Herbal Cosmetics Knowledge of Arab-Choa and Kotoko Ethnic Groups in the Semi-Arid Areas of Far North Cameroon : Ethnobotanical Assessment and Phytochemical Review

The plant-based traditional knowledge of many Cameroonian populations concerning beauty and skin care is still poorly documented, yet they are real resources of innovation and economic development. The aim of this study is to document the indigenous knowledge of Choa Arab and Kotoko ethnic group in Kousséri (Far North Region of Cameroon) about plants used for cosmetics. Ethnobotanical data collected among key informants revealed a total of 13 plants species belonging to 12 families used by local people. Canarium schweinfurthii Engl and Santalum album L. obtained the highest frequency of citation. Trees are the most abundant life forms, while barks and seeds are the most frequently used parts. More than 40% of recorded plants are used for skin care. The cosmetic allegations of recorded plants include: dermatology, anti-cancers, antioxidant agent, perfume, anti-inflammatory, antimicrobial, wounds healing activity, skin lightening, dental caries, astringent and hair care. They all contain various phytochemicals that are of interest in cosmetics. Despite the strong relationship between the Choa Arab and Kotoko people and herbal cosmetic ingredients, these plants are still less investigated for their cosmetic application. The authors urge for the development of sustainable supply chain for plants with potentials as cosmetics, involving local communities in the planning, implementation and monitoring process, following principles of Nagoya protocol on Access and Benefit Sharing.


Introduction
The Far North Region of Cameroon is part of the African dryland ecosystems comprising five main Eco-regions: sahelian Acacia savannah, East sudanian savanna, Mandara Plateau mosaic, afrotropic Lake and Lake Chad flooded savannah [1].This area, known as semi-arid is an important reservoir of plant biodiversity and has been receiving increasing attention from the scientific community [2,3].This is because dryland biodiversity contains distinguishable features that are often overlooked.These include heterogeneity, remarkable diversity of micro-organisms, presence of wild relatives of globally important domesticated species, and traditionally adapted land use systems.As many other dryland ecosystems around the world, the Far North Region of Cameroon is among the most vulnerable to the global environmental problems such as desertification, climate change and loss of genetic resources [4].It contains many of Africa's poorest and most food insecure people [5].
Conserving and valuing drylands natural resources are considered a pathway to raise awareness among all stakeholders and stimulate wider action to boost drylands conservation and development.
In Africa in general, local plant-based traditional knowledge have been used in conserving biodiversity and enhancing many essential services to society including material goods (for example, food, timber, medicines, cosmetics and fiber), ecosystem functions (flood control, climate regulation, and nutrient cycling), and nonmaterial benefits such as recreation [5].Cosmetic products, according to European Union directives is defined as "any substance or preparation intended to be placed in contact with the various external parts of the human body (epidermis, hair system, nails, lips and external genital organs) or with the teeth and the mucous membranes of the oral cavity with a view exclusively or principally to cleaning them, perfuming them, or protecting them in order to keep them in good condition, change their appearance or correct body odours" [6].Cosmetics have been used for as long as there have been people to use them.They have been present in almost all civilizations, and have been used in various forms and in many different circumstances (burial of the dead, religious rituals and everyday life), with the aim of preserving health and amplifying beauty.Researchers have reported the presence of paint pigments in archeological contexts over 75,000 years old.As early as 4000 BC, ancient Egyptians used natural resources to produce cosmetics [7] which were an integral part of their daily hygienic routine.They used creams and oils for protection, because of the hot and dry climatic conditions of Egypt.Of the majority of perfumes used in that period of time in religious practices and preservation of the dead, there were essential elements from herbs like cedar, peppermint, almond oil, rosemary, rose, Aloe vera, sesame oil, chamomile, and lavender [8].Anti-wrinkle preparations with fresh squeezed olive oil, cypress, and scent mixed with freshly obtained milk was applied on the face for a week by Egyptians [9].Furthermore, there is literature evidence supporting that ancient Egypt was the birthplace of aromatherapy; oils, perfumes and fragrance derived from pine trees and flowers were used by women, which demonstrates the vital role cosmetics played for this civilization [8].
Several ethnic groups live in the Far North Region of Cameroon and results from previous ethnographic survey have shown the predominance of five ethnic groups: Mousgoum, Bornouan, Peulhs, Arab Choa and Kotoko.The Kotoko historically trace their origins to the Sao people, early inhabitants of the Lake Chad area who converted to Islam beginning in the 16th century [10].The Arab Choa group is found mainly in the Far North Region of Cameroon.Their origins can be traced as far back as the original seminomadic Arab tribes that populated the reaches of southern Egypt and pushed south into the Lake Chad region in the 14th century, where they live on the borders of Cameroon and Chad [10].
Natural resources extracted from plants have varied uses both on an industrial and traditional scale: pharmacology, herbal medicine, cosmetics, perfumes, dyes, insecticides, etc.Today, with the recent development of green technologies, the use of renewable raw materials plays a central role as an alternative to production processes that are not compatible with the principles of sustainable development.If pharmacopoeia that lists plants for therapeutic use have long been experiencing significant development, work in the field of traditional cosmetics are still poorly documented in writings.Ethnobotanical literature on folklore cosmetic knowledge is lacking in Cameroon, though historical experiences with plants as therapeutic tools have helped to introduce many cosmetic formulations.Indeed, early surveys on active principles of medicinal plants of semi-arid areas showed that a number of them contain numerous phytochemicals of interest in cosmetics [16].As the concept of Cosmetopoeia is being developed today to fill this gap, plants, by their ability to produce a wide variety of molecules, are receiving a growing interest for research in cosmetics.As for pharmacopoeia, cosmetopoeia is the repository of the use of plants for the beauty and body care.It represents an important part of the common history which unites the humans and their environment, and aims at better knowledge of the traditional uses of the plants in cosmetic in order to preserve them, to optimize their use in the respect of biodiversity and equitable benefit sharing.As the use of plant extracts in cosmetic formulation is currently increasing, mostly because of the poor image that chemical products have acquired during the past few years, there are many ongoing ethnobotanical investigations in Cameroon in search of new active cosmetic ingredients in the plant world.Among the Gbays ethnic group in East Cameroon, 36 plants and 78 derived cosmetic recipes were reported as used for facial masks and scrubs, body cream, hair cream, and preparation for teeth hygiene and dandruff among the Gbaya ethnic group in East Cameroon [17].They all contained phytochemicals like enzymes, minerals, vitamins, alkaloids, phenolic compounds, steroids, saponins, glycosides, carbohydrates, coumarins, lecithin, and essential oils that are all active cosmetic ingredients.
This ethnobotanical survey for herbal cosmetics was carried out to document the indigenous knowledge of Choa Arab and Kotoko ethnic group about plants used for cosmetics.

