Unravelling the synergistic potential of Olibanum extract and Bacillus clausii in combating intestinal cryptosporidiosis in immunosuppressed mice

Given the grave risk posed by intestinal cryptosporidiosis to vulnerable populations, the current research focused on a new therapeutic avenue. Olibanum (OL) extract and probiotic Bacillus clausii ( B. clausii ) and their combination were evaluated against Cryptosporidium in vivo in immunosuppressed mice via parasitological, ultrastructural, biochemical, and histopathological analysis. Liquid chromatography-mass spectrometry (LC–MS) analysis of OL revealed the predominance of incensole isomers in its chemical composition. Regarding oocyst count in stool, the highest percentage of oocyst reduction was achieved after combined therapy (98.4%) on the 19 th day post-infection, followed by B. clausii- treated group (87.6%), then the OL-treated group (87%). Similar ultrastructural alterations were noticed by scanning electron microscopy (SEM) following treatment by both OL and B. clausii , ranging from shrunken oocysts to severely deformed ones with extensive pits or protrusions. Nonetheless, their combination resulted in complete distortion of the oocysts, leading to their rupture. Biochemically, both OL and B. clausii treatment, either alone or in combination, provoked a decrease in the serum MDA levels, together with a corresponding rise in the mean levels of GSH. Concerning the histopathological findings, the best results were achieved following the combined OL and B. clausii treatment, which has restored villus architecture and remarkably ameliorated detrimental intestinal inflammation and goblet cell count. Finally, immunohistochemical analysis of the lymphocytic population of the intestinal villi revealed a statistically significant rise in the CD4+ /CD8+ ratio after treatment with either OL, B. clausii or their combination, which signals their proficient use for this therapeutic endeavour.