Medicinal Plants from the Ouaddaï Province (Chad): An Ethnobotanical Survey of Plants Used in Traditional Medicine

Abstract

Background/Objective:

Plants are the basis of all health care systems. This study sought to inventory the most used medicinal plants in the local therapeutic patrimony of the Ouaddaï (East Chad) through an ethnobotanical investigation.

Methods:

The inventory described the plant parts used, their mode of preparation, and their therapeutic uses.

Results:

Thirty-eight plants species are used for different purposes and diseases. The most used species belongs to the Mimosaceae (eight species), Caesalpiniaceae (four species), and Combretaceae (four species) families. The traditional medicinal uses, as well as the preparations, of these plants are diverse. The used parts are leaves (36.4%), peels (23.7%), fruits (18.2%), roots (10.9%), stems (5.5%), and other (5.3%). These plants are used to treat 16 different illnesses, notably amoebiasis (26.8%), respiratory infections (14.3%), fever (12.5%), kidney stones (7.1%), snake bites (7.1%), tooth decay (5.4%), and leprosy (5.4%).

Conclusion:

The results obtained from this survey constitute the starting point of an inventory of local medicinal plants to be completed by phytochemical, pharmacologic, and toxicologic studies to allow good exploitation of the local medicinal flora.

Introduction

Modern medicine is becoming more and more expensive. It may become unreachable for most Africans in general and for the Chadian population in particular. That is why, despite the dominant role of modern therapeutics, most Chadians turn to traditional medicine to solve their health problems. Given this intensive use of the local flora, an inventory of the healing plants of this country is more than necessary— it is essential because such a study would undoubtedly help resolve some public health problems.¹

Medication consisting of herbs and plants has been used since the dawn of time, and humans continue to select curative plants from their environment. In particular, they have done so since the time of the Babylonian and Chaldean civilizations along the Tigris and Euphrates rivers, as they did in ancient Egypt on the edge of the Nile. Scholars of Egyptian civilization even analyzed these plants, defined drugs, recorded their ways of use, applied them in trials, and prescribed their principles to heal numerous diseases. Traditional medicine is still used by a majority of people in the world and still represents a good strategy for drug discovery.²

In Africa, researchers have been scientifically studying the medicinal plants used in different regions. Certain uses were confirmed and active ingredients isolated.³ In addition, over the past three decades numerous African countries have been paying more and more attention to traditional medicine and their medicinal plants. Chad, by its geographic location, offers an important ecologic and floral diversity. However, Chadian pharmacopeia has heretofore been relatively unknown. For this reason, and considering the biodiversity of natural resources (mineral, animal, and vegetal),⁴ the present study sought to inventory the healing plants of the regions of Bithéa, Abker, and Goz-Beïda, located, respectively, 35, 82, and 217 km from Abéché, Chad.

Materials and Methods

Study area

The study zone is in the region of Ouaddaï-Biltine (East of Chad) (Fig. 1). It extends between 11 and 16 degrees of latitude in the North and 17 and 20 degrees of longitude. It is limited in the North by the prefecture of Borkou-Ennedi-Tibesti, in the South by the Central African Republic and the prefecture of Salamat, in the East by the Sudan, and in the West by the prefectures of Batha and Guéra. It covers a surface of 123,090 km². The study zone has an intertropical climate with a dry season and a rainy season.

FIG. 1.

Administrative map of Ouaddaï-Biltine (from TMEP, 1998).

These two seasons are defined by the fluctuations between masses of dry air from the North (harmattan) and masses of maritime wet air from the Southwest (monsoon). Thus, the presence of the intertropical front in this area brings the rain, and its absence is related to the dry season. The annual pluviometry in Ouaddaï-Biltine is between 200 mm for the North and 950 mm for the South.

The vegetation of Ouaddaï appears as follows: Ouadis in the Northwest has a shrubby aspect, often scattered and composed of, among others, Acacia species, Balanites aegyptiaca, Boscia senegalensis, and Salvadora persica. In the forest galleries of the South, one finds Tamarindus indica, Anogeissus leiocarpus, and Combretum glutinosum. On sandy to sandy-clays soils of the bottom of valleys, one finds Acacia seyal along the Ouadi Bithéa toward Oum-Hadjer, and along the road to Am-Zoer. It is a herbaceous area and very diversified but often overgrazed. On clay soils of the South, the vegetation is more wooded. The most typical trees are A. seyal, Albizia amara, and C. glutinosum. Sclerocarya birrea is frequent on the more sandy soils. The herbaceous plant cover is average with 30% of bulk soil. A little bit further south, toward Goz-Beïda, the vegetation is relatively well preserved.⁵

