Medicinal Flora of Chad: An Ethnobotanical Investigation into Traditional Healing Practices in N’djamena City

Introduction

Improving human health is a pressing concern for many countries and international organizations worldwide, as it is a key aspect of sustainable development [1]. Despite the spectacular growth of the pharmaceutical industry, herbal medicine retains its significance, given that 25% of drugs produced and marketed globally are derived from plants. The African continent harbors a vast diversity of medicinal plants, with two-thirds of identified plant species residing in the tropical countries of Africa [2]. Access to these species is essentially cost-free for the population, with nearly 80% relying on them due to limited access to pharmaceutical drugs. However, the widespread adoption of traditional medicine poses several challenges, including insufficient scientific data resulting from tests evaluating the safety and efficacy of these traditional products [3]. The importance of plants for food, crafts, traditional medicine, pharmaceutical and phytopharmaceutical production, industry, economy, culture, and plant conservation in Africa, especially in Chad, remains in its infancy, despite being an essential resource for the planet. Additionally, very few inventories of medicinal plants have been conducted, despite the majority of the population relying on them for medical care. Given the variety and richness of Chad’s flora, coupled with the limited number of local plants subjected to clinical investigations, it is crucial to conduct an ethnobotanical survey of plants used in traditional Chadian medicine, specifically in the city of N’Djamena.

N’Djamena lies within a dry tropical climate that has transitioned from the Sudanian-Sahelian type between 1951-1967 to a Sahelian type. Its climate is characterized by distinct seasons, including a long dry season lasting 7 to 8 months (from November to May) and a short rainy season spanning 3 to 5 months (from May to October). Precipitation levels range between 400 and 700 mm per year, occurring mainly as intermittent downpours, with recent years witnessing a concentration of rainfall over a three-month period (July to September). Temperature variations are considerable, ranging from 20°C to 45°C during the dry season and from 18°C to 30°C during the rainy season [4]. The soils in N’Djamena are predominantly clay-sandy to clayey, often containing limestone nodules. Soil composition varies depending on the location, and despite the presence of clayey horizons, soil permeability is not negligible. Evaporation is the primary mechanism for dissipating surface water stagnation, despite the presence of clay. The characteristic vegetation formation in the area is shrub savanna dominated by Acacias, with additional steppic vegetation and varying densities of Balanite eagyptiaca and some species from the Combretaceae family. There is also a noticeable increase in urban tree planting initiatives as part of the government’s environmental policy.

This survey aims to not only document the diversity of medicinal plants but also to contribute to the scientific understanding of their therapeutic potential and cultural significance in addressing health needs in Chad. By bridging traditional knowledge with modern scientific methods, we can unlock the full potential of Chad’s rich botanical heritage for the benefit of its people and the wider global community.

Materials and Methods

Study Area Description

Our investigations were conducted in the city of N’Djamena, the capital and largest city of Chad, located in the central-western part of the country, on the right bank of the Chari River, at the confluence of the Chari and Logone rivers, approximately 100 km from Lake Chad. N’Djamena is situated at coordinates 12° 08’ North latitude, 15° 02’ East longitude, and an altitude of 295 meters [4]. N’Djamena serves as a vital hub for commerce, culture, and administration in Chad, making it an ideal location for studying traditional medicinal practices. Its geographical position at the convergence of major waterways and its proximity to Lake Chad contribute to its rich biodiversity and cultural heritage, including the utilization of medicinal plants in traditional healing methods. The city’s diverse population, comprising various ethnic groups and communities, further enriches its traditional knowledge of medicinal plants. Our study aimed to explore and document this rich botanical heritage within the urban landscape of N’Djamena, shedding light on the use of medicinal plants in local healthcare practices.

Figure 1: Geographical Map of N’Djamena

Material

All the medicinal plants listed in the province of N’Djaména.

