**3.1. Methods of preparation and dosage forms**

Methods of preparation of herbal medicines may vary according to place and culture. The plant materials may be used fresh or dry. With experience, a particular method is chosen to increase efficiency and decrease toxicity. Generally, different methods of preparation include:


There are also different methods of administration. Apart from the common routes such as oral, rectal, topical, and nasal, other methods include smoking a crudely prepared cigar containing dried plant materials or by passive inhalation. Others are steaming and inhaling the volatile oils exuding from the boiling plant material. These can be used to relieve congestion, headaches, or pulmonary problems. Sitz baths are used for piles [19, 20].

#### **3.2. Ethnobotanical surveys**

Information on plants is obtained through ethnobotanical surveys, which involves the study of plants in relation to the culture of the people. Many plants are used in African traditional medicine, but little information is available on their active ingredients/constituents. Ethnobotanical surveys involve the interaction with the people and their environment and are therefore participatory approaches, in which local people are able to contribute their knowledge on the uses of plants within their environment. This may involve the identification, documentation, conservation, and utilization of medicinal plants. Much of the ethnomedicinal information is largely not validated. In Nigeria, a number of authors have published a lot of data on plants with their curative values [16, 20, 21]. These provide a vast array of information for scientific research and validation. Preliminary scientific knowledge is drawn from studies on *in vitro* and *in vivo* bioassays on crude extracts of various plants.

certain therapeutic effects. Chemical components or phytochemicals found in plants that are responsible for the various therapeutic effects include alkaloids, glycosides, tannins, acids, coumarins, sterols, phenols, etc. Many modern pharmaceuticals have been modeled on or were originally derived from these chemicals, for example, aspirin is synthesized from salicylic acid derived from the bark of *Salix alba* and the meadowsweet plant, *Filipendula ulmaria*. Quinine from *Cinchona pubescens* bark and artemisinin from *Artemisia annua* plant are antimalarial drugs. Vincristine and vinblastine are anticancer drugs derived from Madagascar periwinkle (*Catharanthus roseus*), used for treating leukemia. Morphine and codeine, derived from the opium poppy (*Papaver somniferum)*, are used in the treatment of diarrhea and pain relief, while digitoxin is a cardiac glycoside derived from foxglove plant (*Digitalis purpurea*)

alilibarrafi

akpalata

baurere

**Family Specie Local name Part used Medicinal uses**

Apocynaceae *Alstonia boonei* Root, bark,

Bombacaceae *Adansonia digitata* leaves, fruit,

Euphorbiaceae *Bridelia ferruginea* iri, kirni leaves,

Hypericaceae *Harungana madagascariensis* Otoro,

Fabaceae *Afzelia africana* Apa-igbo,

Liliaceae *Gloriosa superba* mora, ewe aje,

Combretaceae *Combretum grandiflorum* Ikedike leaves Jaundice

**Table 1.** Some selected Nigerian medicinal plants and their uses. Source: Abd El-Ghani [51].

Acanthaceae *Acanthus montanus* Stem, twig Syphilis, cough, emetic, vaginal

Amaranthaceae *Amaranthus spinosus* Whole plant Abdominal pain, ulcers, gonorrhea

leaves

pulp, bark

stem, bark, root

Stem, bark, root bark

leaves, roots, bark, seeds

tubers, leaves

discharge

Herbal Medicines in African Traditional Medicine http://dx.doi.org/10.5772/intechopen.80348

bladder disease

piles, trypanosomiasis

gonorrhea, hernia

Breast development, filarial worms

197

Fever, antimicrobial, kidney, and

insomnia, mouth wash, gonorrhea

gonorrhea, headlice, antipyretic

[22, 24]. Medicinal plants are also important materials for the cosmetic industries.

**4. Clinical practice of African traditional/herbal medicine**

are derived from plants [25].

The use of herbal drugs dwindled toward the end of the 19th century due to the advent of synthetic chemistry. However, there was a resurgence of interest in plant medicines in more recent years, as synthetic drugs became less effective due to high levels of resistance and also due to higher toxicity and cost. It is estimated that more than half of all synthetic drugs in use

In African traditional medicine, the curative, training, promotive, and rehabilitative services are referred to as clinical practices Clinical practice can also be viewed as the process of

Using plants as medicine provides significant advantages for treating many chronic conditions. For example, information from folklore medicine in Nigeria has it that *Rauvolfia vomitoria* is used for treating hypertension and other nervous conditions while *Ocimum gratissimum* is used for treating diarrheal diseases. Others include *Citrus paradise* seeds for resistant urinary tract infections, pure honey for chronic wound treatment, *Carica papaya* seeds for intestinal parasites, *Garcinia kola* seeds for pain and inflammation, and *Aloe vera* for skin diseases. The same is also true for plants from other African countries [22]. Knowledge of most of these curative properties was accumulated over time from evidence-based observations. A few examples of some Nigerian plants and their uses are shown in **Table 1**.