The temperature of the region changes according to seasons. In the cold season (December–February), the daily temperatures are between 16 and 35°C; in the dry season (April), they are between 25 and 41°C; in rainy season (August), these temperatures fall and vary between 21 and 31°C. The annual average temperature in Abéché is about 28°C; the maximum is 49°C.⁵

The geologic base of Ouaddaï-Biltine is almost completely formed by granite of the Precambrian base, a wrinkled, magmatic metamorphic setgroup that is crossed by intrusions. The granite of calco-alkaline typechap and the magma dominate. The granodiorite and the mica-schists are rare. In the neighborhood of Adré, sandstones of paleozoic age are present. The southern part is characterized by old duricrust, is really hardened, and dates from the end of the Tertiary period.⁵

Ethnobotanical survey and study method

A pre-established questionnaire was used to ask 30 traditional healers (average age, 45.3±6 years; men only) were questioned about the plants used, parts of the plants used, the modes of preparation, and the therapeutic and traditional practices. The interviews and discussions were carried out in Chadian Arabic. During this study, the following information was obtained: (1) For every collected medicinal plant, the local or vernacular name was given, as well as the part used, the mode of preparation, as well as the way of administration of the remedy; (2) each traditional healer was individually questioned, and only the species of which more than 50% of these healers make the same use were retained as healing plants of the studied zone.

All in all, three sites in the South of the city of Abéché, namely Bithéa, Abker, and Goz-Beïda (located, respectively, 35, 82, and 217 km of Abéché) were chosen. At every site, prospecting followed by collection of botanical specimens was organized. Any organ taken on the same plant was allocated by the same number. All information taken was then recorded on the survey sheet of the ethnobotanical investigation.

Pictures of all the plants used in the local therapeutic heritage were taken and the collected samples were identified by Aouadalkarim Moussa Chahad. The identities were confirmed by comparison with the herbarium of the Veterinary and Zootechnic Research Laboratory of N' Djaména, the Ecological Museum of the Millennium and the National Herbarium of Yaoundé (Cameroon). Voucher specimens were deposited at the Ecological Museum of the Millennium of Yaoundé (Cameroon), and a voucher number has been assigned to each of them as follows: AB for samples collected around Abker, GZ for Goz-Beïda, and BI for Bithéa. Species collected at the same location were increasingly annotated (Table 1).

Table 1.

Plants with Multiple Uses

Family	Species	Medicinal uses
Anacardiaceae	Mangifera indica	Amebiasis, fever
Asclepiadaceae	Leptadenia hastata	Aphrodisiac, digestion incentive
Balanitaceae	Balanites aegyptiaca	Kidney stones, cold, intestinal worms
Capparaceae	Cadaba farinosa	Cough, cold
	Boscia senegalensis	Snake bites, colic, bilharzia
Caesalpiniaceae	Bauhinia rufescens	Diarrhea, dysentery
	Parkinsonia aculeata	Fever, dysentery
	Piliostigma reticulatum	Diarrhea, dysentery
	Tamarindus indica	Fever, hemorrhoids
Combretaceae	Anogeissus leiocarpus	Diarrhea, aphrodisiac
	Combretum glutinosum	Itching, calamity, wound, cough, stomach diseases
	Guiera senegalensis	Diarrhea, lactation incentive, snake bites, leprosy, dermatitis
	Terminalia macroptera	Hepatitis, wound
Ebenaceae	Diospyrosmespiliformis	Diarrhea, fever
Liliaceae	Allium cepa	Cough, headache, abscess, typhoid fever
Meliaceae	Khaya senegalensis	Jaundice, dermatitis.
	Azadirachta indica	Fever, malaria, intestinal worms, ulcer, leprosy
Mimosaceae	Acacia albida	Cold, influenza, pneumonia, tooth decay
	Acacia seyal	Dysentery, gastric intestinal affections, leprosy
	Acacia raddiana	Jaundice, rheumatisms.
	Dichrostachys cinerea	Bone fractures, intestinal worms, dysentery
Rhamnaceae	Ziziphus mauritiana	Colic, snake bites
Rutaceae	Citrus aurantium	Insomnia, headache, intestinal parasites

Data were handled and analyzed by using Excel software (Microsoft Corp., Redmond, WA).

