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Cinnamic alcohol, cinnamic aldehyde, and cinnamic acid are compounds commonly found in the volatile oil of barks of species in the genus Cinnamomum spp. Schaeff., Lauraceae, popularly known as cinnamon. Cinnamon has been used for millennia for both food and medicinal purposes. The present study reviews the main pharmacological studies on cinnamic alcohol and its derivatives, in order to stress out that cinnamon is a natural product, enriched with compounds endowed of important pharmacological effects that can be benefic to the human health. As a literature review using a qualitative approach, covering articles published between 1970 and 2020, the databases consulted were Pubmed, Web of Science, Science Direct, and Scopus. The following descriptors were searched: “cinnamon,” “cinnamic alcohol,” “cinnamyl alcohol,” “cinnamaldehyde,” “cinnamic aldehyde,” “cinnamic acid,” and “benzoate.” We selected 32 articles studying non-clinical pharmacological aspects of cinnamic alcohol and its derivatives, with emphasis on their central nervous system activities and anti-inflammatory, antioxidant, and antimicrobial potential. In conclusion, the present review demonstrates non-clinical evidence for cinnamic alcohol and its derivatives as bioactive compounds with pharmacological importance, yet we note the lack of clinical studies.

(1S)-(-)-verbenone (VRB) is a monoterpene present in the essential oils of many plants which has shown therapeutic effect; however, its anticonvulsant activity has not yet been evaluated. The present work sought to investigate the anticonvulsant activity of VRB using pilocarpine and pentylenetetrazole-induced seizure testing; seeking also probable mechanisms of action. VRB caused no significant changes in motor coordination. Also, no significant data was observed in the pilocarpine-induced seizure tests. In the PTZ-induced seizures test, VRB showed anticonvulsant activity at doses of 200 mg/kg i.p. (733 ± 109.4 s) and 250 mg/kg i.p. (648.8 ± 124.5 s) significantly increasing the latency to onset of first seizure as compared with the vehicle group (51.8 ± 2.84 s). Pretreatment with flumazenil (FLU) did not reverse the anticonvulsive effect of VRB; however, it was able to upregulate BDNF and COX-2 genes and downregulate c-fos. The findings suggest that the anticonvulsant effects of VRB may be related to RNA expression modulations of COX-2, BDNF, and c-fos.

Immunomodulatory actions exerted by some classes of tryptamines, such as benzoyltryptamine analogues, suggest these molecules as promising candidates to develop new therapies to treat conditions associated to acute and chronic pain and inflammation. N-salicyloyltryptamine (STP) was observed to act as an anticonvulsive agent and exert antinociceptive effects in mouse. In the present work, we performed a screening of cytotoxic, cytoprotective, immunomodulatory, and redox properties of STP in RAW 264.7 macrophages challenged with hydrogen peroxide and LPS. Our results show that STP presents no cytotoxicity in the range of 0.001 to 1 μg/mL, but doses of 50 and 100 μg/mL caused loss of cell viability (IC(50) = 22.75 μg/mL). Similarly, STP at 0.001 to 1 μg/mL did not cause oxidative stress to RAW 264.7 cells, although it did not prevent cell death induced by H(2)O(2) 0.5 mM. At 1 μg/mL, STP reversed some redox and inflammatory parameters induced by LPS. These include thiol (sulfhydryl) oxidation, superoxide dismutase activation, and morphological changes associated to macrophage activation. Besides, STP significantly inhibited LPS-induced TNF-α and IL-1β release, as well as CD40 and TNF-α protein upregulation. Signaling events induced by LPS, such as phosphorylation of ERK 1/2 and IκBα and p65 nuclear translocation (NF-kB activation) were also inhibited by STP. These data indicate that STP is able to modulate inflammatory parameters at doses that do not interfere in cell viability.

α,β-Epoxy-carvone (EC) is a monoterpene found in the essential oils of many species of plants. It can also be obtained by organic synthesis. EC exerts a depressant effect on the central nervous system and is also known to have anticonvulsant, antimicrobial and antioxidant effects. The present study investigated the antinociceptive and anti-inflammatory effects of EC. Intraperitoneal administration of EC at doses of 100, 200 or 300 mg/kg promoted a significant antinociceptive effect, as shown in the acetic acid-induced abdominal writhing test. EC also provoked a reduction in formalin-induced nociception in the first (300 mg/kg) and second phases (200 and 300 mg/kg). In the hot-plate test, an increase in response latency was found at 30 min (at 100, 200 and 300 mg/kg), and at 60 and 120 min (at 300 mg/kg) following administration of EC, an effect that was reversed by naloxone. Intraperitoneal administration of EC (300 mg/kg) inhibited the increased vascular permeability provoked by acetic acid. These findings suggest that EC inhibited the acute inflammatory reaction, with a pronounced peripheral and central antinociceptive effect in mice that is probably associated with activation of the opioidergic system, which appears to play a role in the antinociceptive activity induced by EC.

