**2.3** *Azadirachta indica* **A. Juss. (Meliaceae)**

*Azadirachta indica*, commonly known as neem, is a fast-growing and long lived evergreen tree which grows up to about 15 m tall with long, spreading branches that form a dense, large rounded crown. The plant is a multipurpose medicinal plant which also provides food and timber and is widely distributed in several regions of Asia and Africa. It is well known for its insecticidal and insect-repelling property. Various parts of the plants are reported to be used for the treatment of many ailments in traditional medicine including malaria, fever, upper respiratory tract infections, wound healing, sexually transmitted infections and skin diseases [37].

The anthelmintic activity of the ethanolic extract of *A. indica* seeds was investigated *in vivo* using albino rats (*Rattus norvegicus*) infected with helminth species including: *Hymenolepsis diminuta*, *Enterbius vermicularis* and hookworm. The rats were treated with the alcoholic extracts (20–60%) over a 3-week period and fecal samples were examined for eggs. The extract treated groups showed declining levels of egg count by the 3rd week and complete elimination of worms by the end of 21 days when treated with 40–60% of neem seed extract. Weight loss and death were however recorded at 60% concentration of extract raising some concern about the toxicity of the seed extract [38].

## **2.4** *Carica papaya* **Linn. (Caricaceae)**

The pawpaw tree is well known for its nutritional and medicinal values. The leaf decoction is used as a galactogogue and in the treatment of tonsillitis, ulcerative stomatitis, hemorrhoids, asthma, urinary tract infections, as poultice for sores and gingivitis and in the treatment of helminth infections. The roots are used as antidote to various poisons. The fruits are used to treat indigestion, chronic diarrhea, ringworm infections, bleeding piles, and amoebic dysentery [39]. Almost all parts of the plant are documented to be used for managing helminth infections. In Ghana, 74% traditional healers used this plant for treating helminth infections [40].

In a comparative assessment of the anthelminthic activity of various parts of the plant, the hydroethanolic extracts of the leaves, stem bark, and seeds of *Carica papaya* were tested against *P. posthuma* as the target organism. The results indicated that all crude extracts prepared were more effective than albendazole in reducing paralysis (p < 0.0001) and death times (p < 0.0001) of worms. Extracts from the seeds at 2.5 mg/mL were the most effective causing worm paralysis and death at 9.26 ± 0.03 and 20.12 ± 0.01 mins respectively. This was more potent than the standard anthelmintic albendazole at the same concentration which gave paralysis and death times of 19.45 ± 0.57 and 31.43 ± 0.28 mins respectively [41].

### **2.5** *Combretum mucronatum* **Schumach & Thonn. (Combretaceae)**

Ethnopharmacological reports from parts of Ghana revealed the extensive use of the leaves of *Combretum mucronatum* for treatment of human and livestock helminth infection [40]. The leaves from this plant species is monographed in the Ghana Herbal Pharmacopeia for the treatment of infections with worms [42].

In a previous study, the alcoholic leaf extract of *C. mucronatum* was assayed *in vitro* for anthelmintic activity against free-living nematode, *Caenorhabditis elegans* using levamisole as a positive control. The extract demonstrated anthelmintic activity with a worm survival rate of 89.2% at 0.1 mg/mL and 58.1% at 1 mg/mL [40].

In another study, fractions and purified compounds from *C. mucronatum* leaves were tested *in vitro* for their anthelmintic activity against *C. elegans*. Unsubstituted oligomeric proanthocyanidins (PACs) mainly composed of epicatechin units were identified as the active compounds of the hydroethanolic leaf extracts. The compounds demonstrated a dose-dependent anthelmintic activity ranging from 1 to 1000 mM and activity was found to increase with increasing molecular size. The anthelmintic activity was suggested to be by interaction of the PACs with some unidentified proteins of the target organism [43]. Further, the mechanism of anthelmintic activity of the PACs was determined by transcriptome analysis. PACs were found to interact with proteins within the worm's intestinal membrane as well as enzymes and peptides to elicit anthelmintic effects [44]. Another proposed mechanism was interaction of the tannins with cuticular proteins, particularly proline-rich collagen in the worm cuticle [45].

#### **2.6** *Cyperus difformis* **Linn. (Cyperaceae)**

*Cyperus difformis* is an annual plant with smooth leaves and fibrous reddish roots. It is native to the subtropical and tropical areas but also distributed and widespread in South Europe, Asia and Americas. It is regarded as one of the world's commonest weeds found growing in wet swampy soils among rice plantation. It is very common in Ghana and traditionally used for the management of scorpion bites and malaria [46].

The anthelmintic and helminth resistance modifying activities of methanol extract of *C. difformis* was investigated against the adult Indian worm, *P. posthuma* using albendazole, mebendazole and levamisole as reference anthelmintics. The extract exhibited a concentration dependent anthelmintic activity against *P. posthuma* with significant (*p* < 0.001) paralysis and death times of 66.67 ± 1.8 and 140.7 ± 2.3 mins respectively at extract concentration of 20 mg/mL [47].

