利用云南红豆杉悬浮细胞生产紫杉醇和紫杉烷类化合物(英文)

云南红豆杉 (TaxusyunnanensisChengetL .K .Fu)的一株紫杉醇高产细胞系经过 8年多的继代培养 ,仍保持较稳定的紫杉烷类化合物的生物合成能力。从此株紫杉醇高产细胞系的悬浮培养物中分离到 8个紫杉烷类化合物 ,经核磁共振光谱和质谱数据分析 ,它们的化学结构分别是 2 ,5 ,10_三乙酰氧基_14_丙酰氧基紫杉二烯 (1)、2 ,5 ,10_三乙酰氧基_14_(2′_甲基丙酰氧基 )紫杉二烯 (2 )、2 ,5 ,10 ,14_四乙酰氧基紫杉二烯 (3)、2 ,5 ,10_三乙酰氧基_14_(2′_甲基_3′_羟基丁酰氧基 )紫杉二烯及其差向异构体 (4和 5 )、巴卡亭Ⅳ (6 )、巴卡亭Ⅲ (7)和紫杉醇 (8)。化合物 3、5 - 7为首次从云南红豆杉细胞培养物中分离到。定性分析表明 ,云南红豆杉细胞悬浮培养液中的化学成分与培养细胞中的相似。另外 ,此株紫杉醇高产细胞系的紫杉醇含量可高达 0 .3% ,可用来进行大规模培养     

利用云南红豆杉悬浮细胞生产紫杉醇和紫杉烷类化合物

云南红豆杉(Taxus yunnanensis Cheng et L. K. Fu)的一株紫杉醇高产细胞系经过8年多的继代培养,仍保持较稳定的紫杉烷类化合物的生物合成能力.从此株紫杉醇高产细胞系的悬浮培养物中分离到8个紫杉烷类化合物,经核磁共振光谱和质谱数据分析,它们的化学结构分别是2,5,10-三乙酰氧基-14-丙酰氧基紫杉二烯(1)、 2,5,10-三乙酰氧基-14-(2′-甲基丙酰氧基)紫杉二烯(2)、 2,5,10,14-四乙酰氧基紫杉二烯(3)、 2,5,10-三乙酰氧基-14-(2′-甲基-3′-羟基丁酰氧基)紫杉二烯及其差向异构体(4和5)、巴卡亭Ⅳ(6)、巴卡亭Ⅲ (7)和紫杉醇(8).化合物3、 5-7为首次从云南红豆杉细胞培养物中分离到.定性分析表明,云南红豆杉细胞悬浮培养液中的化学成分与培养细胞中的相似.另外,此株紫杉醇高产细胞系的紫杉醇含量可高达0.3%,可用来进行大规模培养.     

马特链霉菌7-木糖紫杉烷糖基水解酶初步研究

酶法转化7-木糖紫杉烷(7-XDT)为10-脱乙酰基紫杉醇(10-DAT)是目前合成紫杉醇的最主要途径.本研究分离到一株具有产生7-木糖紫杉烷(7-XDT)糖基水解酶能力的马特链霉菌(Streptomyces matensi YUCM 410051),通过酶的最适反应温度、硫酸铵分级沉淀、最适反应pH和酶的有机试剂耐受等研究,发现最适反应温度为25～30℃,硫酸铵分级沉淀酶活在20％～70％的盐浓度时活性最高;粗酶液最适反应pH在6.0～7.5,酶的甲醇耐受浓度和DMSO耐受浓度均为10％.深入研究该酶对开发具有水解7-木糖紫杉烷(7-XDT)中木糖基的酶资源和提高红豆杉中的紫杉烷类化合物的利用率具有重要价值.     

同型半胱氨酸诱导血管内皮细胞凋亡的研究

观察不同浓度同型半胱氨酸(homocysteine,HCY)在Cu2 介导下,能否诱导培养的人脐静脉内皮细胞凋亡,以揭示HCY致血管内皮损伤的机制。采用细胞计数板检测脱落细胞量;比色法分别测定乳酸脱氢酶释放率、细胞内丙二醛含量和超氧化物歧化酶、谷胱甘肽过氧化物酶活力的改变;Hoechst 33258染色观察凋亡细胞核形态变化及流式细胞术定量测定细胞凋亡。结果表明HCY在生理浓度Cu2 的介导下,可能通过氧化应激损伤的机制而导致血管内皮细胞凋亡,这提示在体内可能通过此途径诱发动脉粥样硬化。     

