Novel 1,3,4-Oxadiazole Derivatives of Pyrrolo[3,4-d]Pyridazinone Exert Anti-Inflammatory Activity without Acute Gastrotoxicity in the Carrageenan-Induced Rat Paw Edema Test.

BACKGROUND AND PURPOSE: Due to the risk of gastrointestinal damage and various tissue toxicity associated with non-steroidal anti-inflammatory drugs (NSAIDs) use, investigating new anti-inflammatory agents with efficacy comparable to that of NSAIDs but reduced toxicity is still a major challenge and a clinical need. Based on our previous study, new 1,3,4-oxadiazole derivatives of pyrrolo[3,4-d]pyridazinone, especially 6-butyl-3,5,7-trimethyl-1-[[4-[[4-(4-nitrophenyl)piperazin-1-yl]methyl]-5-thioxo-1,3,4-oxadiazol-2-yl]methoxy]pyrrolo[3,4-d]pyridazin-4-one and 6-butyl-1-[[4-[[4-(4-chlorophenyl)-4-hydroxy-1-piperidyl]methyl]-2-thioxo-1,3,4-oxadiazol-5-yl]methoxy]-3,5,7-trimethyl-pyrrolo[3,4-d]pyridazin-4-one (hereafter referred to as the compounds 10b and 13b, respectively) seem to be promising anti-inflammatory agents. This study aimed to elucidate the effects of these two new derivatives on the course of experimental rat inflammation, liver and kidney function, and gastric mucosa. METHODS: The anti-inflammatory effect of compounds 10b and 13b was evaluated using the carrageenan-induced paw edema test in rats. The increase in paw volume (paw edema), prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α) and myeloperoxidase (MPO) levels, histological alterations, and inflammatory cell infiltration in paw tissue were determined. Serum alanine transaminase (ALT) and aspartate transaminase (AST) activities, serum urea and creatinine levels, as well as changes in gastric mucosa, were measured as indicators of hepatic, renal, and gastric toxicity. RESULTS: Pretreatment with both novel derivatives at 10 mg/kg and 20 mg/kg doses reduced paw edema, counteracted the increased PGE2 and TNF-α levels, reduced the influx of inflammatory cells, and decreased histopathological alterations in paw tissue. Compound 13b at a dose of 20 mg/kg was more effective than indomethacin in reversing the increased TNF-α levels and reducing the influx of inflammatory cells. Only compound 13b at all studied doses (5, 10, or 20 mg/kg) counteracted the increased MPO level in paw tissue. Both compounds neither caused alterations in ALT, AST, urea, creatinine parameters nor gastric mucosal lesions. CONCLUSION: New compounds exert an anti-inflammatory effect, presumably via inhibiting inflammatory mediators release and inflammatory cell infiltration. Moreover, both possess a more favorable benefit-risk profile than indomethacin, especially compound 13b.

Morin-5'-Sulfonic Acid Sodium Salt (NaMSA) Attenuates Cyclophosphamide-Induced Histological Changes in Genitourinary Tract in Rats-Short Report.

Cyclophosphamide (CPX) exerts toxicity in the urogenital system. The current study was designed to evaluate the effect of morin-5'-sulfonic acid sodium salt (NaMSA) on CPX-induced urogenital toxicity in rats. NaMSA (100 mg/kg/daily) and CPX (15 mg/kg/daily) alone or in combination and 0.9% NaCl (as a control) were given intragastrically for 10 days. Testes and epididymes from male and urinary bladders from male and female rats were evaluated histologically. In testes and epididymes, morphological changes and relative decrease in sperm count were assessed. In urinary bladders edema, hemorrhage and urothelium erosions were described by 0-2 points scoring system. Reproductive score (RS-in total 6 points) and urinary bladder score (BS-in total 6 points) were thereafter calculated. In CPX-receiving group RS (2.7) and BS (3.3) were significantly higher than in the control (0.5 and 0.25 for RS and BS, respectively). Co-administration of NaMSA reversed most of the morphological changes, which was reflected by lower RS and BS score (0.5 and 1.2 for RS and BS, respectively). The preliminary findings suggest that NaMSA may attenuate CPX-induced histological changes in rat urogenital tract.