Intellectual property agreement statement

The traditional healers who provided information during the survey were adequately financially rewarded after a verbal agreement that this research will not be used for commercial purposes.

Results and Discussion

The floral analysis of the realized catalog allowed the identification of 38 botanical species used in traditional medicine in this part of the Chad (Tables 1 and 2). From the botanical point of view, these 38 species are spread into 31 genera and 19 families (according to Cronquist's classification).⁶ The most represented families are Mimosaceae (eight species), Caesalpiniaceae (four species), and Combretaceae (four species) and the most represented genera are Acacia (eight species), Zizyphus (two species), and Citrus (two species). The 19 families were spread over 11 orders. The most diversely represented order is Fabales, with 13 species, distributed among the three families (Mimosaceae, Caesalpiniaceae, and Fabaceae). These results relative to the listed botanical families are similar to those reported by Guigma et al. and Zerbo et al. in Burkina-Faso, where the most represented families were Poaceae, Caesalpiniaceae, Mimosaceae, Combretaceae, Rubiaceae, and Anacardiaceae.^7,8

Table 2.

Therapeutic Uses, Parts Used, and Comparison with Literature

Family	Species	Voucher number	Vernacular name	Parts used in Ouaddaï	Parts used in the other regions of Sahel (Pousset, 1989; Maydell, 1992)	Medicinal uses in Ouaddai	Medicinal uses in other regions of Sahel (Pousset, 1989; Maydell, 1992)
Anacardiaceae	Mangifera indica L	GZ_25	Mangaye	Leaves	Leaves, barks	Amoebiasis, fever	Diarrhea, diuretic
	Sclerocarya birrea 5A. Rich. Hochst.	GZ_15	Himmedeaye	Leaves	Leaves	Diabetes	Diabetes
Asclepiadaceae	Calotropis procera (Ait.) Ait.F.	GZ_03	Acharro	Leaves, barks	Leaves, roots, barks	Leprosy	Leprosy, worms, syphilis, cold, stimulant of digestion, diuretic, sedative
	Leptadenia hastata (Pers.) Decne	GZ_26	Chaalob	Leaves	Leaves, seeds	Aphrodisiac, stimulant of digestion	Smallpox
Balanitaceae	Balanites aegyptiaca (L.) Del.	GZ_12	Hadjlidjaye	Fruits, roots	Fruits	Kidney stones, cold, intestinal grubs, snake bites	Anti-inflammatory, molluscidal
Boraginaceae	Cordia sinensis Lam.	GZ_04	Andarabaye	Leaves	None	Tooth decay	No use
	Cadaba farinosa Forsk.	GZ_27	Sirré	Leaves, roots	Leaves, roots	Cough, cold	Cough cold, dysentery
Capparaceae	Boscia senegalensis (Pers.) Lam. Ex. Poir.	GZ_13	Mikhet	Leaves, roots	Leaves, roots	Snake bites, diarrhea, bilharzia	Pains, diarrhea, bilharzia, worms, syphilis, ulcer, jaundice
Caesalpiniaceae	Bauhinia rufescens Lam.	GZ_09	Koulkoulaye	Leaves, fruits	Leaves, fruits, roots	Diarrhea, dysentery	Fever, leprosy, diarrhea, dysentery, eye diseases
	Parkinsonia aculeate L.	GZ_14	Sessabanaye	Leaves, seeds	Leaves, seeds, flowers, barks	Fever, dysentery	Fever, atony, dysentery
	Piliostigma reticulatum (DC.) Hochst.	GZ_21	Kharroubaye	Leaves, barks	Leaves, barks	Diarrhea, dysentery	Ophthalmia, cough, bronchitis, headache, neuralgia, mumps, toothache, rheumatisms, ulcer, cut, diarrhea, dysentery
	Tamarindus indica L.	AB_02	Ardebaye	Fruits, leaves	Fruits	Fever, hemorrhoids	Laxative
Combretaceae	Anogeissus leiocarpus (DC.) Guill. Et Perr.	GZ_02	Sahabaye	Barks, roots	Barks, roots	Diarrhea, aphrodisiac	Fever, diarrhea, dermatitis, ulcer, anthelmintic, aphrodisiac
	Combretum glutinosum Perr. Ex DC.	AB_01	Habilaye	Leaves, roots	Leaves, seeds, roots	Itching, wounds, cough, stomach diseases	Wounds, liver ache, cold, bronchitis, fever, malaria, anemia, bleeding, syphilis, cough, stomach diseases