Description of the Study Site
The far North region of Cameroon is part of the Sudano-Zambesian Region in Africa.The climate is semi arid, characterized by a long dry season (October to May) and a short rainy season (June to September).Annual rainfall varies between 850 and 1100 mm per year [18], with an average of 529 mm.The temperature varies from 21.7 to 35.7 • C, with an average of 28.4 • C. The hydrology distribution is characterized by river flow in two main drainage basins associated with the river Niger and Lake Chad.The Logone river is the major one.The surrounding vegetation corresponds to a typical Sudano-sahelian type, comprising thorn-bush steppe and savanna dominated by Acacia species, with variations depending upon groundwater supply.Continuous vegetative cover is largely restricted to the margins of watercourses [19].Major ethnic groups populating the far North Cameroon include Arab-choa, Bornoa, Kotoko, Mandara from Cameroon and Kaninsou people who came from Chad.They practice agriculture, livestock farming, and fishing.

Research Method
Ethnobotanical data collection was done through interviews conducted with key knowledgeable native informants.A total of 24 key informants including 13 Kotokos and 11 Choa arabs participated in the survey.Information regarding plants, parts used, usage, mode of preparation and administration were documented.Plant species were identified using reference floras of drylands areas [20].Voucher specimens of unknown species were collected and preserved using standard herbarium techniques, and their identification was confirmed at the National Herbarium of Cameroon.

Plants Used As Traditional Cosmetics
A total of 13 plants species belonging to 13 genera and 12 families has been recorded during this study (Table 1).The plant Canarium schweinfurthii and Santalum album obtained the highest frequency of citation.

Research Method
Ethnobotanical data collection was done through interviews conducted with key knowledgeable native informants.A total of 24 key informants including 13 Kotokos and 11 Choa arabs participated in the survey.Information regarding plants, parts used, usage, mode of preparation and administration were documented.Plant species were identified using reference floras of drylands areas [20].Voucher specimens of unknown species were collected and preserved using standard herbarium techniques, and their identification was confirmed at the National Herbarium of Cameroon.

Plants Used As Traditional Cosmetics
A total of 13 plants species belonging to 13 genera and 12 families has been recorded during this study (Table 1).The plant Canarium schweinfurthii and Santalum album obtained the highest frequency of citation.

