Apigenin inhibits pancreatic stellate cell activity in pancreatitis.

BACKGROUND: Chronic pancreatitis (CP) is characterized by recurrent pancreatic injury, resulting in inflammation, necrosis, and fibrosis. There are currently no drugs limiting pancreatic fibrosis associated with CP, and there is a definite need to fill this void in patient care. MATERIALS AND METHODS: Pancreatitis was induced in C57/BL6 mice using supraphysiologic doses of cerulein, and apigenin treatment (once daily, 50 µg per mouse by oral gavage) was initiated 1 wk into the recurrent acute pancreatitis (RAP) protocol. Pancreata were harvested after 4 wk of RAP. Immunostaining with fibronectin antibody was used to quantify the extent of pancreatic fibrosis. To assess how apigenin may decrease organ fibrosis, we evaluated the effect of apigenin on the proliferation and apoptosis of human pancreatic stellate cells (PSCs) in vitro. Finally, we assessed apigenin's effect on the gene expression in PSCs stimulated with parathyroid hormone-related protein, a profibrotic and proinflammatory mediator of pancreatitis, using reverse transcription-polymerase chain reaction. RESULTS: After 4 wk of RAP, apigenin significantly reduced the fibrotic response to injury while preserving acinar units. Apigenin inhibited viability and induced apoptosis of PSCs in a time- and dose-dependent manner. Finally, apigenin reduced parathyroid hormone-related protein-stimulated increases in the PSC messenger RNA expression levels of extracellular matrix proteins collagen 1A1 and fibronectin, proliferating cell nuclear antigen, transforming growth factor-beta, and interleukin-6. CONCLUSIONS: These in vivo and in vitro studies provide novel insights regarding apigenin's mechanism(s) of action in reducing the severity of RAP. Additional preclinical testing of apigenin analogs is warranted to develop a therapeutic agent for patients at risk for CP.

Design, synthesis, and characterization of novel apigenin analogues that suppress pancreatic stellate cell proliferation in vitro and associated pancreatic fibrosis in vivo.

Accumulating evidence suggests that activated pancreatic stellate cells (PSC) play an important role in chronic pancreatitis (CP), and inhibition of the activated PSC is considered as a potential strategy for the treatment and prevention of CP. Herein, we disclose our findings that apigenin and its novel analogues suppress the proliferation and induce apoptosis in PSC, which reduce the PSC-mediated fibrosis in CP. Chemical modifications of apigenin have been directed to build a focused library of O-alkylamino-tethered apigenin derivatives at 4'-O position of the ring C with the attempt to enhance the potency and drug-like properties including aqueous solubility. A number of compounds such as 14, 16, and 24 exhibited potent antiproliferative effects as well as improved aqueous solubility. Intriguingly, apigenin, new analogues 23 and 24 displayed significant efficacy to reduce pancreatic fibrosis even at a low dose of 0.5mg/kg in our proof-of-concept study using a preclinical in vivo mouse model of CP.

Dual inhibition of PI3K and mTOR signaling pathways decreases human pancreatic neuroendocrine tumor metastatic progression.

OBJECTIVES: Patients with advanced pancreatic neuroendocrine tumors have limited therapeutic options. Everolimus (RAD001), an inhibitor of the mammalian target of rapamycin (mTOR) pathway, has been shown to increase progression-free survival, but not overall survival, indicating a need to identify additional therapeutic targets. Inhibition of mTOR complex 1 by RAD001 may induce upstream AKT upregulation. We hypothesized that dual inhibition of AKT along with mTOR will overcome the limited activity of RAD001 alone. METHODS: The BON cell line has been used as a model to study pancreatic neuroendocrine tumor cell biology. Western blots and cell growth assays were performed with mTOR inhibitor RAD001 (50 nM), mitogen-activated protein kinase inhibitor PD0325901 (50 nM), PI3K (phosphatidylinositol 3-kinase) inhibitor LY294002 (25 µM), or vehicle control. Nude mice were treated daily for 6 weeks with RAD001 (oral gavage) and with LY29400 (subcutaneous) 1 week after intrasplenic injection of BON cells. RESULTS: Cellular proliferation was most attenuated with the combination therapy of LY29400 and RAD001. Similarly, the volume of liver metastasis was lowest in the group treated with both LY29400 (100 mg/kg per week, subcutaneous) and RAD001 (2.5 mg/kg per day) compared with that in the vehicle group (P = 0.04). CONCLUSION: The combination therapy of LY29400 and RAD001 decreased the cell growth in vitro and progression of liver metastasis in vivo compared with vehicle or with single-drug therapy.

