Toxic effects of adriamycin on the central nervous system. Ultrastructural changes in some circumventricular organs of the mouse after intravenous administration of the drug

The safety of current pharmacotherapeutic strategies for osteosarcoma

Introduction: Peri-operative chemotherapy is the backbone of treatment for patients with osteosarcoma. Methotrexate, cisplatinum, doxorubicin and ifosfamide are the main drugs used in chemotherapy regimens used for osteosarcoma.Areas covered: We have reviewed here the relevant literature related to the incidence and management of acute and late toxicities of systemic treatment used for the management of patients with osteosarcoma.Expert opinion: Early diagnosis and appropriate management of acute and late toxicities of chemotherapy is crucial for an efficient care of osteosarcoma patients. Although the incidence and management of chemotherapy-related acute toxicities are well known by most oncologists, the use of high doses of methotrexate have the potential to cause fatal toxicities and, therefore, needs careful monitoring. Moreover, the diagnosis of late toxicities is more challenging and requires long-term follow-up for an appropriate management.

Neurotoxicity of antineoplastic drugs: Mechanisms, susceptibility, and neuroprotective strategies

This review summarizes the adverse effects on the central and/or peripheral nervous systems that may occur in response to antineoplastic drugs. In particular, we describe the neurotoxic side effects of the most commonly used drugs, such as platinum compounds, doxorubicin, ifosfamide, 5-fluorouracil, vinca alkaloids, taxanes, methotrexate, bortezomib and thalidomide. Neurotoxicity may result from direct action of compounds on the nervous system or from metabolic alterations produced indirectly by these drugs, and either the central nervous system or the peripheral nervous system, or both, may be affected. The incidence and severity of neurotoxicity are principally related to the dose, to the duration of treatment, and to the dose intensity, though other factors, such as age, concurrent pathologies, and genetic predisposition may enhance the occurrence of side effects. To avoid or reduce the onset and severity of these neurotoxic effects, the use of neuroprotective compounds and/or strategies may be helpful, thereby enhancing the therapeutic effectiveness of antineoplastic drug.

The predominant protective effect of tianeptine over other antidepressants in models of neuronal apoptosis: the effect blocked by inhibitors of MAPK/ERK1/2 and PI3-K/Akt pathways

Tianeptine (Tian) possesses neuroprotective potential, however, little is known about the effect of this drug in models of neuronal apoptosis. In the present study, we aimed (1) to compare the neuroprotective capacities of some antidepressants (ADs) in the models of staurosporine (St)- and doxorubicin (Dox)-evoked cell death, activating the intracellular and the extracellular apoptotic pathway, respectively; (2) to identify the Tian-modulated steps underlying its neuroprotective action; (3) to test the effect of various ADs against Dox-evoked cell damage in glia cells. Primary neuronal and glia cell cultures and retinoic acid-differentiated human neuroblastoma SH-SY5Y (RA-SH-SY5Y) cells were co-treated with imipramine, fluoxetine, citalopram, reboxetine, mirtazapine or Tian and St or Dox. The data showed the predominant neuroprotective effect of Tian over other tested ADs against St- and Dox-induced cell damage in primary neurons and in RA-SH-SY5Y cells. This effect was shown to be caspase-3-independent but connected with attenuation of DNA fragmentation. Moreover, neuroprotection elicited by Tian was blocked by pharmacological inhibitors of MAPK/ERK1/2 and PI3-K/Akt signaling pathways as well by inhibitor of necroptosis, necrostatin-1. Interestingly, the protective effects of all tested ADs were demonstrated in primary glia cells against the Dox-evoked cell damage. The obtained data suggests the glial cells as a common target for protective action of various ADs whereas in relation to neuronal cells only Tian possesses such properties, at least against St- and Dox-induced cell damage. Moreover, this neuroprotective effect of Tian is caspase-3-independent and engages the regulation of survival pathways (MAPK/ERK1/2 and PI3-K/Akt).

The distributional nexus of choroid plexus to cerebrospinal fluid, ependyma and brain: toxicologic/pathologic phenomena, periventricular destabilization, and lesion spread

Bordering the ventricular cerebrospinal fluid (CSF) are epithelial cells of choroid plexus (CP), ependyma and circumventricular organs (CVOs) that contain homeostatic transporters for mediating secretion/reabsorption. The distributional pathway ("nexus") of CP-CSF-ependyma-brain furnishes peptides, hormones, and micronutrients to periventricular regions. In disease/toxicity, this nexus becomes a conduit for infectious and xenobiotic agents. The sleeping sickness trypanosome (a protozoan) disrupts CP and downstream CSF-brain. Piperamide is anti-trypanosomic but distorts CP epithelial ultrastructure by engendering hydropic vacuoles; this reflects phospholipidosis and altered lysosomal metabolism. CP swelling by vacuolation may occlude CSF flow. Toxic drug tools delineate injuries to choroidal compartments: cyclophosphamide (vasculature), methylcellulose (interstitium), and piperazine (epithelium). Structurally perturbed CP allows solutes to penetrate the ventricles. There, CSF-borne pathogens and xenobiotics may permeate the ependyma to harm neurogenic stem cell niches. Amoscanate, an anti-helmintic, potently injures rodent ependyma. Ependymal/brain regions near CP are vulnerable to CSF-borne toxicants; this proximity factor links regional barrier breakdown to nearby periventricular pathology. Diverse diseases (e.g., African sleeping sickness, multiple sclerosis) take early root in choroidal, circumventricular, or perivascular loci. Toxicokinetics informs on pathogen, anti-parasitic agent, and auto-antibody distribution along the CSF nexus. CVOs are susceptible to plasma-borne toxicants/pathogens. Countering the physico-chemical and pathogenic insults to the homeostasis-mediating ventricle-bordering cells sustains brain health and fluid balance.

