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Essential oils and their corresponding hydrosols, obtained after distillation of various scented Pelargonium (Geraniaceae) leaves were assessed for their antimicrobial activity in a model food system. Both the essential oils and hydrosols were used at 1000 ppm in broccoli soup, previously inoculated with Enterobacter aerogenes (at 10(5) cfu g(-1)) and Staphylococcus aureus (at 10(4) cfu g(-1)). The results showed a complete inhibition of S. aureus in the broccoli soup by the essential oils of 'Sweet Mimosa', 'Mabel Grey', P. graveolens, 'Atomic Snowflake', 'Royal Oak', 'Attar of Roses' and a lesser effect by 'Chocolate Peppermint' and 'Clorinda'; the hydrosols, however, had a potentiating effect on the bacterial population in the food. Both extracts showed a complete inhibition of S. aureus in the Maximum Recovery Diluent (MRD). Antibacterial activity against E. aerogenes in the broccoli soup was generally very much reduced: only the essential oil of 'Mabel Grey' showed complete inhibition and virtually no reductions in colonies were seen with the other essential oils; the hydrosols again caused an increase in bacterial colonies. All the essential oils, bar Chocolate Peppermint showed complete inhibition of E. aerogenes in MRD, but the hydrosols showed no effect. The results strongly suggest that the residual hydrosols from distillation of these plant essential oils have no potential as antibacterial agents in foods, in contrast to most of the essential oils, which show potential against some micro-organisms, but only in some food systems. The problem of food component interference and its possible management is discussed.

Three different species of Myrtaceae growing in Australia and New Zealand are known as 'Tea-tree': the Australian Tea tree (Melaleuca alternifolia), the New Zealand Manuka (Leptospermum scoparium) and Kanuka (Kunzea ericoides). All three essential oils are used by aromatherapists, although only Melaleuca has been tested for toxicity, and its antimicrobial effects studied. The pharmacology and antimicrobial activity of the three 'tea-tree' oils was determined using guinea-pig ileum, skeletal muscle (chick biventer muscle and the rat phrenic nerve diaphragm) and also rat uterus in vitro. Differences were shown between the three essential oils in their action on smooth muscle: Manuka had a spasmolytic action, while Kanuka and Melaleuca had an initial spasmogenic action. Using the diaphragm, Manuka and Melaleuca decreased the tension and caused a delayed contracture; Kanuka had no activity at the same concentration. The action on chick biventer muscle was, however, similar for all three oils, as was the action on the uterus, where they caused a decrease in the force of the spontaneous contractions. The latter action suggests caution in the use of these essential oils during childbirth, as cessation of contractions could put the baby, and mother, at risk. The comparative antimicrobial activity showed greater differences between different samples of Manuka and Kanuka than Melaleuca samples. The antifungal activity of Kanuka was inversely proportional to its strong antibacterial activity, whilst Manuka displayed a stronger antifungal effect, though not as potent as Melaleuca. The antioxidant activity of Manuka samples was more consistent than that of Kanuka, while Melaleuca showed no activity. The variability in the Manuka and Kanuka essential oils suggests caution in their usage, as does the fact that the oils have not been tested for toxicity.

Childhood atopic eczema is an increasingly common condition in young children. As well as being irritating to the child, it causes sleepless nights for both the child and the family and leads to difficulties in parental relationships and can have severe effects on employment. A group of eight children, born to professional working mothers were studied to test the hypothesis that massage with essential oils (aromatherapy) used as a complementary therapy in conjunction with normal medical treatment, would help to alleviate the symptoms of childhood atopic eczema. The children were randomly allocated to the massage with essential oils group and both counselled and massaged with a mixture of essential oils by the therapist once a week and the mother every day over a period of 8 weeks. The preferred essential oils, chosen by the mothers for their child, from 36 commonly used aromatherapy oils, were: sweet marjoram, frankinsence, German chamomile, myrrh, thyme, benzoin, spike lavender and Litsea cubeba. A control group of children received the counselling and massage without essential oils. The treatments were evaluated by means of daily day-time irritation scores and night time disturbance scores, determined by the mother before and during the treatment, both over an 8 week period; finally general improvement scores were allocated 2 weeks after the treatment by the therapist, the general practitioner and the mother. The study employed a single case experimental design across subjects, such that there were both a within-subject control and between-subjects control, through the interventions being introduced at different times. The results showed a significant improvement in the eczema in the two groups of children following therapy, but there was no significant difference in improvement shown between the aromatherapy massage and massage only group. Thus there is evidence that tactile contact between mother and child benefits the symptoms of atopic eczema but there is no proof that adding essential oils is more beneficial than massage alone. Further studies on the essential oil massage group showed a deterioration in the eczematous condition after two further 8 week periods of therapy, following a period of rest after the initial period of contact. This may have been due to a decline in the novelty of the treatment, or, it strongly suggests possible allergic contact dermatitis provoked by the essential oils themselves. The results of this study indicate the necessity of prolonged studies with novel plant extracts as short-term beneficial results could be overturned by adverse effects after repeated usage.

