ETHNOBOTANICAL SURVEY OF MEDICINAL PLANTS USED IN THE MANAGEMENT OF HYPERTENSION IN THE MARITIME REGION OF TOGO

Background: Hypertension is one of the most common chronic diseases in modern societies and there is evidence that its incidence and severity are increasing. This survey was conducted to investigate the plants used by the Togolese traditional healers to treat the disease. Method: From January to June 2016, an ethnobotanical survey was conducted using a semi-structured questionnaire with traditional healers (TH) in the southern region of Togo. The importance of the plants was assessed by the calculation of the use value (UV). Results: In Total, 128 TH male and female were interviewed and 116 plants species belonging to 46 families were identified as treating hypertension. The most represented families were: Fabaceae with 16 species followed by Euphorbiaceae and Rutaceae contributing with 8 and 6 species respectively. Based on the calculated use values the most important species were Byrsocarpus coccineus Schum. Et thonn. (UV = 0.47); Crateva religiosa G.Forst. (UV = 0.47), Boerhavia diffusa Engelm. &A.Gray L. (UV = 0.47), Xylopia aethiopica A. Rich. (UV = 0.42), Mangnifera indica L. (UV = 0.38). The leaves and the roots were the parts of plant predominantly used to prepare the recipes, mainly decoctions administrated by oral route. Clinical manifestations such as dizzy spells, swarming, loss of consciousness, severe headache, severe anxiety and shortness of breath, nosebleed, and fear of heights were used by TH to diagnose the disease. Conclusion: This study showed initial evidence of the use of plant materials by Togolese TH to treat hypertension. These results constitute a database for pharmacological screenings with the aim of developing new therapies.


Introduction
Nowadays, there is a renewed interest in medicinal plants research because of health problems that remained unsolved (Briskin, 2000;Rafieian-Kopaei, 2011;Atanasov et al., 2015).The main examples are infectious disease such as malaria (Larremore et al., 2015;Rosa et al., 2015) and bacterial infections (Cohen et al., 2015;Le Doare et al., 2015;Oneko et al., 2015).To these diseases are added cancer and metabolic diseases such as diabetes and arterial hypertension whose incidence is increasing (Frohlich, 2001;Sowers et al., 2009).Hypertension is generally a chronic condition and is often associated with few or no symptoms.Symptoms usually occur when blood pressure spikes suddenly and extremely enough to be considered as a medical emergency.Rare symptoms include dizzy spells, headaches, and nosebleeds (Svilaas et al., 2008).Many people may suffer from the disease without knowing it.Uncontrolled high blood pressure, or hypertension, causes damage to arteries.It is also a risk factor for stroke, heart attack, and other cardiovascular problems.
There are a number of treatments for high blood pressure, ranging from lifestyle changes, weight loss, and medication.Many efforts are being made in synthetic chemistry to bring to market new drugs against the disease, but the need for new molecules arises today with acuity.This current situation justifies the new resurgence of interest in medicinal plants, given their potential in this matter (Gali-Muhtasib et al., 2015; Baharvand-Ahmadi and Asadi-Samani, 2016).In the particular case of hypertension, there is a high prevalence of usage of complementary medicine.Indeed, plants have always contributed largely in the fight against various diseases, considering the number of remedies derived directly or indirectly from plants (Dzib-Guerra et al., 2016;Rouhi-Boroujeni et al., 2016).Consequently, in the recent decades, the medicinal plants used in the management of the disease have attracted the attention of some authors, through the screening for loss level blood pressure activity of plant extracts.
In Africa, it is a question of culture and tradition and it is estimated that over 80% of the population in rural areas have exclusive use of plants for their primary health care needs (Baharvand-Ahmadi et al., 2016).Increasingly, studies related to medicinal plants are conducted by researchers in Africa and some lead to the identification of active principles (Tchacondo et al., 2012;Ilboudo et al., 2013).However, data on the ethnobotany of plants used in the management of Hypertension are scanty.In the particular case of Togo, Karou et al. (2011) conducted a study of the plants used in the treatment of diabetes and hypertension in the central region, one of five regions in the country.Data are missing for the rest of the country.The present study was undertaken to investigate the treatment of Hypertension by traditional healers in the Southern region of Togo.