Ethnobotanical Survey

The ethnobotanical survey was conducted across the ten different districts of N’Djamena, with two traditional practitioners selected from each district based on a sampling plan considering their ethnicities, religions, and various characteristics (including gender). With a total of 64 neighborhoods in N’Djamena distributed among the ten districts, our survey plan involved selecting two traditional practitioners from each district’s different neighborhoods, except for the 5th district where we interviewed seven traditional practitioners. We interviewed a total of 25 traditional practitioners representing the main ethnic groups in the region, including Hausa, Arab, Baguirmi, Boulala, Mandra, Kotoko, Moundang, Sara, Yoruba, Borno, and Mousgoum. To ensure a comprehensive understanding of the subject matter, our survey utilized a pre-established questionnaire containing specific questions tailored for traditional practitioners and herbalists. These questions covered ethnobotanical characteristics (such as the form of usage and the plant parts used) and ethno-pharmacological aspects (including preparation methods, administration modes, and essential effects). This approach aimed to provide a more representative insight into the local therapeutic and traditional applications within the population of N’Djamena. Fieldwork was conducted primarily during daylight hours, either after sunrise or before sunset, to facilitate effective data collection and plant specimen gathering.

Selection of Plant Species

Three criteria guided the selection of medicinal plant species used:

1. Plants most commonly used by multiple traditional practitioners to treat a single ailment without the association of another plant.

2. Plants notable for their quality of treatment in Chadian traditional medicine, especially those used to treat specific ailments.

3. Plants that are diverse and accessible for collection.

Data Processing

The data recorded on the survey forms were processed and entered into GraphPad software. Data analysis utilized simple descriptive statistical methods. Quantitative variables were described using the usual descriptive statistics, including measures of central tendency (mean, median) and measures of dispersion (standard deviation, range). Qualitative variables were summarized using frequencies and percentages. Additionally, graphical representations such as histograms and pie charts were used to illustrate the distribution and characteristics of the collected data.

Statistical Analysis

The quantitative data collected underwent analysis of variance using GraphPad, version 5.0 software. The Tukey test was employed to discern differences between means. The analysis aimed to identify any significant variations or disparities among the collected data sets. Using ANOVA, we assessed the impact of different factors on the observed outcomes. Subsequently, the Tukey test was employed to conduct pairwise comparisons between multiple groups, enabling us to determine which means were significantly different from each other.

Results and Discussion

Floristic Aspect

Medicinal Plants Listed in the Province of N'Djamena

Most Represented Botanical Families in the City of N'Djamena

Figure 2: Percentage of Most Commonly Used Families in the Study Area

During our survey, we documented, collected, and identified 60 species of medicinal plants (Table 1). These 60 species, classified into 47 genera, belong to 37 plant families. Among these families, Fabaceae and Combretaceae were the most represented, accounting for 26.67% and 6.67% of the total species, respectively. Fabaceae emerged as the predominant family. This observation highlights the significance of Fabaceae and Combretaceae in the traditional medicinal practices of N;Djamena. These families likely contain species with potent therapeutic properties, contributing to their frequent utilization by traditional healers in the region.

Frequency of the Most Utilized Medicinal Plants

Analysis of the collected botanical data reveals that seven medicinal plants are the most commonly used in the survey area (see Figure 1). The species Khaya senegalensis, Guiera senegalensis, Allium sp, and Balanites egyptiaca are the most represented, accounting for 44%, 40%, 40%, and 36% respectively, followed by Diospyros mespiliformis, Prosopis africana, and Cassia italica with respective frequencies of 28%, 28%, and 24%.

Figure 3: Frequency of Most Commonly Used Plants in the Study Area

Ethnobotanical and Pharmacological Aspect

Classes of Traditional Practitioners

The ethnobotanical survey was conducted among 25 traditional practitioners, with a distribution of 96% men and 4% women. This gender distribution is also reported in the work of Mamadou Aissa et al. in 2017 [5]. According to traditional medical experience, 64% of traditional practitioners acquired their knowledge verbally from their parents or through involvement of the entire family in this field.

Preparation of Remedies

Medicinal species are used either alone or in combination with other plants for the treatment of various ailments, including malaria, typhoid fever, hemorrhoids (internal, external), diarrhea, constipation, diabetes, gonorrhea, jaundice, colic (intestinal, renal), parasitic diseases, and sexual weakness. The survey allowed us to record the recipes presented in the following tables:

                      Table 1: List of Plant Species Found by Traditional Practitioners and Areas of Therapeutic Indication

Parts of Plants Used

According to the data collected during the survey, 11 different parts of plants are utilized for treating illnesses based on their therapeutic properties. Among the 159 recorded recipes, we present the utilization of these different parts in order of prevalence: roots (23.33%), leaves (21.67%), fruits (11.67%), bark, whole plant, and seeds (10% each), bulbs (5%), tubers (3.33%), stems (2.62%), pods, and epicarp (1.67% each). Overall, traditional practitioners primarily utilize roots, accounting for 23.33% of plant parts used, compared to other parts (Figure 4).

