Diversity and Endogenous Knowledge of Aphrodisiac Plants in South and Central Benin

Background: The use of aphrodisiac plants is a very common and ancient practice in Africa. This study, conducted in central and southern Benin, aimed to document endogenous knowledge related to ora, valorization, promotion and conservation of plants species used for aphrodisiac purposes. Methods: Data were collected using ethnobotanical and market surveys from 134 people followed by observations. Results: A total of 138 aphrodisiac plants species were recorded, including 72 from Center Benin and 20 from South Benin while 46 species were common to both areas. These species belong to 124 genera from 59 families mostly represented by Fabaceae (14.49%), Euphorbiaceae (8.76%), and Poaceae (4.38%). The predominant biological type was Phanerophytes (57.25%). The chorological analysis identied a dominance of Sudano-Guinean (26.09%), Pantropical (24.64%) and Guinea-Congolian species (19.57%). Aphrodisiac plants were used for 220 recipes to treat eight affections from which the common was sexual weakness (88.80%). Roots (33.12%) and leaves (20.13%) were the most used parts. The maceration (44.76%) and oral route (88.11%) were the main galenic form and the main mode of administration, respectively. Conclusion: This ora represents a raw material for subsequent phytochemical characterization to identify new aphrodisiac properties, leading to produce Improved Traditional Medicines against sexual disorders. frequent. Other sexual disturbances treated were azoospermia (12.80%), premature ejaculation (12.80%), sperm deciency (11.20%), impotence (8%), lack of libido (4.80%), frigidity (4%) and non-development of the penis (2.40%). Informants were agreed more in the treatment of sexual weakness (ICF = 0.75) followed by sperm deciency (ICF = 0.67), precocious ejaculation (ICF = 0.55) and the lack of libido (ICF = 0.52). The informant consensus factors for the other ailments treated were 0.5, 0.37, 0.33 and 0.25 respectively for non-development of the penis, azoospermia, frigidity and Impotence. Aphrodisiac plants with the highest Fidelity Level (FL = 100%) accounted for 79.71% (110/138) of all species recorded. High degree of consensus was observed among informants on the use of a great number of aphrodisiac plants (96 species, 69.57%) to manage sexual weakness such as Acridocarpus smeathmannii, Citrus aurantifolia, Cyperus esculentus, Garcina kola, Imperata cylindrical and Pachycarpus lineolatus which were cited among commonly used species. But few aphrodisiac plants with highest delity level were found for other sexual dysfunction treated. Early ejaculation was more treated with Solenostemon monostachyus (FL = 100%), azoospermia more treated with Dioscorea praehensislis, Heliotropium indicum and Tragia senegalensis (FL = 100% for each), impotence more treated with Blumea viscosa, Icacina oliviformis, Mallotus oppositifolius and Sida garckeana (FL = 100% for each), the lack of libido more treated with Saccharum ocinarum (FL = 100%), sperm deciency more treated with Acacia polyacantha, Abelmoschus esculentus, Desmodium gangeticum (FL in the wild (EW), four (04) were endangered (EN) and eleven (11) were vulnerable. Based on the ongoing degradation and conversion of natural habitats in Benin, awareness-raising actions on the risks of residual populations of aphrodisiac plant, reforestation and promotion of medicinal plant gardens should be encouraged. the common sexual dysfunction treat and for which nine (9) aphrodisiac plants were mostly used: Acridocarpus smeathmannii, Citrus aurantifolia, Cyperus esculentus, Garcina kola, Imperata cylindrica, Pachycarpus lineolatus, Borassus aethiopum, Cola acuminata and Caesalpinia bonduc (FL ≥ 91% for each species). Some previous studies revealed that Acridocarpus smeathmannii (Kale et al. 2018), Borassus aethiopum (Gbesso et al. 2016), Garcinia kola (Ojo et al. 2019), Caesalpinia bonduc (Gbankoto et al. 2015), Cyperus esculentus (koud et al, 2016), Imperata cylindrica (Gaikwad al. 2019) and Cola acuminata (Eromosele et al. 2018), contained pharmacological agents for the treatment of erectile dysfunction. But According to Idris et al. Citrus aurantifolia juice should be consumed with caution due to its potential to cause infertility in males.

