Buformin alleviates sepsis-induced acute lung injury via inhibiting NLRP3-mediated pyroptosis through an AMPK-dependent pathway.

BACKGROUND: NOD-like receptor family pyrin domain containing 3 (NLRP3)-mediated macrophage pyroptosis plays an important role in sepsis-induced acute lung injury (ALI). Inhibition of pyroptosis may be a way to alleviate inflammation as well as tissue damage triggered after lipopolysaccharide (LPS) stimulation. The aim of the present study was to explore whether buformin (BF), a hypoglycemic agent, could alleviate sepsis-induced ALI by inhibiting pyroptosis. METHODS: Wildtype C57BL/6 mice were randomly divided into control group, BF group, LPS group and LPS+BF group. BF group and LPS+BF group were pretreated with BF at a dose of 25 mg/kg, and the changes were observed. In addition, BF was used to interfere with THP-1 cells. The therapeutic effect of BF has been verified by intraperitoneal injection of BF in vivo after LPS stimulation. RESULTS: Inflammation and injury was significantly reduced in BF pretreated mice, and the indexes related to pyroptosis were suppressed. The phosphorylation of AMP-activated protein kinase (AMPK) in lung tissues of mice in the BF and LPS+BF groups was significantly higher. In THP-1 cells, the AMPK inhibitor, Compound C was added to demonstrate that BF worked via AMPK to inhibit NLRP3 inflammasome. It was further demonstrated that BF up-regulated autophagy, which in turn promoted NLRP3 inflammasome degradation. On the other hand, BF decreased NLRP3 mRNA level by increasing nuclear factor-erythroid 2 related factor 2 (Nrf2). And BF showed a therapeutic effect after LPS challenge. CONCLUSION: Our study confirmed that BF inhibited NLRP3-mediated pyroptosis in sepsis-induced ALI by up-regulating autophagy and Nrf2 protein level through an AMPK-dependent pathway. This provides a new strategy for clinical mitigation of sepsis-induced ALI.

Buformin suppresses proliferation and invasion via AMPK/S6 pathway in cervical cancer and synergizes with paclitaxel.

Buformin is an old anti-diabetic agent and manifests potent anti-tumor activities in several malignancies. In the present study, we aimed to explore the functions of buformin in human cervical cancer. As our data shown, buformin exhibited significant anti-proliferative effects in a dose-dependent manner in 4 cervical cancer cell lines. Compared to the control, buformin notably suppressed colony formation and increased ROS production in C33A, Hcc94 and SiHa cells. Flow cytometric analysis showed that buformin induced marked cell cycle arrest but only resulted in mild apoptosis. The invasion of C33A and SiHa cells sharply declined with buformin treatment. Consistently, western blotting showed that buformin activated AMPK and suppressed S6, cyclin D1, CDK4, and MMP9. Moreover, we found that buformin enhanced glucose uptake and LDH activity, increased lactate level, while decreased ATP production in cervical cancer cells. In addition, low doses of buformin synergized with routine chemotherapeutic drugs (such as paclitaxel, cisplatin, and 5-FU) to achieve more significant anti-tumor effects. In vivo, a single use of buformin exerted moderate anti-tumor effects, and the combination with buformin and paclitaxel exhibited even greater suppressive effects. Buformin also consistently showed synergistic effects with paclitaxel in treating primary cultures of cervical cancer cells. Take together, we are the first to demonstrate that buformin suppresses cellular proliferation and invasion through the AMPK/S6 signaling pathway, which arrests cell cycle and inhibits cellular invasion. Buformin also could synergize with routine chemotherapies, producing much more powerful anti-tumor effects. With these findings, we strongly support buformin as a potent choice for treating cervical cancer, especially in combination with routine chemotherapy.

Therapeutic inhibition of mitochondrial function induces cell death in starvation-resistant renal cell carcinomas.

Renal cell carcinomas (RCC) have two types of cells for carbon metabolism and for cell signaling under nutrient-deprivation conditions, namely starvation-resistant and starvation-sensitive cells. Here, we evaluated the mitochondrial characteristics of these cell types and found that the resistant type possessed higher activities for both mitochondrial oxidative phosphorylation and glycolysis than the sensitive types. These higher activities were supported by the stored carbon, lipid and carbohydrate sources, and by a low level of mitochondrial reactive oxygen species (ROS) due to sustained SOD2 expression in the resistant RCC cells. In metastatic RCC cases, higher SOD2 expression was associated with a significantly shorter survival period. We found that treatment with the drugs etomoxir and buformin significantly reduced mitochondrial oxidative phosphorylation and induced cell death under glucose-deprivation conditions in starvation-resistant RCC cells. Our data suggest that inhibitory targeting of mitochondria might offer an effective therapeutic option for metastatic RCC that is resistant to current treatments.