自噬抑制剂3-MA上调H2O2损伤的PC12细胞氧化应激水平

为探究自噬抑制剂6-氨基-3-甲基腺嘌呤（3-methyladenine,3-MA）对损伤细胞氧化应激水平的影响,将3-MA作用于H2O2诱导的PC12细胞损伤模型,以自噬增强剂雷帕霉素（rapamycin,Rap）作为对照,探讨自噬与氧化应激的关系。测定线粒体的膜电位和细胞内的活性氧（reactive oxygen species, ROS）与丙二醛(malondialdehyde, MDA)含量,以及超氧化物歧化酶(superoxide dismutase,SOD)和过氧化氢酶(catalase,CAT)活性,评价损伤细胞的氧化应激状态。单丹(磺)酰戊二胺（monodansylcadaverine,MDC）染色,观察损伤细胞的自噬情况。蛋白质印迹分析损伤细胞中的自噬相关蛋白质LC3-II/LC3-I比值变化。实验结果显示：与正常组相比,H2O2损伤细胞的ROS水平上升到正常组的141%,MDA含量增加(P<0.001);CAT与SOD酶活力显著降低(P<0.001),差异均有统计学意义,证明损伤细胞氧化应激水平增加;MDC染色结果表明,H2O2组自噬明显增加。Western印迹结果表明,LC3-II/LC3-I值显著升高（P<0.05）;与损伤组相比,3-MA组MDC染色结果表明,自噬水平降低。Western印迹结果表明,LC3-II/LC3-I值下降;细胞内ROS水平升高,增加到正常组的208%。MDA含量增加(P<0.001),CAT、SOD酶活力降低(P<0.001)。综上结果表明,自噬抑制剂可增加H2O2诱导的PC12细胞损伤模型的氧化应激水平,增加细胞凋亡。     

间期和有丝分裂期HeLa细胞中核仁蛋白B23的分布和含量的差异

B23蛋白是真核细胞核仁的两种主要蛋白成份之一。已往的工作表明,细胞内B23蛋白的分布与rRNA合成速率和细胞的生长状况密切相关。本工作利用抗B23蛋白单克隆抗体,研究了被两种作用于微管的药物秋水仙酰胺(colcemid)和紫杉酚(taxol)阻断的有丝分裂期和间期HeLa细胞内B23蛋白的分布和含量的差异。结果发现有丝分裂期细胞内B23蛋白含量明显高于间期细胞,而且B23蛋白在两类细胞中的分布也有明显的不同。     

葡萄籽原花青素通过Nrf2/ARE信号通路抗高糖诱导的HUVEC-12细胞氧化损伤

研究葡萄籽原花青素提取物(GSPE)对高糖诱导的人脐静脉内皮细胞HUVEC-12氧化应激损伤的保护作用及其相关机制。建立高糖诱导的HUVEC-12细胞模型,测定细胞活力,检测细胞内活性氧(ROS)水平、乳酸脱氢酶(LDH)与超氧化物歧化酶(SOD)活性及Nrf2/ARE信号通路中相关基因mRNA水平和蛋白含量。结果显示GSPE作用后显著提高HUVEC-12细胞活力,抑制高糖诱导的细胞内ROS水平升高,增强SOD活性(P0.05),并呈现剂量依赖效应。GSPE作用能同时提高抗氧化转录因子Nrf2和下游区GSH-Px、HO-1、γ-GCS、NQO1基因的表达量以及HO-1、NQO1蛋白的含量(P0.05)。结果表明GSPE能通过激活Nrf2/ARE通路对抗高糖诱导的HUVEC-12细胞氧化应激损伤。     