Figure 4: Graphical Representation of the Number of Plant Parts Used

Mode of Administration

The findings of this survey reveal that oral administration (71.67%) is the most preferred method among traditional healers, as well as their patients, followed by Oral use (16.67%). Other modes of administration did not exceed a rate of more than 7% (Figure 5).

Figure 5: Graphical Representation of the Different Types of Administration Identified

Mode of Preparation

Many traditional healers always seek the simplest method to prepare herbal medicines. Consequently, it is recognized that decoction, with its percentage of 46.67% (Figure 6), represents the most suitable method for preparation.

Figure 6: Graphs of the Different Preparation Methods Used

Discussion

The ethnobotanical survey conducted among 25 traditional healers has allowed for the inventory of potentially used medicinal plants in the city of N’Djamena. The utilization of these plants is closely linked to the profile of the respondents. Both elderly individuals and the younger generation share medicinal knowledge, albeit with slight differences in usage percentages. Women are nearly absent in the traditional medical field. Despite the challenges of life in the city, traditional healers often show great understanding regarding the pricing of herbal medicines, as prices are usually tailored to the financial capacity of their patients.

The investigations have gathered information concerning therapeutic practices in this city. The analysis of the results obtained by this survey identifies an inventory of 90 plants distributed among 37 families. It also shows that among the 37 families, Fabaceae is the most recorded (35%). From an ethnobotanical and pharmacological perspective, roots constitute the most utilized part (23.4%), decoction is the most practiced pharmaceutical form (52%), and traditional remedies are more commonly consumed orally (68%). Similarly, among all treated diseases, digestive disorders and infectious diseases represent the most frequently mentioned ailments.

The most represented Botanical Families used by traditional healer in the City of N’Djamena was Fabaceae. This result is similar to that observed in the capital of a neighbouring country of Chad in Bangui by Lakouéténé and colleagues in 2009 [6]. The Fabaceae, or Leguminosae, are a family of dicotyledonous plants in the order Fabales. It is one of the largest families of flowering plants, third only to the Orchidaceae and Asteraceae in terms of the number of species and is most easily found in the towns and cities of Central Africa. In contrast the most commonly used medicinal plants in the survey area were Khaya senegalensis and Guiera senegalensis and has been previously documented in the literature by Haidara et al. in 2020 [7]. Similarly, the multiple uses of Balanites egyptiaca by local populations in the Ouaddai province of Chad have been reported by Abdoulaye Brahim et al. in 2017 [8].

These findings underscore the importance of these medicinal plants in the traditional healing practices of the region. The high frequency of utilization those plants suggests that these species possess potent therapeutic properties and are valued by traditional healers for their efficacy in treating various ailments. Further research into the pharmacological properties and mechanisms of action of these plants could provide valuable insights for their potential integration into modern healthcare systems. This study reveals that in the study area, there are more men working as traditional healers. The ethnobotanical survey was conducted among 25 traditional practitioners, with a distribution of 96% men and 4% women. This gender distribution is also reported in the work of Mamadou Aïssa et al. in 2017 [7]. Indeed, age emerged as a predominant factor in qualifying a traditional healer. The majority of traditional healers were elderly individuals, as these older individuals are often considered to provide more reliable information. Traditional medicine (TM) is deeply rooted in ancestral knowledge and oral tradition, with younger generations often lacking interest in traditional practices. This finding aligns with ethnobotanical surveys conducted in Benin by Koudokpon et al. in 2017 and by Bentabet et al. in 2022 in Algeria [9,10].

