CHAPTER ONE
INTRODUCTION AND LITERATURE
1.1 Background of the study
Medicinal plants represent a rich source of antimicrobials and many other drugs. The potentials of higher plants as source for new drugs is still largely unexplored. Antibiotic resistance has become a global concern (Westhet al., 2004). The clinical efficacy of many existing antibiotics is being threatened by the emergence of multidrug-resistant pathogens (Bandow, 2003). Many infectious diseases have been known to be treated with herbal remedies throughout the history of mankind. Natural products, either as pure compounds or as standardized plant extracts, provide unlimited opportunities for new drug leads because of the unmatched availability ofchemical diversity.
There is a continuous and urgent need to discover new antimicrobial compounds with diverse chemical structures and novel mechanisms of action for new and re-emerging infectious diseases (Rojas et al., 1992). Therefore, researchers are increasingly turning their attention tolocal herbs, looking for new leads todevelop better drugs against microbial infections (Benkeblia, 2004). The increasingfailure of chemotherapeutics and antibiotic resistanceexhibited by pathogenic microbial infectious agents has led to the screening of several medicinal plants for their potential antimicrobial activity (Kapila, 2005 ;Runyoro et al.,2006). The rising prevalence of antibiotics resistant pathogenic microorganisms raises the demand for finding new alternative antimicrobial agents. The drugs already in use to treat infectious diseaseare of concern because drug safety remains an enormous global issue. Most of the synthetic drugscause side effects and also most of the microbesdeveloped resistant against the synthetic drugs (Chanda and Rakholiya 2011). To alleviate this problem, antimicrobial compounds from potential plants should be explored. These drugs fromplants are less toxic; side effects are scanty
and alsocost effective. They are effective in the treatment of infectious diseases while simultaneously mitigating many of the side effects that are often associated withsynthetic antimicrobials (Harishchandraet al., 2012). Published studies in medical journals show that coconut in one form or another may provide a wide range of health benefits. The coconut plant Cocos nucifera (family Arecaceae) is considered as an important fruit crop in tropical countries. It is commonly available plant with wide variety of applications in food, drinks, fibers, building materials and various chemicals finding their way into a huge range of modern day products. Being highly nutritious coconuts have also been studied for medicinal qualities. Modern medical science is now confirming the medicinal qualities of Cocos nucifera which are used for the treatment wide range of infections. Based on the knowledge of the traditional herbs used for the treatment for local application, coconut husk can be use as a topical antimicrobial. As preliminary investigation of the use of coconut husk, the antimicrobial activity can be evaluated.
1.2 AIM AND OBJECTIVES
The specific objectives are to:
(a) Evaluate the phytochemical and antimicrobial activities of Methalonic extract of young Cocos nucifera husk on selected pathogenic microorganisms.
(b) Evaluate the antimicrobial activities andyoung Cocos nucifera water on selected pathogenic microorganisms
1.3 JUSTIFICATION OF THE RESEARCH
Cocos nucifera husk and Cocos nucifera water are traditionally used in the treatment of wide variety of diseases, it has been used from time immemorial for the treatment of carcinogenic infections. This study scientifically justifies the use of young Coconut husk and young Coconut water in traditional folk medicine and to compare their antimicrobial potency with the commercial antibiotics. 1.4LITERATURE REVIEW
1.4.1 MEDICINAL PLANTS AS ANTIMICROBIAL AGENT
Medicinal plants have always been considered as a source for healthy life for people. Therapeutical properties of medical plants are very useful in healing various diseases and the advantage of these medicinal plants are natural (Kalemba and Kunicka, 2003). In many parts of the world, medicinal plants have been used for its antibacterial, antifungal and antiviral activities for hundreds of years (Ali et al., 1998; Barbour et al., 2004; Yasunakaet al., 2005). Researchers are increasingly turning their attention to natural products and looking for new leads to develop better drugs against cancer, as well as viral and microbial infections (Ibrahim, 1997; Towers et al., 2001; Koshy et al., 2009). Several synthetic antibiotics are employed in the treatment of infections and communicable diseases. The harmful microorganisms can be controlled with drugs and this has resulted in the emergence of multiple drug resistant bacteria and it has created alarming clinical situations in the treatment of infections. In general, bacteria have the genetic ability to transmit and acquire resistance to synthetic drugs which are utilized as therapeutic agents (Murray, 1992; Madunaguet al., 2001; Koshy et al., 2009;