东北红豆杉的化学成分和药理作用研究进展

本文综述了东北红豆杉(Taxus cuspidata)在化学成分和药理学方面的研究进展,着重强调了近年来紫杉烷类化合物的化学研究和生理活性。     

山楂叶金丝桃苷对高糖诱导SH-SY5Y细胞损伤的保护作用及机制

为研究金丝桃苷对高糖诱导的人神经母细胞瘤(SH-SY5Y)细胞氧化损伤的保护作用及机制,用含100mmo L/L葡萄糖和分别为20、50、100μmo L/L金丝桃苷的培养基共同孵育SH-SY5Y细胞36 h,检测细胞活力、细胞培养液中乳酸脱氢酶(LDH)水平及半胱氨酸天冬氨酸蛋白酶-3(caspase-3)活性,细胞内活性氧(ROS)水平、丙二醛(MDA)、还原型谷胱甘肽(GSH)含量和超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性及SIRT1和NF-кB基因的mRNA水平和蛋白含量。结果显示金丝桃苷可提高高糖诱导后SH-SY5Y细胞的存活率,抑制细胞LDH释放,清除ROS,降低MDA含量与caspase-3活性,增强SOD、CAT活性和GSH含量;同时,金丝桃苷还能提高SIRT1基因的mR-NA表达及蛋白含量,降低NF-кB基因的mRNA水平和蛋白含量。结果表明金丝桃苷能通过激活SIRT1基因,抑制NF-кB基因保护高糖所致SH-SY5Y细胞的氧化损伤。     

人工诱骗子的入核分布对核因子-κB活性的调控作用

探讨了由核定位信号(NLS)多肽介导的核因子-κB(NF-κB)寡核苷酸诱骗子(ODNs decoy)进入HeLa细胞核的效率,以及对细胞核内NF-κB活性的调控作用。利用双功能交联剂(Sulfo-SMCC)共价交联末端氨基修饰的ODNs decoy和末端巯基修饰的NLS多肽,形成NLS多肽共价连接的ODNs decoy。依靠TransME转染试剂的辅助转染NLS-ODNs decoy进入HeLa细胞,用荧光显微镜观察荧光标记的NLS-ODNs在细胞内的分布。用MTT法检测HeLa细胞的活力,以凝胶迁移实验(EMSA)检测TNF-α诱导的HeLa细胞核抽提物中NF-κB的活性。结果表明,NLS多肽成功地连接到ODNs decoy上,NLS-ODNs可高效入核,入核率达到17.9%。转染NLS-ODNs进入HeLa细胞,对细胞活力无明显影响,而显著抑制核内NF-κB的活性。结果表明NLS多肽可提高ODNs decoy的入核效率,显著增强诱骗子对NF-κB活性的抑制效果。     

Cytoprotection against hydrogen peroxide-induced cell death in cultured mouse mesangial cells by erigeroflavanone, a novel compound from the flowers of Erigeron annuus

Hyperglycemia-induced oxidative stress has been suggested as a mechanism underlying diabetic complications. Oxidative stress triggers cell death in various cell types, including glomerular mesangial cells which play important roles in diabetic nephropathy. In the present study, we investigated the potential cytoprotective effect of erigeroflavanone, a novel flavanone derivative from the flowers of Erigeron annuus, in cultured mouse mesangial cells using hydrogen peroxide (H₂O₂) as an oxidative stress inducer. Our data show that hydrogen peroxide induced a decrease in cell viability that was attenuated by erigeroflavanone. Hydrogen peroxide treatment increased formation of dichlorofluorescein (DCF)-sensitive intracellular reactive oxygen species (ROS). This enhanced ROS formation was significantly reduced by pretreatment with erigeroflavanone in a dose-dependent manner. Hydrogen peroxide treatment also induced phosphorylation of the mitogen-activated protein kinases (MAPKs), c-Jun terminal kinase (JNK), extracellular-regulated kinase (ERK) and p38, and activated caspase-3. Pretreatment with erigeroflavanone inhibited hydrogen peroxide-induced activation of MAPKs and caspase-3. From these data we conclude that erigeroflavanone provides a protective effect against oxidative stress-induced cell death in mesangial cells that is associated with its antioxidant action and inhibition of MAPKs and caspase-3. These results suggest that erigeroflavanone has potential as a therapeutic agent in the treatment of renal diabetic complications.     