seasons. Annual mean temperature ranges from 26 to 28 °C and annual rainfall varies between 800 to 1400 mm (Yabi and Afouda 2012). Central Benin is characterized by a Sudano-Guinean climate with annual rainfall ranging from 800 to 1200 mm (Adam and Boko 1993). The vegetation mainly consists of savannahs, grasslands, farmlands, and fallows intermingled with small islands of closed forest (semi-deciduous forest and swamp forest) (Adomou 2005).
They are source of aphrodisiac plants for people. According to the national statistic, the population of all surveyed districts is estimated to 3,526,182 inhabitants (INSAE 2016). The main ethnic groups are: Mahi, Fon, Idaatcha, Tchabè, Adja, Nago, Holli and Aïzo. People activities are mainly agriculture, farmed, shing, hunting, trade, craft, transport, exploitation of rewood, products transformation and medicinal plants harvesting.

Sampling
Choice of sites surveyed was based on sociolinguistic groups that dominated the villages and the presence of a category group of people such as traditional doctors, polygamists (considered as the main users of aphrodisiac plants), herb sellers, hunters, farmers, and resource people who hold endogenous knowledge on aphrodisiac plants. Considering these two fundamental criteria, nineteen (19) villages and six (6) markets were selected after exploratory survey. The sample size of the respondents in central and southern of Benin was determined according to the formula of Dagnelie (1998): n where, n is the sample size of surveyed people considered in each region; is the value of the normal random variable for a probability value of α = 0.05, = 1.96; p is the proportion of people who know and had already used at least one aphrodisiac plant (the value of p is respectively 0.82 and 0.92 in Central and South Benin; result from a preliminary survey) and d is the expected error margin of any parameter to be computed from the survey, which is xed at 0.08. Under those assumptions, the sample size (n) equal to 90 people in Central Benin and 44 people in South Benin. Thus, a total of 134 respondents were surveyed throughout the study area. The "snowball" method (Johnston & Sabin, 2010) was used to identify majority of people surveyed per village. However, people were reticence in some villages leading sometimes to a very low number of respondents. Sellers of medicinal herbs surveyed in markets were selected based on two criteria: the great number of medicinal plant parts sold (Ambé et al. 2015) and the presence of aphrodisiac plant organs in their display.

Ethnobotanical Data Collection
Data were collected using ethnobotanical and market surveys followed with direct observations of aphrodisiac plants in their habitat. Structural individual interviews technique using a questionnaire was used. In each village, interviews were conducted with the help of a local translator. Data collection included socio-demographic characteristics (name, age, sex, ethnic group, religion, main activity, etc.), list of aphrodisiac plants used, supply habitats and organ harvesting period; status (wild, cultivated, weed) of each plant, forms of usage, knowledge related to the medicinal properties (diseases treated, plant organs used, associated ingredients, the mode of remedy preparation and administration) and causes of sexual dysfunction symptoms. Market data were related to aphrodisiac plants sold (inventory, organs used, preparation methods, and posology). Throughout the market survey, the interview was followed by aphrodisiac plants parts purchasing that are placed in a herbarium (Adomou et al. 2012).

Data analysis
Data from ethnobotanical and market surveys were analyzed through descriptive statistical as frequency, mean (± sd); some results were presented using gures and tables. Synthesis in tabular form was done in order to perform results. We applied the Relative Frequency of Citation (RFC) according to Tardìo and Pardo de Santayana (2008) to assess the importance of each species and determine the commonly used aphrodisiac plants. RFC = FC/N with FC: number of people having quoted the species; and N: total number of interviewed people.
The response rate by use categories was calculated using the following formula: F = S/N x 100, with F the response rate for a given use, S the number of informants who mention a given use of the species and N the number of informants participating in the study.
The Shannon-Weaver Diversity Index (Dajoz 1985) was computed to assess the level of speci c diversity of aphrodisiac plants used in the study area. Its formula is: H' with ni = number of aphrodisiac plants identi ed in zone i and N = total number of aphrodisiac plants recorded throughout the study area.
In order to compare the diversity of aphrodisiac species inventoried in central Benin to that of south Benin, the Student's t-test and the Mann-Whitney test were performed using the software Minitab 17.
The similarity index of Jaccard (Jaccard, 1908) was determined as: SJ with N x = number of species in southern Benin, N y =number of species in central Benin and N xy the number of common species to two areas. This allowed us to calculate the similarity rate between the two zones (SJ x 100).
The endogenous knowledge on aphrodisiac plants was evaluated for all sociocultural groups computing knowledge indices (KI) analogous to the use value of Phillips and Gentry (1993) as follows: KI=s/n with S = number of useful aphrodisiac species cited by a given sociocultural group and n = number of informants within the sociocultural group.    herbaceous and lianas were least represented respectively with 29.71% and 11.59%. The biological spectrum (Fig. 2) showed that Phanerophytes (57.25%) were largely dominant followed by Therophytes (13.77%), Geophytes (10.14%), Chamephytes (6.52%), and Hemicryptophytes (4.35%).
Our results also revealed that 35.42% of aphrodisiac plants species grown in natural habitats (savannah, saxicolous meadows and gallery forests etc.) while 27.92% originated from home gardens, 20.83% were found in fallow and 15.83% were domesticated and cultivated as crops.

