BACKGROUND: Hyperthermia (HT), while a cancer treatment approach, isn't always effective alone. Therefore, identifying hyperthermia enhancers is crucial. We demonstrated that Mito-TEMPO ([2-[(1-Hydroxy-2,2,6,6-tetramethylpiperidin-4-yl) amino]-2-oxoethyl]-triphenylphosphanium, MT) acts as a potent thermosensitizer, promoting cell death in human cervical cancer (HeLa) cells. METHODS: Cells were pretreated with 0.4 mM MT for 5 minutes, followed by exposure to hyperthermia (42 °C for 60 minutes). The impacts of MT/HT on cell viability, proliferation, apoptosis, endoplasmic reticulum (ER) stress, apoptosis-related proteins and autophagy, autophagy-related proteins expression were measured. The relationships between autophagy and apoptosis were further investigated using the specific autophagy inhibitor chloroquine (CQ) and the autophagy inducer rapamycin (Rapa). RESULTS: The combined treatment reduced the mitochondrial membrane potential (MMP) and increased ROS production. It also upregulated the pro-apoptotic protein Bax and downregulated anti-apoptotic proteins such as Bcl-2 and MCL-1. As a result, Caspase-3 was activated. Additionally, the combined treatment upregulated the expression of p-PERK/PERK, ATF-4, CHOP proteins. Moreover, the combined treatment also increased the expression of LC3 II and p62, decreased expression of LAMP 1 and Cathepsin D and increased lysosomal pH, indicating coordinated changes in autophagy regulation. Notably, intensification of apoptosis induced by the combined treatment was observed with CQ, whereas attenuation was seen with Rapa. CONCLUSIONS MT effectively enhanced HT-induced apoptosis in HeLa cells. Elevated ER stress and interruption of autophagy flux are the possible underlying molecular mechanisms for this phenomenon. These findings suggested MT can act as a potential thermosensitizer, highlighting its versatility in cancer treatment strategies.
Humans ; Apoptosis/drug effects* ; Autophagy/drug effects* ; HeLa Cells ; Uterine Cervical Neoplasms/therapy* ; Female ; Hyperthermia, Induced ; Spin Labels ; Endoplasmic Reticulum Stress/drug effects* ; Cyclic N-Oxides/pharmacology* ; Cell Survival/drug effects*

OBJECTIVE: To investigate the effect of the chemoprotectant tempol on the anti-tumor activity of cisplatin (DDP). METHODS: The cellular toxicity of tempol in human colon cancer SW480 cells and mouse colon cancer CT26 cells were evaluated using MTT and cell counting kit-8 assays. CalcuSyn software analysis was used to determine the interaction between tempol and DDP in inhibition of the cell viability. A subcutaneous homograft mouse model of colon cancer was established. The mice were randomly divided into control group, tempol group, cisplatin group and tempol + DDP treatment group with intraperitoneal injections of the indicated agents. The tumor size, body weight and lifespan of the mice were measured, and HE staining was used to analyze the cytotoxic effect of the agents on the kidney and liver. Immunohistochemistry and Western blotting were performed to detect the expression of Bax and Bcl2 in the tumor tissue, and TUNEL staining was used to analyze the tumor cell apoptosis. The level of reactive oxygen species (ROS) in the tumor tissue was determined using flow cytometry. RESULTS: Tempol showed inhibitory effects on the viability of SW480 and CT26 cells. CalcuSyn software analysis showed that tempol had a synergistic anti-tumor effect with DDP (CI < 1). In the homograft mouse model, tempol treatment alone did not produce obvious anti-tumor effect. HE staining showed that the combined use of tempol and DDP alleviated DDP-induced fibrogenesis in the kidneys, but tempol also reduced the anti-tumor activity of DDP. Compared with the mice treated with DDP alone, the mice treated with both tempol and DDP had a significantly larger tumor size ( < 0.01) and a shorter lifespan ( < 0.05). Tempol significantly reversed DDP-induced expression of Bax and Bcl2 in the tumor tissue and tumor cell apoptosis ( < 0.001), and obviously reduced the elevation of ROS level in the tumor tissue induced by DDP treatment ( < 0.05). CONCLUSIONS Tempol can attenuate the anti-tumor effect of DDP while reducing the side effects of DDP. Caution must be taken and the risks and benefits should be carefully weighed when considering the use of tempol as an anti-oxidant to reduce the toxicities of DDP.
Animals ; Antineoplastic Agents ; Antioxidants ; Apoptosis ; Cell Line, Tumor ; Cell Proliferation ; Cisplatin ; Cyclic N-Oxides ; pharmacology ; Drug Resistance, Neoplasm ; Humans ; Mice ; Spin Labels