蝉虫草菌丝体胞内和胞外多糖抗肝细胞氧化损伤比较研究

蝉虫草（蝉花）作为我国传统的中药材,是一种药食两用的虫生真菌,因含有丰富的活性物质而具有广泛的医疗保健价值。本研究以自由基清除率为指标分析蝉虫草胞内和胞外多糖的化学抗氧化活性,再以H₂O₂诱导的人肝LO2细胞氧化损伤为模型,进而分析比较二者对肝细胞氧化应激损伤的改善作用。结果表明,在化学抗氧化能力比较上,蝉虫草菌丝体胞外多糖有效清除?OH自由基、ABTS自由基和DPPH自由基的EC₅₀值分别为1.06mg/mL、0.96mg/mL和0.63mg/mL,而胞内多糖的EC₅₀值分别为3.71mg/mL、2.83mg/mL和1.70mg/mL,表明蝉虫草胞外多糖的化学抗氧化能力更强;在改善细胞氧化应激损伤比较上,与模型组对比,二者均能随着浓度递增而显著地提高细胞存活率,但胞外多糖比胞内多糖更强,当多糖浓度为5mg/mL时,胞外多糖细胞存活率达到92.36%,胞内多糖只达到82.07%;在调节细胞抗氧化酶清除ROS的机制上,与模型组对比,胞外多糖分别上调SOD酶活力2.51倍和CAT酶活力2.91倍,极显著地降低了细胞ROS水平（P<0.01）来改善细胞的氧化应激损伤作用。相应地,胞内多糖只上调了1.85倍和2.33倍,显著性地清除了ROS（P<0.05）,表明蝉虫草菌丝体胞外多糖具有更显著的抗肝细胞氧化损伤作用。本研究结果显示蝉虫草菌丝体胞外和胞内多糖均具有良好的抗肝氧化损伤活性,且胞外多糖比胞内多糖活性更好,为蝉虫草菌丝体多糖在保肝产品中的开发和应用提供了科学依据。     

Human selenium-containing single-chain variable fragment with glutathione peroxidase activity protects NIH3T3 fibroblast against oxidative damage

Ultraviolet B (UVB medium wave, 280–315 nm) induces cellular oxidative damage and apoptosis by producing reactive oxygen species (ROS). Glutathione peroxidase functions as an antioxidant by catalyzing the reduction of hydrogen peroxide, the more important member of reactive oxygen species. A human selenium-containing single-chain variable fragment (se-scFv-B3) with glutathione peroxidase activity of 1288 U/μmol was generated and investigated for its antioxidant effects in UVB-induced oxidative damage model. In particular, cell viability, lipid peroxidation extent, cell apoptosis, the change of mitochondrial membrane potential, caspase-3 activity and the levels of intracellular reactive oxygen species were assayed. Human se-scFv-B3 protects NIH3T3 cells against ultraviolet B-induced oxidative damage and subsequent apoptosis by prevention of lipid peroxidation, inhibition of the collapse of mitochondrial membrane potential as well as the suppression of the caspase-3 activity and the level of intracellular ROS. It seems that antioxidant effects of human se-scFv-B3 are mainly associated with its capability to scavenge reactive oxygen species, which is similar to that of the natural glutathione peroxidase.     

Heme Oxygenase-1 Protects Retinal Endothelial Cells against High Glucose- and Oxidative/Nitrosative Stress-Induced Toxicity

Diabetic retinopathy is a leading cause of visual loss and blindness, characterized by microvascular dysfunction. Hyperglycemia is considered the major pathogenic factor for the development of diabetic retinopathy and is associated with increased oxidative/nitrosative stress in the retina. Since heme oxygenase-1 (HO-1) is an enzyme with antioxidant and protective properties, we investigated the potential protective role of HO-1 in retinal endothelial cells exposed to high glucose and oxidative/nitrosative stress conditions. Retinal endothelial cells were exposed to elevated glucose, nitric oxide (NO) and hydrogen peroxide (H(2)O(2)). Cell viability and apoptosis were assessed by MTT assay, Hoechst staining, TUNEL assay and Annexin V labeling. The production of reactive oxygen species (ROS) was detected by the oxidation of 2',7'-dichlorodihydrofluorescein diacetate. The content of HO-1 was assessed by immunobloting and immunofluorescence. HO activity was determined by bilirubin production. Long-term exposure (7 days) of retinal endothelial cells to elevated glucose decreased cell viability and had no effect on HO-1 content. However, a short-time exposure (24 h) to elevated glucose did not alter cell viability, but increased both the levels of intracellular ROS and HO-1 content. Moreover, the inhibition of HO with SnPPIX unmasked the toxic effect of high glucose and revealed the protection conferred by HO-1. Oxidative/nitrosative stress conditions increased cell death and HO-1 protein levels. These effects of elevated glucose and HO inhibition on cell death were confirmed in primary endothelial cells (HUVECs). When cells were exposed to oxidative/nitrosative stress conditions there was also an increase in retinal endothelial cell death and HO-1 content. The inhibition of HO enhanced ROS production and the toxic effect induced by exposure to H(2)O(2) and NOC-18 (NO donor). Overexpression of HO-1 prevented the toxic effect induced by H(2)O(2) and NOC-18. In conclusion, HO-1 exerts a protective effect in retinal endothelial cells exposed to hyperglycemic and oxidative/nitrosative stress conditions.     