An investigation of the cytotoxicity of the morpholino anthracycline MX2 against glioma cells in vitro

MX2 is a novel morpholino anthracycline reported to have lower systemic toxicity than other anthracyclines. It has similar antitumour activity to adriamycin and is cytotoxic towards multi-drug resistant cells and anthracycline sensitive sublines of human and murine tumour cells. In this study MX2 showed a marked cytocidal effect compared to M2, the most cytotoxically active metabolite, and the nitrosourea, BCNU, when 30 ng/ml of each drug was added to separate flasks of C6 glioma cells grown in monolayer. The colony formation of C6 glioma cells was markedly inhibited by MX2 in a dose dependent manner. The LD50 values for MX2, M2 and BCNU were 10.5 ng/ml, 15.8 ng/ml and 465 ng/ml respectively. MX2 is likely to be bound to the main plasma protein, albumin, and can also interact with the plasma lipoproteins, particularly high density lipoprotein. The results in this study strongly support the further investigation of MX2 as a potential chemotherapeutic agent against brain tumours.

Neurotoxicity of adriamycin passed through the transiently disrupted blood-brain barrier by mannitol in the rat brain

Neurotoxicity of adriamycin (ADM) was investigated following the transient disruption of the blood-brain barrier (BBB) in rats. The BBB disruption by the hyperosmotic agent (1.4 M mannitol) was confirmed by the leakage of ADM and Evans blue administered intravenously. Neuropathological changes due to the toxicity of ADM were found as early as day 4. The neurons in the cerebral cortex and nucleus caudatus-putamen showed focal clearing of the nuclear chromatin, increased dense bodies in the cytoplasm and dilatation of the cisternae of the rough endoplasmic reticulum (r-ER) and Golgi apparatus. By day 7, nucleolar segregation and irregular membranous structures appeared in the nuclei with the progression of cytoplasmic changes. By day 10, the cytoplasm of many neurons was vacuolated. Electron-microscopically, the cisternae of the r-ER and Golgi apparatus were prominently dilated in these neurons. Neuronal microtubules were increased in number, in particular in the perinuclear region. Numerous whorl-like membranous structures and separation of nuclear membrane were also observed. Some astrocytic processes surrounding the blood vessels revealed loss of organelles and a few pericytes showed an increased number of lysosomes on days 7 and 10. This experiment clearly demonstrates that ADM has strong neurotoxic effects in the central nervous system when the BBB is disrupted, and provides the warning for the possibilities of neurotoxic side effects when ADM is administered, in combination with a hyperosmotic agent, for the treatment of human malignant tumors, including brain tumors.

Neurotoxicity in primary sensory neurons of adriamycin administered through retrograde axoplasmic transport in rats

Neurotoxic effects of adriamycin (ADM) were examined in rats. The drug was administered through retrograde axoplasmic transport from the transected sciatic nerve in very small amounts (0.05 mg of adriamycin). Using the autofluorescence specific to adriamycin as a histological tracer, alterations in primary sensory neurons in dorsal root ganglia (DRG) and in motor neurons in the spinal cord were observed chronologically by light and electron microscopy. In the DRG at the fifth and sixth lumbar levels, small neurons initially showed alterations in mitochondria, wavy nuclear membranes and enlarged cisternae of rough endoplasmic reticulum, and disappeared early in the experiments. Large neurons, which showed accumulation of neurofilaments, dense bodies and vacuoles in the perikarya in addition to nucleolar and nuclear chromatin alterations, degenerated slowly. In contrast, motor neurons in the anterior horn at the sixth lumbar level survived throughout the administration of adriamycin despite the presence of transient weak adriamycin autofluorescence and vacuoles in the cytoplasm. Thus, the susceptibility and vulnerability of motor neurons in spinal cord to adriamycin differed from that of primary sensory neurons; small neurons in the DRG were more susceptible than large sensory neurons. Administration through retrograde axoplasmic transport proved to be a useful technique for the evaluation of the neurotoxicity of adriamycin without the complications of systemic effects.

Impairment of motor coordination induced by doxorubicin in mice

The neurotoxic effects of a single intraperitoneal or intravenous injection of doxorubicin were evaluated in CD1 mice by means of the rotarod test. The test was performed daily for nine weeks after treatment. For both routes of administration, animals were treated with various doxorubicin dosages ranging from 18 to 5.9 mg/kg. The three higher i.v. doses (18, 14.4 and 12.5 mg/kg) of doxorubicin induced a severe motor coordination impairment. The histopathological analysis of these animals showed severe damage of sensory nerves. On the contrary, all the i.p. treated animals did not show any sign of motor impairment and of appreciable neurohistological lesion.