Further the extract at 1, 2 and 5 mg/mL significantly potentiated the activity of albendazole, mebendazole and levamisole against the test organism. In the presence of 2 mg/mL of the extract the paralysis and death times of albendazole (8 mg/mL) against *P. posthuma* were reduced from 41.33 ± 0.33 and 106.67 ± 0.88 min respectively to 33.33 ± 0.88 and 85.67 ± 1.2 min, respectively. Similar results were obtained for mebendazole and levamisole [47].

#### **2.7** *Garcinia cola* **Heckel (Guttiferae)**

*Garcinia cola* also known as "bitter cola" is a valuable medicinal plant in African traditional medicine widely accepted for its numerous medicinal properties. It is usually called the wonder plant due to the usefulness of every part of the plant. The seeds are chewed as an aphrodisiac and used to cure cough, dysentery and upper respiratory tract infections [48, 49]. The latex from the stem is used against sexually transmitted infections and applied externally to heal wounds. The sap is used in curing parasitic diseases. Chewing sticks produced from the stems are used as masticatory for nervous alertness and for treating coughs and throat infections [50].

In a previous study, the methanol stem bark extract of *G. cola* (1—50 mg/ mL) demonstrated a concentration dependent anthelmintic activity, decreasing paralytic and death times of *P. posthuma* with increasing extract concentrations. At 50 mg/mL, the extract had a paralytic time of 39.29 ± 0.12 min and death time of 54.29 ± 0.01 [51].

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

#### **2.8** *Morinda lucida* **Benth. (Rubiaceae)**

*Morinda lucida* is an evergreen shrub growing from about 3 m to 18 m tall. It has a dense crown with slim, crooked branches. The plant is occasionally grown in home gardens. It is locally called '*konkroma'* in the Ghanaian Akan language. It is a multipurpose species yielding dyes, timber, fuel and traditional medicines. The plant is reported to be used in managing diabetes, hypertension, dysentery, stomach-ache, leprosy and gonorrhea. Traditionally, the stems are used to treat piles while the leaves are used to treat fever. A decoction of the bark or leaf is used in the treatment of jaundice and against itch and ringworm. The leaves and twigs are sold as a medicinal tonic for young children [52].

In a previous study, the methanol stem bark extract of *M. lucida* (10–50 mg/mL) reduced worm motility and caused death of the adult Indian earth worm, *P. posthuma* with a paralytic time of 18.17 ± 0.03 min and death time of 24.34 ± 0.21 min at 50 mg/mL [51].

#### **2.9** *Moringa oleifera* **Lam. (Moringaceae)**

*Moringa oleifera* is a fast growing perennial evergreen or deciduous plant which grows up to a maximum height of 7–12 m. It has an open crown of drooping fragile branches bearing feathery foliage of opposite pinnate leaves, a crooked bole and dark gray stem bark. *M. oleifera* has been naturalized in many tropical and subtropical regions of the world including Africa, Arabia, South Asia, South America and India where it is commonly referred to as horseradish tree and drumstick tree [53]. Various parts of the plant are used in traditional medicine to treat various diseases including skin infections, anemia, asthma, bronchitis, catarrh, chest congestion, cholera, diabetes, hypertension and many other illnesses [54].

The foliage of *M. oleifera* was investigated for anthelmintic activity in wild caught *Achatina achatina* Linnaeus (edible snails). After feeding the snails on the foliage for 10 weeks, the proportion of parasitic infection in the treated group was estimated using dissecting and microscopic techniques. At the end of the treatment period, 96% of snails in the untreated group were observed to have their kidneys infected with roundworms as opposed to 24% of snails in the treated group. The percentage prevalence of parasitic infection in the treated and control groups was significantly different (*p* < 0.0001). Similar results were recorded for the infection of the lungs highlighting the anthelmintic value of *M. oleifera* in the control of worm infection in edible snails [55].

#### **2.10** *Ocimum basilicum* **Linn (Lamiaceae)**

*Ocimum basilicum* is a tender-growing aromatic annual herb indigenous to West Africa and India. It is commonly called basil or sweet basil and locally known in the Ghanaian Akan language as '*Nunum'*. The herb is ubiquitously known for its therapeutic potentials in African folk medicine. In Ghana, basil is used in its fresh form as spice and flavoring in soups and sauces due to its strong spicy aroma. The whole plant is used to treat worm infestation, inflammation, pain, diarrhea, gastrointestinal infections and eye-related diseases [56].

*In vitro* anthelmintic activity of the hexane and ethanolic extracts of the fruits of *O. basilicum* was investigated against *Eudrilus eugeniae*. At a concentration range of 0.25–5 mg/mL, the extracts displayed a concentration dependent anthelmintic activity which was observed to be significantly (*p* < 0.001) higher compared to mebendazole-treated worms. At 5 mg/mL, paralysis was observed at 11.85 ± 0.71,

27.90 ± 0.42 and 94.04 ± 2.57 mins for the ethanol extract, hexane extracts and mebendazole-treat worms respectively. Similarly, death of worms was recorded at 24.74 ± 0.42, 85.18 ± 0.07 and 522.77 ± 1.53 mins respectively for the ethanol extract, hexane extracts and mebendazole [57].