**Table 1** shows some selected Nigerian medicinal plants and their uses.

The curative properties of herbal medicine are validated through scientific investigations, which seek to understand the active chemistry of the plants [23]. The therapeutic activity of a plant is due to its complex chemical nature with different parts of the plant providing


**Table 1.** Some selected Nigerian medicinal plants and their uses. Source: Abd El-Ghani [51].

**4.** Tinctures are alcoholic infusions which if concentrated may be diluted before administration. **5.** Ashing—The dried parts are incinerated to ash, then sieved and added as such to water or food. **6.** Miscellaneous—Other types include liniments for external applications in liquid, semiliquid, or oily forms containing the active substances; lotions which are liquid preparations intended for skin application. Poultices are prepared from macerated fresh part of plant containing the juice from the plant and applied to skin. Snuffs are powdered dried plant inhaled through the nostrils. Dried plants may be burnt, and their charcoal is used as such. Gruels are cereals/porridges made from grains, to which dried powdered plant or its ash is added to be taken orally. Mixtures are sometimes prepared with more than one plant to

There are also different methods of administration. Apart from the common routes such as oral, rectal, topical, and nasal, other methods include smoking a crudely prepared cigar containing dried plant materials or by passive inhalation. Others are steaming and inhaling the volatile oils exuding from the boiling plant material. These can be used to relieve congestion,

Information on plants is obtained through ethnobotanical surveys, which involves the study of plants in relation to the culture of the people. Many plants are used in African traditional medicine, but little information is available on their active ingredients/constituents. Ethnobotanical surveys involve the interaction with the people and their environment and are therefore participatory approaches, in which local people are able to contribute their knowledge on the uses of plants within their environment. This may involve the identification, documentation, conservation, and utilization of medicinal plants. Much of the ethnomedicinal information is largely not validated. In Nigeria, a number of authors have published a lot of data on plants with their curative values [16, 20, 21]. These provide a vast array of information for scientific research and validation. Preliminary scientific knowledge is drawn from studies

Using plants as medicine provides significant advantages for treating many chronic conditions. For example, information from folklore medicine in Nigeria has it that *Rauvolfia vomitoria* is used for treating hypertension and other nervous conditions while *Ocimum gratissimum* is used for treating diarrheal diseases. Others include *Citrus paradise* seeds for resistant urinary tract infections, pure honey for chronic wound treatment, *Carica papaya* seeds for intestinal parasites, *Garcinia kola* seeds for pain and inflammation, and *Aloe vera* for skin diseases. The same is also true for plants from other African countries [22]. Knowledge of most of these curative properties was accumulated over time from evidence-based observations. A

The curative properties of herbal medicine are validated through scientific investigations, which seek to understand the active chemistry of the plants [23]. The therapeutic activity of a plant is due to its complex chemical nature with different parts of the plant providing

give synergistic or potentiating effects of the composite plants.

headaches, or pulmonary problems. Sitz baths are used for piles [19, 20].

on *in vitro* and *in vivo* bioassays on crude extracts of various plants.

few examples of some Nigerian plants and their uses are shown in **Table 1**.

**Table 1** shows some selected Nigerian medicinal plants and their uses.

**3.2. Ethnobotanical surveys**

196 Herbal Medicine

certain therapeutic effects. Chemical components or phytochemicals found in plants that are responsible for the various therapeutic effects include alkaloids, glycosides, tannins, acids, coumarins, sterols, phenols, etc. Many modern pharmaceuticals have been modeled on or were originally derived from these chemicals, for example, aspirin is synthesized from salicylic acid derived from the bark of *Salix alba* and the meadowsweet plant, *Filipendula ulmaria*. Quinine from *Cinchona pubescens* bark and artemisinin from *Artemisia annua* plant are antimalarial drugs. Vincristine and vinblastine are anticancer drugs derived from Madagascar periwinkle (*Catharanthus roseus*), used for treating leukemia. Morphine and codeine, derived from the opium poppy (*Papaver somniferum)*, are used in the treatment of diarrhea and pain relief, while digitoxin is a cardiac glycoside derived from foxglove plant (*Digitalis purpurea*) [22, 24]. Medicinal plants are also important materials for the cosmetic industries.

The use of herbal drugs dwindled toward the end of the 19th century due to the advent of synthetic chemistry. However, there was a resurgence of interest in plant medicines in more recent years, as synthetic drugs became less effective due to high levels of resistance and also due to higher toxicity and cost. It is estimated that more than half of all synthetic drugs in use are derived from plants [25].
