Background: Pyrimethamine and sulfadiazine, while being effective against toxoplasmosis, are limited by significant adverse effects. On the other hand, 2-isopropyl-5-methyl-1, 4-benzoquinone has been identified as a key bioactive compound. Moreover, studies on thymoquinone (TQ) have demonstrated its cytotoxic activity, inhibiting the growth of various cancer cell lines, including those of the ovary, prostate, colon, pancreas, osteosarcoma, and breast, as well as leukemia cells. This study sought to determine how TQ affected the tachyzoite type of Toxoplasma gondii. Materials and Methods: Different TQ concentrations (6. 25–400 µM) were prepared in microtiter plates for this experiment. The tachyzoite test was used to assess parasite mortality. Flow cytometry was performed to determine whether T. gondii tachyzoites underwent apoptosis. Specifically, 2×10^5 tachyzoites were exposed to TQ at concentrations of 50 µM, 100 µM, and 200 µM, following the kit’s instructions. Results: Light microscopy revealed that TQ had lethal and damaging effects on T. gondii. Based on 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assays, 400 µM of TQ exhibited the most toxic effects on macrophages. Furthermore, the MTT assay determined a half-maximal inhibitory concentration (CC50 ) for macrophages. Flow cytometric analysis indicated that the percentages of total apoptosis in parasites exposed to 50 µM, 100 µM, and 200 µM TQ were 51. 3%, 64. 9%, and 70. 8%, respectively. Conclusion: The results demonstrated that TQ is toxic to T. gondii and induces apoptosis in this parasite. This work provides supporting evidence for the use of TQ in antiparasitic assays.

Background: Thymoquinone (TQ) has some beneficial roles in bone repair. Local administration of the drugs by loading them into a scaffold leads to releasing higher concentrations of a drug in the appropriate position. This study was conducted to evaluate the effects of the local administration of TQ loaded in an alginate scaffold on bone regeneration in rabbit mandibular defect. Materials and Methods: In this experimental study, male rabbits with mandible defect were divided into 3 groups that received either alginate containing 50µM TQ, alginate or remained untreated. Then each group was subdivided into 2 groups that followed for 4 and 8 weeks (n=5). The radiological opacity, histopathology, and histomorphometrical analysis were done and data were analyzed by ANOVA and Tukey. Results: Radiological examination indicated that the presence of TQ had no significant effect on the turbidity of the images (P=0. 595). TQ treatment significantly increased the bone area after 4 (P=0. 011, P=0. 0021, respectively) and 8 weeks (8w P=0. 019, P<0. 001, respectively) compared to alginate-treated and control defects. TQ also elevated the number of osteocytes (4wP<0. 001, P=0. 001 and 8w P<0. 001, P<0. 001, respectively) and osteoblasts (P<0. 001, P<0. 001, respectively) compared to the group receiving alginate and control. However, at 8 weeks, the number of osteoblasts was statistically similar in all the groups. In this week, although the average number of osteoblasts in the defects treated with TQ was significantly higher than the control group (P=0. 01), it was similar to the group that received alginate. Conclusion: It seems that alginate containing TQ has positive effects on bone healing. TQ can be suggested as a good additive to improve bone healing and accelerate bone repair.

Objective(s): The current study, the first of its kind in the literature, aimed to observe the toxic effects of Tartrazine, a commonly used dyestuff in industries and foods, on the liver, and investigate whether this toxicity could be eliminated with thymoquinone coadministration. Materials and Methods: 32 male Wistar albino rats were procured from İ, nö, nü,University Experimental Animals Breeding and Research Center. The rats were randomly assigned to 4 equal groups: Control group, Thymoquinone group, Tartrazine group, and Thymoquinone + Tartrazine group. Rat liver tissue and blood samples were obtained and biochemical and histopathological examinations were conducted on the samples. Results: Tartrazine administration increased the oxidant (malondialdehyde and superoxide dismutase) and oxidative stress index parameters (total oxidant status) in the liver tissue and decreased the antioxidant parameters (glutathione, glutathione peroxidase, catalase, and total antioxidant status) leading to histopathological problems (hematoxylin-eosin staining and Caspase-3 immunoreactivity) and inflammation (tumor necrosis factor-α,and interleukin-6) in the serum samples. Thymoquinone, on the other hand, improved antioxidant and anti-inflammatory effects. Conclusion: At this time and dose, thymoquinone has a protective effect against tartrazine hepatotoxicity. Thymoquinone can be used as a protective agent against tartrazine toxicity.

Thymoquinone is the major active constituent of the volatile oil of Nigella sativa seeds. It has been previously reported that thymoquinone prevents oxidative injury in various hepatotoxicity models and may prevent membrane lipid peroxidation. In order to clarify the effect of thymoquinone on lipid peroxidation in CNS, we induced cerebral ischemic/reperfusion injury in rats using four-vessel occlusion (4-VO) method and consequently determined malondialdehyde (MDA) levels in hippocampus based on its reaction with thiobarbituric acid (TBA). Thymoquinone (2.5-10 mg/kg), phenytoin (50 mg/kg) and control (l0 ml/kg) were administered immediately after reperfusion. The MDA level was higher in control group (normal saline) following ischemic-reperfusion than thymoquinone treated groups. The MDA levels recovered significantly upon phenytoin and thymoquinone (5, 10 mg/kg) therapy following ischemic/reperfusion. These results suggest that thymoquinone may exhibit neuroprotective effect through an inhibitory activity against lipid peroxidation during cerebral ischemia in rats.