[Levels of lactic acid in type II diabetics treated with buformin]. / Hladiny kyseliny mlécné u diabetiku II. typu lécených buforminem.

The objective of the work was to assess the blood lactate levels in type 2 diabetics selected at random, treated for prolonged periods with buformin. 77% of the investigated group of diabetics (N = 70) had elevated blood lactate levels and 16% of them had hyperlactataemia (more than 5.0 mmol/l). In 33% patients with an originally elevated lactataemia after 12 weeks of discontinued buformin treatment the lactic acid blood levels reached normal values. The lactate levels declined significantly (by more than 25% of the original value) after 6 weeks without buformin treatment in another 45% of the diabetic patients. In 18% of the investigated patients, who had high lactate levels even after discontinuation of treatment, in two-thirds neither impaired function of the kidneys and liver nor cardiac disease or alcoholism were detected.

[Hypoglycemic activity of bicyclic diterpenoids of the clerodane series as compared to adebit and maninil]. / Izuchenie gipoglikemicheskoi aktivnosti bitsiklicheskikh diterpenoidov klerodanovogo riada v sravnenii s adebitom i maninilom.

Biocyclic diterpenoids--salvin, salvicin and salvifolin, administered per os to rats at a dose of 50 mg/kg show marked hypoglycemic activity in intact animals as well as in animals with experimental hyperglycemia developing against a background of GTT (3000 mg/kg intraperitoneally) or alloxan (150 mg/kg subcutaneously). They are superior to adebit but inferior to maninil. Prophylactic and therapeutic administration of these compounds ensure the preservation of islet beta-cells in animals with alloxan diabetes.

[Correction of dyslipoproteinemia in middle-aged and elderly patients with atherosclerosis using Essentiale in combination with adebit]. / Korrektsiia dislipoproteidemii u bol'nykh aterosklerozom pozhilogo i starcheskogo vozrasta éssentsiale v sochetanii s adebitom.

A combination of Essentiale and adebit was used in the treatment of 62 patients (age: 60-89 years) with stable stenocardia. Essentiale normalizes the cholesterol metabolism, adebit normalizes the carbohydrate metabolism. Results of the treatment indicate that elderly and old, in particular, showed an improvement of the clinical condition of the disease, normalization of the lipid metabolism.

Usefulness of anaerobic threshold in estimating intensity of exercise for diabetics.

We examined the utility of the anaerobic threshold (AT) for quantifying the intensity of exercise that a diabetic patient is capable of handling. Thirteen diabetic patients treated with buformin exercised on a bicycle ergometer, and comparison was made with 20 healthy subjects matched for age and sex. The AT was determined from VO2 and VE with a personal computer. The intensity of exercise at the AT was 93 +/- 6 W in diabetic men and 80 +/- 10 W in diabetic women, values that were less than those of healthy subjects (P less than 0.05). There was a negative correlation between the intensity of exercise at the AT and the plasma concentration of buformin (P less than 0.01). There were no significant differences in either plasma lactic acid or pyruvic acid concentration at the AT between healthy subjects and diabetics. The plasma glucose at the AT or after exercise was lower than the baseline values in all subjects (P less than 0.01). The plasma insulin at the AT was lower than the baseline values in healthy subjects (P less than 0.01), but not in diabetics. There were no changes in plasma glucagon in any group. We concluded that determination of the AT is a simple, non-invasive procedure useful for ascertaining the optimal intensity of exercise for diabetics.

Valoración del tratamiento con butformin en la diabetes mellitus tipo 2 / Assessment of treatment with butformine in diabetes mellitus type 2

