Kava pyrones exert effects on neuronal transmission and transmembraneous cation currents similar to established mood stabilizers--a review

Protective effect of kavain in meristematic cells of Allium cepa L

Kavain is one of the main kavalactones of Piper methysticum (Piperaceae) with anxiolytic, analgesic, and antioxidant activities. Therefore, the aim of the study was to evaluate the cytotoxic, mutagenic, and antimutagenic potential of kavain in Allium cepa cells. Roots of A. cepa were transferred to the negative (2% acetone) and positive (10 µg/mL of Methylmethanesulfonate, MMS) controls and to the concentrations of kavain (32, 64 and 128 µg/mL) for 48 h. A total of 5,000 meristematic cells were analyzed under an optical microscope to determine the mitotic index, mean number of chromosomal alterations and percentage of damage reduction. Data were analyzed by Kruskal-Wallis test (p <0.05). All concentrations of kavain were not cytotoxic and did not show significant chromosomal changes when compared to 2% acetone. Kavain showed a cytoprotective effect in the pre (128 μg/mL) and in the post-treatment (32 and 64 μg/mL) and reduced damage against the mutagenic action of MMS in all concentrations of the pre and simultaneous and at the highest of post (128 μg/mL). Kavain promoted a significant reduction in micronuclei, nuclear buds and chromosomal losses in relation to MMS. The observed data indicate the importance of kavain for the inhibition of damage and chemoprevention.

Modulating effect of DL-kavain on the mutagenicity and carcinogenicity induced by doxorubicin in Drosophila melanogaster

Kavain, kavalactone, present in Piper methysticum exhibits anticonvulsive, analgesic, anxiolytic, antiepileptic, antithrombotic, anti-inflammatory and antioxidant properties. Given its importance, the aim of the present study was to assess (1) the mutagenic and carcinogenicity of kavain administered alone and (2) the antimutagenic and anticarcinogenic potential when administered simultaneously with the chemotherapeutic drug doxorubicin (DXR) using the Somatic Mutation and Recombination Test (SMART) and Epithelial Tumor Test (ETT) using Drosophila melanogaster as a model system. Third-stage larvae from a standard (ST) and high metabolic bioactivation (HB) crosses were treated with different kavain concentrations (32, 64 or 128 μg/ml), alone or in conjunction with DXR (0.125 mg/ml). In ST descendants, kavain produced no significant mutagenic or recombinogenic effects. In the HB cross, mutagenic activity was observed at kavain concentrations of 64 and 128 μg/ml. In the DXR and kavain co-treatment, a modulating effect of the DXR-mediated mutagenic response dependent upon the concentration was detected in both crosses. In ETT, no marked carcinogenic or anticarcinogenic activity was noted for kavain. However, when kavain was combined with DXR synergistic induction of tumors by the chemotherapeutic drug occurred indicating that kavain enhanced the carcinogenic action of DXR.

The Therapeutic Prospects of Naturally Occurring and Synthetic Indole Alkaloids for Depression and Anxiety Disorders

Depression and anxiety are the most common disorders among all age groups. Several antidepressant drugs including benzodiazepine, antidepressant tricyclics, azapirone, noradrenaline reuptake inhibitors, serotonin selective reuptake inhibitors, serotonin, noradrenaline reuptake inhibitors, and monoamine oxidase inhibitors have been used to treat these psychiatric disorders. However, these antidepressants are generally synthetic agents and can cause a wide range of side effects. The potential efficacy of plant-derived alkaloids has been reviewed against various neurodegenerative diseases including Alzheimer's disease, Huntington disease, Parkinson's disease, schizophrenia, and epilepsy. However, data correlating the indole alkaloids and antidepressant activity are limited. Natural products, especially plants and the marine environment, are rich sources of potential new drugs. Plants possess a variety of indole alkaloids, and compounds that have an indole moiety are related to serotonin, which is a neurotransmitter that regulates brain function and cognition, which in turn alleviates anxiety, and ensures a good mood and happiness. The present review is a summary of the bioactive compounds from plants and marine sources that contain the indole moiety, which can serve as potent antidepressants. The prospects of naturally occurring as well as synthetic indole alkaloids for the amelioration of anxiety and depression-related disorders, structure-activity relationship, and their therapeutic prospects have been discussed.

