MYCOLOGICAL AND AFLATOXIN PROFILE OF HERBAL MEDICINAL PRODUCTS IN NORTH WESTERN-NIGERIA
MYCOLOGICAL AND AFLATOXIN PROFILE OF HERBAL MEDICINAL PRODUCTS IN NORTH WESTERN-NIGERIA
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Date
2014-11
Authors
ABBA, DANLADI
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Abstract
ABSTRACT The increase in the consumption of natural drugs has made their use a source public health concern. This concern arises from the possibility of the presence of fungal contaminants and the risk of mycotoxins such as aflatoxins. A total of four hundred and thirty two(432) powdered herbal medicinal preparations consisting of twelve (12) each from six(6) localities in each of the six(6) states‟ of the North Western Nigeria were obtained. These samples were subjected to various mycological analyses. The parameters measured, were grouped as follows: Mycoflora type and their level of contaminations, physicochemical properties (moisture content and pH), molecular identification of aflatoxigenic and level of total aflatoxins. Result indicated that all the samples tested did not comply with the maximum acceptable limit of 2x102 cfu/g for fungal load as specified by United State Pharmacopoeia, but the distribution of fungi in the herbal preparations varies from state to state and from species to species. Kaduna and Birnin Kebbi states had significantly (at p≤0.05) higher mean fungal count of 1.1x105cfu/g and 1.1x105 cfu/g respectively. Gusau had the lowest mean value of fungal load of 7.8x104cfu/g. The fungal load in Katsina, Sokoto, Kano and Gusau were not the same but not significantly different (p≤0.05) as indicated by Analysis Of Variance (ANOVA). The mean of frequency of occurrence of the fungi isolates showed that incidence of Aspergillus flavus, Aspergillus parasiticus, Aspergillus niger and Penicillium spp were not significantly different at p≤0.05, but significantly higher than Aspergillus ochraceus and Aspergillus versicolor. The mean frequency of occurrence of Rhizopus spp and Fusarium spp were significantly lowest. Fungi of the genus Aspergillus spp and Penicillium spp were observed to be the most frequently isolated, and among the Aspergillus spp, A. flavus, A. parasiticus, A. niger were the most frequently occurred fungi and the major contaminants of the herbal medicinal products viii in all the six states of the North Western Nigeria. Both toxigenic and atoxigenic strains of A. flavus and A. parasiticus were identified through molecular characterizations. Approximately, 85.88% of the samples had their moisture content above the stated limit set by Nigerian appropriate regulatory body (National Agency for Food and Drugs Administration and Control). Most of the fungal species were able to grow over a broad pH range, but generally the fungal isolates grew more in number in samples with acidic properties. Chi- square correlation test showed positive correlation between moisture content and fungal load in all the six states while correlation between pH and fungal load in Gusau, Kaduna and Kano were negative. The total aflatoxin value ranged from the highest (>20ppb)in all the six towns to the lowest (1.6ppb). Kastina showed the highest number of samples n=65(90.28%) contaminated with aflatoxin above the acceptable limit of 10ppb.The mean value of total aflatoxin of herbal medicinal preparations is significantly high in Katsina with a value of 18.73ppb, and significantly lowest in Gusau with a value of 9.40ppb. This suggests that Katsina and Gusau had the highest lowest aflatoxin contamination respectively. The investigation also showed that both the mean of fungal count and mean of aflatoxin level were significantly higher(p≤0.05) in the wet season than in the dry season , with a few exceptions as Lalan Area (Gusau) and Old market and Gawon Nama (Sokoto) where the mean fungal count was found to be significantly higher (p≤0.05) in the dry season than in the wet seasons. In Argungun Motor Park, the mean aflatoxin level was significantly higher (p≤0.05) in the dry season than in the wet season. There was a significant and positive correlation between total aflatoxin and fungal load (p≤0.05; r =+0.123) in the preparations obtained in the sample area.
Description
A DESSERTATION SUMMITTED TO THE POSTGRADUATE
SCHOOL, AHMADU BELLO UNIVERSITY, ZARIA IN PARTIAL
FULFILMENT FOR THE REQUIREMENT FOR THE AWARD OF A
DOCTOR OF PHILOSOPHY IN MICROBIOLOGY
DEPARTMENT OF MICROBIOLOGY,
FACULTY OF SCIENCE
AHMADU BELLO UNIVERSITY, ZARIA
NIGERIA
Keywords
MYCOLOGICAL, AFLATOXIN, HERBAL, MEDICINAL, PRODUCTS, NORTH WESTERN, NIGERIA