Plant parts and uses
Parts of plants used as aphrodisiac in sexual dysfunction treatment were presented in Fig. 3. Roots (33.12% representing of herbal preparation) followed by leaves (20.13%) and fruits (12.99%) were the most used part of aphrodisiac plants. These results were illustrated by a great proportion of roots observed among different plants parts sold in the markets surveyed.
The most frequent mode of remedy preparation was maceration (44.76%, Fig. 4). This is alcoholic in most cases so that aphrodisiac plant organs (often roots) were soaked in palm wine or other alcoholic solvent for 24 to 72 hours before used. The other modes of preparation are pounding (22.38%), crudity (17.13%), trituration (6.29%), decoction (5.59%), powdering (3.15%) and calcination (0.70%). In order to make aphrodisiac remedy e ciency, some traditional healers associated different ingredients with plant parts when prepared their concoction. Ingredients included parts of wild animals (ivory and elephant penis, buffalo horn, horse penis, squirrel penis etc.), penis of domestic animals (goat, dog, rooster, duck etc.), food supplements (Eggs, cow's milk, honey, lemon juice, palm oil, sugar etc.), mineral and similar elements such as kaolin, white gravel, spike etc.
Application of the aphrodisiac remedies was generally done by oral route through drinking, porridge, others (88.11%) followed by mastication (6.99%), local application (4.20%) and anal route (0.70%) (Fig. 5). Mastication was linked to raw vegetables including vegetable brushes. Local application concerned the application on the penis (3.50%) and in the vagina (0.70%). The anal route (suppository) can be perceived here as purgation.

Disorders frequently treated by aphrodisiac plants and consensus evaluation on remedy
The total of 138 aphrodisiac plants recorded is used in the formulation of 220 recipes to treat eight (8)

Causes of sexual dysfunction according to informants
Our ethnobotanical survey revealed ten (10) causes of sexual dysfunction of which excess alcohol drinking and some diseases/infection (hemorrhoids, diabetes, ulcers, hypertension, gonorrhea, chancroid etc.) were the most represented (with a proportion of 17.46% each). Other causes such as abuse of sex (11.11%) especially during youth, excess of table (very fat and very sweet dishes, 9.52%), psychological troubles (fear, nervousness, worries etc., 9.52%), mystical causes (bewitchment, adultery, contact of breast milk with the boy's penis during breastfeeding etc. 9.52% each), age increased (7.94%), others causes such as excessive consumption of pharmaceuticals and bitter herbal teas, excess plowing, accidents and sexual abstinence (7.94%), heredity (4.76%) and lack of sport (4.76%).