	Guiera senegalensis J.F. Gmel.	GZ_10	Khibechaye	Leaves	Leaves, roots, barks	Diarrhea, lactation incentive, snake bites, leprosy, dermatitis	Cough, toothache, diarrhea, dysentery, cold, malaria
	Terminalia macroptera Guill. Et Perr.	AB_03	Darotaye	Leaves, roots	Leaves, roots, seeds, fruits	Hepatitis, wounds	Hepatitis, depression, fever, syphilis, aphrodisiac, diuretic, dermatitis, migraines, wounds
Ebenaceae	Diospyros mespiliformis Hochst. Ex A. DC.	GZ_05	Djokhanaye	Leaves, barks, roots	Leaves, barks, roots	Diarrhea, fever	Fever, malaria, syphilis, leprosy, diarrhea, dermatitis, neuralgia, toothache
Fabaceae	Dalbergia melanoxylon Guill. Et Perr.	GZ_22	Babamossaye	Barks	Barks, roots	Diarrhea	Diarrhea, syphilis, headache, bronchitis
Liliaceae	Allium cepa L.	GZ_06	Bassalaye	Bulbs	None	Cough, headache, abscess, typhoid	No use
Meliaceae	Khaya senegalensis (Desv.) A. Juss.	BI_01	Mourraye	Barks, roots	Barks, roots, seeds, leaves	Jaundice, dermatitis	Sting of scorpion, jaundice, dermatitis, allergy, abscess on the gum, tapeworm, bloody wound, fever, neuralgia, sterility, syphilis, leprosy, mental illness, aphrodisiac
	Azadirachta indica A. Juss.	BI_06	Nimaye	Leaves, barks	Barks, roots, leaves, seeds	Fever, malaria, intestinal worms, ulcer, leprosy	Fever, weakness, dermatitis, scorpion sting, snake bites, leprosy, ulcer, worm
Mimosaceae	Acacia albida Del.	GZ_20	Harazaye	Leaves, fruits, roots	Barks, roots	Cold, influenza, tooth decay, pneumonia	Cold, toothache, cardiotonic, fever, kidney diseases, mental illness
	Acacia nilotica (L.) Wild. Ex Del.	GZ_17	Garadaye	Fruits, barks	Fruits, barks, pods	Dysentery	Diarrhea, bilharzia, dysentery, scurvy, toothache, inflammations
	Acacia senegal (L.) Wild.	GZ_01	Kitiraye	Barks	Barks	Gastric affections	Stomach diseases
	Acacia seyal Del.	GZ_07	Talhaye	Barks, roots	Barks, roots	Dysentery, leprosy, gastric and intestinal affections	Dysentery, leprosy, stomach diseases, syphilis, headache, aphrodisiac
	Acacia pennata (L.) Wild.	GZ_08	Aradaye	Leaves	Leaves, barks	Fever	Cold, dermatitis, aphrodisiac, snake bites, fever, toothache
	Acacia raddiana Savi.	GZ_11	Sayalaye	Barks, stem wood	Leaves, barks	Jaundice, rheumatism	Worms, dermatitis, edema
	Dichrostachys cinerea (L.) Wight Et Arn.	GZ_16	Kadadaye	Leaves	Barks, leaves	Fracture, intestinal worms, dysentery	Dysentery, worms, snake bites, leprosy, syphilis, cough, gonorrhea, eczema, furuncle, bones fracture
	Prosopis juliflora (Sw.) DC.	GZ_18	Pispissaye	Barks	Barks	Ulcer	Ulcer
Myrtaceae	Psidium guajava L.	BI_07	Giayafaye	Leaves	Leaves	Diarrhea	Children's diarrhea
Palmae	Hyphaene thebaica (Sw.) DC.	BI_04	Domaye	Fruits	Different members	Asthma	Bilharzia
Rhamnaceae	Ziziphus mauritiana Lam.	GZ_24	Nabagaye	Barks, fruits	Roots	Diarrhea, rib cage illness, snake bites	Colic, venereal disease, intestine inflammation, hepatitis
	Ziziphus spina-christi (L.) desf.	GZ_28	Cornaye	Thorns	Thorns	Snake bite	Snake bite, blood cleansing
Rutaceae	Citrus aurantium L.	BI-05	Bourdoukhnaye	Flower, barks	No known use	Insomnia, headache, intestinal parasites	No known use
	Citrus aurantifolia (Christm.) Swengle	BI-02	Lemounaye	Fruits	No known use	Cold	No known use
Salvadoraceae	Salvadora persica L.	GZ_23	Chawaye	Stems, roots	Total plant	Tooth decay	Fever, liver illness, rheumatisms, gonorrhea, bronchitis, asthma, diuretic, toothache
Solanaceae	Capsicum annuum L.	GZ_19	Chattaye	Fruits	No known use	Colic	No known use
Tiliaceae	Grewia tenax (Forssk.) fiori	BI-03	Guiddemaye	Fruits	No known use	Anemia	No known use

