GASTRO PROTECTIVE EFFECTS OF USNEA LONGISSIMA METABOLITES ON PROBIOTIC LACTOBACILLUS CASEI

Protective effect of the probiotic combination of usnic acid and Lactobacillus casei in experimentally induced ulcer in rats was investigated. Rats inward usnic acid (100 mg/kg),  L. casei (10^-8 con.), usnic acid (100 mg/kg) + L. casei (10^-8 con.), and omeprazole (30 mg/kg)  twice daily  for 5 days for prevention against aspirin (ASP), ethanol (EtOH), cold restraint stress (CRS) and pylorus ligation-induced ulcer (PL). The results of the present study showed the first time that the usnic acid (100 mg/kg) + L. casei (10^-8 con.) as probiotic combination significantly inhibited the ulcer index in ASP, EtOH, CRS and PL to 3.4 ± 0.12, 6.3 ± 1.8, 3.4 ± 0.8 and 4.3 ± 0.9 (p<0.001) respectively, as compared to control group (19.2 ± 1.6, 22.5 ± 6.3, 24.2 ± 3.2, 14.2 ± 2.7). Besides usnic acid (100 mg/kg) + L. casei (10^-8 con.) offered protection (72%, p<0.001) against ethanol-induced depletion of gastric wall mucus. The usnic acid (100 mg/kg) + L. casei (10^-8 con.) showed significant inhibition of lipid peroxidation and superoxide dismutase (5.46 ± 1.30, 120.6 ± 3.2) (p<0.01, p<0.001) respectively and enhance activity of catalase (32.2 ± 1.3, p<0.001) to healthy group range (34.2 ± 2.7, p<0.001). However, it elevated the decreased level of PGE₂ from 0.62 ± 0.12 (p<0.05) to 2.03 ± 0.51 (p<0.001) as compared to omeprazole. These results suggest that probiotic combination could attenuate the severity of gastric ulcer and prevent the toxicity level of usnic acid in the liver.