The present study was aimed to investigate the roles of renal sympathetic nerve and oxidative stress in the development of foot shock-induced hypertension. Ninety rats were divided into 6 groups (the number of each group was 15): control group, foot shock group, denervation of renal sympathetic nerve group, denervation of renal sympathetic nerve + foot shock group, Tempol treatment + foot shock group, denervation of renal sympathetic nerve + Tempol treatment + foot shock group. Rats were received electrical foot shock for 14 days (2-4 mA, 75 V, shocks of 50-100 ms every 30 s, for 4 h each session through an electrified grid floor every day). Renal sympathetic ablation was used to remove bilateral renal sympathetic nerve in rats (rats were allowed to recover for one week before the beginning of the foot shock procedure). The antioxidant Tempol was injected intraperitoneally at 1 h before foot shock. Systolic blood pressure was measured at 1 h after foot shock on day 0, 3, 7, 10 and 14. Contents of thiobarbituric acid reactive substance (TBARS), renin, angiotensin II (AngII) and glutathione peroxidase (GSH-Px) in plasma were measured by ELISA after 14-day foot shock. The results showed that systolic blood pressure of foot shock group was significantly increased (P < 0.05) compared with that of control group from day 7 to day 14 of foot shock. Denervation of renal sympathetic nerve and/or Tempol treatment significantly reduced the increase of systolic blood pressure induced by foot shock. Levels of TBARS, renin and AngII in plasma were increased significantly in foot shock group compared with that of control group (P < 0.05). Plasma GSH-Px concentration was decreased in foot shock group rats compared with that of control group (P < 0.05). Denervation of renal sympathetic nerve and/or tempol treatment significantly reduced the increase in TBARS, renin, AngII levels induced by foot shock in comparison with that of foot shock group (P < 0.05), but had no effects on the reduction of GSH-Px concentration. The results suggest that renal sympathetic nerve may play an important role in the development of foot shock-induced hypertension, and renal sympathetic nerve may influence oxidative stress and directly or indirectly activate renin-angiotensin-aldosterone system, so the foot shock-induced high blood pressure may be maintained and hypertension may therefore be produced.
Animals ; Antioxidants ; pharmacology ; Blood Pressure ; Cyclic N-Oxides ; pharmacology ; Denervation ; Electric Stimulation ; Hypertension ; physiopathology ; Kidney ; innervation ; Oxidative Stress ; Rats ; Renin-Angiotensin System ; Spin Labels ; Sympathetic Nervous System ; physiology

OBJECTIVETo investigate whether brain reactive oxygen species mediate sympathoexcitation and arterial pressure elevation in DOCA-salt hypertensive rats.

METHODSDOCA-salt hypertensive model was established in male SD rats by subcutaneous injection of DOCA after uninephrectomy and drinking 1% NaCl solution for 4 weeks. The baseline mean arterial pressure (MAP), heart rate (HR) and renal sympathetic nerve activity (RSNA) were recorded in the rats under mild anesthesia, and MAP changes following intravenous hexamethonium injection were observed. The responses of MAP, HR and RSNA to intracerebroventricular administration of tempol (20 µmol/L in 10 µl) were evaluated; plasma NE level was measured with ELISA, and ROS level and NAD(P)H oxidase activity in the hypothalamus were detected using chemiluminescence assay.

RESULTSMAP and plasma NE levels were significantly increased in DOCA-salt rats as compared with those in the control group (P<0.01). In DOCA-salt hypertensive rats, intravenous hexamethonium injection induced a blood pressure reduction 240% of that in control rats, and significantly increased the levels of superoxide anion and NAD(P)H oxidase activity in the hypothalamus. Intracerebroventricular microinjection of tempol also resulted in more significant changes of MAP, HR and RSNA in DOCA-salt rats than in the control group (P<0.01).

CONCLUSIONSympathoexcitation due to increased NAD(P)H oxidase-derived ROS levels in the hypothalamus may mediate arterial pressure elevation in DOCA-salt hypertensive rats.

Animals ; Antioxidants ; Arterial Pressure ; Blood Pressure ; Brain ; metabolism ; Cyclic N-Oxides ; pharmacology ; Desoxycorticosterone ; Desoxycorticosterone Acetate ; Disease Models, Animal ; Heart Rate ; Hypertension ; Kidney ; innervation ; Male ; NADPH Oxidases ; metabolism ; Rats ; Rats, Sprague-Dawley ; Reactive Oxygen Species ; metabolism ; Sodium Chloride ; Spin Labels ; Superoxides ; metabolism ; Sympathetic Nervous System