Estudiamos 14 pacientes diabéticos tipo 2, mayores de 35 años de edad, los cuales no lograban un control metabólico adecuado con dieta y glibenclamida a dosis máxima (30 mg/día) por un período no menor de dos meses. Se incluyó en el estudio diez sujetos sanos como grupo control, de edades y sexo comparables. A todos los diabéticos se les adicionó al tratamiento 100 mg diario de butformín (divididos en dos dosis). No se incluyó en la investigación ningún paciente con factores predisponentes al desarrollo de una acidosis láctica. Previamente a la administración del butformín se les realizaron pruebas de glicemias, HbA1c colesterol, triglicéridos, HDL-c, LDL-c, lactato, piruvato, betahidroxibutirato y acetato-acetato e índice L/P y ß-OH/acetato-acetato. Este mismo estudio se repitió al mes y a los 4 meses de tratamiento. Los niveles de lactato plasmático fueron en los controles de 1,84 ñ 0,13 mmol/L. En los diabéticos, antes de imponerse el tratamiento con butformín, eran de 1,87 ñ 0,24 mmol/L, que aumentó significativamente (p < 0,02) al mes de tratamiento, para luego disminuir a 1,59 ñ 0,12 mmol/L a los cuatro meses. En el resto de las variables estudiadas no se hallaron diferencias significativas, excepto en los valores de acetato-acetato, que fueron significativamente elevados en los diabéticos antes de comenzar el tratamiento. No logramos un buen control metabólico con el esquema de tratamiento empleado. Las manifestaciones indeseables del aparato digestivo fueron escasas. No comprobamos modificaciones significativas de la curva de peso. Ninguno de nuestros pacientes desarrolló acidosis láctica en el curso del tratamiento con butformín, lo que pensamos ocurrió por la selección de los pacientes y por la dosis empleadas

Valoración del tratamiento con butformin en la diabetes mellitus tipo 2 / Assessent of treatment with butformine in diabetes mellitus type 2

Estudiamos 14 pacientes diabéticos tipo 2, mayores de 35 años de edad, los cuales no lograban un control metabólico adecuado con dieta y glibenclamida a dosis máxima (30 mg/día) por un período no menor de dos meses. Se incluyó en el estudio diez sujetos sanos como grupo control, de edades y sexo comparables. A todos los diabéticos se les adicionó al tratamiento 100 mg diario de butformín (divididos en dos dosis). No se incluyó en la investigación ningún paciente con factores predisponentes al desarrollo de una acidosis láctica. Previamente a la administración del butformín se les realizaron pruebas de glicemias, HbA1c colesterol, triglicéridos, HDL-c, LDL-c, lactato, piruvato, betahidroxibutirato y acetato-acetato e índice L/P y ß-OH/acetato-acetato. Este mismo estudio se repitió al mes y a los 4 meses de tratamiento. Los niveles de lactato plasmático fueron en los controles de 1,84 ñ 0,13 mmol/L. En los diabéticos, antes de imponerse el tratamiento con butformín, eran de 1,87 ñ 0,24 mmol/L, que aumentó significativamente (p < 0,02) al mes de tratamiento, para luego disminuir a 1,59 ñ 0,12 mmol/L a los cuatro meses. En el resto de las variables estudiadas no se hallaron diferencias significativas, excepto en los valores de acetato-acetato, que fueron significativamente elevados en los diabéticos antes de comenzar el tratamiento. No logramos un buen control metabólico con el esquema de tratamiento empleado. Las manifestaciones indeseables del aparato digestivo fueron escasas. No comprobamos modificaciones significativas de la curva de peso. Ninguno de nuestros pacientes desarrolló acidosis láctica en el curso del tratamiento con butformín, lo que pensamos ocurrió por la selección de los pacientes y por la dosis empleadas

[Metabolism kinetic characterization of hypertriglyceridemias in drug therapy variations]. / Stoffwechselkinetische Charakterisierung von Hypertriglyceridämien unter medikamentösen Therapievarianten.

In 26 male patients with primary hypertriglyceridemia (HTG) the radioglycerol labelling technique was used to assess triglyceride production rates and fractional catabolic rates pertaining to the rapidly turning-over compartment of endogenously produced triglycerides (TG). On the basis of these data the patients were allotted to 3 groups: group I with predominating TG overproduction, group II with predominating disturbances of TG removal from the bloodstream, and group III with a combination of both dysfunctions. All patients were examined prior to and after 4 weeks of drug intake at the metabolic ward. Each group got a medical treatment aiming at removing the pathogenetic cause of the HTG. Biguanides used in group I decreased TG production rates without affecting fractional catabolic rates. In group II an anabolic steroid (chlormethyltestosterone) proved to be able to improve TG removal, but this improvement was accompanied by a significant lowering of HDL cholesterol and an increase in LDL cholesterol. In contrast, clofibric acid influenced both overproduction and removal impairment in group III. Our results give an insight into mechanisms of action of certain lipid-lowering drugs providing a basis for future improvements in the elimination of the risk factor HTG.

