Osteomyelitis is a severe bone disease that is difficult to treat and causes serious socioeconomic problems. This study aimed to examine the bioactivity of hesperidin in an in vivo Staphylococcus aureus-induced osteomyelitis model. Total of 28 male Wistar Albino rats were randomly divided into 4 equal groups (n=7). Groups were designated as Group 1: Control group, Group 2: Sham group, Group 3: Osteomyelitis group, and Group 4: Treatment group (Hesperidin+Osteomyelitis). Unilateral tibial osteomyelitis was induced by administering arachidonic acid and 1×106 CFU-1 bacterial suspension through a hole drilled from the tibial crest. The rats in the treatment group were given hesperidin once a day by oral gavage for 28 days. At the end of the treatment, the effectiveness of the treatment was evaluated radiographically, biochemically, and histopathologically. The mean scores of intraosseous acute inflammation, intraosseous chronic inflammation, periosteal inflammation, and bone necrosis were evaluated histopathologically. The score was 0 in the control group, 0-2 in the sham group, 9-14 in the osteomyelitis group, and 2-6 in the treatment group. The median values of IAI, ICI, PI, BN, and total histopathological scores of the treatment group were significantly lower than the osteomyelitis group. Biochemically, oxidative stress increased significantly in the osteomyelitis model, however, it significantly decreased in the group treated with hesperidin. Nrf-2 translation levels increased by 0.2% in the sham group compared to the control group and decreased by 26% in the osteomyelitis group but increased by 42% in the treatment group compared to the osteomyelitis group. Compared to the control group, NF-kB translation levels increased by 6% and 21% in the sham and osteomyelitis groups, respectively. However, this value decreased by 9% in the treatment group compared to the osteomyelitis group. Radiographically, the combined score reduced by 65% in the treatment group in comparison to the osteomyelitis group. In conclusion, hesperidin showed anti-inflammatory activity by suppressing NF-kB and antioxidant activity by increasing Nrf-2, both of which play a role in inflammatory pathways. In light of all these findings, it can be said that hesperidin can be used as a potential therapeutic or an agent that can contribute to the treatment of osteomyelitis.

Fenbendazole (FBZ) is a commonly used anthelmintic in veterinary medicine that has recently been found to have anticancer effects in humans. On the other hand, few studies have examined the anti-inflammatory effects of FBZ, and its mechanism is unknown. In this study, mouse bone marrow cells (BMs) were treated with lipopolysaccharide (LPS), a representative inflammation-inducing substance, to generate a situation similar to osteomyelitis in vitro. The effect of FBZ on inflammatory BMs was examined by measuring the metabolic activity, surface marker expression, cell nuclear morphology, and mitochondrial membrane potential (MMP) of BMs. FBZ decreased the metabolic activity and MMP of LPS-treated BMs. Annexin Ⅴ-fluorescein isothiocyanate/propidium iodide staining and Hoechst 33342 staining showed that FBZ reduced the number of viable cells and induced the cell death of inflammatory BMs. In addition, FBZ reduced the proportion of granulocytes more than B lymphocytes in LPS-treated BMs. Overall, FBZ induces cell death by destabilizing the MMP of LPS-induced inflammatory BMs. FBZ can play a role as an anthelmintic and anticancer agent and an anti-inflammatory agent.

This study was conducted to investigate the beneficial effects of chitosan in the immunopathology of osteomyelitis in diabetic rabbits; therefore, the experimental design was carried out on 40 rabbits. They were  divided into 5 groups each of 8 animals, diabetes mellitus was induced in rabbits , then infected by Staphylococcus aureus and treated as following: First group (G1) was induced diabetes mellitus then immunized by whole sonicated S. aureus antigens (WSSAG) and induced experimentally osteomyelitis. The second group (G2) was induced diabetes mellitus, then immunized by (WSSAG) and induced experimentally osteomyelitis and fed on diet containing chitosan. Third group (G3) was induced diabetes mellitus, and induced experimentally osteomyelitis only. Fourth group (G4) was induction of diabetes mellitus, and induced experimentally osteomyelitis and fed on diet containing chitosan. Fifth group (G5) was induced experimentally osteomyelitis only without diabetes mellitus induction. Then at day 28th - 30th post immunization, skin test was performed to each of the immunized groups, and at day 30th the antibodies titer was measured by passive hemagglutination assay and phagocytic activity, then the animals were sacrificed and the treated bone taken for histopathological examination. In the present study , a significant increase was noted in the value of skin thickness of G2 at 48 and 72 hrs PI.  A significant increase was also noted in the value of antibodies titers of G2. We also showed a marked decrease   in the t1/2 of carbon clearance of G2. The histopathological results of G2 showed normal periosteal surface and compact bone with active osteoblasts lining the trabecular bones 30 days PI. However, other groups showed many histopathological lesions like infiltration of inflammatory cells and proliferation of fibrous connective tissue in G1, G3, and G4.The results also showed necrotic bone, hemorrhage, inflammatory cells infiltration and fibrosis in G5. Taken together, these findings indicate that the chitosan had a beneficial effect in bone healing of diabetic animals after infection in S. aureus.

Cortical bone concentrations of enrofloxacin were determined over time in dogs after SC administration of the drug. Nineteen healthy adult dogs were anesthetized and were given 2.5 or 5.0 mg of enrofloxacin/kg of body weight, SC. Serial serum and bone samples were obtained for determination of enrofloxacin concentrations at intervals until 8 hours after drug administration. Cortical bone samples were procured by surgical disarticulation of successive second phalanges. Additional cortical bone samples were taken from long bones in 4 dogs. Mean +/- SD peak serum enrofloxacin concentration was 0.54 +/- 0.10 micrograms/ml for the 2.5-mg/kg dosage and 0.97 +/- 0.34 micrograms/ml for the 5.0-mg/kg dosage. Serum concentration was significantly higher than bone concentration for each dosage. Mean peak bone concentrations reached 29% of peak serum values: 0.15 +/- 0.09 micrograms/g and 0.29 +/- 0.09 micrograms/g for 2.5-mg/kg and 5.0-mg/kg dosages, respectively. Serum concentration for the 5.0-mg/kg dosage was significantly greater than that for the 2.5-mg/kg dosage for all times, whereas bone concentrations for the 5.0-mg/kg dosage were significantly higher at all times after 180 minutes. For the duration of the study, cortical bone concentrations of enrofloxacin at either dosage exceeded the minimum inhibitory concentration (MIC) for the Enterobacteriaceae, but reliably exceeded the MIC for Staphylococcus sp only at the 5.0-mg/kg dosage. At no time did cortical bone concentrations of enrofloxacin exceed the MIC for Pseudomonas aeruginosa at either dosage. To validate extrapolation of data from the second phalanx to long bones and from anesthetized to awake dogs, 16 healthy dogs being euthanatized in unrelated studies were given 2.5 or 5.0 mg of enrofloxacin/kg, sc. These dogs were not anesthetized but were euthanatized at 60, 120, or 240 minutes after drug administration, and multiple cortical bone samples were taken. Antibiotic concentrations in the second phalanx were not significantly different from those in long bones. Comparison of enrofloxacin concentrations in cortical bone of awake and anesthetized dogs suggested no differences between groups. We concluded that general anesthesia and use of the antibiotic concentrations in the second phalanx as representative of those in long bones did not affect results of this study.