Ethnobotanical plants and their tradomedicinal values: A review

Since ancient times, plants with medicinal properties possessing no or little toxicological potentials have been relevant for the treatment of several diseases and healing purposes. Medicinal plants serve as important therapeutic agents and valuable resources for manufacturing numerous modern and traditional medicines. Many developing nations still rely on herbal remedies as their mainstay of health-care. This review study is aimed to report the trado-medicinal values of some ethnobotanical plants commonly used in traditional formulations as well as the scientific investigations of these plants for their acclaimed use in traditional practices. Essential phytochemicals and bioactive compounds of these plants are also reviewed.


Introduction
Medicinal plants have been a major and essential resource in trado-medicine and modern drugs for treating and managing several human diseases and ailments [1]. Traditional medicine is the most easily accessible and affordable source of treatment in the primary health care system, most especially in rural and poor communities. In recent years, the use of traditional medicine derived from plants has received considerable interest due to the diversity and biological activities of naturally occurring secondary metabolites derived from plants, and the development of new and sensitive techniques to detect, isolate, purify and characterize plants' biologically active natural compounds [2,3].
Several medicinal plants have been scientifically evaluated and validated for their applications in the management and treatments of several diseases and disorders like malaria, nephrolithiasis, liver problems, kidney pain, oedema, worm infestation, nausea, bronchial, jaundice and gastrointestinal disorders, rheumatism, muscle swelling, insect bites, ulcers, diabetes, and so on. Some of these important medicinal plants include Artemisia annua, Ficus vallis-choudae, Bouea macrophylla, Aspalathus linearis, Synedrella nodiflora and Nauclea latifolia etc. [3][4][5][6]; they are reviewed in this work.
Tracing of the medicinal value of plants and their bioactive substances that generate a definite physiologic action on the human body have been achieved through phytochemical screening [7,8]. Some important bioactive compounds in plants are the glycosides, flavanol, alkaloids, flavonoids, saponins, cardenolides, tannins, proanthocyanidins and polyphenolic compounds. These compounds are valued for their antioxidants and enzymes inhibiting activities and desirable for their roles in disease prevention and therapy [3,9,10].

Artemisia annua L.
Artemisia annua L. is herbaceous perennial herb also known as sweet wormwood belonging to the family Asteraceae. It is of Asia origin and widely dispersed throughout the world temperate region. It is widely applied in folklore medicine. A. annua is traditionally used to treat fevers, remove intestinal worms, gush menstruation, repel intestinal gases, treat hemorrhoids and boils, etc. [11]. The plant shows promising ethnopharmacological activities such as antifungal, antipyretic, antiplasmodia, anti-inflammatory and antioxidant [11]. A. annua is famously known for its application in treatment of malaria. It is the primary source of artemisinin, a sesquiterpene lactone possessing antimalarial activity. For the production of artemisinin, the plant is cultivated on a large scale in countries like Vietnam, China, Turkey, Iran, Afghanistan, Madagascar and Australia. Artemisinin based Combination Therapies (ACTs) comprising artemisinin, its derivatives like artemether, arteether, etc, and few long acting drugs like lumefantrine and amodiaquine are effectively used worldwide for the treatment of malaria caused by Plasmodium falciparum [11][12][13]. Various species of Artemisia, including A. annua, are characterized with essential oils that exhibit strong bio-herbicidal and insecticidal activities [6,14,15,17,18].

Ficus vallis-choudae Delile
Ficus vallis-choudae D. is a tropical tree of the Moraceae family, with white latex [19]. Ficus vallis-choudae is known as a riverine fig tree. It is widely distributed in Tropical African countries like Nigeria, Senegal, Cameroon, Sudan, Malawi and Ethiopia [20]. According to Oliver [21], the leaves and young leafy stems are used as local drug for nausea, bronchial, jaundice and gastrointestinal disorders. The figs are edible and mostly appreciated by children in some parts of Africa [20]. The bark extracts of Ficus vallis-choudae in organic media have been reported to possess anticonvulsant and antifungal activities as well as anti-inflammatory and antinociceptive effects [4,22,23].