In Vitro and In Vivo Efficacy of a Novel Glucose-Methotrexate Conjugate in Targeted Cancer Treatment.

Methotrexate (MTX) is a commonly used antimetabolite, which inhibits folate and DNA synthesis to be effective in the treatment of various malignancies. However, MTX therapy is hindered by the lack of target tumor selectivity. We have designed, synthesized and evaluated a novel glucose-methotrexate conjugate (GLU-MTX) both in vitro and in vivo, in which a cleavable linkage allows intracellular MTX release after selective uptake through glucose transporter-1 (GLUT1). GLU-MTX inhibited the growth of colorectal (DLD-1), breast (MCF-7) and lung (A427) adenocarcinomas, squamous cell carcinoma (SCC-25), osteosarcoma (MG63) cell lines, but not in WI-38 healthy fibroblasts. In tumor cells, GLU-MTX uptake increased 17-fold compared to unconjugated MTX. 4,6-O-ethylidene-α-D-glucose (EDG), a GLUT1 inhibitor, significantly interfered with GLU-MTX induced growth inhibition, suggesting a glucose-mediated drug uptake. Glu-MTX also caused significant tumor growth delay in vivo in breast cancer-bearing mice. These results show that our GLUT-MTX conjugate can be selectively uptake by a range of tumor cells to cause their significant growth inhibition in vitro, which was also confirmed in a breast cancer model in vivo. GLUT1 inhibitor EDG interfered with these effects verifying the selective drug uptake. Accordingly, GLU-MTX offers a considerable tumor selectivity and may offer cancer growth inhibition at reduced toxicity.

Expression of syndecan-1 in oral cavity squamous cell carcinoma.

Syndecan-1 (SDC1) belongs to heparan sulfate proteoglycans which may interact with different growth factors, cytokines, morphogens and promote tumor growth and invasion. The aim of the present study was to assess the immunohistochemical expression of syndecan-1 in oral squamous cell carcinoma (OSCC) and oral cysts. Evaluation of the staining pattern with the clinico-histological characteristics of patients was performed. A total of 42 OSCC and 23 oral cysts tissue samples were examined. Statistical tests were used for the significance analysis. The positive expression of syndecan-1 was significantly higher in OSCC compared to cyst located in the oral cavity. Moreover, the results indicate that the intensity of the expression correlated with grading score (p = 0.046). The data indicate that syndecan-1 is altered in OSCC and its excessive amount relates in a predictive manner to neoplastic transformation. As such, SDC1 expression may be used as an adjunctive biomarker in molecular diagnostics of oral squamous cell carcinoma.

Effects of efavirenz and tenofovir on bone tissue in Wistar rats.

BACKGROUND: Clinical trials indicate an increased risk of osteoporosis and bone fractures in people infected with human immunodeficiency virus (HIV). The pathogenesis of bone disturbances in HIV-positive patients is unknown, but it is suggested that antiretroviral drugs may be involved. OBJECTIVES: To assess the effects of efavirenz (EF) and tenofovir (T) on bone remodeling in rats. MATERIAL AND METHODS: The study involved 36 male Wistar rats divided into 3 groups, receiving normal saline (control group - group C), efavirenz (group EF) or tenofovir disoproxil (group T). RESULTS: After 24 weeks of the study, the following observations were made: In blood serum of the EF group compared to group C, there were increased levels of tartrate-resistant acid phosphatase form 5b (TRAP) and inorganic phosphorus. In the densitometric examination, group T showed a lower total body (TB) bone mineral density (BMD) than group C. In the immunohistochemical assessment, group EF showed a higher intensity and extension of anti-tartrate resistant acid phosphatase antibodies (abTRAP) compared to group C. In the histopathological examination of the second lumbar vertebra (L2), group EF showed a lower bone surface/volume ratio (BS/BV) and higher trabecular thickness (Tb.Th) than the control group. In the histopathological examination of the femur, a lower bone surface/tissue volume (BS/TV) and lower trabecular number (Tb.N) were found in group T compared to in group C. A lower value of the Young's modulus was observed in the four-point bending trial in groups EF and T compared to group C. CONCLUSIONS: The results of this study indicate that EF affects bone microarchitecture and leads to impaired biomechanical properties of bones in rats. Additionally, the negative effect of T on bone tissue was confirmed.