Indole Alkaloids from Plants as Potential Leads for Antidepressant Drugs: A Mini Review

Depression is the most common illness observed in the elderly, adults, and children. Antidepressants prescribed are usually synthetic drugs and these can sometimes cause a wide range of unpleasant side effects. Current research is focussed on natural products from plants as they are a rich source of potent new drug leads. Besides Hypericum perforatum (St. John’s wort), the plants studied include Passiflora incarnata L. (passion flower), Mitragyna speciosa (kratom), Piper methysticum G. Forst (kava) and Valeriana officinalis L. Harman, harmol, harmine, harmalol and harmaline are indole alkaloids isolated from P. incarnata, while mitragynine is isolated from M. speciosa. The structure of isolated compounds from P. methysticum G. Forst and V. officinalis L. contains an indole moiety. The indole moiety is related to the neurotransmitter serotonin which is widely implicated for brain function and cognition as the endogenous receptor agonist. An imbalance in serotonin levels may influence mood in a way that leads to depression. The moiety is present in a number of antidepressants already on the market. Hence, the objective of this review is to discuss bioactive compounds containing the indole moiety from plants that can serve as potent antidepressants.

Safety and Efficacy of Herbal Sedatives in Cancer Care

Insomnia and other sleep disturbances are common in cancer patients. Insomnia is a multifactorial health concern that currently affects at least 1 in 3 cancer patients, and yet most insomnia sufferers do not consult their physician regarding pharmaceutical options for relief. Use of hypnotic drugs (primarily benzodiazepines) is associated with increasing tolerance, dependence, and adverse effects on the central nervous system. While hypnotic drug use declined substantially in the past decade, the use of herbal sedatives appeared to increase. Mostly self-prescribed by lay people, herbal sedatives hold widespread appeal, presumably because of their lower cost and higher margin of safety when compared to pharmaceuticals. Studies of better-known herbal sedatives, notably valerian and kava, showed moderate evidence for both safety and efficacy for valerian while revealing disturbing toxicity concerns for kava. Milder sedatives or anxiolytics in need of clinical study include German chamomile, lavender, hops, lemon balm, and passionflower; St. John’s wort may have anxiolytic effects with relevance to sleep. Herb-drug interactions are a possibility for some of these species, including St. John’s wort. Although sufficient evidence exists to recommend some of these agents for short-term relief of mild insomnia, long-term trials and observational studies are needed to establish the safety of prolonged use as well as overall efficacy in the context of cancer treatment and management.

Kava in the treatment of generalized anxiety disorder: a double-blind, randomized, placebo-controlled study

Kava (Piper methysticum) is a plant-based medicine, which has been previously shown to reduce anxiety. To date, however, no placebo-controlled trial assessing kava in the treatment of generalized anxiety disorder (GAD) has been completed. A total of 75 participants with GAD and no comorbid mood disorder were enrolled in a 6-week double-blind trial of an aqueous extract of kava (120/240 mg of kavalactones per day depending on response) versus placebo. γ-Aminobutyric acid (GABA) and noradrenaline transporter polymorphisms were also analyzed as potential pharmacogenetic markers of response. Reduction in anxiety was measured using the Hamilton Anxiety Rating Scale (HAMA) as the primary outcome. Intention-to-treat analysis was performed on 58 participants who met inclusion criteria after an initial 1 week placebo run-in phase. Results revealed a significant reduction in anxiety for the kava group compared with the placebo group with a moderate effect size (P = 0.046, Cohen d = 0.62). Among participants with moderate to severe Diagnostic and Statistical Manual of Mental Disorders-diagnosed GAD, this effect was larger (P = 0.02; d = 0.82). At conclusion of the controlled phase, 26% of the kava group were classified as remitted (HAMA ≤ 7) compared with 6% of the placebo group (P = 0.04). Within the kava group, GABA transporter polymorphisms rs2601126 (P = 0.021) and rs2697153 (P = 0.046) were associated with HAMA reduction. Kava was well tolerated, and aside from more headaches reported in the kava group (P = 0.05), no other significant differences between groups occurred for any other adverse effects, nor for liver function tests. Standardized kava may be a moderately effective short-term option for the treatment of GAD. Furthermore, specific GABA transporter polymorphisms appear to potentially modify anxiolytic response to kava.

Herbs in epilepsy: evidence for efficacy, toxicity, and interactions

Herbs and dietary supplements enjoy widespread use in the treatment of epilepsy although supportive data yielding efficacy and safety are lacking. Ten specific products, American hellebore, betony, blue cohosh, kava, mistletoe, mugwort, pipsissiwa, skullcap, valerian, and melatonin, have either multiple-cited recommendations for use in epilepsy or a rationale for antiepileptic action and are discussed in detail. These items paradoxically often have a proconvulsant effect in addition to potentially serious adverse effects. Herb-drug interactions also occur at the level of the P450 hepatic enzyme system of drug catabolism and the P-glycoprotein transport system regulating the entry of exogenous compounds into the vasculature or blood-brain barrier. Thus, significant pharmacokinetic interactions may occur, in addition to pharmacodynamic interactions and proconvulsant effects of alternative medications themselves. Patients should be inquired as to the nature of any alternative medicine products they are using, with the view that these products may be reasonable if traditional antiepileptic drug therapy is continued, potential adverse effects of the alternative agents are monitored, and the alternative and traditional agents do not conflict.