In traditional medicine, the parts of the plant used to make the traditional potion are also important. Overall, traditional practitioners primarily utilize roots, accounting for 23.3% of plant parts used, compared to other parts. This finding differs from those found in Niger, where bark is the most utilized due to its high yield in active ingredients, efficacy, and conditions of use [11]. Roots are readily available throughout the year, even for non-annual plants. Despite the delicacy of their harvest, they remain the most resilient to heat, humidity, and transportation. Although the dry season is preferable for harvesting among traditional practitioners, it was noted that certain plant parts require collection during or at the end of the rainy season, such as leaves and fruits. This exploration revealed that plant parts are often used in combination to enhance efficacy, especially for treating infectious diseases [12-14]. However, the association is not limited to plants alone; sometimes, plants need to be mixed with an acidified solution (such as natural yogurt, tamarind fruit juice, etc.), or a vehicle to enhance their effects.

The mode of drug administration is also important. The findings of this survey reveal that oral administration (71.67%) is the most preferred method among traditional healers, as well as their patients, followed by Oral use (16.67%). Other modes of administration did not exceed a rate of more than 7%. For both traditional healers and patients, the oral route is the royal road for administering medicines. Oral administration appears to be the quickest in terms of absorption and distribution, enabling the treatment of diseases related to unknown or incurable causes, including witchcraft. Therefore, administering orally is deemed necessary, followed by body cleansing treatments. All diseases with internal triggers (such as hemorrhoids, intestinal worms, etc.) typically require this mode of administration. This investigation aligns with similar findings reported by Dibong and colleagues in 2011 in Cameroon [15]. This preference for oral administration underscores the perceived efficacy and convenience associated with this mode of delivery. It allows for rapid absorption and systemic distribution of the medicinal components, facilitating their therapeutic effects on internal ailments. Additionally, the cultural and traditional beliefs surrounding the perceived potency of orally administered remedies may contribute to its widespread adoption among traditional healers and patients alike.

Many traditional healers always seek the simplest method to prepare herbal medicines. Consequently, it is recognized that decoction, with its percentage of 46.67% (Figure 6), represents the most suitable method for preparation. Decoction allows for the extraction of a maximum of active principles and helps to mitigate or eliminate the toxicity of certain recipes. It also facilitates the homogeneous combination of multiple plants. Additionally, maceration and infusion also play a significant role in maximizing the extraction of active principles and therapeutic effects. Numerous studies have echoed similar approaches, including the ethnobotanical study conducted by Mehdioui and Kahoudji in 2007 among the riparian population of the Amsittène forest [16].

This emphasis on decoction aligns with the traditional practices of many cultures, where boiling plant materials in water is a common method for preparing herbal remedies. Decoction is valued for its ability to release active compounds from plant tissues, making them more readily available for absorption and exerting therapeutic effects. Moreover, the simplicity and accessibility of this method make it particularly suitable for traditional healers who may lack sophisticated equipment or resources for more complex extraction techniques.

Highlights

• Traditional medicine is widely used by Chadians, with more than 80% of the population relying on it, even in the capital city of Ndjamena.

• The study revealed a remarkable wealth of traditional knowledge in primary healthcare, highlighting the importance of plants in the local pharmacopoeia.

• The results obtained will be used by the Ministry of Health to create a positive list of plants to be recommended to the population for primary care.

Conclusion

In conclusion, this study is a source of information on not only the medicinal flora found around Chad’s capital, but also on the diseases treated by traditional healers and the population concerned. This study will serve as a basis for the development of improved traditional medicines for our populations.

Authors Contribution Statement

Abakar Bechir Seid: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Validation, Resources, Visualization, Writing – original draft.

Joseph Ngoupayo and Giulia Cappelli: Methodology, Validation. Bernard Gressier: Conceptualization, Writing.

Bruno ETO: Conceptualization, Data curation, Formal analysis, Methodology, Software, Supervision, Validation, Visualization, Writing – original draft, Writing – review & editing.

A B Bechir, A B Mahamat, Ngameni Barthelemy: Investigation.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Data Availability

Data will be made available on request.

Acknowledgements

The authors would like to thank the direction of Pharmacopeia and Traditional Medicine, Ministry of Health and Prevention, B.P. 440, N’djamena, Chad and TBC Laboratory (Faculty of Pharmacy, University of Lille) for assistance and helpful discussion.

References