Effects of two doses of glucose and a caffeine-glucose combination on cognitive performance and mood during multi-tasking.

BACKGROUND: This study assessed the effects of two doses of glucose and a caffeine-glucose combination on mood and performance of an ecologically valid, computerised multi-tasking platform. MATERIALS AND METHODS: Following a double-blind, placebo-controlled, randomised, parallel-groups design, 150 healthy adults (mean age 34.78 years) consumed drinks containing placebo, 25 g glucose, 60 g glucose or 60 g glucose with 40 mg caffeine. They completed a multi-tasking framework at baseline and then 30 min following drink consumption with mood assessments immediately before and after the multi-tasking framework. Blood glucose and salivary caffeine were co-monitored. RESULTS: The caffeine-glucose group had significantly better total multi-tasking scores than the placebo or 60 g glucose groups and were significantly faster at mental arithmetic tasks than either glucose drink group. There were no significant treatment effects on mood. Caffeine and glucose levels confirmed compliance with overnight abstinence/fasting, respectively, and followed the predicted post-drink patterns. CONCLUSION: These data suggest that co-administration of glucose and caffeine allows greater allocation of attentional resources than placebo or glucose alone. At present, we cannot rule out the possibility that the effects are due to caffeine alone Future studies should aim at disentangling caffeine and glucose effects.

Medicinal and local food plants in the south of Alava (Basque Country, Spain).

ETHNOBOTANICAL RELEVANCE: Medicinal and food plants in the Basque Country are an integral part of a fast changing culture. With a distinct tradition and language, this region of Europe provides an important example demonstrating the changing role of local and traditional knowledge in industrial countries. As other Mediterranean regions it preserves a rich heritage of using plants as medicine and food, offering a unique opportunity for studying the medicine food interface in an ethnopharmacological context. Therefore, the key goal of this study has been to contribute to an understanding of local and traditional plant usage, to evaluate their uses as food and medicine as well as to critically assess the role of these plants in the south of the Basque Country contributing to an understanding of how foods and medicines are used. METHODS: A mixed methods approach, including participant observation; open and semi structured interviews was used. Ethnobotanical field work included 183 people, ages ranged from 24 to 98 years old with a majority being between 70 and 80 years old (mean age 71) from 31 towns of three different regions. The basic interview was a one-to-one meeting, which often included field walking and collection of samples as directed by the informants. 700 voucher specimens (most of them with duplicates) were collected for the data obtained. Using SPSS version 20 the gathered information was processed and the replies of the different informants were subsequently organised in variables like medicine and food plants, part of the plants used, forms of preparations, zones preferred for collecting these plants. The data were analysed based on the frequency of records. This type of approach allows us to understand the way the informant's categorize the species, and how these categories are distributed along the sample. In order to analyse the data three main categories of use were distinguished: Medicine (M), Food (F) and an intermediate Health-Food (H-F). The three categories were divided in 27 subcategories (common uses). RESULTS AND DISCUSSION: The informants recognise and use a total of 184 species from 49 families. During interviews, 5658 individual use-reports were collected relating to three use-categories - as medicines, food and health-food. The two main groups with almost the same number of species each are health-food (75 species) and (locally gathered) food only (73), with medicinal uses only (36) being the smallest group. This highlights the important overlap between food and medicines. Overall, three core families were identified (based on the number of use reports and in the number of species): Asteraceae (25 species), Lamiaceae and Rosaceae (24 each). The most frequently reported species are Jasonia glutinosa, Chamaemelum nobile, Prunus spinosa and Quercus ilex subsp. ballota. The most important general use-subcategories are as raw vegetables (27.43% of the use-reports and including 81 species), infusions (14.74%/42) and gastrointestinal (12.53%/42). Conceptually foods and medicines are clearly distinguished but the intermediate group of health foods is more ambiguous. CONCLUSION: Food and medicinal uses of plants are culturally closely linked. A wide range of plants are known and many still used. The analysis shows that the Basques use a wide range of species which are typical for Western European cultures. In comparison to other studies in the Mediterranean countries there are many similarities in the uses of different families, species of plants and their use and preparations. Some of these plants are key Mediterranean species, often used for a multitude of uses as food and medicine.

Thymol, a constituent of thyme essential oil, is a positive allosteric modulator of human GABA(A) receptors and a homo-oligomeric GABA receptor from Drosophila melanogaster.