This study investigated whether tempol, an anti-oxidant, protects against renal injury by modulating phosphatidylinositol 3-kinase (PI3K)-Akt-Forkhead homeobox O (FoxO) signaling. Mice received unilateral ureteral obstruction (UUO) surgery with or without administration of tempol. We evaluated renal damage, oxidative stress and the expression of PI3K, Akt, FoxO3a and their target molecules including manganese superoxide dismutase (MnSOD), catalase, Bax, and Bcl-2 on day 3 and day 7 after UUO. Tubulointerstitial fibrosis, collagen deposition, alpha-smooth muscle actin-positive area, and F4/80-positive macrophage infiltration were significantly lower in tempol-treated mice compared with control mice. The expression of PI3K, phosphorylated Akt, and phosphorylated FoxO3a markedly decreased in tempol-treated mice compared with control mice. Tempol prominently increased the expressions of MnSOD and catalase, and decreased the production of hydrogen peroxide and lipid peroxidation in the obstructed kidneys. Significantly less apoptosis, a lower ratio of Bax to Bcl-2 expression and fewer apoptotic cells in TUNEL staining, and decreased expression of transforming growth factor-beta1 were observed in the obstructed kidneys from tempol-treated mice compared with those from control mice. Tempol attenuates oxidative stress, inflammation, and fibrosis in the obstructed kidneys of UUO mice, and the modulation of PI3K-Akt-FoxO3a signaling may be involved in this pathogenesis.
Animals ; Antioxidants/pharmacology/therapeutic use ; Collagen/metabolism ; Cyclic N-Oxides/*pharmacology/therapeutic use ; Fibrosis ; Forkhead Transcription Factors/*metabolism ; Hydrogen Peroxide/metabolism ; Kidney Diseases/drug therapy/metabolism/pathology ; Lipid Peroxidation ; Male ; Mice ; Mice, Inbred C57BL ; Oxidative Stress/drug effects ; Phosphatidylinositol 3-Kinases/*metabolism ; Phosphorylation/drug effects ; Proto-Oncogene Proteins c-akt/*metabolism ; Severity of Illness Index ; Signal Transduction/*drug effects ; Spin Labels ; Superoxide Dismutase/metabolism ; Ureteral Obstruction/complications/drug therapy/*metabolism/pathology

OBJECTIVE: To determine whether SC-435, a new ileal apical sodium-codependent bile acid transporter (IBAT) inhibitor, can alter the gastrointestinal motility in guinea pigs. METHODS: Sixty guinea pigs received regular diet or IBAT inhibitor (SC-435) diet for 2, 4, and 8 weeks, respectively. At the end of the feeding period, the gallbladder motility was assessed and then four bipolar silver electrodes were implanted on the antrum, duodenum, jejunum, and ileum. Seven days later, migrating motor complex (MMC) was recorded and the total bile acid pool size was measured according to the isotope dilution principle in the meantime. RESULTS: After feeding SC435, the gallbladder motility was declined in the 4-week group and the 8-week group. The bile acid pool size decreased by 17.11% (P <0.05) in the 4-week group and 48.35% (P < 0.05) in the 8-week group. The places of origin of MMC were changed where antral origins (37%) and duodenal origins (46%) decreased whereas jejunal origins (17%) increased. The MMC cycle period was prolonged in the duodenum (1.16 times in the 4-week group, P < 0.05; 1.38 times in the 8-week group, P < 0.05) whereas MMC amplitude fell in the duodenum (10.58% in the 4-week group, P <0.05; 49.17% in the 8-week group, P <0.05). There were not significant differences in all parameters of MMC between the control group and the 2-week group in guinea pigs. CONCLUSION The IBAT inhibitor (SC-435) reduces the bile acid pool size and inhibits the MMC cycle activity. MMC is related to the enterohepatic circulation of bile acids, which is consistent with the changes of the bile acid pool size in guinea pigs.
Animals ; Bile Acids and Salts ; Cyclic N-Oxides ; pharmacology ; Female ; Gallbladder ; physiology ; Gastrointestinal Motility ; drug effects ; physiology ; Guinea Pigs ; Myoelectric Complex, Migrating ; drug effects ; Organic Anion Transporters, Sodium-Dependent ; antagonists & inhibitors ; Random Allocation ; Symporters ; antagonists & inhibitors ; Tropanes ; pharmacology

AIMTo search for new derivatives of diclofenac (DC) having higher potency than the parent drug and lacking its undesirable effects.

METHODSCoupling DC with NO donor 3-hydroxymethyl-4-phenylfuroxan and its isomer through esterification, evaluating anti-inflammatory and analgesic activities, observing side effects in the rat gastrointestinal (GI) tract and assessing NO releasing ability both in vitro and in vivo.

RESULTSFifteen new compounds including nine target ones (II1-9) were synthesized, and their structures were determined by IR, 1HNMR, MS and elemental analysis. Compounds II3 and II9 showed anti-inflammatory activity comparable to DC. Compound II2 showed stronger anti-inflammatory and analgesic activities and less GI side effect than DC, and released NO in vivo.

CONCLUSIONCompound II2 is worthy to be intensively studied.

Analgesics ; chemical synthesis ; pharmacology ; therapeutic use ; Animals ; Anti-Inflammatory Agents, Non-Steroidal ; chemical synthesis ; pharmacology ; therapeutic use ; Cyclic N-Oxides ; administration & dosage ; chemistry ; pharmacology ; Diclofenac ; chemical synthesis ; pharmacology ; therapeutic use ; Digestive System ; drug effects ; Edema ; drug therapy ; Gastrointestinal Hemorrhage ; chemically induced ; Mice ; Molecular Structure ; Nitric Oxide ; metabolism ; Nitric Oxide Donors ; chemistry ; pharmacology ; Oxadiazoles ; administration & dosage ; chemistry ; pharmacology ; Pain Threshold ; drug effects ; Rats ; Structure-Activity Relationship