Sorghum bicolor L.
Sorghum bicolor is commonly known as Sorghum. It is the fifth most commonly consumed cereal crop by human after rice, wheat, corn, and barley. The majority (about 65%) of cultivated Sorghum is commonly used to make animal feeds and industrial products, while about 35% of it is directly consumed by humans. It is a plant that is well grown across Asia, Africa and America. It is a member of the plant family Poaceae and is well-known for its diverse phytochemical composition possessing antioxidant properties and effectiveness in cholesterol control [24]. In trado-medicine, the stem is used to treat anaemia and blood related ailments; it also possess both an anti-malarial and anthelminthic properties [25].

Theobroma cacao
Theobroma cacao is a tree usually cultivated in some West African Countries like Ghana and Nigeria, and predominantly cultivated in Brazil for its industrial value. It belongs to the family Malvaceae and is popularly called Cocoa tree. The seed is the main source of chocolate; the ash from pod from the pod is used as source of lye for soap making. Cocoa butter extracted from the seed of cocoa is used in cosmetics and formulations for skin care products.

Figure 4 Theobroma cacao plant
The seed of cocoa has been evaluated for its phytochemicals and has been found to contain a high content of important bioactive compounds like phenolics, flavonoids and theobromine which are important antioxidants [26]. Chocolate was found useful for healthy function of the spleen and stimulating other digestive functions. In the 17th and 18th centuries, chocolate was recommended or mixed into medications for various kinds of diseases and ailments, to enhance digestion, reinforce mental performance, improve fertility and as an antidepressant remedy [27]. Cocoa products are also rich in methylxanthines such as caffeine and theophylline which are known possess both negative and positive health effects. For instance, caffeine intake has been reported to have negative effects on mental and reproductive health while, its supplementation enhanced net hepatic glucose uptake through increment of glucose-6-phosphate production in the liver [27]. Insufficient iron in the diets results to iron deficiency anaemia, a condition in which the red blood cells becomes low in hemoglobin and correspondingly carry less oxygen [28]. In Nigeria, a mix of Sorghum bicolor sheath and Theobroma cacao stem bark extracts of water and/or alcohol are used to treat anaemia.

Centaurea austro-anatolica
Centaurea austro-anatolica is a 30-60 cm tall perennial herb with branches, tomentose and hairy leaves as well as pink flowers. The plant belongs to the family Asteraceae. It mostly grows in Antalya and Muğla Provinces in Turkey [29]. While several species of the genus Centaurea are widely applied in ethnomedicines for the treatment of diarrhoea, diabetes, hypertension, microbial infections, rheumatism and ulcers [30][31][32], there is little or no report on any medicinal uses of C. austro-anatolica in folklore medicines in Antalya, Muğla or Konya provinces. There is a report on GC-MS based volatile component analysis and antimicrobial activity assessment of C. austro-anatolica [32]. Fraxinus excelsior L. also known as European ash or common ash is widely distributed in Europe and usually cultivated as an ornamental plant in Canada, New Zealand and United States. It belongs to the Olive family Oleaceae. Fraxinus excelsior is a large tree that grows up to 40 m tall, with ascending branches, pale grey smooth bark, serrated and stalkless; flowers usually open before the leaves unfold; flattened seeds of about 2-5 cm long in bunches and ripen individually [33].

Senna sulfurea (Collad.)
Senna sulfurea (Collad.) which is known as glossy sulphur-flowered senna, glaucous cassia, kalamona, and smooth senna, is distributed in India, Sri Lanka, Australia, Polynesia, south eastern Asia, Gabon and China. It is a member of the family Caesalpiniaceae and is commonly planted as ornamental plant due to its beautiful flowers. It grows up to 3 m high. Its young shoots are hairy and later become hairless. It's an evergreen, perennial shrub or small tree, with 15-30cm leaves, 3.5-6.5 cm leaf stacks; yellow flowers and flat strap shaped pods with black shiny seeds [42]. The leaves find folksforic application in curing of blennorrhagia when mixed with milk and sugar. The bark and leaves contain antioxidants that are useful to relieve diabetes and are used to treat dysentery and gonorrhea [42,43]. The flowers and pods are purgative; the pods are prepared and used an antiseptic to manage skin diseases [42].

