CHAPTER ONE

INTRODUCTION

Long before mankind discovered the existence of microbes the idea

that plants have some healing potentials i.e. that they contain what we

will currently characterize as antimicrobial principle was well

accepted (Doughari mahmood & Tyoyina 2011). In whatever

manner early man gained his knowledge of the curative powers of

plants one must assume that the was able thereafter to recognize the

plant since the detailed flora available today were not in existence

then (Sofowora 2008). The use of higher plants and their extracts to

treat infectious diseases is an age old practice in traditional African

medicine (Onyeagba ugbogu Okeke & Iroakasi 2004). Traditional

medicine practice has been known for centuries in many parts of the

world (Sofowora 1984). It is however observed that these practices

vary from one country to another (Onyeagba ugbogu Okeke &

Iroakasi 2004). Nature has been a source of medicinal agents for

thousands of years. The use of herbs is the most ancient approach to

healing known (Apata 1979).World Health Organization (WHO) in

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1978 defined traditional medicine as the sum total of knowledge or

practices whether explicable or inexplicable used in diagnosing and

preventing a physical mental or social disease which may rely

exclusively on past experience or observation handed down from

generation to generation verbally or in writings. Since antiquity man

has used plants to treat common infectious diseases and some of these

traditional medicines are still included as part of habitual treatment of

various maladies (Doughari et al). Numerous plants and herbs are

used all over Nigeria as phytomedicine by traditional medicine

practioners. Plant extracts are given singly or as concoction for

various ailments. The medicine could be either in the form of

powders liquids liniments and inclusion accoding to Apata. More

than 70% of people living in Nigeria depend on these various forms of

concoctions and herbal decocotions for the treatment of some diseases

(Kimbi-Beyioku 1996). Many investigators have demonstated the

antimicrobial activity of the constituents of some higher plants

(Akobundu & Agykara 1987; Rocio and Rion 1982; Almagboul et al

1988; Misra et al 1992; Hablemariam et al; 1993) and quite a number

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of chemical compounds of plant origin have been shown to possess

antimicrobial activity (Corthout Piefers & Cleays 1992). One of

such plants is Hibiscus sabdariffa.

Hibiscus sabdariffa (called Roselle in English or Zobo in the northern

part of Nigeria) which belongs to mallow family (malvaceae) is native

to West Africa. Hibiscus sadariffa is cultivated in loamy well drained

soil mainly in tropical climates and requires rainfall averaging about

10 inches (15 cm) each month throughout the growth season. Hibiscus

sabdrriffa is of several use it is considered to have anti-hypertensive

properties. In some places the plant has been used in folk medicine as

diuretic mild laxative and treatment for cardiac and nerve diseases

and cancer to mention but a few.

However the plant (Hibiscus sabdariffa) is rich in anthocyanin. The

dried calyces contained flavonoids gossypetin hibiscentine and

sabdaretine. The major flavonoid formerly reported as hibiscin has

been identified as daphniphylline. Small amounts of myrillin

(delphinidin 3- monoglucoside) chrysanthenin (cyanide 3-

monoglucoside) and delphinidin are also present (Mohammed

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Fernandez Pineda & Aguilar 2007). All these gave it the qualities to

be regarded as a chemotherapeutic agent against some

microorganisms especially some pathogens of man.

Salmonella typhi is an enteric bacterium responsible for causing

typhoid fever which has affected mankind since human population

became large enough to contaminate the supply of its water. It is a

food borne disease contracted by ingestion of bacteria in contaminated

food or water (jerry 2007). The sources of infection could be through

infected food poor kitchen hygiene and excretions from either sick

people or infected but apparently clinically healthy people and

animals polluted surface water standing water and so on. The signs

and symptoms of the disease has 4 phases first week involves the

slow rise in temperature headache cough malaise and abdominal

pain. In the second week of the infection high fever in plateau around

40

o

C (104

o

F) and bradycardiac (Sphygmothermic dissociation) and

delirium is frequent. The patient may be calm but sometimes agitated

thus it gave typhoid fever the nickname called “Nervous fever”. In

the third week intestinal hemorrhage occurs Encephalitis

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Neuropsychiatric symptoms metastatic abscesses and endocarditis is

seen. The final week (fourth) the patient enters into the typhoid state.

The incidence of Salmonella infection may not be perfectly known.

This is because the majority of patients are treated as outpatients and

therefore hospital based studies will underestimate the true incidence

(W.H.O 2006). However the incidence of typhoid fever in

developing countries is higher compared to other developed countries.

The pathogenesis of typhoid fever is a complex process which

proceeds through several stages with an asymptomatic incubation

period of 7-14days inversely related to the size of the infecting dose

during which bacteria invade macrophages spread throughout the

reticuloendothelial system. After passing through the pathological

stages necrosis may occur. Salmonella typhi infection can be best

prevented by sanitation and hygiene. It can be controlled using a wide

variety of methods such as the use of vaccines e.g live oral Ty2la

vaccine (sold at Vivotif Berna). Diagnosis is by bone marrow or stool

culture and with a widal test i.e (demonstration of Salmonella

antibodies against O and H antigens). Treatment is by the use of

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antibiotics such as ampicillin chloramphenicol trimethoprim

sulfomethriazole and ciprofloxacin. Since some plants have been

shown to have antimicrobial effect against some pathogenic bacteria

especially antibiotic resistant pathogens this study is aimed at testing

the effect of H. sabdariffa on S. typhi and other pathogens such as

Escherichia coli Staphylococcus aureus Pseudomonas aeruginosa

and Klebsiella pneumonia. The aim of the study is to determine the

invitro effect of H. sabdariffa on a clinical isolate of S. typhi and other

pathogens. Below are the objectives of this study.

1.1. Objectives

 Collection and identification of H. sabdariffa flower

 Antibiotic sensitivity testing of the test organism

 Antimicrobial screening of H. sabdariffa extract against the test

organisms.

 Investigation of the susceptibility of S. typhi and other

pathogens to hot water extract of H. sabdariffa flower.

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