*4.4.1 Costus afer Ker-Gawl*

*C. afer*, natively called the bush sugar cane is classified as an endangered medicinal plant in Nigeria. It is a perennial, rhizomatous herb that can grow to a height up to 4 m. Leaves are arranged spirally, simple and entire [32]. It can be found in the forest belt of Senegal, South Africa, Guinea, Niger, Sierra Leone, Ghana, Cameroon and Nigeria [33]. *C. afer* is a useful medicinal plant that is highly valued for its antidiabetic, anti-inflammatory and anti-arthritic properties in South-East and South-West Nigeria, the plant extract is used as fodder to treat goats with retained placenta. The decoction of the stem or powdered fruits is used as a cough remedy. Its boiled root is applied to cuts and sores. A soothing formulation for rheumatic pains is prepared with the boiled leaves [33]. The leaves and stem are cut and crushed into smaller bits and boiled together with other plants such as *Alchornea cordifolia*, pawpaw, citrus species and the bark of *Mangifera indica* for the treatment of hunch back and malaria. Also the juice of *C. afer* is used as eye drop for inflammation and other eye defects. The young and tender leaves when chewed are believed to give strength to the weak and dehydrating patient. An infusion of the inflorescence is taken to treat stomach complaints. The stem or fruit decoction mixed together with sugarcane juice are taken to treat cough, respiratory problem and sore throat [32]. Alkaloids, saponins, flavonoids, anthraquinones, cardiac glycosides, terpenoids, phenolic compounds and tannins have been found to be present in the plant [33]. This plant contains diosgenin which is used as a precursor in the synthesis of a number of steroid drugs including corticosteroids, sex hormones, oral contraceptive and anabolic agents. The rhizome also contains saponins aferosides A–C, as well as diosein and parphyllin c and flavonoid glycoside kaempterol

 3-0-rhamnopyranoside [34]. Extracts from the leaves exhibits antioxidant, hypolipidemic, hepatoprotective, anti-inflammatory, and analgesic, anticancer, antimicrobial, insecticidal and nematcidal activity and also contains verbascoside, which possesses antimicrobial activities [35]. Acute and chronic toxicity studies on *C. afer*  showed no inherent toxic effects in animal models [35]. Liver function experiments of this plant in rats showed significant differences in the test groups when compared with the control while there was no significant effect on kidney function [33].

### **4.5 Euphorbiaceae**
