Supplementation with l-carnitine does not reduce the efficacy of epirubicin treatment in breast cancer cells

Levocarnitine for asparaginase-induced hepatic injury: a multi-institutional case series and review of the literature

Asparaginase, an important treatment component for acute lymphoblastic leukemia (ALL), causes severe hepatotoxicity in some patients. Levocarnitine is a mitochondrial co-factor that can potentially ameliorate the mitochondrial toxicity of asparaginase. In this retrospective case series, we describe the clinical presentation and management of six pediatric and young adult patients (mean age 12.7, range 9-24 years) with ALL who developed Grade 3-4 hyperbilirubinemia following administration of asparaginase as part of induction/re-induction therapy. Five of these patients were treated with levocarnitine with subsequent improvement of hyperbilirubinemia, while one patient was given levocarnitine prophylactically during induction and developed Grade 3 hyperbilirubinemia, but did not require therapy adjustments or delays. Increased awareness in the pediatric oncology community regarding asparaginase-associated hepatic toxicity and the potential role of levocarnitine in management is warranted.

Micronutrients in Oncological Intervention

Nutritional supplements are widely used among patients with cancer who perceive them to be anticancer and antitoxicity agents. Depending on the type of malignancy and the gender 30%-90% of the cancer patients supplement their diets with antioxidant and immuno-stabilizing micronutrients, such as selenium, vitamin C, and vitamin D, often without the knowledge of the treating physician. From the oncological viewpoint, there are justifiable concerns that dietary supplements decrease the effectiveness of chemotherapy and radiotherapy. Recent studies, however, have provided increasing evidence that treatment is tolerated better-with an increase in patient compliance and a lower rate of treatment discontinuations-when micronutrients, such as selenium, are added as appropriate to the patient's medication. Nutritional supplementation tailored to an individual's background diet, genetics, tumor histology, and treatments may yield benefits in subsets of patients. Clinicians should have an open dialogue with patients about nutritional supplements. Supplement advice needs to be individualized and come from a credible source, and it is best communicated by the physician.

Potential nephroprotective effects of l-carnitine against drug-induced nephropathy: a review of literature

INTRODUCTION

Drug-induced nephrotoxicity (DIN) has been reported with a great number of medications and contributes to ∼ 20% of hospital admissions. l-carnitine owing to its antioxidant, anti-inflammatory and antiapoptotic properties has been proposed as a candidate for nephroprotection against DIN. Increasing need to use nephrotoxic therapeutic agents necessitated this review.

AREAS COVERED

The present review covers all published clinical and animal researches on nephroprotective effects of l-carnitine against DIN. l-carnitine significantly ameliorates DIN in animal studies especially against cisplatin-induced renal damage. Inhibition of reactive oxygen species generation, lipid peroxidation, matrix remodeling and apoptosis, anti-inflammatory properties and improvement in carnitine deficiency has been suggested as probable nephroprotective mechanisms of l-carnitine.

EXPERT OPINION

In spite of the evidences that support the nephroprotective effect of l-carnitine, the main problems in this area are inadequacy of reliable studies in humans and difficulty of translating the experimental results into clinical practice. In most of the described studies, l-carnitine treatment is prophylactically given. Use of l-carnitine as a prophylactic agent in clinical situations with an indication for nephrotoxic therapies is rarely possible except for contrast-induced nephrotoxicity. Development of validated early biomarkers to detect DIN may provide the opportunity to use prophylactic nephroprotective agents at golden time.

A review of the logistic role of L-carnitine in the management of radiation toxicity and radiotherapy side effects

Radiation therapy is a key modality in the treatment of different cancer types. Fatigue is the most common side effect of radiotherapy, while others include nausea, hair loss, skin irritation, anemia, infertility, cardiovascular disease, cognitive impairment and even the development of second cancers. Studies in experimental animals have shown protective effects of carnitine against exposure of various organs to ionizing radiation, whereas carnitine deficiency is known to enhance radiation-induced toxicity. This report summarizes the recent literature on the adverse effects of radiotherapy and the impact of radiation on carnitine homeostasis. Although some studies have demonstrated the prophylactic benefits of carnitine against the toxic effects of chemotherapy, the role of carnitine in the prognosis and management of cancer patients receiving radiotherapy is not clear and needs to be explored.