Cytotoxic and cytoprotective effects of tryptamine-4,5-dione on neuronal cells: a double-edged sword

Serotonin (5-hydroxytryptamine) is a putative substrate for myeloperoxidase, which may convert it into the reactive quinone tryptamine-4,5-dione (TD). In this study, we found that the viability of human SH-SY5Y neuroblastoma cells treated with 25?μM TD was increased to approximately 117%. On the other hand, the cell viability was significantly decreased by exposure to TD (150–200?μM), with an increase in intracellular reactive oxygen species (ROS). Interestingly, pre-treatment of SH-SY5Y cells with 100?μM TD prevented cell death and suppressed intracellular ROS generation evoked by the addition of hydrogen peroxide (H₂O₂). Expression of the phase-II antioxidant enzyme NAD(P)H: quinone oxidoreductase 1 and haem oxygenase 1 were upregulated by TD at a concentration of 50–100?μM. Nuclear factor erythroid 2-related factor 2 (Nrf2), the regulator of these enzyme, was translocated from the cytosol to the nucleus by 100?μM TD. In summary, moderate concentrations of TD may increase the self-defence capacity of neuronal cells against oxidative stress.     

Vitamin B6 suppresses apoptosis of NM-1 bovine endothelial cells induced by homocysteine and copper

Hyperhomocysteinemia is an important risk factor for atherosclerosis. We previously reported that formation of early atherosclerosis in the rat aorta was associated with hyperhomocysteinemia and reduction of antioxidant activity caused by low concentration of vitamin B(6)in vivo. In the present study, we examined effects of vitamin B(6) on apoptosis of bovine endothelial cells (NM-1 cells) treated with homocysteine and copper. Homocysteine and copper induced extracellular hydrogen peroxide, intracellular ROS and cellular lipid peroxide levels. Cell viability was reduced to 30% compared to that of control cells. On the other hand, pyridoxal treatment as well as EDTA treatment increased viability of NM-1 cells treated with homocysteine and copper to about 60%, and significantly decreased extracellular hydrogen peroxide, intracellular ROS and cellular lipid peroxide levels. The treatment of catalase recovered cell viability and reduced the level of extracellular hydrogen peroxide and intracellular ROS. Cell death by homocysteine and copper was confirmed to be due to apoptosis by evaluation of DNA fragmentation and by TUNEL assay. However, apoptosis of NM-1 cells induced by homocysteine and copper was due to a caspase-independent pathway as it was not inhibited by the caspase inhibitor, Z-VAD-fmk. Apoptosis of NM-1 cells induced by homocysteine and copper accompanied with mitochondrial permeability but not cytochrome c release. These results suggest that pyridoxal treatment suppresses apoptosis of NM-1 cells induced by homocysteine and copper, most likely through antioxidant effects.     

Protective effects of resveratrol on hydrogen peroxide-induced apoptosis in rat pheochromocytoma (PC12) cells

Oxidative stress has been considered as a major cause of cellular injuries in a variety of clinical abnormalities. One of the plausible ways to prevent the reactive oxygen species (ROS)-mediated cellular injury is dietary or pharmaceutical augmentation of endogenous antioxidant defense capacity. Resveratrol (3,5,4'-trihydroxy-trans-stilbene), one of the major antioxidative constituents found in the skin of grapes, has been considered to be responsible in part for the protective effects of red wine consumption against coronary heart disease ('French Pardox'). In this study, we have investigated the effects of resveratrol on hydrogen peroxide-induced oxidative stress and apoptotic death in cultured rat pheochromocytoma (PC12) cells. PC12 cells treated with hydrogen peroxide underwent apoptotic death as determined by characteristic morphological features, internucleosomal DNA fragmentation and positive in situ end-labeling by terminal transferase (TUNEL staining). Resveratrol pretreatment attenuated hydrogen peroxide-induced cytotoxicity, DNA fragmentation, and intracellular accumulation of ROS. Hydrogen peroxide transiently induced activation of NF-kappaB in PC12 cells, which was mitigated by resveratrol pretreatment. These results suggest that resveratrol has the potential to prevent oxidative stress-induced cell death.     

