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 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 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, 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.