Disease relapse is one of the most important challenges in treating brucellosis. The aim of this study was to investigate the effect of doxycycline-loaded solid nanoparticles (DOX-SLN) on acute and chronic brucellosis, serum levels of trace elements, and biochemical and hematological parameters in rats infected with Brucella melitensis. The treating effect of DOX-SLN was evaluated by investigating serum levels of trace elements such as zinc (Zn), copper (Cu), iron (Fe), magnesium (Mg), calcium (Ca), phosphorus (P), sodium (Na), and potassium (K); biochemical parameters such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and total bilirubin (TBil); and hematological parameters in rats suffering from acute and chronic brucellosis. The mean size, zeta potential, PDI, drug loading, and encapsulation efficiency of the synthesized nanoparticles were 299 ± 34 nm, - 28.7 ± 3.2 mV, 0.29 ± 0.027, 11.2 ± 1.3%, and 94.9 ± 3.2%, respectively. The serum level of trace elements (Zn, Cu, Fe), biochemical parameters (AST, ALT, ALP, TBil), and hematological parameters (white blood cell (WBC) and hemoglobin (HB)) were significantly different between healthy and infected rats. DOX-SLN had an appropriate treating effect on chronic brucellosis through modifying the serum level of mentioned factors. Assessing the serum level of trace elements, biochemical and hematological parameters can be useful in detecting brucellosis with other diagnostic tests and determining its acute or chronic phase. DOX-SLN had a better efficacy in treating chronic brucellosis than ordinary free drugs used routinely in this regard.
Keywords: Brucellosis; Doxycycline; Nanoparticle; Trace elements.