Rita Mattei

Guarana (Paullinia cupana) : toxic behavioral effects in laboratory animals and antioxidant activity in vitro

The effects on toxic and behavioral levels of guarana (Paullinia cupana) were assessed in rats and mice subsequent to acute and chronic administrations and were compared to those produced by Ginseng (Panax ginseng). Experimental parameters included tests for antioxidant capacity in vitro and measured in vivo, toxicological screening, progress in weight, motor activity, death rate, and histopathological examination of the viscera. Guarana showed an antioxidant effect because, even at low concentrations (1.2 microg/ml), it inhibited the process of lipid peroxidation. In high doses of 1000-2000 mg/kg (i.p. and p.o.) it did not induce significant alterations in parameters for toxicological screening. No effects on motor activity were observed, neither did guarana alter the hypnotic effect of pentobarbital. Ginseng (250-1000 mg/kg i.p.), however, elicited reductions in motor activity, eyelid ptosis and bristling fur. Consumption of liquids containing guarana or ginseng and progress in weight of the animals remained at levels similar to the controls, even after prolonged administration. The percentage mortality was equivalent in control and in treated groups. The absence of toxicity of guarana was also demonstrated by histopathological examination, with no alteration being detected in heart, lungs, stomach, small and large intestine, liver, pancreas, kidneys, bladder and spleen.

Pharmacological activity of Guarana (Paullinia cupana Mart.) in laboratory animals.

Mice that ingested a suspension of guarana (Paullinia cupana, Sapindaceae) in a dose of 0.3 mg/ml showed a significant increase in physical capacity when subjected to a stressful situation such as forced swimming after 100 and 200 days of treatment. Such an effect, however, was not obtained with a concentration of 3.0 mg/ml, nor with the ingestion of a suspension of ginseng 5.0 mg/ml, nor of a solution of caffeine 0.1 mg/ml. Guarana, both after a single (3.0 and 30 mg/kg) or chronic administrations (0.3 mg/ml), was able to partially reverse the amnesic effect of scopolamine as measured through a passive avoidance test in mice and rats, indicating a positive effect on memory acquisition. However, no effect was observed when an active avoidance task was used in rats, even after 20 days of guarana administration. There was also a tendency of rats treated with 0.3 mg/ml of guarana to better maintain the memory of a Lashley III maze path. The animals had the same average lifespan, indicating a low toxicity of guarana, even after 23 months of treatment.

Activity of Hypericum brasiliense and Hypericum cordatum on the central nervous system in rodents.

Hydroalcoholic extracts from species Hypericum brasiliense Choisy (HB) and Hypericum cordatum (Vell. Conc.) N. Robson (HC), were evaluated on the central nervous system (CNS) in some pharmacological tests. Signs of toxicity were observed for both species during the initial screening when high doses of up to 100 mg/kg (i.p.) and 1000 mg/kg (oral) were utilized. HC presented greater toxicity, with LD(50) of 269 mg/kg, as compared to HB (537 mg/kg). Alterations in sleeping time and in motor coordination were not observed both for HB and for HC. On the other hand, both species showed signs of general depressant action on the CNS, verified by decreased motor activity. Furthermore, animals treated with HB presented an increase in response time to thermal stimulus with doses of 50 mg/kg (i.p.) and 500 mg/kg (oral) suggesting possible analgesic action. Both HB and HC were tested in animal models to verify antidepressant action (forced swimming and hypothermy induced by apomorphine). In these tests, neither of the plants inhibited hypothermy, nor did they reduce immobility time in forced swimming.

Use of Drugs Among Street Children in Brazil

The purpose of this study has been to assess drug consumption among children in five Brazilian state capitals during 1993. The sample was composed of street children who were given assistance in institutions, and data was collected by means of anonymous individual interviews. Five hundred sixty five boys and girls were interviewed: 74.3% reported having used drugs (not including alcohol and tobacco) at least once in their life. Solvents, followed by marijuana, were the most cited drugs. Important regional differences were observed concerning other drugs. Consumption of cocaine, including crack, seems restricted to the southeast region, whereas psychotropic medication was consumed more in the northeast of the country. Drug initiation among these children seems to be a consequence of street life and is part of their group lifestyle.

Behavioral effects of essential oil of Citrus aurantium L. inhalation in rats

The orange essential oil (OEO) and its components obtained from Citrus aurantium L. (Rutaceae) has been attracting interest due to its sedative and relaxing actions. In the present study, rats previously exposed to OEO at the concentrations of 1.0%; 2.5% and 5.0%, w/w, by inhalation during 7 minutes in acrylic boxes were evaluated in two anxiety models: elevated plus maze (EPM) and open-field. The OEO at the concentration of 2.5% increased both the time of the animals in the open arms of the EPM and the time of active social interaction in the open-field being longer than that of the diazepam group (1.5 mg/kg i.p). In conclusion, the decrease in the level of emotionality of the animals observed in the two experimental models suggests a possible central action, which is in agreement with the phytochemical profile of the oil under study, since it showed the presence of limonene (96.24%) and mircene (2.24%), components with a well-known depressant activity on the central nervous system.