Effect of Supplementation of Tanshinone IIA and Sodium Tanshinone IIA Sulfonate on the Anticancer Effect of Epirubicin: An In Vitro Study

Tanshinone IIA (Tan IIA) and sodium tanshinone IIA sulfonate (STS) were found to have protective effects on cardiomyocyte against adriamycin-induced damage and may be used clinically. It is unclear whether the supplementation of STS or Tan IIA would affect the anticancer activity of anthracycline. To evaluate the effect of Tan IIA or STS on the anticancer of epirubicin, the cell viability, apoptosis, Akt expression, and uptake of epirubicin after supplementation of Tan IIA or STS in the epirubicin-treated BT-20 cells were measured and compared. Tan IIA inhibited BT-20 cell growth and induced apoptosis in a time- and dose-dependent manner. When Tan IIA was used with epirubicin, an increase of BT-20 cells apoptosis was accompanied by the decreasing phosphorylation of Akt. STS had no effect on the cell viability of BT-20 cells. However, when used with epirubicin, STS decreased the epirubicin-induced cytotoxicity and apoptosis in BT-20 cells. The antagonistic effect of STS on epirubicin-induced cytotoxicity in BT-20 cells occurred concomitantly with the reduced epirubicin uptake and the increased phosphorylation of Akt. STS decreased the uptake of epirubicin in BT-20 cells and blocked epirubicin-induced apoptosis through activation of Akt.

Serum carnitine levels in childhood leukemia

In patients with malignancies, the system of carnitine seems abnormally expressed. The serum total, free, and acyl carnitine levels in 40 children and adolescents with acute leukemia were determined using electrospray tandem mass spectrometry in 4 different phases of the disease: at the diagnosis, 1 year after the initiation of chemotherapy, at the end of treatment, and 2.4+/-1.668 years after the completion of chemotherapy. The age, sex, hemoglobin values, serum biochemistry, somatometric features of the patients, and the risk group of the disease were examined. Although the carnitine levels were found higher in patients compared with the control group from diagnosis to treatment completion, statistically significant decrease in carnitine levels was observed in patients within different phases of the disease especially during induction and consolidation treatment (phase A to B) for both free and total (P=0.023) carnitine. In addition, a statistically significant recovery in carnitine levels was observed between phase B (end of intensive chemotherapy) and D (some years after the completion of treatment) for free and total carnitine (P=0.054 and 0.035, respectively). No statistical correlation was documented between the carnitine levels and somatometric parameters or other variables studied. In conclusion, a significant transient decrease in the levels of carnitine during the treatment was observed in children with acute leukemia. Further studies are required to clarify the role of carnitine status in patients with malignancies and possibly the necessity of carnitine supplementation during chemotherapy administration.

Drugs and pharmaceuticals: management of intoxication and antidotes

The treatment of patients poisoned with drugs and pharmaceuticals can be quite challenging. Diverse exposure circumstances, varied clinical presentations, unique patient-specific factors, and inconsistent diagnostic and therapeutic infrastructure support, coupled with relatively few definitive antidotes, may complicate evaluation and management. The historical approach to poisoned patients (patient arousal, toxin elimination, and toxin identification) has given way to rigorous attention to the fundamental aspects of basic life support--airway management, oxygenation and ventilation, circulatory competence, thermoregulation, and substrate availability. Selected patients may benefit from methods to alter toxin pharmacokinetics to minimize systemic, target organ, or tissue compartment exposure (either by decreasing absorption or increasing elimination). These may include syrup of ipecac, orogastric lavage, activated single- or multi-dose charcoal, whole bowel irrigation, endoscopy and surgery, urinary alkalinization, saline diuresis, or extracorporeal methods (hemodialysis, charcoal hemoperfusion, continuous venovenous hemofiltration, and exchange transfusion). Pharmaceutical adjuncts and antidotes may be useful in toxicant-induced hyperthermias. In the context of analgesic, anti-inflammatory, anticholinergic, anticonvulsant, antihyperglycemic, antimicrobial, antineoplastic, cardiovascular, opioid, or sedative-hypnotic agents overdose, N-acetylcysteine, physostigmine, L-carnitine, dextrose, octreotide, pyridoxine, dexrazoxane, leucovorin, glucarpidase, atropine, calcium, digoxin-specific antibody fragments, glucagon, high-dose insulin euglycemia therapy, lipid emulsion, magnesium, sodium bicarbonate, naloxone, and flumazenil are specifically reviewed. In summary, patients generally benefit from aggressive support of vital functions, careful history and physical examination, specific laboratory analyses, a thoughtful consideration of the risks and benefits of decontamination and enhanced elimination, and the use of specific antidotes where warranted. Data supporting antidotes effectiveness vary considerably. Clinicians are encouraged to utilize consultation with regional poison centers or those with toxicology training to assist with diagnosis, management, and administration of antidotes, particularly in unfamiliar cases.