Market data
Most plant organs sold for aphrodisiac purposes in the six (06) markets surveyed, resulted in a total of nineteen (19) plant species. All these species were recorded during ethnobotanical survey; eight (8) of them were among the fteen aphrodisiac species commonly used. Moreover these eight (8) Table 3 listed these aphrodisiac plants recorded, the main organs sold and their status. Herb sellers interviewed mentioned that their customers were mostly old and adults men but rarely young people.  According to van Andel et al. (2015), in order to guarantee a continuous supply of herbal medicine in the future, appropriate management plans must be designed, for which speci ed information on species occurrence and extraction localities is needed.
In addition, the present study showed that aphrodisiac plant buyers were mainly old men. This is not surprising because men's sexual capacities reach their peak in the range of 25 to 35 years of age (Ondele et al. 2015). Sexual intercourse for the elderly aims to maintain health and harmony within the married couple. But it would be wise not to have sexual intercourse too prolonged at the old age (60 to 70 years). .  Plant parts and manner of use There is a need for phytochemical data on underutilized parts of species such as Pachycarpus lineolatus, Acridocarpus smeathmannii, Curculigo pilosa and Caesalpinia bonduc which were cited by herbs sellers as rare species to nd while its demand is growing. Contrary to the devastating effect that the use of roots can cause to plant biodiversity, the high frequency of use of leaf in recipes is a great advantage for the preservation of plant biodiversity because they are less dangerous apart from owering delay due to allocations.

Ecological parameters of aphrodisiac plants
Moreover, maceration (44.76%) was the most frequent mode of aphrodisiac remedies preparation. These result contrasted those on leaf decoction obtained by Kambalé (2012). For the present study, alcoholic maceration was the most suitable for extracting aphrodisiac active ingredients from the roots. According to Lévy and Garnier (2006), the consumption of alcohol in moderate quantities would constitute a substance lifting inhibitions, which would amplify sensations and contribute to increase sexual arousal. Chikere et al. (2011) reported also that alcohol drinking enhances pleasure during period of sex. But studies are needed in order to nd more suitable solvent for the human body other than alcohol that can be one cause of sexual weakness. Indeed, with the unrestrained quest for income following the world economic crisis, the traditional alcohol resulting from the distillation of palm wine and the other solvents are often adulterated alcohols of all kinds that are unsuitable for human health. Other solvents should be sought, except water.
Moreover, we notice that some traditional healers associated ingredients such as ivory and elephant penis, buffalo horn, horse penis and squirrel penis when prepared their aphrodisiac remedy. This is very dangerous and can lead in disappearance of these wild animals. Sensitization actions are needed in order to discourage this practice reducing animal biodiversity.
Sexual weakness appeared as the common sexual dysfunction treat and for which nine (9)

Causes of sexual dysfunction treated
In this study, it was found that the main causes of sexual dysfunction were excess alcohol drinking and some chronic diseases (17.46% of each) followed by sex abuse (11.11%), excess of table, psychological disorders, mystical causes (9.52% of each), aging (7.94%), heredity and lack of exercise (4.76% of each).
Similar results were found by Jain (2019) and Seisen et al. (2012). Chronic diseases cited here suggested that their prevention can help prevent sexual dysfunctions. Here again, regarding of excess alcohol drinking, there is an urgent need for sensitization people in order to limit human healthy damage.

Conclusion
This ethnobotanical study allowed the registration of aphrodisiac plants species and documented their traditional uses in Central and South Benin. A total of 138 aphrodisiac plants species were recorded, including 72 from Center Benin and 20 from South Benin while 46 species were common to both areas. Fifteen (15) of them were commonly used. Aphrodisiac plant species were mainly phanerophytes. Aphrodisiac plants were used for 220 recipes to treat eight affections from which the common was sexual weakness (88.80%). Roots (33.12%) and leaves (20.13%) were the most used parts. The maceration (44.76%) and oral route (88.11%) were the main galenic form and the main mode of administration, respectively. Study has provided basic information to pharmacological researches. It is therefore desirable that thorough phytochemical and pharmacological studies be carried out on these plants for their scienti c validation. A problematic use of aphrodisiac plant relies on roots overexploitation and their maceration using adulterated alcohols unsuitable for human health. This requires sensitization campaigns.

Declarations
Ethics approval and consent to participate Ethical considerations were addressed prior to starting the interviewing process with each participant. The purpose of the interview and study was explained verbally to each one of the informants. Their consent was requested for recording the process and using the provided information for the purposes of scienti c research. Respondents were explicitly noti ed that their participation is voluntary, con dential, and non-identi able. All participants in this study, including plant sellers and traditional healers agreed to give consent before moving on to the data collection processes.   Geographical location of the study area Figure 2 Biological spectrum of aphrodisiac species Figure 2 Biological spectrum of aphrodisiac species Percentages of aphrodisiac plants parts used Modes of remedy preparation Modes of remedy preparation Mode of recipes administration