Biological Forms and Part Used
These plant species are of three botanical forms: trees, shrubs and herbs.Trees are the most abundant life forms accounting for 60.85% of all plants recorded, followed by herbs (33.33%), shrubs (5.82%) (Figure 2).* Bk = bark; Fb = Flower bud; Rs = resin; Lv = leaves; Fr = fruits; S = seeds; Rt = roots.

Cosmetic Use of the Recorded Plants
A great majority of recorded plants are used for skin care (42% of citations), perfume (27%) and for tattooing (11% of citations).Preparations for hair care were the least frequent use of recorded plants (Figure 4).

Cosmetic Use of the Recorded Plants
A great majority of recorded plants are used for skin care (42% of citations), perfume (27%) and for tattooing (11% of citations).Preparations for hair care were the least frequent use of recorded plants (Figure 4).

Cosmetic Use of the Recorded Plants
A great majority of recorded plants are used for skin care (42% of citations), perfume (27%) and for tattooing (11% of citations).Preparations for hair care were the least frequent use of recorded plants (Figure 4).

Phytochemical Review
For the 13 plants recorded, their cosmetic allegations concern essentially dermatology, anti-cancers, antioxidant agent, perfume, anti-inflammatory, antimicrobial, wounds healing activity, skin lightening, dental caries, astringent and hair care (Table 2).They all contain various phytochemicals that are all of interest in cosmetics.

Discussion
The 13 plant species identified in this study are well known for their various traditional uses in the tropical and semi-arid areas of Africa.Some like Elaeis guineensis, Arachis hypogae, Syzigium aromaticum, Citrus limon, Lawsonia inermis and Vitellaria paradoxa are very popular sources of cosmetic ingredients [17,47,48].
The uses of the resin/Gum, oil and fruits of Canarium schweinfurthii as food and medicine is well documented in Nigeria [49].
Terminalia avicennioides has been employed for many decades as a remedy to many diseases afflicting humans such as dental caries, skin infections, sore and ulcer, syphilis, bloody sputum, ringworm infection, gastrointestinal helminthes and several others [36,37].
Croton zambesicus is used in tropical west and central Africa to treat fever, dysentery and convulsions, urinary infections and malaria-linked fever [38].
Corn (Zea mays) is one of the most commonly grown foods in the world.Besides its use as food, Zea mays is used in therapeutics and cosmetics as analgesic, antiseptic, astringent, anti-diabetes, and diuretic, skin protectant, anti-inflammatory and anti-arthritic.Zea mays is also used to reduce tooth mobility, mitigate gum swelling and for its skin regenerative properties [50].
The Indian Sandalwood (Santalum album) is highly aromatic heartwood used to make artifacts and medicine.Sandalwood is well known for its uses in Indian traditions.In temples it is burned directly or in the form of incense sticks to worship Buddha [51].In modern aromatherapy, it is used as Antiseptic, antinflammatory, Astringent, Disinfecting, Emollient, Soothing, etc. [52].
Proso millet (Panicum miliaceum) is a good source of carbohydrates, protein, oleic acid, linoleic acid, stearic acid; essential minerals like phosphorus, manganese, calcium and magnesium; phytochemicals like phytate, which is associated with reducing cancer risks, along with phenolic acids and benzoic acids [34].
In Islamic Traditional Medicine, Saffron (Crocus sativus), is reported to be used as gastro-hepatoprotective, oxytocic, treatment of urogenital disorders, antidepressant, treatment of ocular disorders, treatment of respiratory disorders, cardioprotective effects, anti-cancer effects, absorption enhancing and anti-inflammatory agent [41].
Vitellaria paradoxa is an important source of fat in food and cosmetics [53].Its fatty matter has long been used in Africa for different purposes: food and soap processing, healthcare and other medicinal uses [54].
Previous ethnobotanical studies in the Sahelian areas of West Africa reported the multipurpose uses of many woody plant species like Piliostigma reticulatum, Azadirachta indica, Acacia albid, Balanites aegyptiacus, Prosopis Africana, Sclerocarya birrea, Acacia nilotica, Guiera senegalensis, Hyphaene thebaica and Combretum glutinosum [55][56][57][58].Cameroon dry land flora is very rich in plant species which produce natural substances, essential oils and organic and wide-ranging aromas, all of which are vital to the food, pharmaceutical and cosmetics industries.Despite these potentials, most plant resources of this area have been overlooked by extension services at the expense of over-promoted exotic species [13].
With the growing demand for beauty and beauty products in the country in recent years, there is a great challenge of how Cameroon can profit from this huge demand while creating opportunity for herbal cosmetics and aroma products.Despite the country's rich endowment in biological resources, there is still little investment in research and development of new phytocosmetics.Yet, some giants of the cosmetics industries are showing increased interest in searching for new cosmetics ingredients from the country's flora.This is the case for the Novella Project in Cameroon, Ghana, Nigeria, Tanzania and Kenya, a collaborative initiative between a commercial company (Unilever), an international Non-Governmental Organization (SNV Netherlands Development Organization), local NGOs, local businesses, collectors, transporters and processors, aimed at developing a sustainable supply chain for Allanblackia oil [59].Echinops giganteus and Mondia whitei are two other species concerned by such pilot initiatives.Their vanilla-odour roots are currently sought by the French company V MANE FILS for the production of perfume, within the framework of a pilot Access and Benefit Sharing (ABS) project implemented in collaboration with the Ministry of Environment, Protection of Nature and Sustainable Development (ABS competent national Authority), the Magha community in South-West Cameroon) and a local non governmental organization Environment and Rural Development Foundation (ERuDeF) [60].However, although an important amount of plant biodiversity is concentrated in the Southern developing countries, the technological capacities for transforming them into commercially viable products are predominantly found in industrialized countries.Recently, there has been an emerging paradigm in most African countries challenging the open access regime resulting in unrestricted South-North flow of plant-based raw materials increasingly translated into Intellectual Property-protected inventions, with the resulting economic benefits being appropriated by private Northern entities.As a result, most countries are currently working towards ratification of the Nagoya protocol on Access to Genetic Resources and the Fair and Equitable Sharing of Benefits Arising from their Utilization (ABS) [61] and developing national tools for the implementation of this protocol.Beyond that, it will be critical for countries to create a conducive environment to promote and encourage research related to conservation and wise use of plant biodiversity and to use the research-development continuum as a model for sustainable development.

