BACKGROUND OF THE STUDY
There are many research investigations concerning antimicrobial properties of plants but few researches are conducted on its antifungal properties. Natives and even the common Filipinos residing in rural areas rely on natural remedies to cure known or unknown skin diseases due to old folklore beliefs albeit they are taking it by chance. Knowledge regarding antifungal phytochemicals derived from plants is less known and needs to be thoroughly researched for further information that specific plants can be alternative antifungal treatments. Also, synthetic fungicides are known to be carcinogenic in nature, thus fungicides derived from plants are safer alternatives. Velvet apple (Diospyros philippensis), commonly known as mabolo is an evergreen forest tree that is medium-sized, and has an oval or conical-shaped crown. Leaf extracts yielded alkaloids, reducing sugar, gum, flavonoids, and tannins. ( Online 1)
STATEMENT OF THE PROBLEM
1. What phytochemicals are present in the leaves of Diospyros blancoi?
2. Will there be significant differences when Diospyros blancoi leaf extract is tested on Aspergillus niger, Candida alblicans, and Trichophyton mentagrophytes?
SIGNIFICANCE OF THE STUDY
The research is to be conducted to examine the antifungal capacity of velvet apple against Aspergillus niger, Candida albicans, and Trichophyton mentagrophytes. Moreover, to test velvet apple leaf extract’s phytochemical constituents. The researchers’ main goal is to provide information regarding organic fungicides such as plant extracts, specifically the velvet apple. This research can also be used as a reference and basis for future researchers with similar studies.
SCOPE AND LIMITATION OF THE STUDY
The scope of the study is limited to the determination of phytochemical constituents of Diospyros philippensis and its potency against Aspergillus niger, Candida albicans, and Trichophyton mentagrophytes.
REVIEW OF RELATED LITERATURE
Various constituents isolated and characterized from Diospyros species include naphthaquinones, triterpenoids and steroids. Some notable activities reported from the various part of the plant and from the extract and isolated constituents are antibacterial, antifungal, antiprotozoal, antimolluscocidal, anti-inflammatory and cytotoxicity activity. (Ethnobotanical Leaflets 12: 231-244. 2008.) Aspergillus niger is a fungus and is one of the most common species of the genus Aspergillus. It causes a disease called black mold on certain fruits and vegetables such as grapes, onions, and peanuts, and is a common contaminant of food. Some strains of A. niger have been reported to produce potent mycotoxins called ochratoxins. The fungus is less likely to cause human disease than some other Aspergillus species, but if large amounts of spores are inhaled, a serious lung disease, aspergillosis can occur. (http://en.wikipedia.org/wiki/Aspergillus_niger). Candida albicans is a diploid asexual fungus that live in the human mouth and gastrointestinal tract. Under normal circumstances, C. albicans lives in 80% of the human population with no harmful effects, although overgrowth results in candidiasis.
Candidiasis also known as “thrush”, is a common condition that is usually easily cured in people who are not immuno-compromised. To infect host tissue, the usual unicellular yeast-like form of Candida albicans reacts to environmental cues and switches into an invasive, multicellular filamentous form (en.wikipedia.org/wikicandida_albicans). Trichophyton mentagrophytes is a keratinophylic fungus belonging to a homogeneous group of fungi called the dermatophytes. The dermatophytes cause a variety of cutaneous infections in humans and animals. T. mentagrophytes has at least five different variants which make up the Trichophyton mentagrophytes complex. Two perfect states Arthroderma benhamiae and Arthroderma vanbreuseghemii have been ascribed for T. mentagrophytes. The organism has variable characteristics with anthropophilic form producing sparse aerial mycelium with numerous spores. The zoophilic isolate produces powdery or granular colonies. Microscopically the most consistent feature of T. mentagrophytes is the production of globose microaleuriospores arranged in grape-like clusters.
The ubiquitous nature of microorganisms such as fungi in the environment makes human contact with them unavoidable. The high temperatures of the tropics coupled with lack of basic infrastructures and unsanitary production conditions prevailing in most developing countries predispose many food products, fruits and vegetables to spoilage. Several outbreaks of aflatoxicosis attributed to A. flavus have been documented in rural human populations in tropical countries (Peraica et al., 1999). Some strains of A. niger produces a potent mycotoxin called ochratoxins A; a human carcinogen found in grains and wine products (Samson et al., 2004; Schuster et al., 2002).
Additionally, many fungi are parasites on plants and animals (including humans) causing serious diseases in humans such as aspergilloses, candidoses, coccidioidomycosis, mycetomas, among others. Furthermore, persons with immuno-deficiencies are particularly susceptible to diseases by Aspergillus, Candida and Cryptoccocus (Hube, 2004; Brakhage, 2005; Nielsen and Heitman, 2007). Candida herbarum is the most important allergenic species and has been shown to have the ability of triggering allergic reactions in sensitive individuals. Prolonged exposure to elevated spore concentrations can elicit chronic allergy and asthma (Samson et al., 2001).
* PHYTOCHEMICAL SCREENING
The phytochemical screening of Diospyros philippensis will be conducted in the Department of Science andTechnology, Bicutan, Taguig City, Metro Manila.
* EXTRACTION OF VELVET APPLE LEAVES
The leaves of Velvet Apple will be extracted using the decoction method. A method of extraction performed through boiling, having the ratio of 50g of leaves per 75ml distilled water.
* ANTIFUNGAL ANALYSIS
Aspergillus niger, Candida albicans, and Trichophyton mentagrophytes will be cultured using potato dextrose agar. Kirby-Bauer disc diffusion assays (zone of inhibition test) will then be performed to measure the susceptibility of the fungi to the plant extracts impregnated onto a thin wafer or paper disc. The susceptibility of the fungi to the extracts is indicated by the appearance of a clear zone surrounding the impregnated disk (i.e. zone of inhibition). The radius of the zone of inhibition corresponds to the degree of susceptibility of the fungi to the antifungal agent. BRASS offers the Kirby-Bauer disc diffusion assay as a rapid screening capability for evaluating the antifungal properties of a specific antifungal agent.