Study area
Togo is a western African country lying between Burkina Faso in the North, Benin in the East, Ghana in the West and the Atlantic Ocean in the South.The country is divided into five economic regions namely Savannah Region, Kara Region, Central Region, Plateau Region, and Maritime Region.The present study was carried out in the Maritime Region (figure 1).It stands between 1°20'-1°50' east and 6°10'-6°60' north of the equator and bordered to the north, West, East and the South by Plateau Region, Republic of Ghana, Republic of Benin and the Atlantic Ocean respectively.This study area is 6100 km 2 big and occupies approximately 10.78% of the country.The climate is subequatorial.The region is inhabited by 1.828.000people (density of 50 -200 persons/km 2 ), the main ethnic groups being Ewe, Ouatchi, Mina, Fon, Adja.

Data collection
Direct interviews with traditional healers (TH) were conducted between June and August 2016 using a semistructured questionnaire.Each TH gave a verbal consent certifying his/her agreement with the form issued to explain the importance of the information they would provide prior to interviews.Questions asked were about (i) the TH identity, i.e. name and surname, sex, age, level of education; (ii) the origin of their knowledge; (iii) the status of the TH, i.e. full-time professional TH or part-time professional TH; (iv) the disease, i.e. name of the disease in the local language; (v) the diagnosis, i.e. main symptoms; and (vi) the remedies, i.e. the number of plants in the remedy, the local names of the plants, the used parts, the mode of preparation, and the administration route.

Plant identification
After interviews, preliminary identification of the plants was done in the field by a botanist.Afterward, herbarium specimens were prepared and pictures were taken to help in the confirmation of the identity of the plants.Plant identities were confirmed by comparison with available voucher specimens in the Herbarium of the Botany Department, University of Lomé, using taxonomic keys of online databases of West African Plants -A photo Guide on the website: http://www.westafricanplants.senckenberg.de/root/index.php.Nomenclature of species was done using the online data base of IPNI website: http://www.ipni.org/ipni/plantnamesearchpage.do.

Statistical analysis
Excel spread sheet was used to make simple calculations and to determine plant frequencies.The use value (UV), a quantitative method that demonstrates the relative importance of species known locally, was calculated according to the following formula (Aburjai et al., 2007;Hudaib et al., 2008): where, UV is the use value of a species; ΣU the total number of citations per species; n the number of informants.The other analyses were performed using PRISM 5.02 program (GraphPad Software, Inc., La Jolla, USA).Since most of the variables did not show a normal distribution, the following tests were chosen: to compare three groups a Kruskal-Wallis-test was performed and, if significant, followed by a Mann-Whitney-U test for a further comparison of the groups.P-values of 0.05 or less were considered significant.

Socio-demographic profile of the traditional healers
One hundred and twenty-eight traditional healers (83 males and 45 females) were interviewed in the present study.Table 1 displays the socio demographic profile of the TH.The TH were divided into five age groups, notably the less than 30 years, 30 to 50, 50 to 70, 70 to 90 and the more than 90 years.According to the recorded data on the TH implicated in the treatment of arterial hypertension in the surveyed region, the 30 years and 70 to 90 years old individuals accounting respectively for 9.38 and 31.25% were less represented compared to either 30-50 years or 50-70 years old people.Only 2 TH were above 90 years.With regards to the ethnic groups the majority belonged to the native ethnics of the region namely the Ewe (50.00%) and Mina (25.00%).Three religions were recorded; the Animists, the Christian and the Muslims, but the most represented were the Animists (43.75%) and the Christians (41.41%).Concerning the educational level, the TH could be ranged the following groups: the illiterates, the primary school level, the secondary school level and the university level, with respective contributions of 23.44, 39.06, 31.25 and 6.25%.The TH who attended primary school level were more compared to secondary school (p=0.0003) and university level.The familial heritance, the initiation from a senior TH and the divine revelation were the recorded means of transmission of the medicinal practice among the surveyed TH.Our results indicated that the family inheritance accounting for 42.97% of TH was the most common mean for the transmission of the knowledge, followed by the divine revelation and the traditional (p<0.0001).The TH in the formal sector (44.53%), thus exerting the traditional medicine as a secondary occupation were more represented in the Hypertension treatment compared to either artisans (p<0.0001) or farmers (p=0.0002).Only 22.66% TH exerted the traditional medicine as the unique source of revenue.Thus we could find that for the payment, the majority (49.22%) of them receives the payment after pain relief but an important portion (35.16%) receives the payment before the treatment.Some of the TH (23.44%) argued they collaborate with the modern medicine by referring the most complicated cases, the other do not collaborate.

