Description
CHAPTER ONE
1.0 INTRODUCTION
1.1 Background of Study
A mushroom (or toadstool) is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground on soil or on its food source. The standard for the name “mushroom” is the cultivated white button mushroom, Agaricus bisporus; hence the word “mushroom” is most often applied to those fungi (Basidiomycota, Agaricomycetes) that have a stem (stipe), a cap (pileus), and gills (lamellae, sing. lamella) on the underside of the cap (Smith et al., 2015). “Mushroom” also describes a variety of other gilled fungi, with or without stems, therefore the term is used to describe the fleshy fruiting bodies of some Ascomycota. These gills produce microscopic spores that help the fungus spread across the ground or its occupant surface.
Forms deviating from the standard morphology usually have more specific names, such as “bolete”, “puffball”, “stinkhorn”, and “morel”, and gilled mushrooms themselves are often called “agarics” in reference to their similarity to Agaricus or their order Agaricales. By extension, the term “mushroom” can also designate the entire fungus when in culture; the thallus (called a mycelium) of species forming the fruiting bodies called mushrooms; or the species itself (Smith et al., 2015).
Mushrooms are well known all over the world and the edible ones have been considered as functional foods. They serve to enrich food as supplements and they provide health benefits beyond the traditional nutrients they contain (Smith et al., 2015).
1.2 Statement of the Problem
Globally, millions of deaths attributed to malaria are being recorded. The disease constitutes a huge epidemiologic burden in Africa and continues and continues to cripple the economic development in the region (Trudell and Ammirati, 2009). In Nigeria, the disease is responsible for 60% outpatient visits to health facilities, 30% childhood death, 25% of death in children under one year and 11% maternal death (Philips, 2011). The financial loss due to malaria annually is estimated to be about 132 billion Naira in form of treatment costs, prevention, loss of man-hour, etc.; yet, it is a treatable and completely evitable disease (Philips, 2011). Malaria is endemic in Nigeria with 97% of the population of 170 million living in areas of high malaria risk and an estimated 3% living in malaria free highlands. Nigeria bears up to 25% of the malarial disease burden in Africa, making this country with the highest malaria mortality (WHO, 2014).
The Global Fund (TGF)’s response in the fight against malaria in Nigeria is co-managed by the National Malaria Elimination Programme (NMEP). Currently NMEP is implementing New Funding Model (NFM) of TGF which began in January 2015 (WHO, 2014). Implementation of malaria control interventions is broad-based and includes: Case Management; Integrated Vector Management; Special Interventions such as Intermittent Presumptive treatment with Sulphadoxine and Pyrimethamine; and other supportive interventions (WHO, 2014).
Edible mushrooms have been source of food to man, even before the for-knowledge of its nutritional content. It has served as major source of food in several African countries including Nigeria (Smith et al., 2015). However, its use as an antimalarial agent has not been documented. There is therefore, the need to assess the suppressive effect of the extract of this mushroom on albino mice.
1.3 Justification of the Research
Although the parasite responsible for P. falciparum malaria has been in existence for 50,000–100,000 years, the population size of the parasite did not increase until about 10,000 years ago, concurrently with advances in agriculture (Harper et al., 2011) and the development of human settlements. Close relatives of the human malaria parasites remain common in chimpanzees. Some evidence suggests that the P. falciparum malaria may have originated in gorillas (Prugnolle et al., 2011). References to the unique periodic fevers of malaria are found throughout recorded history (Cox, 2013). The advent of multiple drug resisitant malaria led to the continuous effort to curb the menace it has created through the use of all possible approaches for its eradication. However, P. berghei is used as a model organism for the investigation of human malaria because of its similarity to the Plasmodium species which cause human malaria. P. berghei has a very similar life-cycle to the species that infect humans, and it causes disease in mice which has signs similar to those seen in human malaria. Importantly, P. berghei can be genetically manipulated more easily than the species which infect humans, making it a useful model for research into Plasmodium genetics.
In several aspects the pathology caused by P. berghei in mice differs from malaria caused by P. falciparum in humans. In particular, while death from P. falciparum malaria in humans is most frequently caused by the accumulation of red blood cells in the blood vessels of the brain, it is unclear to what extent this occurs in mice infected with P. berghei (Craig et al., 2012). Instead, in P. berghei infection, mice are found to have an accumulation of immune cells in brain blood vessels (Craig et al., 2012). This has led some to question the use of P. berghei infections in mice as an appropriate model of cerebral malaria in humans (Craig et al., 2012).
Although the decreased sensitivity of malaria parasites to an antimalarial drug was first reported about a century ago in association with quinine, the term drug-resistant malaria was rarely used; resistance was not considered a major problem until the late 1950s, after chloroquine resistance emerged. Historically, chloroquine was widely used as the standard first-line drug against P. falciparum. Resistance was first detected on the Thailand–Cambodia and the Venezuela–Colombia borders, near areas where chloroquinated salt was used for malaria control, forcing the affected countries to begin switching to sulfadoxine–pyrimethamine (SP) in the 1970s. Resistance to SP developed quickly, again on the Thailand–Cambodia border. The spread of chloroquine and SP resistance to other parts of Asia and as far as Africa is well documented (Plowe, 2009). Several articles have been published on the use of various extracts with antiplasmodial properties to eradicate Plasmodium falciparum from the blood stream of induced albino mice. Hence, a need for further review of the work to ascertain the effects of these compounds with antiplasmodial activities.
1.4 Aim and Objectives
1.4.1 Aim
To determine the antiplasmodial activity of extracts of edible mushroom: Agaricus bisporus on Plasmodium berghei in albino mice.
