**2.12** *Plumbago zeylanica* **Linn. (Plumbaginaceae)**

*Plumbago zeylanica* is a perennial shrub with semi woody stems and numerous branches. It is a valuable medicinal plant widely used in Africa and Asia for the treatments of common ailments like hemorrhoids, diarrhea, leprosy, arthritic pains, toothache and as aphrodisiac and wound healing [61].

In a previous, observations were made for the time taken for different solvent extracts of the leaves of *P. zeylanicum* at concentrations of 300, 100 and 30 mg/mL to paralyze and kill *Pheretima posthuma*. The ethyl acetate extracts showed significant (*p* < 0.0001) concentration-dependent anthelminthic activity with the highest effect at 300 mg/mL causing paralysis at 7.39 ± 0.94 min and death at 11.81 ± 1.10 min. The methanol extract at 300 mg/mL demonstrated slightly lower anthelmintic effect with paralysis at 17.23 ± 1.68 min and death at 21.83 ± 2.60 min [62].

#### **2.13** *Rauwolfia vomitoria* **Afzel. (Apocynaceae)**

*Rauwolfia vomitoria* commonly called the African Snakeroot or African Serpent root is a small tree or shrub that grows up to about 20 m tall in tropical Africa. It is locally called '*kakapenpen'* in the Asante dialect of Ghana. In traditional medicine,

*The Ghanaian Flora as a Potential Source of Anthelmintic and Anti-Schistosomal Agents DOI: http://dx.doi.org/10.5772/intechopen.97417*

the plant is recorded to be used in the treatment of convulsions, malaria fever, insomnia, arthritis, pain, high blood pressure, diabetes, stomach problems and as an emetic. The leaves are applied topically for skin infections, swelling and snake bites. It is placed in the rectum for the expulsion of worms and for dysmenorrhea [46].

The leaves and stem bark of *R. vomitoria* demonstrated significant (*p* < 0.001) anthelmintic activity against the Indian adult earthworm *P. posthuma*. The methanol extracts of the stem bark caused paralysis of worms at 11.17 ± 0.088 min and reduced the death time to 21.67 ± 0.733 similar to the effect of albendazole at 10 mg/mL which had a worm death time of 21.03 ± 0.258 min [63].

#### **2.14** *Sclerocarya birrea* **(A. Rich) Hochst (Anacardiaceae)**

*Sclerocarya birrea* is a dioecious small to medium sized tree growing up to about 20 m high and 1.2 m in diameter. The plant is distributed from Gambia, Ghana and Nigeria in West Africa, across Cameroon in Central Africa, to Ethiopia and Sudan in East Africa and to South Africa, usually found growing in open farm lands and natural vegetation [64]. The stem-bark, roots and leaves are used to treat several ailments including diabetes mellitus, diarrhea, dysentery, proctitis, ulcers, inflammation, arthritis, hypertension, skin diseases, and malaria [65].

The anthelmintic activity of the aqueous and ethanolic extracts of the roots of *S. birrea* were evaluated against earth worms. The extracts displayed significant (*p* < 0.001) concentration-dependent anthelmintic activity at 12.00 to 0.1875 mg/mL. The observed effect was higher compared to albendazole-treated worms [66].

#### **2.15** *Vernonia amygdalina* **Del. (Asteraceae)**

*Vernonia amygdalina* is tropical shrub which grows up to about 3 m high. The plant is distributed throughout tropical Africa and has been domesticated in some parts of West Africa including Nigeria and Ghana where it is commonly called the bitter leaf. It is a highly valuable vegetable in West and Central Africa which is consumed as part of various dishes. In traditional medicine the leaf decoction is used to treat fever, malaria, diarrhea, dysentery, hepatitis and cough, as a laxative and as a fertility inducer [67]. The root extracts are also used for treating malaria and gastrointestinal disorders. One of the most common medicinal uses of *V. amygdalina* is as a treatment against intestinal worms including nematode infections [68]. The use of the leave decoctions against intestinal worms, especially pinworms was confirmed in an ethnobotanical survey in the Ashanti Region of Ghana [40].

In a previous study, the anthelmintic activity *of V. amygdalina* leaves were investigated against *Lumbricus terrestris* (earth worm). Unlike the negative control groups which remained alive and active after 6 hours of exposure to normal saline, all worms treated with the aqueous and ethanol leaf extracts (50–200 mg/mL) of *V. amygdalina* were noted to be paralyzed within 4.05 ± 1.06 to 59.94 ± 8.25 and 3.56 ± 0.37 to 33.18 ± 12.4 mins respectively (*p* < 0.0001). The effect was concentration dependent [36].

In another study, the stem bark extracts (ethanol and chloroform extracts) of *V. amygdalina* were observed to produce a synergistic anthelmintic effect when combined with the seeds of *Carica papaya* [69].

#### **2.16** *Voacanga Africana* **Stapf. (Apocynaceae)**

*Voacanga africana* is a small tree or shrub, reaching up to 6 m tall in height with a low widely spreading crown. In Ghana, it is locally known as '*ofruma'* in the Asante

language. Various plant parts are used medicinally throughout its distribution area [70]. The leaf decoction is used to treat dysentery, diarrhea, cutaneous and subcutaneous parasitic infections, leprosy, oedema, gout, paralysis and convulsion. The stem bark or roots decoctions are used as wound healing agents and used to treat boils, malaria, sexually transmitted diseases like gonorrhea, and skin diseases such as eczema and scabies. They are also taken to treat cardiovascular diseases and rheumatoid arthritis. The leaf latex is put in the teeth to treat dental caries or dripped in the eye to cure ophthalmia [46].

The methanol extracts of the leaves and stem bark *V. africana* were evaluated for *in vitro* anthelmintic activity by determining the effects of the extracts on the paralytic and death time of *P. posthuma* using albendazole as reference. The bark extract (20–50 mg/mL) demonstrated a significant (*p* < 0.001) concentration dependent anthelmintic effect by decreasing the paralysis and death times of worms. At 50 mg/mL, the stem bark extract caused worm paralysis within 7.03 ± 0.491 min and death at 14.77 ± 0.117 min [63].
