Effects of the Non-Volatile Residue from the Essential Oil of Citrus bergamia on the Central Nervous System

Psychopharmacological properties of an aqueous extract of Tetracarpidium conophorum Hutch. & Dalziel in mice

The extract of the nut of Tetracarpidium conophorum (TC), commonly known as African walnut, is widely used to relieve pain, increase sperm count, enhance sexual performance in males and as a nerve tonic in ethnomedicine. This study describes the psychopharmacological properties of the aqueous extract of the nut of TC in mice. The spectrum of activities studied were the effects of TC on the duration of immobility in the forced swim test of the behavioural despair model of depression; prolongation of the duration of sleep produced by thiopentone; amphetamine-induced stereotyped behaviour; and on pain episodes produced by acetic acid and by formalin. Orally administered TC (50-200 mg/kg) produced a significant and dose-related decrease in the duration of immobility in the forced swim test in mice. TC also exhibited analgesic property, as shown by its ability to reduce the frequency of abdominal constrictions induced by acetic acid and to inhibit the nociceptive responses produced by formalin. However, at the tested oral doses of 50-200 mg/kg, TC did not prolong the duration of sleep produced by thiopentone nor alter the pattern of the stereotyped behaviour induced by amphetamine. This investigation provides evidence that may support the ethnomedicinal applications of the extract of the nut of TC in the treatment of pain. The study also revealed that TC seems to demonstrate antidepressant-like activity, as evidenced by its ability to shorten the period of immobility in the forced swim test; however, further studies are necessary to clearly define the role of TC in depression.

Aromatherapy in the management of psychiatric disorders: clinical and neuropharmacological perspectives

Aromatherapy is currently used worldwide in the management of chronic pain, depression, anxiety, some cognitive disorders, insomnia and stress-related disorders. Although essential oils have been used, reputedly effectively, for centuries as a traditional medicine, there is very little verified science behind this use. The pharmacology of the essential oils and/or their single chemical constituents, therefore, remains largely undiscovered. However, accumulating evidence that inhaled or dermally applied essential oils enter the blood stream and, in relevant molecular, cellular or animal models, exert measurable psychological effects, indicates that the effects are primarily pharmacological.This review includes evidence from the limited number of clinical trials that have been published of 'psychoaromatherapy' in relation to psychiatric disorders, together with evidence from mechanistic, neuropharmacological studies of the effects of essential oils in relevant in vitro and in vivo models. It is concluded that aromatherapy provides a potentially effective treatment for a range of psychiatric disorders. In addition, taking into account the available information on safety, aromatherapy appears to be without the adverse effects of many conventional psychotropic drugs. Investment in further clinical and scientific research is clearly warranted.

Anticonvulsant properties of gamma-decanolactone in mice

Lactones have been proven to be bioactive. We have shown that compounds present in the essential oil from Aeollanthus suaveolens, used as an anticonvulsant in the Brazilian Amazon, has sedative properties. This paper reports on the evaluation of the systemic administration of gamma-decanolactone, structurally related to lactones present in the essential oil of A. suaveolens, on mice experimental models useful for detecting psychopharmacological activity. The results show that gamma-decanolactone has dose-dependent marked effects on the central nervous system, including hypnotic, anticonvulsant and hypothermic activity. The effects of gamma-decanolactone revealed by this evaluation point to the validity of exploring lactones as sources of new anticonvulsant agents.