By comparison with literature data, the following species seem to have no therapeutic uses reported in the other parts of Sahelian Africa: Allium cepa, Capsicum annuum, Citrus aurantifolia, Citrus aurantium, Cordia sinensis, and Grewia tenax (Table 2).

Moreover, in Ouaddaï Acacia raddiana and Hyphaene thebaica have diverse therapeutic uses different from those in other areas of Sahel; they are, respectively, used against icterus, rheumatism, and asthma. In contrast, in other areas of Sahel, they are used against intestinal worms, dermatitis, edemas, and bilharzia (Table 2). In addition, from the 30 remaining species whose uses remain the same in Sahelian local medicine, 28 species (93.3%) have at least one therapeutic use identical to that of the other regions of Sahel.^3,9
–11

In addition, this survey reveals that the same species sometimes has multiple therapeutic practices: 23 species out of the 38 inventoried (60%) were used to treat multiple diseases and the symptoms of 16 different pathologic abnormalities, of which amoebiasis and respiratory diseases are treated by this panel of medicinal plants (Table 1). This multiplicity of therapeutic uses shows the richness in active ingredients of these plants, which must be looked after. The same observations have been made by Guigma et al.,⁷ Zerbo et al.,⁸ Séreme et al.,¹² and Nacoulma-Ouédraogo (1996),¹³ who reported that the diversity of plants and the variability of the proposed therapeutic uses could be related to their various properties and could be considered a form of cultural heritage capitalized upon by generations of local populations. The variability of these therapeutic practices was also observed in Burkina-Faso (Nacoulma-Ouédraogo,¹³ Thiombiano et al.¹⁴), Niger (Wezel¹⁵), the Ivory Coast (Koné et al.¹⁶), and Mali (Kouyaté¹⁷).

In Ouaddaï, the same plant parts are used as in the rest of Sahelian Africa. However, the rate of use differs from one part to another (Zerbo et al.⁸). Thus, leaves are used in 36.4% of the cases, barks in 23.7%, fruits in 18.2%, roots in 10.9%, stems in 5.5%, seeds in 1.8%, bulbs in 1.8% and thorns 1.8% (Fig. 2). Zerbo et al.⁸ also showed in a similar study in Burkina-Faso that leaves are used in 31%, roots in 25%, and trunk barks in 23%. Several types of preparation were described and plant parts were used in fresh or dry state (Table 3), including classical herbal preparations, namely decoctions (35.7%), infusions (22.8%), macerations (11%), and powders (30.5%) (Fig. 3).⁷ Of note, no essential oils are used. Identical preparations were also described by Pousset³ and Salhi et al.¹⁸

FIG. 2.

Use rate for parts.

FIG. 3.

Rate of the different types of preparation modes (in percentages).

Table 3.