Hydrogen-rich water achieves cytoprotection from oxidative stress injury in human gingival fibroblasts in culture or 3D-tissue equivalents,and wound-healing promotion,together with ROS-scavenging and relief from glutathione diminishment

The aim of the present study is to investigate protective effects of hydrogen-rich water (HW) against reactive oxygen species (ROS)-induced cellular harmful events and cell death in human gingival fibroblasts (HGF) and three-dimensional (3D-) gingival tissue equivalents. HW was prepared with a magnesium stick in 600-mL double distilled water (DDW) overnight. Dissolved hydrogen was about 1460 ± 50 μg/L versus approximately 1600 μg/L for the saturated hydrogen. Under cell-free conditions, HW, dose-dependently, significantly scavenged peroxyl radicals (ROO·) derived from 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH). Extract from HW-treated HGF cells scavenged ROO· more markedly than that from DDW-treated cells, suggesting that HW can increase the intracellular antioxidant capacity. Hydrogen peroxide dose-dependently increased the intracellular ROS generation, which was significantly repressed by HW, both in the cytoplasm and nuclei. LIVE/DEAD staining and our original cell viability dye-extraction assay showed that HW significantly protected HGF cells from hydrogen peroxide-induced cell death. Hydrogen peroxide also diminished the contents of intracellular glutathione, which were appreciably relieved by HW-pretreatment. Additionally, HW noticeably prevented cumene hydroperoxide-induced generation of cellular ROS in epidermis parts of 3D-gingival equivalents. The in vitro scratch assay showed that HW was able to diminish physical injury-induced ROS generation and promote wound healing in HGF cell monolayer sheets. In summary, HW was able to increase intracellular antioxidative capacity and to protect cells and tissue from oxidative damage. Thus, HW might be used for prevention/treatment of oxidative stress-related diseases.     

The Effect of SOD1 Mutation on Cellular Bioenergetic Profile and Viability in Response to Oxidative Stress and Influence of Mutation-Type

Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disorder characterized by the progressive degeneration of motor neurons. Substantial evidence implicates oxidative stress and mitochondrial dysfunction as early events in disease progression. Our aim was to ascertain whether mutation of the SOD1 protein increases metabolic functional susceptibility to oxidative stress. Here we used a motor neuron-like cell line (NSC34) stably transfected with various human mutant SOD1 transgenes (G93A, G37R, H48Q) to investigate the impact of oxidative stress on cell viability and metabolic function within intact cells. NSC34 cells expressing mutant SOD1 showed a dose dependent reduction in cell viability when exposed to oxidative stress induced by hydrogen peroxide, with variation between mutations. The G93A transfectants showed greater cell death and LDH release compared to cells transfected with the other SOD1 mutations, and H48Q showed an accelerated decline at later time points. Differences in mitochondrial bioenergetics, including mitochondrial respiration, coupling efficiency and proton leak, were identified between the mutations, consistent with the differences observed in viability. NSC34 cells expressing G93A SOD1 displayed reduced coupled respiration and mitochondrial membrane potential compared to controls. Furthermore, the G93A mutation had significantly increased metabolic susceptibility to oxidative stress, with hydrogen peroxide increasing ROS production, reducing both cellular oxygen consumption and glycolytic flux in the cell. This study highlights bioenergetic defects within a cellular model of ALS and suggests that oxidative stress is not only detrimental to oxygen consumption but also glycolytic flux, which could lead to an energy deficit in the cell.     

Impact of oxidative stress on cellular biomechanics and rho signaling in C2C12 myoblasts

Although cells often can tolerate oxidative environments, abnormal oxidative stress has been identified in inflammation, cardiovascular and neurodegenerative diseases, and aging. The impact of oxidative stress on the cellular biomechanics is poorly understood, however. In this study, we used C2C12 myoblasts to investigate the effect of oxidative stress, mimicked by hydrogen peroxide (H₂O₂), on the cell elasticity (i.e., Young?s modulus), viability, and production of intracellular reactive oxygen species (ROS). To better understand the mechanisms underlying the impact of H₂O₂, we examined various effectors of the Rho signaling pathway, which has been shown to play a key role in the control of cell mechanics. H₂O₂ decreased the cell stiffness in a dose-dependent manner, caused cell death, and reduced the RhoA expression that was accompanied by down-regulation of α-actin, cytoskeleton-membrane linker proteins (ezrin–radixin–moesion proteins), and focal adhesion. Modulating the Rho signaling by using a Rho activator partially restored the cell stiffness, enhanced the cell viability, and decreased the intracellular ROS level, suggesting a potential intervention strategy to maintain the cellular biomechanical homeostasis and rescue cell damage in the threat of oxidative stresses.