SUSCEPTIBILITY OF DERMATOPHYTES TO THE METHANOL EXTRACTS OF MUSA PARADISIACA LEAF
CHAPTER ONE
INTRODUCTION
The word dermatophyte is from the Greek word “derma” meaning skin and “phyton” meaning plant. Dermatophytes are commonly referred to as ringworm or tinea infections. The name ringworm was coined to describe the circular lesion produced by the dermatophytes on the skin or scalp. The term ‘tinea’ is derived from the Latin word meaning “worm” or “moth” (Coulibaly and Coralie, 2018) and the second part of the name identifies the part of the body infected, example ‘tinea faciei’ (ringworm of the face). Dermatophytes cause infections of the skin, hair, and nails, obtaining nutrients from keratinized material. The organisms colonize the keratin tissues causing inflammation as the host responds to metabolic by-products of the fungi. Colonies of dermatophytes are usually restricted to the nonliving cornified layer of the epidermis because of their inability to penetrate viable tissue of an immunocompetent host. The serum fungal inhibitory factors in the extravascular space prevent their penetration in the living tissues, also their inability to tolerate human body temperature at 37oC and the antifungal activity of blood proteins. Occasionally the organisms do invade subcutaneous tissues, resulting in kerion development (Goldsmith and Fitzpatrick 2012).
Diseases caused by fungi known as mycoses can be classified clinically as superficial, deep, or systemic mycoses. Dermatophytes are the most important organisms causing superficial mycoses (Molina de Diego, 2011). Dermatophytes lesion take a ring shape with inflammatory edges and clear center of normal skin. The lesions are often roughly circular with raised border but may coalesce to form confluent areas of dry, scaling skin, inducing itching and scratching which in severe cases may ulcerate (Abdul and Al-Janabi, 2014). Fungal elements are always found in active state in the edges of lesion and that is why it is preferable to take scrapping sample for microscopic diagnosis from the edges of lesion and not from the clear zone. The ring shapes of the dermatophyte infections can also be used to differentiate it from other skin diseases such as psoriasis or lichen planus in which the inflammatory responses tend to be uniform over the lesion (Hainer, 2003).
Invasive fungal infections, especially those caused by the species Candida and Aspergillus, continue to rise in frequency, (Brown, et al., 2012) and, alarmingly, are associated with antifungal resistance (Fisher, et al., 2018), which makes the management of patients with such infections particularly challenging (Arendrup and Patterson, 2017; Chowdhury. et al., 2017). Except for infections due to inherently antifungal-resistant species, the majority of these infections are clinically treatable by three currently available antifungal drug classes: triazoles (fluconazole, itraconazole, voriconazole, posaconazole, isavuconazole), echinocandins (anidulafungin, caspofungin, micafungin), and polyenes (amphotericin B-deoxycholate with its lipid and liposomal formulations) (Pappas, et al., 2016, Patterson, et al., 2016). Paralleling the relatively recent introduction of new antifungal drug classes (Robbins, et al 2016) and the discovery of novel agents (McCarthy, et al., 2017), for the treatment of invasive fungal infections, the field of antifungal susceptibility testing (AFST) has progressed tremendously in the past several years (Ostrosky-Zeichner and Andes, 2017).
Medicinal plants are frequently used in traditional medicine to treat different diseases. The World Health Organization (WHO) estimated that 80% of the earth’s inhabitants depend on traditional medicine for their primary health care needs, and most of this therapy involves the use of plant extracts or their active components. This helped in exploration of different medicinal plants to find the scientific basis of their traditional uses, (Jachak, 2007). Medicinal plants contain a number of medicinal properties, (Prasobh et al., 2016). One of such plant is Musa paradisiaca, from the family Musaceae, also known as plantain is a tropical plant that is native to India. It is extensively cultivated in the tropics and is a staple crop for over 70 million people of the sub-Saharan Africa. The plant is an evergreen plant with an aerial pseudostem, an underground rhizome and a height of 2 to 9metes (Ekunwe and Ajayi, 2010). The leaves are oblong, deep green and narrowed to the base (Iman and Akter 2011). The fruit are edible, contain about 220 calories and are traditionally used in the treatment of various ailments (Lakshmi et al., 2015). It has been reported to have pharmacological activities such as antifungal, antilithiatic, antioxidant, antibacterial, antidiabetic, antiulcer, antidiarrhoeal, hypocholesterolaemic, hepatoprotective, antisnakevenom, wound healing, hair growth promoting and antimenorrhagic activity.
SUSCEPTIBILITY OF DERMATOPHYTES TO THE METHANOL EXTRACTS OF MUSA PARADISIACA LEAF