Symptoms used by TH for the diagnosis of High Blood Pressure
A total of 8 symptoms were identified (table 2).A particular symptom was not used alone to identified the disease, hence a TH could cited more than two symptoms in the diagnosis of the disease.According to table 2, all the TH cited the nosebleeds as the main symptom of hypertension.In the order of importance the other symptoms were ranged as follows: Headache, swarming, loss of consciousness, dizzy spells, anxiety, shortness of breath and the fear of height.

Diversity of medicinal plants and their usage in the treatment of Hypertensionin the maritime region
A total of 116 plants species ranged in 46 families were recorded in the present study.The plants consisted of trees, herbs, lianas and shrubs; the most frequent growth habits being the trees and shrubs.They accounted for 56.41% and 22.05 % respectively (figure 2).The species were diversely distributed among botanical families.Thus, some families were more represented than others.The most represented family was the Fabaceae that contributed with 16 species namely Baphia nitida Lodd., Indigofera pulchra Willd., Milletia thonningii Baker., Parkia biglobosa Benth., Pericopsis laxiflora Benth.Ex Baker Meeuwen , Xeroderris stuhlmannii Taub Mendoça & E.P. Sousa , Callindra haematocephala , Afzelia Africana Sm. , Cassia occidentalis L. , Senna hirsute, Piliostigma thonningii (Schum.)Milne-Redh., Senna occidentalis (L.) Link ,Senna alata(L.)Roxb,), Albizia adianthifolia schumwhight, Uraria picta , Afrormosia laxiflora Benth.Exbak.Harms.This was followed by Euphorbiaceae contributing with 8 species (Croton lobatus L., Elophorbia grandifolia (Haw.)Croizat, Euphorbia hirta L., Jatropha curcas L., Jatropha gossypiifolia L., Phyllanthus amarus Schum., Ricinus communis L. and Securinega virosa Willd.Baill.) and Rutaceae with 6 species(Citrus aurantifolia (Christm.)Swingle, Citrus aurantium L., Citrus grandis Hassk., Clausena anisata (Willd.)Hook.f.ex Benth., Fagara macrophylla Engl., and Zanthoxylum zanthoxyloides (Lam.)Zepern.& Timler).The other families contributed with less than 5 species.The importance of medicinal plants was assayed by the calculated use values (UV) that were ranged between 0.05 for the less used species and 0.47 for the most used species (table 3).Considering these UV, the following species appeared to be of great importance for the management of hypertension in the surveyed region: Byrsocarpus coccineus The TH in the maritime region of Togo were found to use various parts of plant in the treatment of hypertension.Figure 3 displays the trends of use of the various plants parts.The leaves (52.63%) are the main parts of plants used in the preparations of recipes for the treatment of High Blood Pressure.A total of 7 modes of preparation including decoction, infusion, powder, tea, crushing, alcoholic maceration and juice, were identified.Decoctions were obtained by boiling either fresh or dried materials in water.However the amount and the duration varied from one TH to another.In some cases, the TH could give the prepared decoction or in other cases the TH gives the plant materials and the indications to prepare the recipes.Crushing was obtained from fresh materials by direct pounding in a mortar and the filtration through a tissue and the filtrate could be directly administrated in the appropriate dose by oral route.The juice from Rutaceae was obtained by pressure of the fruit.The tea was obtained by maceration of dried materials in water for the appropriate time and administrated by oral route.Only one case of alcohol maceration was recorded in the case of Chenopodium ambrosiodes L. This is prepared by maceration of the powder of leaves in the traditionally distillated liquor from palm wine locally known as Sodabi.In some cases, there are additives such as honey, or milk the TH recommend the use.According to our results, decoctions were more used by TH compared to the powder (p=0.15).Both were predominantly used by TH compared to other formulations (Figure 4).As indicated in figure 5, most of the formulations were administrated by the oral route (91.06 %, p<0.0001).This was followed by bath (5.28 %).In contrast, few TH preferred bandage, massage, poultice, cataplasm and smoking.

