Synthesis and biological evaluation of substituted N-[3-(1H-pyrrol-1-yl)methyl]-1,2,5,6-tetrahydropyridin-1-yl]benzamide/benzene sulfonamides as anti-inflammatory agents

Comparison of the effect of rotenone and 1‑methyl‑4‑phenyl‑1,2,3,6‑tetrahydropyridine on inducing chronic Parkinson's disease in mouse models

Animal models for Parkinson's disease (PD) are very useful in understanding the pathogenesis of PD and screening for new therapeutic approaches. The present study compared two commonly used neurotoxin‑induced mouse models of chronic PD to guide model selection, explore the pathogenesis and mechanisms underlying PD and develop effective treatments. The chronic PD mouse models were established via treatment with rotenone or 1‑methyl‑4‑phenyl‑1,2,3,6-tetrahydropyridine (MPTP) for 6 weeks. The effects of rotenone and MPTP in the mice were compared by assessing neurobehavior, neuropathology and mitochondrial function through the use of the pole, rotarod and open field tests, immunohistochemistry for tyrosine hydroxylase (TH), glial fibrillary acidic protein (GFAP), ionized calcium‑binding adapter molecule 1 (Iba‑1), neuronal nuclear antigen (NeuN) and (p)S129 α‑synuclein, immunofluorescence for GFAP, Iba‑1 and NeuN, western blotting for TH, oxygen consumption, complex I enzyme activity. The locomotor activity, motor coordination and exploratory behavior in both rotenone and MPTP groups were significantly lower compared with the control group. However, behavioral tests were no significant differences between the two groups. In the MPTP group, the loss of dopaminergic (DA) neurons in the substantia nigra (SN) pars compacta, the reduction of the tyrosine hydroxylase content in the SN and striatum and the astrocyte proliferation and microglial activation in the SN were more significant compared with the rotenone group. Notably, mitochondrial‑dependent oxygen consumption and complex I enzyme activity in the SN were significantly reduced in the rotenone group compared with the MPTP group. In addition, Lewy bodies were present only in SN neurons in the rotenone group. Although no significant differences in neurobehavior were observed between the two mouse models, the MPTP model reproduced the pathological features of PD more precisely in terms of the loss of DA neurons, decreased dopamine levels and neuroinflammation in the SN. On the other hand, the rotenone model was more suitable for studying the role of mitochondrial dysfunction (deficient complex I activity) and Lewy body formation in the SN, which is a characteristic pathological feature of PD. The results indicated that MPTP and rotenone PD models have advantages and disadvantages, therefore one or both should be selected based on the purpose of the study.

Substituted Tetrahydroisoquinolines as Microtubule-destabilizing Agents in Triple Negative Human Breast Cancer Cells

Triple-negative breast cancer (TNBC) occurs at greater frequency amongst African-Americans, being characterized by the absence of estrogen receptor (ER), progesterone receptor (PR) and human epidermal receptor 2 (HER2). TNBC is often invasive and typically treated with cytostatic agents such as taxanes in combination with anthracyclines or platinum-based drugs. In this study, we synthesized a number of tetrahydroisoquinoline moieties by N-amination of substituted isoquinolines by O-mesytelene sulfonylhydroxylamine followed by ylide formation and reduction, which yielded the desired, substituted tetrahydroisoquinolines (THIQs) in moderate to good yield. Using a differential scatter plot to identify potential selective ER-modulating drugs in ER-positive control cells (MCF-7) driven by estradiol vs. TNBC (MDA-MB-231) cells, the in vitro data showed an absence of effects on the ER (compared to 4-hydroxytamoxifen and raloxifene). In contrast, two lead compounds halted proliferation (cytostatic) in MDA-MB-231 TNBC cells at a potency level below 2.5 μM concomitant with mitotic arrest, attenuated replicative DNA synthesis, halted microtubule nucleation/stunted tubulin polymerization, abnormal expansive cytoskeletal tubulin and actin morphologies with multinucleation of cells. The most effective cytostatic compounds GM-4-53 and GM-3-121 blocked replicative processes at the G₂ growth phase. These findings suggest that specific THIQs work independently of the ER, by holding static the microtubule network thereby preventing mitosis. Future work is required to establish the safety and efficacy of these drugs and their potential adjunct therapeutic gain in the presence of taxanes in TNBC.