharmacological studies validated a large scale of significant health benefits. It appeared that many monoterpenes are antioxidant, insecticidal, trypanocidal, analgesic, antifungal, anti-inflammatory, anti-arthritic, acaricidal, amoebicidal, anthelmintic, anticancer, antibacterial, antidiabetic, antidiarrheal, antifertility, antifungal, anti-leishmanial, antimalarial, antipyretic, antisickling, antischistosomal, antiulcer, anxiolytic, immunomodulatory, molluscicidal, and vasorelaxant agents.

Short conclusion

Thus, the Chenopodium ambrosioides species necessitates further chemical studies to isolate and characterize new bioactive secondary metabolites and pharmacological investigations to precise the mechanisms of action before clinical trials.

Traditional Foods and Sustainable Rural Development: Exploiting the Case of the Comoros Tea as a Potential Source of Bioactive Compounds

Although modern medicine is available in many developing countries, such as the Comoros Islands, the primary health-care needs of the local population are based on traditional foods and beverages derived from natural resources and medicinal plants for cultural and historical reasons. Aphloia theiformis (Vahl) Benn. (‘Mfandrabo’), Cinnamomum verum J.Presl (‘Mani yamdrara’), Ocimum gratissimum L. (‘Roulé’), Plectranthus amboinicus (Lour.) Spreng. (‘Ynadombwe’), Cymbopogon nardus (L.) Rendle (‘Sandze monach’) and Ocimum americanum L. (‘Kandza’) are six wild plants that are largely utilised to treat many diseases. The leaves of these plants are used in the traditional Comorian tea (aqueous infusion). This study aimed to identify and quantify the main health-promoting compounds in the traditional formulation of Comorian tea by HPLC profiling together with a preliminary assessment of antioxidant capacity to confirm the traditional use of these plants by the local population. The single plants were also studied. The Comoros tea presented a total polyphenolic content (TPC) of 4511.50 ± 74.41 mgGAE/100 g DW, a value higher than the TPCs of the different plants included in the Comorian tea. Moreover, the Comorian tea showed an antioxidant capacity (AOC) of 578.65 ± 6.48 mmol Fe2+/Kg DW, a value higher if compared to all the AOC values obtained in the single plants. The polyphenolic fraction (771.37 ± 35.76 mg/100 g DW) and organic acids (981.40 ± 38.38 mg/100 g DW) were the most important phytochemical classes in the Comorian tea (40.68% and 51.75% of the total phytocomplex, respectively), followed by the monoterpenes (5.88%) and vitamin C (1.67%), while carotenoids were detected in trace (0.02%). The Comorian tea could be important in meeting the high demand in the Comoros Islands and other developing countries for cost-effective and natural health-promoting foods and/or beverages to be produced by agri-food industries and used by the local population. This study may promote traditional foods in rural communities in the Comoros Islands and contribute to sustainable rural development and a commercial valorisation of these plants for health-promoting and food applications.

Connaraceae: An updated overview of research and the pharmacological potential of 39 species

ETHNOPHARMACOLOGICAL RELEVANCE

An interdisciplinary scientific investigation of biologically active agents is fundamental to search for natural substances with therapeutic action. This review collected the most relevant information on traditional knowledge related to the use of plants of the Connaraceae family. This work is the first to compile all the published ethnobotanical, chemical, pharmacological, and toxicological information about this important plant family.

AIM OF THE STUDY

Our objective was to provide the scientific community with an up-to-date overview of the pharmacological potential of Connaraceae species.

MATERIAL AND METHODS

We searched NCBI Pubmed Central, Google Scholar, Scientific Electronic Library Online (SciELO), ScienceDirect, SciFinder, and Scopus databases to review the research on ethnobotanical, chemical, pharmacognostical, pharmacological, and toxicological studies with Connaraceaes. Books that address the theme were also included.

DISCUSSION AND CONCLUSION

The literature review indicated that 39 species of Connaraceaes have pharmacological potentiality. Ethnobotany reports listed 36 of the 39 species discussed. Pharmacognostical studies have been conducted with 23 species and isolates, and chemical compounds have been identified for only 15 species. At least one study has been published concerning the pharmacological activities for 20 of the 39 species analyzed. For Agelaea pentagyna, Cnestis ferruginea, Connars suberosus, and Rourea minor, pharmacological activity experiments were performed using isolated compounds, which have the highest current pharmacological potential. Studies employing a toxicological approach cover only 10 of the 39 Connaraceaes species. Thus, scientific community should conduct much more research for a broader understanding of this plant family.