Some compounds present in therapeutic plants may be responsible for the occurrence of adverse side effects. Coumarin and flavonoids are substances found in many plant species that showed antifertility activity in female rats and dogs, respectively. Mikania glomerata Spreng., Asteraceae, known as guaco in Brazil, is a plant largely used in folk medicine and its leaves are reported to have coumarin and flavonoids. This work analyzes the effect of chronic administration of M. glomerata on the reproductive system of male rats. Thirty-day-old Wistar rats were treated with M. glomerata hydroalcoholic extract at a dose of 3.3 g/kg of body weight for ninety days. Body and organ weights, gamete concentration on the epididymis cauda, serum testosterone level and food consumption were evaluated. No significant alteration was observed in any of the variables analyzed, suggesting the absence of toxic action or antifertility activity of the M. glomerata hydroalcoholic extract. As plantas medicinais podem apresentar na sua constituição compostos capazes de causar efeitos adversos no organismo. Cumarina e flavonoides são substâncias encontradas em muitas espécies vegetais, cuja interferência na fertilidade de ratas e cadelas, respectivamente, foi evidenciada em estudos prévios. Mikania glomerata Spreng., Asteraceae, (guaco) é uma planta usada no tratamento de doenças respiratórias e em suas folhas foi detectada a presença de cumarina e flavonoides. Neste estudo, avaliou-se o efeito do extrato hidroalcoólico, preparado com partes aéreas de guaco, no sistema reprodutor de ratos submetidos a tratamento crônico. Ratos Wistar (trinta dias de idade) foram tratados com extrato hidroalcoólico de guaco na dose de 3,3 g/kg de peso corporal durante noventa dias. O peso corporal e de órgãos, a produção de espermatozoides, a concentração de testosterona plasmática e o consumo de ração foram avaliados. Não foi observada nenhuma alteração significativa das variáveis analisadas e o tratamento não afetou o consumo de ração. Estes dados sugerem que, na dose utilizada, o extrato hidroalcoólico de guaco não teve efeito tóxico e nem interferiu com a fertilidade de ratos Wistar submetidos a um tratamento de longa duração.

Rauvolfia ligustrina Roem et. Schult (Apocynaceae), commonly known as "paratudo" and "arrebenta-boi" is a small tree found in Brazilian Northeastern. Previous studies have demonstrated depressant and anticonvulsant properties of the ethanol extract of Rauvolfia ligustrina. The aim of the present study was the determination of the lethal dose 50% (LD50) and the effects of total alkaloid fraction (TAF) of the aerial parts of R. ligustrina in animal models of convulsion. It was found that the acute toxicity of TAF was 127.8 (112.5-145.2) mg/kg (i.p.) in mice. TAF (20 mg/kg, ip) significantly increased (p < 0.05) the latencies of clonic seizures induced by pentylenetetrazol (PTZ) and picrotoxin (PIC). However, TAF did not protect the animals in maximal electroshock (MES) induced seizures. These results suggest that TAF of R. ligustrina possesses anticonvulsant properties. Rauvolfia ligustrina Roem. et Schult. (Apocynaceae) é uma planta amplamente distribuída no Nordeste Brasileiro, rica em alcalóides indólicos, conhecida popularmente como "paratudo" e "arrebenta-boi". O presente estudo buscou avaliar a dose letal 50 % (DL50) da fração de alcalóides totais (FAT) das partes aéreas da R. ligustrina e a sua possível atividade anticonvulsivantes em roedores. A FAT apresentou uma DL50, via intraperitoneal (i.p.), de 127,8 (112,5-145,2) mg/kg e foi efetiva, na dose de 20 mg/kg (i.p.), em proteger os animais das convulsões induzidas pelo pentilenotetrazol (PTZ) e picrotoxina (PIC) aumentando significativamente (p < 0,05) a latência para o aparecimento das convulsões, sendo um indicativo de um efeito anticonvulsivante.