Six different combinations of three different essential oil mixtures were studied for their possible synergistic activity against 13 food bacteria in vitro. The individual composition of each essential oil as well as that of the mixture was also determined. The results indicated that there was no apparent synergistic activity exhibited by any of the mixtures used. The use of a highly active essential oil with less effective ones simply diluted out the activity of the strongest component. Although there was lack of synergism, there was usually no great loss of activity when the mixture was used compared with the antibacterial activity of the most potent essential oil in the mix (except where clove and cassia was used); this suggests that mixtures of essential oils could be used in processed foods in order to diminish the odour of each individual component which would have been more apparent at the higher concentration if the oils were used singly. Copyright © 1998 John Wiley & Sons, Ltd.

Cellasene, a product containing Ginkgo biloba, sweet clover, sea-weed, grape seed oil, lecithins and evening primrose oil, has been marketed all over the world as a miracle cure for cellulite. As the efficacy of the product was in doubt, a parallel placebo-controlled clinical study was undertaken in a group of women to see whether the product had any effect on cellulite, or on the body weight, fat content, circumference of thighs, hips, etc. No significant changes were found in these parameters compared with the starting values, nor compared with the placebo control after a 2 month course of Cellasene, except for an increase in the cellulite, assessed by the author, compared with that initially. Seven of 11 women taking Cellasene gained weight, as did eight in the placebo control group, taking Colonease, where significance was achieved. The weight gain in both groups was apparent after the first 2 weeks, and all women had to reduce their food consumption. Only three of the women in the Cellasene group thought that their cellulite had slightly improved against two women in the control group.

Lavender (Lavandula angustifolia, P. Miller) is used in aromatherapy as a holistic relaxant and is said to have carminative, antiflatulence and anticolic properties. Its sedative nature, on inhalation, has been shown both in animals and man. Lavender has a spasmolytic activity on guineapig ileum and rat uterus in vitro and it also decreases the tone in the skeletal muscle preparation of the phrenic nerve-diaphragm of rats. As the mechanism of action has not been studied previously, the spasmolytic activity was studied in vitro using a guinea-pig ileum smooth muscle preparation. The mechanism of action was postsynaptic and not atropine-like. The spasmolytic effect of lavender oil was most likely to be mediated through cAMP, and not through cGMP. The mode of action of linalool, one of lavender's major components, reflected that of the whole oil. The mode of action of lavender oil resembled that of geranium and peppermint oils.

A selection of essential oils obtained by steam distillation from scented-leaf Pelargonium species, hybrids and cultivars were assessed for their method of spasmolytic activity in vitro using an isolated smooth muscle preparation. Their mechanism of action was postsynaptic and not atropine-like. The spasmolytic action was correlated with the chemical composition of the essential oils assessed by gas chromatography and mass spectroscopy. The spasmolytic effect of Pelargonium essential oils with a rose-like odour was most likely mediated through cAMP, and not through cGMP; the action of all other essential oils with diverse odours was neither through cAMP, cGMP, nor via calcium channel blockade or potassium channel activation. The mechanism of action of the main components of the rose-like pelargoniums, citronellol and geraniol, reflected that of the whole oils. © 1998 John Wiley & Sons, Ltd.

A selection of essential oils obtained by steam distillation from scented-leaf Pelargonium species, hybrids and cultivars were assessed for their pharmacological activity using guinea-pig ileum in vitro. All the essential oils tested were spasmolytic. Their relative spasmolytic activity was related to the yield obtained from the leaves. The pharmacological activity was comparable to that of commercial geranium oils. The mechanism of action was postsynaptic and not atropine-like. Different Pelargonium oils could be exploited for their antispasmodic and possibly other functions.