Chiral toxicology: it's the same thing...only different

Chiral substances possess a unique architecture such that, despite sharing identical molecular formulas, atom-to-atom linkages, and bonding distances, they cannot be superimposed. Thus, in the environment of living systems, where specific structure-activity relationships may be required for effect (e.g., enzymes, receptors, transporters, and DNA), the physiochemical and biochemical properties of racemic mixtures and individual stereoisomers can differ significantly. In drug development, enantiomeric selection to maximize clinical effects or mitigate drug toxicity has yielded both success and failure. Further complicating genetic polymorphisms in drug disposition, stereoselective metabolism of chiral compounds can additionally influence pharmacokinetics, pharmacodynamics, and toxicity. Optically pure pharmaceuticals may undergo racemization in vivo, negating single enantiomer benefits or inducing unexpected effects. Appropriate chiral antidotes must be selected for therapeutic benefit and to minimize adverse events. Enantiomers may possess different carcinogenicity and teratogenicity. Environmental toxicology provides several examples in which compound bioaccumulation, persistence, and toxicity show chiral dependence. In forensic toxicology, chiral analysis has been applied to illicit drug preparations and biological specimens, with the potential to assist in determination of cause of death and aid in the correct interpretation of substance abuse and "doping" screens. Adrenergic agonists and antagonist, nonsteroidal anti-inflammatory agents, SSRIs, opioids, warfarin, valproate, thalidomide, retinoic acid, N-acetylcysteine, carnitine, penicillamine, leucovorin, glucarpidase, pesticides, polychlorinated biphenyls, phenylethylamines, and additional compounds will be discussed to illustrate important concepts in "chiral toxicology."

HL-37, a novel anthracene derivative, induces Ca(2+)-mediated apoptosis in human breast cancer cells

HL-37, a novel anthracene derivative, exhibited potent anticancer activity in many kinds of cancer cells. However, the exact mechanism and signaling pathway involved in HL-37-induced apoptosis have not been fully elucidated. Therefore, we explored the mechanisms of HL-37-mediated apoptosis in MCF-7 and MDA-MB-435 human breast cancer cells. When MCF-7 cells or MDA-MB-435 cells were co-incubated with HL-37, the percentage of apoptotic cell and S phase of cell cycle was markedly increased. In addition, a rise in intracellular calcium levels, ROS production, phosphorylation of JNK and activation of calpain were found in both MCF-7 cells and MDA-MB-435 cells after exposure to HL-37. With the HL-37-mediated reduction of mitochondrial membrane potential, cytochrome c was released from mitochondria to cytosol. Moreover, HL-37 strongly induced cleavage of caspase-4, caspase-9, as well as caspase-3 in MDA-MB-435 cells, whereas, activation of caspase-4, caspase-9 and caspase-7 but not caspase-3 was detected in MCF-7 cells. These results suggested that HL-37 induced MDA-MB-435 and MCF-7 cells apoptosis via oxidative stress and Ca(2+)/calpain/caspase-4 pathway.

The need for a multi-level biochemical approach to defeat cancer that will also support the host

Cited research papers support the main hypothesis that selected publications supply sufficient information for a combined multi-level treatment strategy against cancer that will also strengthen the host. The three major elements of the proposal are: (A) metastasis being separate from tumor growth requires specific antimetastatic treatments. For this, manipulation of the composition of phospholipids will alter cellular charge characteristics which are instrumental in adhesion. (B) Formate metabolism is at the center of many activities that are controlling tumor growth. The rational and consequences of this are as follows. Supply of formate depends mainly on serine, and consumption on conversion to CO2 yielding needed NADPH. The remainder is used to complete IMP configuration with 5-aminoimidazole-4-carboxamide ribonucleotide (ZMP). At homeostasis residual ZMP activates AMP-activated protein kinase (AMPK) to curb growth promoting phosphatidylinositol-3-kinase (PI3PK). Residual ZMP also activates the oxidation of choline to betaine supplying methyl groups needed for global methylation of DNA while increased oxidation of choline also alters cellular phospholipid composition (refer to metastasis). At low formate level, increased accumulated ZMP becomes pyrophosporylated to ZTP. AMPK activation shifts to PI3PK activity for insulin action restoring formate supplied by serine derived from glycolysis. Increased NADPH-generating glucose-6-phosphate dehydrogenase is diminishing NADP+ required for dehydrogenation of formate. This is restoring the formate balance while lowering ZMP levels to that of homeostasis. Evidence suggests that transformed cells exceed up-regulation of formate thus suppressing all ZMP accumulations resulting in limited AMPK activation, cessation of choline oxidation to betaine and loss of global methylation of DNA. This scenario appears to be tied to tumor survival, a state that could be altered by metabolic interventions using mild agents as described in the research reports cited. (C) Because of a preponderance of pyrimidines in cancer supporting UTP requiring immune evasion, exogenous IMP may offset this imbalance and thus hinder tumor anti-immune activities while strengthen host immune functions. For studies to confirm the proposal, the overall expected result is that a combined administration of all these agents cited here will outperform any single agent considered so far for anticancer treatment.