The GABA-modulating and GABA-mimetic activities of the monoterpenoid thymol were explored on human GABAA and Drosophila melanogaster homomeric RDLac GABA receptors expressed in Xenopus laevis oocytes, voltage-clamped at -60 mV. The site of action of thymol was also investigated. Thymol, 1-100 microm, resulted in a dose-dependent potentiation of the EC20 GABA response in oocytes injected with either alpha1beta3gamma2s GABAA subunit cDNAs or the RDLac subunit RNA. At 100 microm thymol, current amplitudes in response to GABA were 416+/-72 and 715+/-85% of controls, respectively. On both receptors, thymol, 100 microm, elicited small currents in the absence of GABA. The EC50 for GABA at alpha1beta3gamma2s GABAA receptors was reduced by 50 microm thymol from 15+/-3 to 4+/-1 microm, and the Hill slope changed from 1.35+/-0.14 to 1.04+/-0.16; there was little effect on the maximum GABA response. Thymol (1-100 microm) potentiation of responses to EC20 GABA for alpha1beta1gamma2s, alpha6beta3gamma2s and alpha1beta3gamma2s human GABAA receptors was almost identical, arguing against actions at benzodiazepine or loreclezole sites. Neither flumazenil, 3-hydroxymethyl-beta-carboline (3-HMC), nor 5alpha-pregnane-3alpha, 20alpha-diol (5alpha-pregnanediol) affected thymol potentiation of the GABA response at alpha1beta3gamma2s receptors, providing evidence against actions at the benzodiazepine/beta-carboline or steroid sites. Thymol stimulated the agonist actions of pentobarbital and propofol on alpha1beta3gamma2s receptors, consistent with a mode of action distinct from that of either compound. These data suggest that thymol potentiates GABAA receptors through a previously unidentified binding site.

Naturalistic Effects of Five Days of Bedtime Caffeine Use on Sleep, Next-Day Cognitive Performance, and Mood.

Background: Disruptive effects of caffeine on sleep have previously been reported, although measures of next-day mood and performance have rarely been included. The present study aims to evaluate the effects of caffeine on sleep and associated next-day effects in a naturalistic field setting. Methods: Nineteen participants (daily caffeine intake 0-141 mg), assessed as good sleepers, took part in a randomized, placebo-controlled, double-blind, 2-week crossover study to assess the effects of bedtime caffeine use (250 mg) on sleep and next-day cognitive performance and mood, which were assessed on a mobile phone in the morning and afternoon. Sleep was assessed objectively (actiwatch) and subjectively (sleep diary). Results: Caffeine's effects on sleep were largely restricted to the first day of administration, with actigraphically measured reduced sleep efficiency, increased activity score and fragmentation index, decreased self-rated sleep quality, and an increased occurrence of participants waking early; only decreased sleep efficiency remained over the week. Effects on next-day performance and mood were evident over the whole week, although despite disrupting sleep, accuracy on a working memory task was higher after caffeine than placebo administration. Conclusions: Caffeine disrupted sleep, although when assessing next-day performance, which may have been affected by the presence of residual caffeine, performance appeared better after caffeine compared to placebo, although this was most likely due to prevention of the effects of overnight withdrawal from caffeine rather than representing a net benefit. Furthermore, partial tolerance developed to the effects of caffeine on sleep.

Natural products as alternative treatments for metabolic bone disorders and for maintenance of bone health.

Bone metabolism involves a complex balance between the deposition of matrix and mineralization and resorption. There is now good evidence that dietary components and herbal products can influence these processes, particularly by inhibiting bone resorption, thus having beneficial effects on the skeleton. For example, it has been reported that a number of common vegetables, including onion, garlic and parsley, can inhibit bone resorption in ovariectomized rats. Essential oils derived from sage, rosemary, thyme and other herbs inhibit osteoclast activity in vitro and in vitro and leading to an increase in bone mineral density. Soya, a rich source of isoflavones, has shown promising results and epidemiological evidence to support a use in maintaining bone health, and various traditional herbal formulae in Chinese and Ayurvedic medicine also have demonstrable effects in pharmacological models of osteoporosis. Recently, cannabinoids have been described as having positive effects on osteoblast differentiation, and the presence of cannabinoid receptors in bone tissue indicates a more complex role in bone metabolism than previously thought. The first part of this review briefly discusses normal bone metabolism and disorders caused by its disruption, with particular reference to osteoporosis and current pharmacological treatments. The effects of natural products on bone and connective tissue are then discussed, to include items of diet, herbal extracts and food supplements, with evidence for their efficacy outlined.