Hypericum perforatum (HP) belongs to the Hypericaceae family and is one of the oldest used and most extensively investigated medicinal herbs. The medicinal form comprises the leaves and flowering tops of which the primary ingredients of interest are naphthodianthrones, xanthones, flavonoids, phloroglucinols (e.g. hyperforin), and hypericin. Although several constituents elicit pharmacological effects that are consistent with HP's antidepressant activity, no single mechanism of action underlying these effects has thus far been found. Various clinical trials have shown that HP has a comparable antidepressant efficacy as some currently used antidepressant drugs in the treatment of mild/moderate depression. Interestingly, low-hyperforin-content preparations are effective in the treatment of depression. Moreover, HP is also used to treat certain forms of anxiety. However, HP can induce various cytochrome P450s isozymes and/or P-glycoprotein, of which many drugs are substrates and which are the main origin of HP-drug interactions. Here, we analyse the existing evidence describing the clinical consequence of HP-drug interactions. Although some of the reported interactions are based on findings from in vitro studies, the clinical importance of which remain to be demonstrated, others are based on case reports where causality can, in some cases, be determined to reveal clinically significant interactions that suggest caution, consideration, and disclosure of potential interactions prior to informed use of HP.

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SUMMARYPurpose: Depression is most commonly associated with epilepsy. Recent reports have suggested a putative relationship between seizure development and onset of depressive behavior, whereas others proposed that two clinical entities might represent different neuropathologic aspects of the same neurologic disorder. The WAG/Rij rat absence epilepsy model has also been proposed as a suitable model to test antidepressant drugs. We previously reported on a long-term study of two antiepileptic drugs (AEDs) to assess their protective role in absence epileptogenesis. Here, we examined the effects of long-term treatment with several AEDs on absence seizure development and onset of depressive-like behavior in WAG/Rij rats at different ages, using a forced swimming test (FST). Methods: Animals were divided into one untreated control group and four test groups, given ethosuximide, levetiracetam, zonisamide, or carbamazepine. Electroencephalography (EEG) readings were recorded at 6.5 months of age.Key Findings: Ethosuximide-treated animals showed significant reductions in recorded spike-wave discharges (SWDs), and FST immobility time (IT) compared with untreated same age controls. However, zonisamide-and carbamazepine-treated animals had IT values similar to those of controls, but only zonisamide significantly decreased absence seizure development. Carbamazepine increased SWD incidence. Levetiracetam also protected against seizure development, while augmenting IT, suggesting a prodepressive effect. Significance: Although treatment with ethosuximide, levetiracetam, or zonisamide reduced appearance of SWDs in WAG/Rij rats, this was not generally linked to a reduced onset of depressive characteristics, as assessed by FST. Therefore, expression of depressive-like behavior seems unrelated to seizure control in this model. Some possible alternative explanations for the observed data are discussed.

SUMMARYPurpose: Epilepsy is a heterogeneous syndrome characterized by recurrent, spontaneous seizures; continuous medication is, therefore, necessary, even after the seizures have long been suppressed with antiepileptic drug (AED) treatments. The most disturbing issue is the inability of AEDs to provide a persistent cure, because these compounds generally suppress the occurrence of epileptic seizures without necessarily having antiepileptogenic properties. The aim of our experiments was to determine, in the WAG/Rij model of absence epilepsy, if early long-term treatment with some established antiabsence drugs might prevent the development of seizures, and whether such an effect could be sustained.Methods: WAG/Rij rats were treated for 3.5 months (starting at 1.5 months of age, before seizure onset) with either ethosuximide (ETH; drug of choice for absence epilepsy) or levetiracetam (LEV; a broad-spectrum AED with antiabsence and antiepileptogenic properties). Results: We have demonstrated that both drugs are able to reduce the development of absence seizures, exhibiting antiepileptogenic effects in this specific animal model. Discussion: These findings suggest that absence epilepsy in this strain of rats very likely follows an epileptogenic process during life and that early therapeutic intervention is possible, thereby opening a new area of research for absence epilepsy and AED treatment strategies.

Corticosteroids have been used since the 50s as anti-inflammatory and immunosuppressive drugs for the treatment of several pathologies such as asthma, allergy, rheumatoid arthritis, and dermatological disorders. Corticosteroids have three principal mechanisms of action: 1) inhibit the synthesis of inflammatory proteins blocking NF-kB, 2) induce the expression of anti-inflammatory proteins by IkB and MAPK phosphatase I, and 3) inhibit 5-lipoxygenase and cyclooxygenase-2. The efficacy of glucocorticoids in alleviating inflammatory disorders results from the pleiotropic effects of the glucocorticoid receptors on multiple signaling pathways. However, they have adverse effects: Growth retardation in children, immunosuppression, hypertension, hyperglycemia, inhibition of wound repair, osteoporosis, metabolic disturbances, glaucoma, and cataracts. Less is known about psychiatric or side effects on central nervous system, as catatonia, decreased concentration, agitation, insomnia, and abnormal behaviors, which are also often underestimated in clinical practice. The aim of this review is to highlight the correlation between the administration of corticosteroids and CNS adverse effects, giving a useful guide for prescribers including a more careful assessment of risk factors and encourage the use of safer doses of this class of drugs.