Directions for Use and Preparation

Family	Species	Preparation	Administration
Anacardiaceae	Mangifera indica	1. Decoction of 20 leaves with sugar and salt for 30 min	1. Drink 1 soup-spoonful every 24H in amebiasis
		2. Decoction of dried leaves for 15 min in 0.5 L of water	2. Drink hot with sugar, 3 times/day, in high fever
		3. Decoction of 1 kg of barks for 1 h in 3 L of water	3. Hip bath for hemorrhoids
	Sclerocarya birrea	1. Dried and grounded leaves	1. 3 soup-spoonfuls of powder in a glass of boiling water. Drink for a week for diabetes
		2. Decoction of barks for 20 min	2. 3 glasses/day of herbal tea with 1 piece of sugar, for 3 days, for amoebiasis
Asclepiadaceae	Calotropis procera	Dried and grounded leaves	Apply the powder on skin in leprosy
	Leptadenia hastata	Dried and grounded leaves are added to tea leaves	Drink the tea to ease digestion and as aphrodisiac
Balanitaceae	Balanites aegyptiaca	1. Maceration of fruits in water at room temperature	1. Drink all day long for kidney stones
		2. Ground roots of young plants until a paste forms	2. Fix the paste firmly on the snake bite
Boraginaceae	Cordia sinensis	Leaves are burned and grounded	The powder is applied on the tooth cavity
Capparaceae	Cadaba farinosa	Decoction of leaves and/or roots	To drink for cough and cold
	Boscia senegalensis	1. Roots are grounded	1. Firmly apply the cream to the snake bite
		2. Leaves are burned and grounded	2. Drink the powder in water with salt in bilharzia
Caesalpiniaceae	Bauhinia rufescens	Decoction of leaves and fruits	Drink all day long for diarrhea and dysentery
	Parkinsonia aculeata	1. Decoction of leaves and seeds	1. Drink to alleviate fever
		2. Decoction of leaves and stems	2. Drink for dysentery
	Piliostigma reticulatum	Herbal tea of leaves and barks	Drink all day long for diarrhea and dysentery
	Tamarindus indica	Express the juice from fresh leaves	Drink the juice to alleviate hemorrhoids
Combretaceae	Anogeissus leiocarpus	1. One piece of root	1. Chew the root as aphrodisiac
		2. Decoction of barks	2. Drink for diarrhea
	Combretum glutinosum	1. Herbal tea of leaves	1. Drink one glass and wash the body when itching
		2. Leaves are dried and grounded	2. Apply the powder on wounds
		3. Decoction of roots	3. Drink all day long for cough
	Guiera senegalensis	1. Herbal tea of grounded leaves	Drink the tea against snake bites
		2. Herbal tea of grounded leaves and young stems	Drink the tea against skin diseases
		3. Leaves are reduced to a mash with milk	Eat the mash for lactation stimulation
Combretaceae	Terminalia macroptera	1. Herbal tea of leaves	1. Drink all day long to alleviate hepatitis
		2. Roots are burned and grounded	2. Apply the powder on wounds
Ebenaceae	Diospyros mespiliformis	1. Decoction of leaves, barks, and roots	1. Drink all day long to alleviate fever
		2. Decoction of roots	2. Drink all day long to alleviate diarrhea
Fabaceae	Dalbergia melanoxylon	Decoction of barks	Drink all day long to alleviate diarrhea
Liliaceae	Allium cepa	1) 1. Cut 3 onions in slices and prepare a decoction in 3 soupspoons of honey and 0.5 L of water, for 1 h, then filter	1) 1. Drink 1 soup-spoonful, 3 times/day, to alleviate cough
		2) 2. Take 2 slices of onion	2) 2. Put the slices on the head against headaches
		3) 3. Cook an onion in hot ash; prepare a mash	3) 3. Apply the bandage on abscess
		4) 4. Cut onions in slices	4) 4. In typhoid fever, apply in cataplasm on the forehead, neck, wrist, and ankles for few minutes; renew the application until the onion color returns to original
Meliaceae	Khaya senegalensis	Decoction of barks and roots	Drink all day long to alleviate jaundice and dermatitis
	Azadirachta indica	1. Decoction with 40 leaves in 1 L of water and 20 pieces of sugar for 30 min	1. Drink 1 glass, 4 times/day, for malaria
		2. Decoction of leaves	2. Drink all day long to alleviate fever
		3. Prepare a juice with fresh young leaves	3. Drink 2–3 glasses/day to alleviate ulcer and worms
		4. Ferment bark juice for 7 d	4. Drink 2–3 glasses/day to alleviate leprosy
Mimosaceae	Acacia albida	1. Decoction of leaves and fruits	1. Drink all day long to alleviate cold and toothaches
		2. Decoction of roots	2. Drink against pneumonia
	Acacia nilotica	Decoction of fruits and barks	Drink all day long to alleviate dysentery
	Acacia senegal	Decoction of barks	Drink all day long to alleviate stomach diseases
	Acacia seyal	1. Infusion of roots	1. Drink all day long to alleviate dysentery and leprosy
		2. Decoction of roots	2. Drink all day long to alleviate stomachaches
	Acacia pennata	Decoction of leaves	Drink all day long to alleviate fever
	Acacia raddiana	1. Prepare maceration with pieces of bark	1. Drink 3 times/day to alleviate jaundice
		2. Burn the trunk wood	2. Smell the fumes to alleviate rheumatisms
	Dichrostachys cinerea	1. Dry and ground leaves	1. Powder is used in massages to heal broken bones
		2. Decoction of barks	2. Drink to alleviate dysentery and worms
	Prosopis juliflora	Prepare a maceration with pieces of bark	Drink to alleviate ulcers
	Psidium guajava	Decoction of few leaves in 0.5 L of water	Drink to alleviate diarrhea
Myrtaceae	Hyphaene thebaica	Maceration of the pulp of the fruit	Drink in the morning before eating to alleviate asthma
Palmae	Ziziphus mauritiana	1. Take few pieces of bark	1. Chew to alleviate diarrhea
		2. Maceration of fruits	2. Drink 3 times/day to alleviate thorax pain
Rhamnaceae	Ziziphus spina-christi	Burn and grind the thorns	Apply the powder on the snake bite
	Citrus aurantium	1. Boil 4–5 dried flowers in 1 glass of water for 15 min	1. Add sugar and drink 2–3 times/day to alleviate insomnia
		2. Herbal tea of 30 g of bark pieces; infuse for 1 h	2. Drink 1 glass with 2 pieces of sugar every hour to alleviate headaches
		3. Herbal tea of dried bark in 1 L of water; infuse for 2 h	3. Drink 1 glass in the morning and evening for 3 days to alleviate worms
Rutaceae	Citrus aurantifolia	Decoction of 2 lemons (cut in 4 slices) in 0.5 L of water	Add 4 pieces of sugar and drink to alleviate cold
	Salvadora persica	Cut stems and roots in small pieces	Brush teeth to prevent tooth cavity
Salvadoraceae	Capsicum annuum	Infuse 5–6 fruits in warm water	Drink 1 glass to alleviate diarrhea
Solanaceae	Grewia tenax	Maceration of fruits	Drink to alleviate anemia