Prosopis cineraria (L.) Druce
Prosopis cineraria (L.) Druce, also known as called as Indian mesquite and sponge tree, is widely distributed in Asian countries like India, Iran, Afghanistan, Oman, Sri Lanka, Saudi Arab, Pakistan and Yemen. It is member of the family Leguminosae and grows up to 5 m tall tree, with bipinnate leaves consisting of 7-14 leaflets on each of one to three pinnae.

Figure 8 Prosopis cineraria leaves
The tree is characterized by its thorny branches along the internodes; small, creamy-yellow flowers; seeds in pods. The bark is considered as an abortifacient, anthelmintic, laxative, refrigerant, tonic and vermifuge, used to treat anxiety, asthma, bronchitis, dysentery, dyspepsia, fever, leprosy, leucoderma, muscle tremors, piles, rheumatism and tremors [44]. A leaf paste is applied to cure boils, blisters, sores and mouth ulcers. Smoke from the leaves is suggested for eye troubles [45]. The plant material is used to treat snake bite and scorpion sting. The wood ash is rubbed over the skin to remove hair. [46]. A pod extract is used to relieve earache, toothache and fractured bone pain [47].

Bouea macrophylla Griffith
Bouea macrophylla belongs to the Anacardiaceae family and is related to mangoes [48,49]. It is commonly known as the Mariam Plum or Plum Mango. It also has been shown as an evergreen and a perennial tree that grows up to 25 meters of height, highly seasonal and is widely distributed in South East Asia including Malaysia, Indonesia, Laos, Thailand, Java, Myanmar, and Sumatra [50]. The leaves and fruits are edible, popularly eaten in local communities of Sabah, Malaysia and Sarawak [51]. The plant is widely cultivated in Malaysia for shade as well as for ornamental purpose [50]. Traditionally, almost all parts (seeds, unripe and ripe fruits, and leaves) of the plant have been used for various culinary purposes [49]. Ripe fruits of B. macrophylla have sweet taste and have found various applications in preparing snacks, beverages and jellies. On the other hand, unripe fruits with sour taste are used as vegetable [48]. In Indonesia and Malaysia, the tender leaves of the plant are used as a raw vegetable in the preparation of salads [50]. A successful study has been undertaken to show the phytochemical constituents of B. macrophylla Griffith as well as its antioxidant activity [52]. Myrtle (Myrtus communis L.) is a plant that belongs to the Myrtaceae family, a shrub native to the western Asia and Mediterranean countries [53]. It is commonly known as myrtle. Historically, ancient Mediterranean populations used myrtle for its aromatic and ornamental values [53]. Myrtle fruits have a long history of application as a food ingredient in place of pepper; as a spice for meat cooking and tendering; as food integrators (because of its high vitamin contents) [54]. The fruit decoction or infusion of this plant is used in folk medicine as hypoglycemic, stomachic, anti-microbial agent, and to treat cough and oral diseases [54]. It is also used to treat constipation, for appetizing, anti-hemorrhagic and externally for wound healing [54]. In recent years, the greater part of myrtle produced in the Mediterranean area are used for preparation of liqueur [56]. The nutraceutical and antioxidant properties of M. communis have made it found applications in cosmetic, food and pharmaceutical [57,58]. Many studies have been reported on the essential oil composition of the plant [59][60][61][62][63][64]. The pharmacological values of this essential oil have been explored in recent years. The plant is found to possess anti-microbial properties, anti-hyperglycemic and antioxidant activities [5,[61][62][63][65][66][67][68].

