Department of Neurosciences, Psychology, Drug Research and Child Health-Neurofarba-Pharmacology and Toxicology Section, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy.
Department of Experimental and Clinical Medicine, Anatomy Section, University of Florence, Largo Brambilla 3, 50134 Florence, Italy.
Molecules. 2020 Apr 30;25(9):2117. doi: 10.3390/molecules25092117.
Sarcopenia is a clinical problem associated with several pathological and non-pathological conditions. The aim of the present research is the evaluation of the pharmacological profile of the leucine metabolite β-hydroxy-β-methyl butyrate (HMB) associated with the natural R(+) stereoisomer of lipoic acid (R(+)LA) in a cellular model of muscle wasting. The C2C12 cell line is used as myoblasts or is differentiated in myotubes, sarcopenia is induced by dexamethasone (DEX). A Bonferroni significant difference procedure is used for a post hoc comparison. DEX toxicity (0.01-300 µM concentration range) is evaluated in myoblasts to measure cell viability and caspase 3 activation after 24 h and 48 h; cell incubation with 1 µM DEX for 48 h is chosen as optimal treatment for decreasing cell viability and increasing caspase 3 activity. R(+)LA or HMB significantly prevents DEX-induced cell mortality; the efficacy is improved when 100 µM R(+)LA is combined with 1 mM HMB. Regarding myoblasts, this combination significantly reduces DEX-evoked O production and protein oxidative damage. During the early phase of myotube formation, the mixture preserves the number of myogenin-positive cells, whereas it completely prevents the DEX-dependent damage in a later phase of myotube differentiation (7 days), as evaluated by cell diameter and percentage of multinucleated cells. R(+)LA in association with HMB is suggested for sarcopenia therapy.
肌肉减少症是与多种病理和非病理状况相关的临床问题。本研究的目的是评估亮氨酸代谢物β-羟基-β-甲基丁酸（HMB）与天然 R(+)型硫辛酸（R(+)LA）在肌肉减少症的细胞模型中的药理特性。C2C12 细胞系被用作成肌细胞或分化为肌管，用地塞米松（DEX）诱导肌肉减少症。采用 Bonferroni 显著差异程序进行事后比较。在成肌细胞中评估 DEX 毒性（0.01-300 μM 浓度范围），以测量 24 小时和 48 小时后的细胞活力和 caspase 3 激活；选择 1 μM DEX 孵育 48 小时作为降低细胞活力和增加 caspase 3 活性的最佳处理方法。R(+)LA 或 HMB 可显著预防 DEX 诱导的细胞死亡；当 100 μM R(+)LA 与 1 mM HMB 联合使用时，效果得到改善。对于成肌细胞，这种混合物显著减少了 DEX 诱导的 O 产生和蛋白质氧化损伤。在肌管形成的早期阶段，该混合物可保持肌细胞生成素阳性细胞的数量，而在肌管分化的后期阶段（7 天），它完全阻止了 DEX 依赖性损伤，如通过细胞直径和多核细胞的百分比来评估。建议将 R(+)LA 与 HMB 联合用于肌肉减少症的治疗。