Conclusions
In the Far North Region of Cameroon, there is a strong relationship between the Arab Choa and Kotoko people and plant resources.They have good knowledge of utilization of plants for cosmetic purposes.A total of 13 plant species have been reported in this study and their chemical evaluation based on available literature indicated they can be promising resources for cosmetic industry.Trees are the most frequent life forms of plants used as cosmetics; the barks and seeds are the most frequently used plant parts and skin care was the most frequent use of plants recorded.
This knowledge is however only transmitted orally and therefore, likely to be lost because of interference of modern and foreign cultural influence.Therefore, efforts are needed to understand and adequately document the indigenous knowledge about the use of herbal cosmetics.Despite their extensive traditional use in the study area and across semi-arid areas of tropical Africa, these plants have been investigated less for their cosmetic application.This study is an early investigation focusing on cosmetic utilization of local plants and there is further need of detailed and intensive investigations with particular reference to herbal cosmetics in the Far North Region of Cameroon.Indeed, traditional uses of plants are as real resources of innovation and economic development and it is therefore interesting for Cameroon to be familiar with their value and use.In addition, for a better valorization of local cosmetic plants, phytochemical and specific bioassay studies should be performed on promising species.For sustainable and long term conservation and promotion of plant resources of the area, there is a need to actively involve the local communities, planning, implementation and monitoring process following principles of Nagoya protocol on access to genetic resources and sharing of benefits derived from their utilization.

Figure 1 .
Figure 1.Location of study site.

Figure 1 .
Figure 1.Location of study site.

Figure 2 .
Figure 2. Biological forms of plants recorded.

Figure 2 .
Figure 2. Biological forms of plants recorded.

Figure 3 .
Figure 3. Plant parts used as cosmetics.

Figure 4 .Figure 3 .
Figure 4. Cosmetic use of the recorded plants.

Figure 3 .
Figure 3. Plant parts used as cosmetics.

Figure 4 .
Figure 4. Cosmetic use of the recorded plants.

Figure 4 .
Figure 4. Cosmetic use of the recorded plants.

Author
Contributions: E.F.F. and T.Z.conceived the experimental design of this study; E.F.F., T.Z. and S.B. performed the data collection; E.F.F.prepared the first draft of this paper; C.F.N.B. and A.N.B. adjusted the experiments and reviewed the first draft of the manuscript; N.T. revised the first draft of this manuscript.

Table 1 .
Recorded list of plants used as traditional cosmetics among Arab Choa and Kotoko.

Table 1 .
Recorded list of plants used as traditional cosmetics among Arab Choa and Kotoko.

Table 2 .
Phytochemical constituents and biological activity of recorded plants.