Premna mucronata Roxb
Premna mucronata Roxb commonly known as, "Ganiar", "Bari arani", "Agnimatha", Agethu" and "Agyon", is a low bushy tree (with trunk up to 1.2 m height) of great ethnobotanical value belonging to the family Verbenaceae. Furthermore, P. mucronata is a medicinal and aromatic plant and one of the important ingredients of "Dashamula" herbal preparation [69]. The bark finds application in curing boils while the leaves have been applied externally to treat dropsy as diuretic [70,71]. Savasani et al. [72] reported that P. mucronata showed cardioprotective activity in myocardial infarction due to its antioxidants composition. It also possesses larvicidal properties Renjana and John [73]. Antimicrobial, hypocholestremics and wound healing ability as well as anti-inflammatory activities have been demonstrated by this plant [74][75][76]. Recent studies showed that its essential oil has remarkable antifeedant properties [71,74]

Annona mucosa Jacq
Annonaceae is a group of shrubs, aromatic trees and lianas that occur mainly in subtropical and tropical and [77]. It exhibits a pan tropical distribution with 40 genera and about 900 species in the Neotropical region [78]. Despite its diversity, Annonaceae constitutes one of the lesser phytochemically investigated tropical plant families [79]. It is one of the best natural products with insecticidal properties, especially due to the high level of allelochemicals that accumulate in different parts of the plant [78]. Several species of the genus Annona have been used in traditional medicine for pest control and the treatment of various ailments. For instance, Annona muricata L. leaves are widely used in the treatment of diarrhea and arthritis [80]. Annona mucosa (Fig. 12) is a medicinal species from the family Annonaceae, a fruit tree that grows well in different habitats though native in Atlantic and Amazon forests [81]. Annona mucosa grows to a height ranging from 1 m to 4 m, has brown hairy twigs with 1 to 3 flowers forming together in the leaf axils. The fruit (usually 15 cm in diameter) is conical or heart-shaped and is [82]. Annona mucosa Jacq leaves are extensively applied against fleas and other insects [77]. Annona reticulata Linn whole plant is used to control of fever, treat ulcers, and diarrhoea [83]. Annona squamosa L. fruits, leaves and roots are used to overcome fainting and hysteria and relief for vomiting; the plant is used as an expectorant and to treat spinal disease [84]. Phytochemicals like flavonol, flavonoids and glycosides have been isolated from various parts of the plant [85] [86,87,88]. The specie Ficus exasperate Vahl. is an evergreen forest tree that grows up to 20 m height and widely distributed in Zambia, Mozambique, northern Angola, Ethiopia, Senegal and central African countries [89]. It is popularly known as "sand paper tree" due to its leaves' scabrous surface. The leaves is widely used as an abrasive for polishing hard surfaces such as furniture and utensils [90][91][92] Ficus exasperata Vahl. is a useful medicinal plant of biological values for the treatment of many diseases in different parts of Africa. In Cameroonian folk medicine, the leaves are used in the treatment of malaria, hemorrhoids and diarrhea when the water extract is administered orally [93][94][95]. In Ivory Coast, the viscid sap is used for the treatment of sores and stomach pains [96]. Studies on the stem barks, leaves and root extracts of F. exasperata have shown the promising antimicrobial potentials of the plant [86,97]. Antiinflammatory, anti-nociceptive and antipyretic activities of the hydro-alcoholic extract of the plant's leaves have been reported [98]; while the stem-bark hydro-alcoholic extract showed antiulcerogenic, antioxidant, hypotensive, lipid lowering and hypoglycaemic activities [91]. The plant is rich in phytochemicals namely alkaloids, flavonoids and tannins among others [90].

Triclisia subcordata (Oliv)
Triclisia subcordata (Oliv) is a flowering plant in the Menispermaceae family. It is predominantly found west tropical African countries including Ivory Coast, Nigeria, Senegal, Ghana, Sierra Leone and Togo [99]. The plant primarily serves as rope used for tying purposes while the importance of the species however rest with their medicinal applications. The root extract finds folksforic applications in the treatment of ulcer, snake bite, diarrhea, malaria, and pyorrhea, anemia joint pains, swelling of extremities, rheumatic pains and hypertension in Nigeria [100,101]. The plant has also been evaluated for its enzymes inhibition activities, antiulcer, antihistamine, antimicrobial, antioxidant, anticancer, and antidiabetic activities [8,10,15,[102][103][104]

