Behavioral effects of psychollatine, a new glycoside indole monoterpene alkaloid isolated from Psychotria umbellata, was investigated in models of anxiety, depression, memory, tremor, and sedation related to 5-HT and/or GABA neurotransmission. The GABA antagonist picrotoxin and the 5-HT2 antagonist ritanserin were used to examine the role of GABA and 5-HT2 receptors in psychollatine-induced effects. In the light/dark and hole-board models of anxiety, diazepam (0.75 mg/kg) and psychollatine (7.5 and 15 mg/kg) showed anxiolytic-like effect at doses that do not increase sleeping time nor alter spontaneous locomotor activity. The anxiolytic effect of psychollatine was prevented by prior administration of ritanserin, but not of picrotoxin, indicating that 5-HT2 but not GABA receptors are implicated. In the forced swimming model of depression, psychollatine (3 and 7.5 mg/kg) effects were comparable to the antidepressants imipramine (15 mg/kg) and fluoxetine (20 mg/kg). Psychollatine suppressed oxotremorine-induced tremors in all doses. In the step-down learning paradigm, diazepam (0.85 mg/kg), MK-801 (0.15 mg/kg), and psychollatine 100 mg/kg impaired the acquisition of learning and memory consolidation, without interfering with retrieval. It is concluded that the effects of psychollatine at the central nervous system involve serotonergic 5HT2(A/C) receptors.

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Interesting analgesic activity has been previously identified in alkaloids isolated from the genus Psychotria (Rubiaceae). We here report the analgesic activity of umbellatine, a new glycoside indole monoterpene alkaloid isolated from Psychotria umbellata. Umbellatine produced a dose-dependent (100-300 mg/kg) analgesic effect, partially reversed by naloxone, in the tail-flick and hot-plate models. These results suggest an analgesic effect at least in part associated with the activation of opioid receptors. In the formalin-and capsaicininduced pain models, umbellatine (100-300 mg/kg) elicited significant and dose-related antinociception. Umbellatine acts synergistically when co-administered with the NMDA antagonist MK-801. These results indicate the involvement of NMDA receptors in the umbellatine mechanism of action. Such a combined mode of action can be of relevance for developing analgesics useful in neurophatic pain.

Psychollatine (1), a new glycoside indole monoterpene alkaloid isolated from Psychotria umbellata, has shown an interesting psychopharmacological profile. This study aimed to investigate the role of NMDA glutamate and dopamine receptors in mediating the properties of 1. Psychollatine (1) was assessed for NMDA-induced seizures, MK-801-induced hyperlocomotion, amphetamine-induced lethality, and apomorphine-induced climbing behavior in mice. Psychollatine (1) (100 mg/kg) and MK-801 (0.3 mg/kg) prevented NMDA-induced seizures (P < 0.01), while 1 (100 mg/kg) attenuated the MK-801-induced hyperlocomotion (P < 0.05). Compound 1 (3 and 10 mg/kg), as well as chlorpromazine (4 mg/kg), prevented amphetamine-induced lethality (P < 0.05). Finally, 1 (10 mg/kg) (P < 0.05), MK-801 (0.2 mg/kg) (P < 0.01), and chlorpromazine (4 mg/kg) (P < 0.01) attenuated apomorphine-induced climbing behavior. The present results strongly support the involvement of NMDA glutamate receptors in the mode of action of psychollatine (1).

O sushi é um prato japonês que pode oferecer muitos riscos à população se não for bem manipulado e conservado em temperatura adequada. Alguns destes pratos não recebem tratamento térmico e é capaz de terem uma elevada concentração de microrganismos que podem possuir patógenos para a saúde humana. Os microrganismos aeróbios mesófilos (MAM) são os principais indicadores usados para avaliar a higiene e sanitização. Este estudo avaliou a contagem de MAM em sushis de 10 estabelecimentos de Porto Alegre (RS), segundo a validação microbiológica para buffets de sushis criada pela vigilância sanitária municipal. Foram utilizados os dados da contagem de MAM provindos de amostras de sushis coletados de um banco de um laboratório, referentes à exposição dessas amostras. Foram encontradas contagens entre 5,2 x 10² a 5,50 x 105 UFC/g, demonstrando que 60% dos estabelecimentos apresentaram aumento estatístico significativo na contagem de MAM quando comparados em relação ao início e final da exposição no buffet e 50% dos estabelecimentos demonstraram estar com temperaturas inadequadas conforme preconizado pela legislação municipal. Conforme relatos na literatura de que MAM acima de 104 UFC/g em peixes marinhos crus são prejudiciais à saúde, 50% dos estabelecimentos avaliados neste estudo demonstraram sushis impróprios para consumo. Concluímos que há deficiências no controle sanitário das matérias-primas, sugerindo que a legislação seja mais rigorosa quanto à contagem de MAM.