Essential oils in medicine: principles of therapy.

Essential oils (EOs) are extremely complex mixtures containing compounds of several different functional-group classes. A specific aromatic profile should be determined by gas-chromatography-mass detection methods, to define standards for their safety and efficacy. The chemical constituents of the essential oils, their flavour and their taste act both alone and in synergy, always determining a global psychosomatic action. The main therapeutic activities of the EOs are reported as spasmolythic, revulsive, anti-inflammatory and decongestant, immunomodulant, antimicrobial, antimycotic, expectorant, mucolythic, antioxidant, psychotrope, analgesic and acaricide. The use, posology, route of administration as well as toxicity and adverse effects are reviewed.

Clinical and mycological evaluation of an herbal antifungal formulation in canine Malassezia dermatitis.

OBJECTIVE: Malassezia pachydermatis is a common cause of more widespread dermatitis in dogs (CMD). Recurrences are common, and this disorder can be very troubling for both dogs and for the pet owner. MATERIAL AND METHODS: The treatment of 20 dogs affected by dermatitis due to M. pachydermatis, with Malacalm(®), a commercially available mixture consisting of essential oils (Citrus aurantium 1%, Lavandula officinalis 1%, Origanum vulgare 0.5%, Origanum majorana 0.5%, Mentha piperita 0.5% and Helichrysum italicum var. italicum 0.5%, in sweet almond oil and coconut oil) is reported. The effectiveness of the whole mixture, of component essential oils and of their more represented compounds against clinical isolates was evaluated by a microdilution test. Twenty animals were topically administered the mixture twice daily for 1 month. Ten animals were treated with a conventional therapy based on ketoconazole 10mg/kg/day and chlorhexidine 2% twice a week for 3 weeks. At the end of both treatments animals significantly improved their clinical status. Adverse effects were never noticed. Follow-up visit performed on day 180th allowed to observe a recurrence of clinical signs in all the subjects treated conventionally, while not significant clinical changes were referred in dogs treated with Malacalm(®). The overall MIC value of Malacalm(®) was 0.3%. O. vulgare showed the lowest minimum inhibitory concentrations (MIC), being active at 0.8%, followed by M. piperita (1%), O. majorana (1.3%), C. aurantium (2%) and L. officinalis (4%) while H. italicum did not yield any antimycotic effect up to 10%. Active major compounds were thymol, carvacrol, p-cymene, 1,8-cineol, limonene and menthol. CONCLUSION: The phytotherapic treatment achieved a good clinical outcome, and no recurrence of skin disorders on day 180th was recorded. This herbal remedium appeared to be a safe tool for limiting recurrences of CMD.

In vitro and in vivo antifungal activity of some essential oils against feline isolates of Microsporum canis.

The treatment of dermatophytoses due to Microsporum canis is cumbersome and relapses can occur. Volatile essential oils (EOs) obtained from plants would seem to represent suitable tools to contrast mycoses both in human and animals. The anti-M. canis activity of some EOs chemically characterized was evaluated both in vitro and in vivo. Eleven feline isolates of M. canis were tested by microdilution against EOs extracted from Thymus serpillum, Origanum vulgare, Rosmarinus officinalis, Illicium verum and Citrus limon. A mixture composed by 5% O. vulgare, 5% R. officinalis and 2% T. serpillum, in sweet almond oil was administered to seven infected, symptomatic cats. T. serpillum and O. vulgare showed the lowest MICs, followed by I. verum, R. officinalis and C. limon. The assay performed on mixture showed that antimycotic activity of each component was enhanced. Four out of seven treated cats recovered both clinically and culturally. T. serpillum and O. vulgare EOs showed a strong antifungal activity. Preliminary data suggest a possible application in managing feline microsporiasis. Considering the potential zoonotic impact of this infection, the use of alternative antimycotic compounds would be of aid to limit the risk of environmental spreading of arthrospores.

Antifungal activity of tea tree oil from Melaleuca alternifolia against Trichophyton equinum: an in vivo assay.

Dermatophytes are a group of keratinophilic and keratinolytic molds, some of which are responsible for ringworm. Among them Trichophyton equinum, which mostly infects equids, can cause extensive outbreaks in stud farms. The conventional treatment of equine trichophytosis is topic, based upon medicated shampoos to reduce the spread of infection among the animals. Nevertheless the popularity of phytotherapy is at an all-time peak, and the interest for natural alternatives or complements to conventional drug therapy is challenging both in human and veterinary field. Among herbal remedia Tea Tree Oil (TTO) shows a wide range of antimicrobial activities. A randomized open clinical trial was carried out on 60 thoroughbred breeding horses affected by equine ringworm. The animals were randomly divided into 2 groups of 30 subjects. Diagnostic criteria were the presence of clinical signs and positive T. equinum culture. Specificity control using TTO mixture in 5 not dermatophyte affected animals was achieved also. The antimycotic activity against T. equinum of a mixture containing 25% TTO in sweet almond oil, was evaluated in vivo treating 30 subjects, the others were administered enilconazole 2% solution. The animals of both groups were topically treated twice a day for 15 days with a 25% mixture of TTO diluted in sweet almond oil and every 3 days, four times with enilconazole rinses, respectively. The clinical and mycological outcome were evaluated at day 30 from the start of the treatments. Data analysis was performed by chi square test. All the treated animals showed complete clinical and aetiological healing. Part of control subjects also, showed an improvement and none of them exacerbate the lesions. This therapeutic protocol appears to be effective and versatile, being applicable immediately after physical examination, prior to have the laboratory response. It could be an alternative for practitioners interested in herbal medicines, contributing to fulfill the gap existing between in vitro and clinical studies.