[Vitamin B12-level in serum of diabetics receiving long-term buformin therapy]. / Vitamin-B12-Spiegel im Serum von Diabetikern mit Buformin-Langzeittherapie.

Disturbances of the vitamin B12 resorption by the therapy with biguanides above all metformin are known from literature. In 59 patients with Buformin retard-monotherapy we determined in 18.7% slight reductions of the vitamin B12 level in the serum, in one patient the serum concentration was lower than 50 pg/ml. That means that also under therapy with Buformin can be reckoned with easy disturbances of resorption for vitamin B12. Occasional controls of Hb and anamnestic establishment of neurological symptoms are to be recommended during a therapy with Buformin, in order not to overlook the clinical signs of a vitamin B12 hypovitaminosis.

[Inhibition of the transplacental blastomogenic effect of N-nitrosomethylurea in rats by buformin]. / Tormozhenie buforminom transplatsentarnogo blastomogennogo éffekta N-nitrozometilmocheviny u krys.

N-nitrosomethylurea (NMU, 20 mg/kg) was administered to rats intraperitoneally on the 21st day of pregnancy. F1 progeny aged 3 months showed a decrease in glucose utilization and in somatomerin content as measured by the glucose tolerance test. The insulin serum level did not differ from control. The cholesterol blood level was higher in the offspring of NMU-treated rats. The ability of diethylstilbestrol to inhibit the compensatory ovarian hypertrophy was decreased in 3-month-old female hemicastrated rats whose mothers had been exposed to NMU. Administration of the antidiabetic drug buformin decreased 3.5-fold the malignant neurogenic tumor incidence in rats transplacentally treated with NMU.

[Inhibition of the blastomogenic effect of 7,12-dimethylbenz(a)anthracene in female rats by buformin, diphenin, a polypeptide pineal extract and L-DOPA]. / Tormozhenie buforminom, difeninom, polipeptidnym ékstraktom épifiza i L-DOFA blastomogennogo éffekta 7,12-dimetilbenz(a)antratsena u krys-samok.

Female rats were treated with buformin, phenytoin, polypeptide pineal extract, L-DOPA or buformin combined with L-DOPA during 3 weeks before intravenous injections of DMBA (1.5 mg 6 times with one-week intervals) over a period of carcinogen injections and after it till the animals' death. The overall tumour incidence in the control group was 97%, while in buformin, phenytoin, pineal extract, L-DOPA and buformin + L-DOPA treated groups it amounted to 55, 71, 80, 50 and 62%, respectively (P < 0.05). The incidence of mammary adenocarcinoma amounted to 81, 36, 55, 26, 25 and 19%, respectively (P < 0.05). The mechanisms of the similar effects the drugs belonging to different classes produce on chemical carcinogenesis are discussed.

The inhibition of the transplacental blastomogenic effect of nitrosomethylurea by postnatal administration of buformin to rats.

N-Nitrosomethylurea (NMU) (20 mg/kg) was i.p. administered to rats on the 21st day of pregnancy. A decrease of glucose utilisation in the oral glucose tolerance test was found in 3 month old female progeny of NMU-treated rats. The serum insulin level did not differ from control, but serum cholesterol level was higher in offspring of NMU-treated rats. The ability of diethylstilboestrol to inhibit compensatory ovarian hypertrophy was decreased in female hemicastrated 3 month old rats whose mothers were treated with NMU. Postnatal administration of the antidiabetic drug buformin decreased the malignant neurogenic tumor incidence 3.5 times (to rats transplacentally treated with NMU).

[The biological effect of purely synthetic human insulin in patients with diabetes mellitus]. / Die biologische Wirkung von vollsynthetischem humanem Insulin bei Patienten mit Diabetes mellitus.

Six patients with diabetes were treated with fully synthetic human insulin (CGP 12 831) for durations of 3 days (4 patients), 4 days and 13 days (1 patient each). In every case, clinical signs of hypoglycemia were registered and measured by blood sugar determinations. Two patients with insulin-dependent diabetes were maintained on synthetic insulin. Ketoacidosis was corrected in 1 patient. In a hyperglycemic diabetic with failing response to oral antidiabetics, synthetic insulin normalized the hyperglycemia. In 2 juveniles with recent onset of diabetes, every injection of synthetic insulin was followed by a fall in blood sugar. In a normal individual, hypoglycemia developed after a single injection of 8 units. The synthetic human insulin was well tolerated. The 6 diabetics showed evidence of full biological action of the fully synthetic insulin, as was expected from animal experiments.