1.4.2 Objectives
The specific objectives of this study were to:
- assess the analytical components of edible mushroom (Agaricus bisporus) using Gas Chromatography Mass Spectrophotometry (GCMS).
- determine the antiplasmodial activity of edible mushroom extract: (Agaricus bisporus) on Plasmodium berghei.
- determine the effect of mushroom extract on the temperature and weight of mice infected with Plasmodium berghei.
- compare the effect of aqueous and alcoholic mushroom extract on malaria parasitemia.
1.5 Research Hypotheses (Null)
- There is no significant difference in the analytical components of Agaricus bisporus extract and a known standard drug for Plasmodium berghei.
- There is no significant difference in the antiplasmodial activity of Agaricus bisporus extract on Plasmodium berghei and a known standard drug for Plasmodium berghei.
- Agaricus bisporus extract has no significant difference in effect on the temperature and weight of mice infected with Plasmodium berghei.
- Aqueous and alcoholic Agaricus bisporus extract have no significant difference on malaria parasitemia.
CHAPTER FIVE
5.0 Discussion
This result of the Gas Chromatograghy Mass Spectrophotometry identified the compounds present in the fruiting body of A. bisporus. The prevailing compounds in the aqueous extract were 1-Butanamine, 2-methyl-N- (2-methylbtylidene) (2.03%), 2-Pyrorolidinone (7.46%) while the prevailing compounds in the alcoholic extract were n-Hexadecanoic acid (19.47%) and 9,12-Octadecadienoic acid (Z,Z) (80.53%). According to Isaka et al. (2001), these are some of the active ingredients required for the synthesis of a potent drug against Plasmodium berghei. This finding is also in accordance with the result obtained by (Omoya et al., 2017). Further evaluation of pharmacological activity of each compounds in the extract would help identify the most potent compound for curing malaria. This could be synthesized and incorporated into modern drug production (Table 1).
The results of the effect of the suppressive tests and treatments on the weight of the mice shown in table 2 confirmed the effect of infection P. berghei. The reduction in the weight of the albino mice, according to Funmilola et al. (2014) is one of the most important factors that shows sign of infection or that infection has set in. For instance, the fact that the infection caused the reduction in the weight of the mice in group 6 when compared to the group not infected at all is a confirmation of this fact. This finding is also in accordance with the result obtained by (Oladunmoye et al., 2014; Omoya et al., 2017), in which the major sign that the albino rats used for the experiment were infected with Escherichia coli was the reduction of their weight.
Comparatively, while the weight of the control (the group that is neither infected nor treated) that increased from 21.8±0.44g to 24.7±0.65g; about 12% increase in the weight within the period of the experiment. The temperature of the mice as the experiment progressed showed that the infection of the mice caused a reduction in the temperature of the mice. According to Nester et al. (2014), malaria in mice causes the temperature to reduce in mice. This is a complete opposite to the phenomenon in man in which malaria causes a rise in temperature. Most of the mice had an average temperature of 36.8±1.22°C before the commencement of the experiment. This shows that they were apparently healthy and that they were previously not having malaria symptoms. Another confirmation of the effect of the parasites in the mice was the group that the control group had almost constant temperature all through the experiment.
The effect of the treatments on the parasitemia load of the experimental mice after 24 hours of administration of samples showed that the hot water extract of Agaricus bisporus mushroom was most effective. This probably indicates that the local people cooking it with water get sufficient nutrients (Akindahunsi and Oyetayo, 2012; Omoya et al., 2017). The effect of chloroquine may be attributed to the level of purity and extraction (Funmilola et al., 2014), hence the 82.97% suppression attained in the group infected and treated with the drug. Although, the ethanolic extract was equally active in suppressing the parasitemia level, but not as the water extract. The ability of the ethanolic to extract active components of the mushroom may be due to its polar nature, which is similar to water. Owolabi and Olarinoye (2010) reported that water and ethanol have a very close proximity in terms of polarity and as such, both will extract any substance at a very close rate.
Hence, the result of their percentage suppression was almost the same. The percentage suppression between 72 and 96 hours of administration of chloroquine was 100%, which means that the parasites were completely wiped out. This result shows the reason why chloroquine is still a drug of choice in the treatment of malaria today. Brooks et al. (2014) stated that chloroquine is one of the antimalarial drug that have stood the test of time in not being resisted by Plasmodium species. Equally the result of the variation of concentration of the mushroom extracts revealed that the higher the concentration, the higher the effectiveness of the extract as antiPlasmodium substance.
5.1 Conclusion
Agaricus bisporus used in this research revealed medicinal property that could suppress malaria parasites in-vivo and that the hot water extract of the mushroom exerted a higher percentage suppression.
Therefore, the consumption of A. bisporus is highly encouraged as it will help suppress or prevent malaria parasites.
5.2 Recommendations
Pharmacological effects of A. bisporus and other mushroom products on the human body must be ascertained, toxicological studies should be performed, authenticity should be verified, and quality control standards should be maintained to ensure both maximal safety and efficacy to treat malaria and probably other chronic and acute conditions. Modern scientific methodology and medicinal chemistry approaches will continue to identify and evaluate the bioactive components found in phytochemical prescriptions, and validate their use as sources of new, effective, and safe world-class new medicines and dietary supplements.
Further analysis on the active components in A. bisporus that displayed antiplasmodial property should be extracted, purified and incorporated into antimalarial drugs, thereby reducing the menace of Plasmodium resistance.