The present investigation shows that the most frequently treated symptoms are fever and intestinal disorders (diarrhea, dysentery, intestinal worms) and, to a lesser extent, respiratory diseases (Table 2). This confirms the results obtained in Burkina-Faso by Guigma et al.⁷ This is why the species used to treat these recurring conditions must be particularly protected, with the aim of sustainable use and phytochemical analyses as well as pharmacologic evaluations. These species are Psidium guajava, Dalbergia melanoxylon, Mangifera indica, Balanites aegyptiaca, Bauhinia rufescens, Parkinsonia aculeata, Piliostigma reticulatum, Tamarindus indica, Anogeissus leiocarpus, Guiera senegalensis, Diospyros mespiliformis, Allium cepa, Azadirachta indica, Acacia seyal, Dichrostachys cinerea, and Citrus aurantium.

Finally, phytochemical analyses of leaves and barks of Acacia raddiana on the one hand and fruits of Hyphaene thebaica on the other hand are necessary to improve understanding of their effects, respectively, on rheumatism, icterus, and asthma; few data are available on these species.

Conclusion

The present study listed and identified 38 botanical species used in local traditional medicine in Ouaddaï. Through access to the “holders of the knowledge,” with their “know-how on plants,” the study entailed the harvest of the plant samples, their identification, their preparation, and explanation of their therapeutic uses. Thirty-eight studied species belong to 11 orders, 19 families, and 31 genera. With regard to therapeutic application, 32 species were frequently used in all Sahelian Africa, of which 30 are used for at least one indication in almost all of Sahel. From the ethnobotanical and pharmacologic points of view, leaves, barks, and fruits are the parts most used.

This study thus represents the starting point for further phytochemical studies to validate remedies listed by rigorous scientific protocols. It could allow the local sanitary departments to exploit these remedies better in order to cure recurrent conditions. This ancestral knowledge is already approachable in hospitals thanks to the integration of traditional healers. This practice, by becoming widespread, will allow access to additional knowledge in pharmacology and in toxicology.

Footnotes

Acknowledgments

The authors are thankful to the traditional healers, without whose availability this study would not have been possible. The Ministry of French Foreign Affairs, by means of EGIDE (Campus France), financed this study.

Author Disclosure Statement

No competing financial interests exist.

References

Chahad

. Contribution to the study of medicinal plants from eastern Chad: case of Ouaddai region [Contribution à l'étude des plantes médicinales du Tchad oriental: cas du Ouaddaï]. Mémoire de

DEA

, Université de Yaoundé I (Département de Biologie et Physiologie Végétales): 2007.

