Typhoid fever, a disease transmitted by the faecal-oral route via contaminated food and water and is therefore common where sanitary conditions are inadequate and access to clean water is limited. The use of antibiotics is a major strategy for the fight against these bacteria, and antimicrobial agents are commonly used therapeutically and prophylactically in human and animal salmonellosis. However, conventional antityphoid drugs are becoming more and more unavailable to the common man in Africa due to increased cost. Moreover, the typhoid causative organism, S. typhi, has rapidly gained resistance to the previously efficacious drugs like chloramphenicol and ciprofloxacin. Hence, there is a need for new antityphoid agents. Vernonia amygdalina is a medicinal plant, locally used in West Africa by the traditional healer. This work was designed to evaluate the antityphoid and antimicrobial activities of the aqueous extracts of Vernonia amygdalina in-vitro and in-vivo of infected rats. A S. typhi infected rat model was used for this study. The physiological, biochemical and histopathological markers of possible side effects of Vernonia amygdalina on typhoid rats was studied using standard methods. The in-vitro susceptibility test was carried out and it was seen that V. amygdalina showed no inhibition potential in-vitro. Administation of V. amygdalina extract showed insignificant effect on all the haematological parameters of the treated group. The untreated group showed the highest Red blood cell count (8.08 + 1.15) followed by the normal control group (7.04 +0.57), ciprofloxacin treated group (6.82 + 0.15) V. amygdalina (4.95 + 2.11) with chloramphenicol treated group showing the least Red Blood cell counts (1.86 + 0.21). The lipid peroxidation level was lowest in group treated with V. amygdalina (1.26+0.45) while the untreated group has the highest lipid peroxidation (4.62+ 0.00). The histological analysis of test animals revealed the extent of hepatic damage in untreated group when compared to other groups. Groups treated with V. amygdalina showed degenerative histological condition similar to the untreated group and was able to inhibit oxidative stress in test animals. This study however showed that the aqueous extract of V. amydalina possesses anti-salmonella activity.
Typhoid fever, also known simply as typhoid, is a bacterial infection due to Salmonella typhi. It is the major cause of enteric diseases in children in developing countries, resulting in an estimated incidence of 50 cases per year (Crumps, 2011). Globally, it is estimated that typhoid accounts for 16 million cases each year resulting in 6000,000 deaths (Appiah-korang, 2014).The disease is characterized by symptoms such as weakness, abdominal pain, constipation, headaches, diarrhea and vomiting (Anna, 2014). These symptoms may vary from mild to severe and usually begin six to thirty days after exposure (Ochiai, 2015). The severity of the infection depends on the initial infective dose, the virulence of the organism and the host’s immune response (Adams, 1999). Typhoid fever is often contracted by eating or drinking food or water contaminated with the faeces of an infected person (Bhan, 2005). Currently, ciprofloxacin is the drugs of choice used in the treatment of typhoid fever, but the widespread emergence of multi-drug resistant S. typhi (resistant to ampicillin, choramphenicol, and trimethoprim-sulfamethoxazole) has necessitated the search for other therapeutic options such as the use of medicinal plants (Girgis, 2009).
The term of medicinal plants include a various types of plants used in herbalism from plants with medicinal activities (Bassam, 2012). Medicinal plants are the “backbone” of traditional medicine, and more than 3.3 billion people in the less developed countries utilize medicinal plants on a regular basis (Davidson-Hunt, 2000).
Furthermore, an increasing reliance on the use of medicinal plants in the industrialized societies has been traced to the extraction and development of several drugs and chemotherapeutics from these plants as well as from traditionally used rural herbal remedies (Bassam, 2012).
Therefore, medicinal plants are considered a rich resources of ingredients which can be used in drug development and synthesis (Lemma, 1991). In addition, medicinal plants are source of important drugs such as quinine, reserpine, galenicals like tinctures and of intermediates (e.g. diosgenin from Discorea sp.) used as pharmaceuticals (Lemma, 1991).
In this study, Vernonia amygdalina (bitter leaf) was used against S. typhi in-vitro and in-vivo. Previous studies have reported bitter leaf to contain chemical compound such as vernoside which is said to have antimalaria effect, sesquiterpene and lactone that have anti tumor activities (Cimanga, 2004). Traditionally, bitter leaf are commonly used for cooking of soup and porridge, but medicinally, it has been extensively used for the treatment of stomach ache, parasitic infection and has proven to be effective against drug resistant malaria parasites (Ohigashi et al., 1994).
The aim of the study is to investigate the antibacterial activity of Vernonia amygdalina extract against Salmonella typhi.
- to determine the sensitivity of S. typhi to V. amygladina extract
- to determine the inhibition S. typhi by V. amygladina in rats infected with S. typhi.
- to evaluate the effect of amygladina extract on
- to evaluate the organ protective ability of V. amygladina extract in infected rats using histology biochemical analysis.