Aspalathus linearis (Brum.f Dahlg.)
Aspalathus linearis (Brum.f Dahlg.) which is globally known as rooibos is a plant belonging to the family Leguminosae that grows naturally in the Cederberg Mountains in the western parts of the Western Cape Province, South Africa. The rooibos plant has gained transition from being a wild resource to become a plant of great economic and biological importance [105]. Rooibos is cultivated and usually processed to tea. After harvesting, the plant material may be subjected to a fermentation process which involves bruising and oxidizing it in open air. The processed tea is usually referred to as fermented rooibos, while the unprocessed tea is referred to as unfermented or "green" rooibos Joubert and De Villiers [106] with total production including unfermented rooibos was in excess of 14,000 tons [107]. Rooibos tea is believed to possess antispasmodic properties, as well as ability to relieve digestive troubles among others [108,109]. Rooibos have a unique flavonoid composition, containing rare compounds as previously described. Both the fermented and unfermented rooibos possess good antioxidant activities and tyrosinase inhibitory activity as an indication of having diverse health promoting properties, especially to solving problems associated with oxidative stress [3]. The plant contains essential bioactive phytochemicals like flavonoids flavonol, phenolics, tannins and flavanols [3,110,111]

Nauclea latifolia smith
Nauclea latifolia smith is a plant that belongs to the family Rubiaceae; it is an evergreen plant commonly called African peach. It is a multi-stemmed small tree or shrub native to tropical Africa and Asia [112]. Nauclea latifolia is a valuable ethnomedicinal plant that is widely spread in the humid tropical rainforest zone or in savannah woodlands of Central and West Africa. N. latifolia is commonly known as African peach and is used in traditional medicine in the Western and Eastern sub-region parts of Africa [100,113]. Various extracts of the plant parts are used for the therapeutic management of hypertension [114]; malaria [115]; prolonged menstrual flow [116]; gonorrhoea, cough, stomach aches, ulcers, dysentery and liver ailments [113,117]. In West African countries, the plant is commonly used to treat diarrhea, jaundice, dental caries, septic mouth, hypertension, gastrointestinal disorders and diabetes [116,118,119]. In addition, it is used to treat sleeping sickness and prolonged menstrual flow in Nigeria [116]. N. latifolia is known as 'Africa cinchona' or 'Africa quinine' because of its anti-malarial activity [120]. Cold infusion of the leaves and the stem bark are used as anti-helmintic to regularly deworm animals and as diuretic in Northern Nigeria [121,122]. The root is a major ingredient in Nigerian tradomedicine for treating respiratory problems such as asthma, bronchitis, cough and cold [123]. The most frequently used plant parts are the roots, followed by the stem, bark, and leaves. Vicia faba L. (broad bean) is a leguminous plant that belongs to the plant family Fabaceae. The plant is rich in polyphenols, with its beans a popular food in many countries. It is an essential winter crop in Mediterranean areas and is mostly a spring crop in other regions of South America and Europe; it is one of the major plant food items among the Nile River populations [124]. Fava beans are nutritious and very high in protein content as in other beans and lentils. The beans are rich in antioxidants, minerals, vitamins, and plant-sterols. Phytochemicals such as genistein and daidzein present in fava beans have been found to protect breast cancer in laboratory animals; β-sitosterol (a phytosterol) helps lower cholesterol levels in the body [125]. However, only the seeds are used in human nutrition, while the whole plant is used animals feed. The plant is used in folk medicine as antihyperlipidimic to control cholesterol [126]. V. faba L. seed is found to contain a high number of bioactive compounds such as glycosides (α-galactosides, vicine and convicine), proteins (protease inhibitors, α-amylases, lectins), saponins, tannins and alkaloids [127]. In a research by Boukhanouf et al. [128], immature faba bean fractions showed significantly higher phytochemical contents and displayed a better antioxidant activity than those of mature ones.

Pterocarpus soyauxii Taub
Pterocarpus soyauxii Taub (Fabaceae) which is commonly known as African Coral-wood is a popular green vegetable often utilized in the South Eastern part of Nigeria due to its high vitamin C content and unique taste [129,130]. Crude extract of the leaf could potentially increase white and red blood cells as well as haemoglobin [131]. The plant has found wide tradomedicinal applications in treatment various diseases such as renal infections, hypertension, chronic anaemia, fungal infections and skin diseases [132][133][134]. Phytochemical investigations of Pterocarpus soyauxii Taub revealed the presence of flavonoids, bioflavonoids, ascorbic acid and pterostilbene [135][136][137][138].

