Pharmacological and Toxicological Activities of The Aqueous Root Extract of Aristolochia Ringens Vahl

Tunde abasa 224 PAGES (44428 WORDS) Pharmacology Thesis

ABSTRACT

Plants continue to be a major source of medicines as they have been throughout human

history. A 2008 report from the Botanic Gardens Conservation International (representing

botanic gardens in 120 countries) revealed that 5 billion people still use medicinal plants to

partly cater for their health care needs. According to the World Health Organization,

medicinal plants would be the best source of a variety of drugs (Toroglu, 2011). The fact

that plants synthesize a wide variety of chemical compounds that possess important

biological functions accounts for this very important role of medicinal plants in health

care. These chemical compounds known as phytochemicals, have been reported to possess

beneficial effects on health on long-term basis and can be used to effectively treat diseases

that affects humans. About 12,000 of such compounds that have been isolated so far have

been estimated to be less than 10% of the total plant active ingredients available (Tapsell

et al., 2006).

Currently, plant-derived drugs constitute about 25% of conventional medications used

today (Rao et al., 2004). Some of these drugs were obtained from plants reported to be

potentially toxic. Examples of such drugs are colchicine from Colchicum autumnale used

in the management of gout; and digoxin from Digitalis purpurea used in the management

of heart failure. Some medicinal plants in their crude form have also been reported to

produce better pharmacological activity than their isolated active components, and in some

cases, their isolated active components are more toxic (CHEMEXCIL, 1992) or less

efficacious (Kicklighter et al., 2003) than the crude extract. Hence the need to advance the

development of standardized medicinal plant formulations for clinical use among

populations who will use them anyway; either because they have more confidence in the

herbal formulations or they do not have access to conventional medicines.