Evaluation of Effects of Spirulina Extracts on Immunologic Dysfunction and Inflammation Associated with Aflatoxin B1 Induced Toxicity in Mice

The contamination of foods by various mycotoxins has been reported as a major public health concern across the world. The most predominant type of fungal toxins are aflatoxins which are synthesized by certain fungi that contaminate agricultural crops or produce. The main aflatoxin producing fungi are Aspergillus flavus and Aspergillus parasiticus which contaminate food crops in the farm and after harvesting. Out of all the types of aflatoxins, the most potent type is aflatoxin B1. The mechanism of toxicity and health effects of aflatoxins have been studied widely and it has been shown that aflatoxin B1 leads to liver necrosis, inflammation and liver cancer. The use of natural products as a remedy to health consequences of aflatoxins in humans and animals is gaining popularity. Owing to its anti-inflammatory effects, Spirulina plantesis has been studied for its immunomodulatory effects. This study evaluated the effects of spirulina extract on aflatoxin B1 (AFB1) induced immune dysfunction and inflammation. Male BALB/c mice weighing 28-34g were randomly placed into 6 groups and orally treated as follows: Group 1 was not treated but received food and water for entire experimental period. Group 2 received 200 µg/kg b.w of aflatoxin B1 orally. Group 3 received 1g/kg b.w of activated charcoal and an hour later 200 µg/kg b.w of aflatoxin B1 orally. Group 4, 5 and 6 received 50mg/kg, 100mg/kg and 150mg/kg b.w of Spirulina plantesis respectively then an hour later each group received 200 µg/kg b.w of aflatoxin B1 orally. Treatments were done on a daily basis for 14 days. At the last day of the experiment, all the mice were denied food and water for 12 hours, thereafter sacrificed and samples processed for immunological studies. The results indicated that body weight significantly increased when treated with 100mg/kg spirulina+AFB1 and 150mg/kg spirulina+AFB1 groups in compared to AFB1 treated group (p < 0.05). AFB1 was shown to increase serum level of IFN- γ and IL 2 and decrease levels of IL 4. Treatment with spirulina extract had no significant effect on the serum concentrations of IL-4 and IL-2 (p > 0.05) in comparison with aflatoxin B1 treated group, the serum levels of IFN- γ and IL-2 reduced significantly (p<0.05). Treatment with spirulina extract at different doses had no significant effect on serum levels of immunoglobulins A, G and M (p < 0.05). The mRNA expression of IL-4 was downregulated while that of TNFα, and IFNγ were upregulated. The results showed that increasing mRNA expressions of TNFα, and IFNγ as a result of AFB1was prevented (p≤0.01) by administration of spirulina extract. These findings suggests that spirulina extract could be used as a remedy to AFB1 induced immune dysfunction and inflammation.