Withania coagulans (Stocks) Dunal,
Withania coagulans (Stocks) Dunal, is a native plant to Afghanistan, Iran and Indian. Within the Withania genus, W. coagulans (Ashutosh booti) and W. somnifera (Ashwagandha) are economically significant for their medicinal values and distributed in several regions ranging from east of the Mediterranean region to South Asia. W. coagulans is common in many parts of India Afghanistan, Pakistan and Nepal [139]. W. coagulans is a rigid grey-to mentose undershrub, 30-120 cm tall; leaves are lanceolate oblong and sometimes ovate, obtuse and thick. flowers are 7-12 mm in diameter and yellow, (Fig. 1). The plant is propagated by seed; its flowering period is from January to April, while its berries ripen in May [139]. W. coagulans is used as a blood purifier, an anti-cancer drug, to treat diabetes, cure debility, impotence, insomnia and nervous exhaustion; it is externally applied as a therapy to relieve inflammatory conditions, scabies and ulcers [139]. The plant is used to make oil ointment capable of curing several skin diseases when mixed with Ashwagandh powder [139]. It works as an antidote to scorpion sting (Gupta and Singh, 2018). Different parts of plant are applied to treat rheumatism, ulcers, senile debility and dropsy. The fruits are blood purifier, diuretic, emetic, alterative, hepatoprotective, hypolipidemic, hypoglycemic, milk coagulant, sedative, sweet, stomachic and biliousness, used to treat diabetes, asthma, dyspepsia, skin rashes, intestinal infections, stomachache, strangury and wounds. The fruits extracts alongside W. somnifera are used to prepare a composite Ayurvedic medicine 'Liv 52' which is a hepatoprotective herbal formulation [140,42]. The twigs are chewed for cleaning of teeth and to relief toothache [141]. The flowers water extract is taken to control diabetes [142]. The bitter leaves are alterative and febrifuge. The seeds are diuretic anti-inflammatory and emetic [143,144]. Studies on antimicrobial, antiumor, antiinflammatory, Antimutagenic, antihyperglycemic, hepatoprotective, cardiovascular, free radical scavenging, immunosuppressive and central nervous system depressant activities of the plant parts have been reported [145][146][147]. The plant extracts showed the presence of saponins, alkaloids, phenolic compounds, steroids, tannins, proteins, an essential oil, milk-coagulating enzyme, carbohydrates, fatty oil, organic acids and amino acids [140,148]

Zingiber officinale
The Zingiber species are noted for the various biological activities they exhibited. Some Zingiber species found growing in Ninh Bình Province was shown to have possessed essential oil [149,150]. Zingiber zerumbet rhizome oil displayed larvicidal activity against Aedes aegypti, Aedes albopictus and Culex quinquefasciatus [151]. . In addition, both Z. collinsii and Z. zerumbet extracts and essential oils possess larvicidal and antimicrobial properties [152,153]. Zingiber officinale is an evergreen rhizomatous herb forming small clumps (ginger root) that is widely used as spices and in folk medicine. It is commonly known as ginger and belongs to the family Zingiberaceae. The creeping aromatic rhizome (ginger) grows up to 1.5 cm in diameter, internally cream white or yellow and externally light brown. The plant is an herbaceous perennial that has glossy translucent green leaves that are glabrous and false stems made of rolled bases of leaves. It is mostly cultivated in India, China, Nepal, Indonesia, Thailand and Nigeria. Flowering period ranges between July and September. The plant has a numerous phytochemicals responsible for its medicinal properties. The plant is traditionally used to treat arthritis, inflammation, diabetes, bacteria and fungi infections [151].