Hallucinogenic botanicals of America: A growing need for focused drug education and research

Botanical sources for medicines in America have been known since long before the arrival of Columbus. Nevertheless, both scientists and the general public are often unaware that some of these botanical drugs are also potent intoxicants. We provide a quick overview of hallucinogenic and dissociative drugs harvested from nature or that are openly and legally cultivated in the United States. Examples of harmful outcomes reported in the media are contrasted with existing responsible ingestion by others, some of whom have the protected right to do so for traditional or sacramental religious purposes. Despite an ongoing and expensive effort to warn people of the potential harms of recreational drug use, little is known about the extent of use of these psychoactive botanicals, and the recent explosion of information available via the Internet could herald a storm of morbidity to come. Mounting more targeted research and educational efforts today may reduce later use and abuse, inform society about the special circumstances of religious use, and better prepare clinicians and other health care providers about the issues involved when people choose to indigenously source psychoactive drugs for human consumption.

Altered mental status and ataxia secondary to acute Kava ingestion

Kava has traditionally been used for a variety of purposes in the tropical islands of Polynesia but is becoming more frequently available in the United States health supplement market due to its calming effects in patients with anxiety. The side effect profile is poorly known but has recently gained the attention of the Food and Drug Administration (FDA). Although hepatitis and liver failure have been described with chronic ingestion, the effects of acute overdose are poorly described. We present a case of acute Kava overdose resulting in altered mental status and ataxia similar to that seen with ethanol intoxication.

Structural Effects and Neurofunctional Sequelae of Developmental Exposure to Psychotherapeutic Drugs: Experimental and Clinical Aspects

The advent of psychotherapeutic drugs has enabled management of mental illness and other neurological problems such as epilepsy in the general population, without requiring hospitalization. The success of these drugs in controlling symptoms has led to their widespread use in the vulnerable population of pregnant women as well, where the potential embryotoxicity of the drugs has to be weighed against the potential problems of the maternal neurological state. This review focuses on the developmental toxicity and neurotoxicity of five broad categories of widely available psychotherapeutic drugs: the neuroleptics, the antiepileptics, the antidepressants, the anxiolytics and mood stabilizers, and a newly emerging class of nonprescription drugs, the herbal remedies. A brief review of nervous system development during gestation and following parturition in mammals is provided, with a description of the development of neurochemical pathways that may be involved in the action of the psychotherapeutic agents. A thorough discussion of animal research and human clinical studies is used to determine the risk associated with the use of each drug category. The potential risks to the fetus, as demonstrated in well described neurotoxicity studies in animals, are contrasted with the often negative findings in the still limited human studies. The potential risk fo the human fetus in the continued use of these chemicals without more adequate research is also addressed. The direction of future research using psychotherapeutic drugs should more closely parallel the methodology developed in the animal laboratories, especially since these models have already been used extremely successfully in specific instances in the investigation of neurotoxic agents.

Plants and the central nervous system

This review article draws the attention to the many species of plants possessing activity on the central nervous system (CNS). In fact, they cover the whole spectrum of central activity such as psychoanaleptic, psycholeptic and psychodysleptic effects, and several of these plants are currently used in therapeutics to treat human ailments. Among the psychoanaleptic (stimulant) plants, those utilized by human beings to reduce body weight [Ephedra spp. (Ma Huang), Paullinia spp. (guaraná), Catha edulis Forssk. (khat)] and plants used to improve general health conditions (plant adaptogens) were scrutinized. Many species of hallucinogenic (psychodysleptic) plants are used by humans throughout the world to achieve states of mind distortions; among those, a few have been used for therapeutic purposes, such as Cannabis sativa L., Tabernanthe iboga Baill. and the mixture of Psychotria viridis Ruiz and Pav. and Banisteriopsis caapi (Spruce ex Griseb.) C.V. Morton. Plants showing central psycholeptic activities, such as analgesic or anxiolytic actions (Passiflora incarnata L., Valeriana spp. and Piper methysticum G. Forst.), were also analysed.Finally, the use of crude or semipurified extracts of such plants instead of the active substances seemingly responsible for their therapeutic effect is discussed.