Saslis-Lagoudakis

, Savolainen

, Williamson

, et al. Phylogenies reveal predictive power of traditional medicine in bioprospecting. Proc Natl Acad Sci U S A, 2012; 109:15835–15840.

Pousset

. African medicinal plants, practical uses [Plantes médicinales africaines, utilisations pratiques]. Tome I. Paris: Ellipses, Agence de Coopération Culturelle et Technique (ACCT), 1989.

Hmeyada

AOMV

. Contribution to Mauritanian medicinal plants study [Contribution à l'étude des plantes médicinales de Mauritanie]. Tome XVII. Annales de l'Université de Lomé (Togo), série Sciences., 2009:9–27.

Tchad, Ministère de l'Economie et du Plan. Gesellschaft für Technische Zusammenarbeit, 1998. Plan régional de développement. Le Ouaddaï-Biltine vers l'an, 2005; I:1–58.

Cronquist

. An Integrated System of Classification of Flowering Plants. New York: Columbia University Press, 1981.

Guigma

, Zerbo

, Millogo-Rasolodimby

. Use of spontanous species in three villages close to the south of Burkina-Faso [Utilisation des espèces spontanées dans trois villages contigus du sud du Burkina-Faso]. Tropicultura, 2012; 30:230–235.

Zerbo

, Millogo-Rasolodimby

, Nacoulma-Ouédraogo

, Van Damme

. Medicinal plants and medicinal practices in Burkina-Faso: case of the sanans [Plantes médicinales et pratiques médicales au Burkina-Faso: cas des sanan]. Bois et Forêts des Tropiques, 2011; 307:47–53.

Pousset

. African medicinal plants, possibilities of development [Plantes médicinales Africaines, Possibilités de développement]. Tome II. Paris: Ellipses, Agence de Coopération Culturelle et Technique (ACCT), 1992.

10.

Maydell

. Trees and bushes from Sahel: their characteristics and uses [Arbres et arbustes du Sahel : leurs caractéristiques et leurs utilisations]. Margraf Hambourg, 1992.

11.

Sofowora

. Medicinal plants and traditionnal medicine of Africa [Plantes médicinales et médecine traditionnelle d'Afrique]. Karthala, Paris, 1996.

12.

Séreme

, Millogo-Rasolodimby

, Kouda-Bonafos

, Guinko

, Nacro

. Therapeutic values of Anacardiaceae in link with their metabolites and their richness in tanins [Vertus thérapeutiques des Anacardiaceae en liaison avec leurs métabolites et leur richesse en tanins]. Annales de Botanique de l'Afrique de l'Ouest, 2001:63–71.

13.

Nacoulma-Ouédraogo

. Medicinal plants and traditionnal medical practrices in Burkina Faso: case of central area [Plantes médicinales et pratiques médicales traditionnelles au Burkina-Faso: cas du plateau central]. PhD thesis. Faculty of Sciences and Techniques, University of Ouagadougou, Burkina-Faso, 1996.

14.

Thiombiano

, Ouôba

, Guinko

. Place of Combretaceae in gourmantché society in eastern part of Burkina Faso [Place des Combretaceae dans la société gourmantché à l'est du Burkina-Faso]. Études sur la Flore et la Végétation du Burkina-Faso et des Pays Environnants, 2002; 7:17–22.

15.

Wezel

. Medicinal plants and their uses by nigerian farmers [Plantes médicinales et leur utilisation traditionnelle chez les paysans au Niger]. Études sur la Flore et la Végétation du Burkina-Faso et des Pays Environnants, 2001; 6:9–18.

16.

Koné

, Atindehou

, Téré

, Traoré

. Some medicinal plants used in traditionnal pediatry in the region of Ferkessédougou (Ivoiry Coast) [Quelques plantes médicinales utilisées en pédiatrie traditionnelle dans la région de Ferkessédougou (Côte d'Ivoire)]. Bioterre, 2002; 30:30–36.

17.

Kouyaté

. Aspects ethnobotaniques et étude de la variabilité morphologique, biochimique et phénologique de Detarium microcarpum Guill. Et Perr. au Mali. Thèse, Université de Gand (Belgique), 2005.

18.

Sahli

, Fadli

, Zidane

, Douira

. Etude floristique et ethnobotanique des plantes médicinales de la ville de Kénitra (Maroc). Lazaroa, 2010; 31:133–146.