Phyllanthus niruri Linn
Phyllanthus niruri Linn belongs to the family Euphorbiaceae and is an annual herb that is widely spread throughout the subtropical and tropical countries of the world including India and Sri Lanka. It is an important ethnobotanical plant of the Ayurveda system of medicine mentioned in all the relevant ancient Ayurvedic texts [154]. It is commonly found growing as weed in both cultivated and wasteland areas particularly in the rainy season. P. niruri Linn is commonly known as, 'Chancapiedra' (stone breaker), 'Gale of the wind' and 'Seed under a leaf' according to its pharmacological activities and morphology [155]. It is stated that the plant's extract is one of the most widely used remedies in Ayurveda system of medicine especially for anaemia, bronchitis, skin diseases, cough, kidney, liver, asthma and urinary tract disorders [156]. P. niruri Linn has a growing value as researches have uncovered more of its medicinal properties in recent years [154]. The plant demonstrates antimicrobial, anti-inflammatory and anti-diabetic activities, antiviral activity against hepatitis B virus, litholisis action of kidney and gall bladder stones, hepatoprotective activities, lipid lowering and immunomodulatory activities [157][158][159][160][161][162].

Synedrella nodiflora
Synedrella nodiflora is from the kingdom Plantae, infrakingdom of Streptophyta, subkingdom of Viridiplantae, division of Tracheophyta, subdivision of Spermatophytina, superdivision of Embryophyta, class of Magnoliopsida, order of Asterales, superorder of Asteranae, family of Asteraceae, genus of Synedrella Gaertn., and species of Synedrella nodiflora (L.) Gaertn [163]. S. nodiflora is a branched ephemeral herb that can grow up to 80 cm in height. It is has a shallow root system that is usually strongly branched. The leaves exist in opposite pairs and are usually 4-9 cm long while the lower part of the stem may root at the nodes, especially in moist conditions.

Figure 22 Synedrella nodiflora plant
The presence of various phytochemicals in the leaf extracts of Synedrella nodiflora was reported after screening in studies by Amoateng et al. [164]; Amoateng et al. [165]; Popoola et al. [166]. Solvent extracts of S. nodiflora have been shown to contain glycosides, flavonoids, alkaloids, saponins steroids, tannins, phytosterols, triterpenoids gums and reducing sugars [167][168][169][170]. The plant is useful for the treatment of various diseases while its leaves are eaten as a vegetable by some livestock and human [166]. A study shows it possess sex hormone activity [171]. The leaves can be used as Pregnant Mare Serum Gonadotrophin supplier in animal husbandry and to improve reproductive parameters in female animals [172]. A study by Popoola et al. [166] showed enzymes (tyrosinase and elastase) inhibiting activities of the plant and its antioxidant properties to support and validate its acclaimed ethnopharmacological applications.

Melanthera scanden and Aspilia africana (Compositae)
Melanthera scanden and Aspilia africana (Compositae) are medicinal plants considered to be of great biological importance. Aspilia africana (Compositae) is a semi-woody herb that grows up to 2 meters high and widely distributed across tropical Africa [173]. Melanthera scanden is a scrambling herb of waste thickets, commonly dispersed in the forested areas and extending widely across tropical Africa. Melanthera scanden has similar medicinal uses with Aspilia africana. They are known to provide forage for all stock in thicket edges around villages. With haemostatic preparations they are used on cuts and fresh wounds [174,175]. They are used to draw up exudations from open fresh sores and promote healing as well as curbing inflammation [176,177]. Antimicrobial, antioxidant, anti-inflammatory, Antidiabietic, hypolipidemic and antiplasmodial activities of the plants have been reported in some studies [175,[178][179][180]. Both plants contain essential phytochemicals; possess mild antityrosinase and antioxidant capacities that provide clues to further understand their applications in folk medicine.

Conclusion
The plants: source of alternative medicine to conventional synthetic drugs in treatments of diseases and disorders like ulcer, diarrhea, malaria, pyorrhea, anemia, joint pains, swelling of extremities, rheumatic pains, hypertension, skin diseases, cough, kidney, liver, asthma and urinary tract disorders as well as oxidative stress related diseases most especially in developing countries. The plants are rich sources of natural antioxidants. They invariably show antitumor, antinociceptive and antipyretic, antiinflammatory, Antimutagenic, antihyperglycemic, hepatoprotective, antimicrobials, antiplasmodial and larvicidal properties. The dosages and toxicological impacts of the plants on system functioning are not reported in this review and may become a subject of discussion in future reviews.

Acknowledgments
The immense contribution of all the authors to the success of this review work is highly appreciated.