Exercise training after burn injury: a survey of practice.

Exercise programs capable of contributing positively to the long-term rehabilitation of burn patients should be included in outpatient rehabilitation programs. However, the extent and intensity of the resistance and cardiopulmonary exercise prescribed are unclear. This study was conducted to investigate the existence, design, content, and prescription of outpatient cardiopulmonary and resistance exercise programs within outpatient burn rehabilitation. A survey was designed to gather information on existing exercise programs for burn survivors and to assess the extent to which these programs are included in overall outpatient rehabilitation programs. Three hundred and twenty-seven surveys were distributed in the licensed physical and occupational therapists part of the American Burn Association Physical Therapy/Occupational Therapy Special Interest Group. One hundred and three surveys were completed. Eighty-two percent of respondents indicated that their institutions offered outpatient therapy after discharge. The frequency of therapists' contact with patients during this period varied greatly. Interestingly, 81% of therapists stated that no hospital-based cardiopulmonary endurance exercise programs were available. Patients' physical function was infrequently determined through the use of cardiopulmonary parameters (oxygen consumption and heart rate) or muscle strength. Instead, more subjective parameters such as range of motion (75%), manual muscle testing (61%), and quality of life (61%) were used. Prescription and follow-up assessment of cardiopulmonary endurance training are inconsistent among institutions, underscoring the need for greater awareness of the importance of exercise in any burn rehabilitation program. Identification of cardiopulmonary and progressive resistance parameters for establishing and tracking exercise training is also needed to maximize exercise-induced benefits.

Effects of propranolol and exercise training in children with severe burns.

OBJECTIVES: To investigate whether propranolol administration blocks the benefits induced by exercise training in severely burned children. STUDY DESIGN: Children aged 7-18 years (n = 58) with burns covering ≥30% of the total body surface area were enrolled in this randomized trial during their acute hospital admission. Twenty-seven patients were randomized to receive propranolol, whereas 31 served as untreated controls. Both groups participated in 12 weeks of in-hospital resistance and aerobic exercise training. Muscle strength, lean body mass, and peak oxygen consumption (VO2 peak) were measured before and after exercise training. Paired and unpaired Student t tests were used for within and between group comparisons, and χ(2) tests for nominal data. RESULTS: Age, length of hospitalization, and total body surface area burned were similar between groups. In both groups, muscle strength, lean body mass, and VO2 peak were significantly greater after exercise training than at baseline. The percent change in VO2 peak was significantly greater in the propranolol group than in the control group (P < .05). CONCLUSIONS: Exercise-induced enhancements in muscle mass, strength, and VO2 peak are not impaired by propranolol. Moreover, propranolol improves the aerobic response to exercise in massively burned children.

Five-year outcomes after oxandrolone administration in severely burned children: a randomized clinical trial of safety and efficacy.

BACKGROUND: Oxandrolone, an anabolic agent, has been administered for 1 year post burn with beneficial effects in pediatric patients. However, the long-lasting effects of this treatment have not been studied. This single-center prospective trial determined the long-term effects of 1 year of oxandrolone administration in severely burned children; assessments were continued for up to 4 years post therapy. STUDY DESIGN: Patients 0 to 18 years old with burns covering >30% of the total body surface area were randomized to receive placebo (n = 152) or oxandrolone, 0.1 mg/kg twice daily for 12 months (n = 70). At hospital discharge, patients were randomized to a 12-week exercise program or to standard of care. Resting energy expenditure, standing height, weight, lean body mass, muscle strength, bone mineral content (BMC), cardiac work, rate pressure product, sexual maturation, and concentrations of serum inflammatory cytokines, hormones, and liver enzymes were monitored. RESULTS: Oxandrolone substantially decreased resting energy expenditure and rate pressure product, increased insulin-like growth factor-1 secretion during the first year after burn injury, and, in combination with exercise, increased lean body mass and muscle strength considerably. Oxandrolone-treated children exhibited improved height percentile and BMC content compared with controls. The maximal effect of oxandrolone was found in children aged 7 to 18 years. No deleterious side effects were attributed to long-term administration. CONCLUSIONS: Administration of oxandrolone improves long-term recovery of severely burned children in height, BMC, cardiac work, and muscle strength; the increase in BMC is likely to occur by means of insulin-like growth factor-1. These benefits persist for up to 5 years post burn.