Senthilkumar and Reetha, 2009) Therefore, actions must be taken to reduce this problem, such as to minimize the use of antibiotics, develop research of resistance among microorganism and to continue studies to develop new antibiotic and immune modulating compounds with diverse chemical structures and novel mechanisms of action, either synthetic or natural to control pathogenic microorganisms because there has also been an alarming increase in the incidence of new and re-emerging infectious diseases (Ikenebomeh and Metitiri, 1988; Rojas et al., 2003) Antimicrobial studies have shown that Gram-negative bacteria show a higher resistance to plant extracts than Gram-positive bacteria. This may be due to the variation in the cell wall structures of Gram-positive and Gram-negative bacteria. More specifically, Gram-negative bacteria has an outer membrane that is composed of high density lipopolysaccharides that serves as a barrier to many environmental substances including antibiotics (Paz et al., 1995; Vlietincket al., 1995; Kudiet al., 1999; Palombo and Semple, 2001). Although hundreds of plant species have been tested for antimicrobial properties, the vast majority of have not been adequately evaluated (Onwuliri and Dawang, 2006; Mahesh and Sathish, 2008). The coconut (Cocos nucifera L. family Arecaceae) is a well distributed fruit tree all around the world, providing food, especially in the tropical and subtropical regions and for its many uses it is often called the “tree of life”. There are 12 different crops of nuts under the name of coconut palm (DebMandal and Mandal, 2011). Cocos nucifera is widely distributed over the Brazilian northeastern coast, where is known as “Coco-da-Bahia”. Popular medicinal uses (against arthritis and diarrhea) of coconut husk fiber have been reported (Rinaldi et al., 2009), but the knowledge of its potential benefit or adverse effects in human beings is still very preliminary. Coconut, Cocos nucifera, is a tree that is cultivated for its multiple utilities, mainly for its nutritional and medicinal values. The various products of coconut include tender coconut water, copra, coconut oil, raw kernel, coconut cake, coconut toddy, coconut shell and wood based products, coconut leaves, coir pith etc. It’s all parts are used in some way or another in the daily life of the people in the traditional coconut growing areas. It is the unique source of various natural products for the development of medicines against various diseases and also for the development of industrial products. The parts of its fruit like coconut husk and tender coconut water have numerous medicinal properties such as antibacterial, antifungal, antiviral, antiparasitic, antidermatophytic, antioxidant, hypoglycemic, hepatoprotective, immunostimulant. Coconut water and coconut kernel contain micro minerals and nutrients, which are essential to human health, and hence coconut is used as food by the peoples in the
globe, mainly in the tropical countries. The coconut palm is, therefore, eulogizedas ‘Kalpavriksha’ (the all giving tree) in Indian classics. India is the third largest coconut producing country, after Indonesia and the Philippines, having an area of about 1.78 million hectares under the crop. Annual production is about 7,562 million nuts with an average of 5 295 nuts/hectare (Rinaldi et al., 2009). In India, the four south Indian states namely Kerala, Tamil Nadu, Karnataka and Andhra Pradesh account for around 90% of the coconut production in the country (Rinaldi et al., 2009). For thousands of years, coconut products have held a respected and valuable placein Indianfolk medicine. It is believed to be antiblenorrhagic, antibronchitis, febrifugal, and antigingivitic. In Ayurvedic medicine, the oil, milk, cream and water of the coconut are all used to treat hair loss, burns and heart problems. In India, the use of coconut for food, and its applications in the Ayurvedic medicine were documented in Sanskrit 4 000 years ago. Records show that in the United States, coconut oil was one of the major sources of dietary fats, aside from dairy and animal fats, prior to the advent of the American edible oil (soybean and corn) industry in the mid-1940s(Dayrit,2005). Virgin coconut oil (VCO) is completely non-toxic to humans, and is referred to as the “drugstore in a bottle”. In India, the coconut has religious connotations; it is described as “The fruit of aspiration” and a coconut is offered to the gods and cut at the start of many new projects. Coconut water is produced by a 5 month old nut that during World War II, was used in emergencies, and put directly into a patient’s veins. From ancient times the coconut is used as a very effective remedy for intestinal worms of all kinds. Boiled toddy, known as jaggery, with lime makes a good cement. Nutmeat of immature coconuts is eaten or extracted cream is used on various foods.
