ANTI-INFLAMMATORY ACTIVITY OF LACTIC ACID BACTERIA ISOLATED FROM FERMENTED LOCUST BEANS ON FORMALIN INDUCED PAW OEDEMA IN WISTAR RATS.

Abstract

Inflammation is the process by which the immune system recognizes and removes harmful stimuli and begins the healing process. Considering the potential side effects of anti- inflammatory drugs, there is a need to explore for more naturally available alternatives. Therefore, this study was designed to evaluate the anti-inflammatory activity of lactic acid bacteria (LAB) isolated from fermented locust beans (‘Iru’) using paw oedema inflammatory model induced by 1% formalin in Wistar rats. ‘Iru’ samples were purchased from Oja-Oba market, Akure, Ondo State and transported to the Microbiology laboratory of FUTA for bacteriological analyses. Isolation and identification of lactic acid bacteria (LAB) were carried out using standard microbiological techniques. The isolated LAB strains were used to treat acute inflammation in the rats. The rats were divided into six groups (A-F). Rats in group A were neither injected with formalin nor treated, while Group B rats were injected but not treated. Groups C, D and E rats received 2 × 10 7 CFU/mL of the various strains of LAB while Group F rats received diclofenac sodium (150 mg/Kg body weight) treatment following the injection of formalin. Paw thickness (mm) was checked at t = 0, 1, 4, 8, 24, 72, 168 and 336 hrs. Hematological parameters were analyzed using standard hematological techniques. Biomarkers assay for C-Reactive Protein (CRP), Interleukin-10 (IL-10) and Transforming Growth Factor-β (TGF-β) was performed on serum samples of the rats using Enzyme Linked Immunosorbent Assay (ELISA). The LAB isolated from ‘Iru’ were identified to be Weissella cibaria II-1-59, Weissella confusa JMC 1093, and Pediococcus pentosaceus DSM20336. Treatment with W. cibaria II-1-59 showed the best significant decrease in the paw oedema of the rats followed by P. pentosaceus DSM20336 and W. confusa JMC 1093 which was shown to be statistically significant at P<0.05. Oral administration of these LABs significantly decreased the WBC count in LAB treated rats. Weissella cibaria II-1-59 and Weissella confusa JMC 1093 showed a better ability to regulate leucocytes infiltration in the blood circulation of the inflamed rats than Pediococcus pentosaceus DSM20336. Also treatment with these LABs showed that they have better ability to regulate decrease in the RBC of the rats compared to diclofenac sodium. A significant decrease in the secretion of Pro-inflammatory biomarker (CRP) and increase in the serum levels of anti-inflammatory cytokines IL-10 and TGF-β were observed in all LAB treated groups. Weissella confusa JMC 1093 have a better ability to upregulate IL-10 production while Weissella cibaria II-1-59 and Pediococcus pentosaceus DSM20336 showed similar but less significant results. This suggests that these lactic acid bacteria isolated from ‘iru’ that were able to induce IL-10 production are promising anti-inflammatory agents in the treatment of inflammation, which further ascertain the health beneficial effect of the consumption of ‘iru’.