Anticonvulsant effect of a natural compound α,β-epoxy-carvone and its action on the nerve excitability

The anticonvulsant effect of alpha,beta-epoxy-carvone (EC), a monoterpene monocyclic, was investigated in three animal models. EC at 300 or 400 mg/kg promoted protection of 75% and 87.5%, respectively, against convulsions induced chemically by pentylenetetrazole (PTZ) and it was efficient in prevents the tonic convulsions induced by maximal electroshock (MES) in doses of 200, 300 or 400 mg/kg, resulting in 25%, 25% and 100% of protection, respectively. This monoterpene was also capable to promote an increase of latency for development of convulsions induced by picrotoxin (PIC) at 300 or 400 mg/kg and presented a significant protection against convulsions at doses of 200, 300 or 400 mg/kg, resulting in 12.5%, 12.5% and 100% of protection, respectively. On the other hand, the anticonvulsant effect of EC, was not affected by pretreatment with flumazenil (FLU), a selective antagonist of benzodiazepine site of GABA(A) receptor. Additionally was observed that EC treatment reduced the levels of in vitro lipoperoxidation and decreased (21.2%) the amplitude of compound action potential after 30 min of incubation. The present results clearly indicate the ability of EC to modulate the anticonvulsant and antioxidant effects. However, our data suggests that the action mechanisms are not due a direct activation of the GABA(A) benzodiazepine receptors, but could be associated with the reduction of isolated nerve excitability, possibly involving a voltage-gated Na(+) channels blockade.

Rosewood oil induces sedation and inhibits compound action potential in rodents

AIM OF THE STUDY Aniba rosaeodora is an aromatic plant which has been used in Brazil folk medicine due to its sedative effect. Therefore, the purpose of the present study was to evaluate the sedative effect of linalool-rich rosewood oil in mice. In addition we sought to investigate the linalool-rich oil effects on the isolated nerve using the single sucrose-gap technique. MATERIALS AND METHODS Sedative effect was determined by measuring the potentiation of the pentobarbital-induced sleeping time. The compound action potential amplitude was evaluated as a way to detect changes in excitability of the isolated nerve. RESULTS The results showed that administration of rosewood oil at the doses of 200 and 300 mg/kg significantly decreased latency and increased the duration of sleeping time. On the other hand, the dose of 100 mg/kg potentiated significantly the pentobarbital action decreasing pentobarbital latency time and increasing pentobarbital sleeping time. In addition, the effect of linalool-rich rosewood oil on the isolated nerve of the rat was also investigated through the single sucrose-gap technique. The amplitude of the action potential decreased almost 100% when it was incubated for 30 min at 100 microg/ml. CONCLUSIONS From this study, it is suggested a sedative effect of linalool-rich rosewood oil that could, at least in part, be explained by the reduction in action potential amplitude that provokes a decrease in neuronal excitability.

Pharmacological effects of the monoterpene alpha,beta-epoxy-carvone in mice

The monoterpene a,b-epoxy-carvone (EC) in doses of 200, 300 or 400 mg/kg injected by i.p. route in mice caused a significant decrease in the motor activity of animals when compared with the control group, up to 120 minutes after the administration. The doses of 300 or 400 mg/kg had induced a significant increase of in the sleeping time of animals not having modified, however, the latency. The EC in the dose of 400 mg/kg reduced the remaining time of the animals on the rotating rod (Rotarod test). These results suggest a possible central effect.

Combined astaxanthin and fish oil supplementation improves glutathione-based redox balance in rat plasma and neutrophils

The present study aimed to investigate the effects of daily (45 days) intake of fish oil (FO; 10mg EPA/kg body weight (BW) and 7 mg DHA/kg BW) and/or natural ASTA (1mg ASTA/kg BW) on oxidative stress and functional indexes of neutrophils isolated from Wistar rats by monitoring superoxide (O(2)(-)), hydrogen peroxide (H(2)O(2)), and nitric oxide (NO()) production compared to the progression of auto-induced lipid peroxidation and Ca(2+) release in activated neutrophils. Furthermore, phagocytic capacity, antioxidant enzyme activities, glutathione-recycling system, and biomarkers of lipid and protein oxidation in neutrophils were compared to the redox status. Our results show evidence of the beneficial effects of FO+ASTA supplementation for immune competence based on the redox balance in plasma (significant increase in GSH-dependent reducing power), non-activated neutrophils (increased activity of the glutathione-recycling enzymes GPx and GR) and PMA-activated neutrophils (lower O(2)(-), H(2)O(2), and NO() generation, reduced membrane oxidation, but higher phagocytic activity). Combined application of ASTA and FO promoted hypolipidemic/hypocholesterolemic effects in plasma and resulted in increased phagocytic activity of activated neutrophils when compared with ASTA or FO applied alone. In PMA-activated neutrophils, ASTA was superior to FO in exerting antioxidant effects. The bulk of data reinforces the hypothesis that habitual consumption of marine fish (e.g. salmon, which is a natural source of both astaxanthin and fish oil) is beneficial to human health, in particular by improving immune response and lowering the risk of vascular and infectious diseases.

Pharmacological evaluation of a phytotherapeutic product - CPV (dry extract of Crataegus oxyacantha L., Passiflora incarnata L. and Valeriana officinalis L.) in laboratory animals

The aim of the present study was to evaluate the central effects of the phytotherapeutic product-CPV (dry extract of Crataegus oxyacantha, Passiflora incarnata and Valeriana officinalis) in animals models. In order to investigate the psychopharmacological profile of CPV extract, an evaluation toward anxiolytic effect of this extract on the elevated plus-maze (EPM) was carried out. Other effects such as neuroleptic (blockade of the stereotyped behavior induced by apomorphine), analgesic (hot plate; acetic acid writhing and tail-flick tests) and on the memory (passive avoidance test) were also analyzed. CPV extract (430 and 860 mg/ kg) presented an anxiolytic effect on rats (increased the number of entries into the open arms in the EPM) and, furthermore, a tendency of slight amnesic effect for the doses (430 and 860 mg/kg), but less intense when compared to diazepam (1.5 mg/kg). The extract did not show neuroleptic or analgesic effects.