Discussion
The present survey was undertaken to identify medicinal plants used in the south of Togo for the treatment of hypertension.We were first interested in the mode diagnosis of the disease by the TH.The results revealed that all the surveyed TH were able to cite the mains symptoms.We observed that severe headache, severe anxiety, shortness of breath, nosebleed, Loss of consciousness and fear of heights were commonly used by TP to diagnose the disease before the treatment.However the risk of misdiagnosis remains, as very few of them collaborate with the modern medicine.In fact, some authors reported the problems of misdiagnosis by traditional healers for some diseases that were not common in African areas.These diseases often called emerging diseases in Africa included cancers and metabolic diseases like hypertension (Alonso-Castro et al., 2011; Taylor et al., 2014).
Different plants species were used by Togolese TH to heal hypertension attack.There were 116 species of plants with the Fabaceae family as the most dominant with 16 species.In the same context, a previous study was carried out in the central region of the Togo (Karou et al., 2011).The study enabled the identification of 38 antihypertensive recipes; while in a similar study Tsabang et al. (2016) identified 71 recipes both treating arterial hypertension and diabetes in Cameroon.The recipes from Togolese TH were made from 64 plant species in the flora of Togo.The most commonly cited as antihypertensive were Parkia biglobosa, Khaya senegalensis, Gardenia ternifolia, and Persea americana.In comparison with previous published reports, the THs of the Togo Central Region were found to have basic knowledge regarding herbal medicine for the treatment of hypertension [19].Investigations on medicinal plants in the markets of Abidjan allowed the inventory of 58 species of plants used to treat 19 current diseases (N' Guessan et al., 2009).Thirty-nine of these plants were used against arterial hypertension and diabetes.These plants were Catharanthus roseus (L.) G Don, Ageratum conyzoides L, Vernonia colorata (Willd.)Drake, Alchornea cordifolia (Schum.&Thonn.)Müll.Arg., Phyllanthus amarus Schum.&Thonn.andParkia biglobosa (Jacq.)Benth (N' Guessan et al., 2009).In morocco an ethnobotanical surveys allowed an inventory of 57 medicinal plant species belonging to 52 genera and 30 families.Of these, 40 are traditionally used against diabetes and 30 against hypertension (Ziyyat et al., 1997;Tahraoui et al., 2007).
In Benin a neighboring country of Togo, ethnobotanical surveys were carried out with 36 trait-therapists from the Bassila district using individual interviews.A total of 23 plant species belonging to 16 botanical families were reported to have antihypertensive properties.The most cited species were Parkia biglosa, Allium sativum, Allium cepa and Cassia sieberiana.The root was the most widely used plant organ and the decoction was the main mode of preparation of medicinal products which are generally administered orally (Anselme Bio et al., 2005).Another ethnopharmacological studies have identified medicinal plants used for their antihypertensive properties of which eleven were harvested and tested for the vasodilatory activity.Two species namely Parkia biglobosa and Spondias mombin displayed promising results (Anselme Bio et al., 2005).
In the present study the most important plants were Byrsocarpus coccineus, Crateva religiosa and Boerhavia diffusa on the basis of the use value.These three plants were already cited in the literature for similar use in the traditional medicine.Moreover, Dada et al. screened Byrsocarpus coccineus for its antihypertensive activity and found an interesting activity of the hydroethanolic leaf extract in relation with the antioxidant property and improvement of lipid profile (Dada et al., 2013).

Conclusion
This survey provides initial evidence of the use of plants by Togolese traditional medicine practitioners to manage Hypertension and this by family inheritance in traditional initiation manner, as the species were cited at least once in previous ethnobotanical reports.It is therefore necessary for scientist to go further in characterization of the biomolecules.The present inventory therefore represents the contribution of natural flora of Togo to the global approach in controlling hypertension.

Figure 1 :
Figure 1: Map of Togo showing the Maritime Region

Figure 2 :
Figure 2 : Parts of the plants used for the treatment of High Blood Pressure.

Figure 3 :
Figure 3 : Mode of preparation of recipes used in the management of hypertension

Figure 4 :
Figure 4 : Administration route of medicinal recipes used in the management of hypertension

Table 1 :
Socio-demographic profile of the surveyed traditional healers

Table 2 :
The symptoms of hypertension cited by the surveyed traditional healers