Citral relaxes umbilical vessels of normotensive and preeclamptic parturients.

INTRODUCTION: Citral is a low-toxicity monoterpene that has a vasodilator effect on various smooth muscles, and The present study aimed to evaluate its vasorelaxant effect on umbilical vessels of normotensive parturients (NTP) and with preeclampsia parturients (PEP). METHOD: Segments of human umbilical artery (HUA) and vein (HUV) of NTP or PEP were mounted in a bath to record the force of contraction, under tension of 3.0 gf and contracted with the contracting agents: K+ (60 mM), 5 -HT (10 µM) and Ba2+ (1-30 mM). Next, the effect of citral (1-3000 µM) on these contractions and on basal tone was evaluated. RESULTS: In HUA and HUV, citral (1-1000 µM), in NTP condition, inhibited contractions evoked by K+ (IC50 of 413.5 and 271.3, respectively) and by 5-HT (IC50 of 164.8 and 574.3). In the PEP condition, in HUA and HUV, citral also inhibited the contractions evoked by K+ (IC50 of 363.3 and 218.3, respectively) and 5-HT (IC50 of 432.1 and 520.4). At a concentration of 1000 µM, citral completely or almost completely (>90 %) inhibited all contractions. At a concentration of 100-1000 µM, citral, in general, was already able to reduce the contraction induced by 1-3 mM Ba2+ in both AUH and VUH, under NTP and PEP conditions. DISCUSSION: Citral has been shown to be an effective HUA and HUV vasodilator in NTP and PEP. As its toxicity is low, it suggests that this substance can be considered a potential therapeutic agent.

Perillyl Alcohol Promotes Relaxation in Human Umbilical Artery.

BACKGROUND: Perillyl alcohol (POH) is a monoterpenoid found in plant essential oils and has been shown to relax murine vessels, but its effect on human vessels remains poorly studied. OBJECTIVE: The study aimed to characterize the effect of POH on human umbilical arteries (HUA). METHODS: Rings of HUA were obtained from uncomplicated patients and suspended in an organ bath for isometric recording. The vasorelaxant effect of POH in HUA was evaluated on basal tone and electromechanical or pharmacomechanical contractions, and possible mechanisms of action were also investigated. RESULTS: POH (1-1000 µM) altered the basal tone of HUA and completely relaxed HUA rings precontracted with KCl (60 mM) or 5-HT (10 µM), obtaining greater potency in the pharmacomechanical pathway (EC50 110.1 µM), suggesting a complex interference in the mobilization of extra- and intracellular Ca2+. POH (1000 µM) inhibited contractions induced by BaCl2 (0.1-30 mM) in a similar way to nifedipine (10 µM), indicating a possible blockade of L-type VOCC. In the presence of potassium channel blockers, tetraethylammonium (1 mM), 4-aminopyridine (1 mM), or glibenclamide (10 µM), an increase in the EC50 value of the POH was observed, suggesting a modulation of the activity of BKCa, KV, and KATP channels. CONCLUSION: The data from this study suggest that POH modulates Ca2+ and K+ ion channels to induce a relaxant response in HUA.

The preeclampsia condition alters external potassium-evoked contraction of human umbilical vessels.

INTRODUCTION: Pre-eclampsia (PE) is a disease of high incidence in parturients, that adversely affects both mother and fetus. Although PE prevalence is high, there are few studies on literature describing its etiology or its mechanism of action. Thus, the aim of this study was to elucidate PE-induced alterations of contractile reactivity in umbilical vessels. METHOD: Segments of human umbilical artery (HUA) and human umbilical vein (HUV) from neonates of normotensive or PE parturients were obtained and contractile responses measured with a myograph. The segments were allowed to stabilize (2 h) under 1.0, 2.0 and 3.0 g force (gf) at pre-stimulation and, then, were stimulated with high isotonic K+ concentrations ([K+]o; 10-120 mM). RESULTS: All preparations responded to increases in isotonic K+ concentrations. In HUA and HUV of neonates of normotensive parturients, and in HUV of neonates of PE parturients, the contraction saturated at nearly 50 mM [K+]o, while in HUA of neonates of PE parturients, saturation occurred at 30 mM [K+]o. Additionally, several differences between contractile responses of HUA and HUV from neonates of normotensive parturients and those from neonates of parturients with PE were observed. PE alters the contractile response of the HUA and HUV to increased [K+]o, and its contractile modulation by the pre-stimulus basal tension. Moreover, in HUA of PE, reactivity is decreased for 2.0 and 3.0 gf basal tensions and increased for 1.0 gf; in the HUV of PE condition, it is increased for all basal tensions. DISCUSSION: In conclusion, PE promotes several alterations in HUA and HUV contractile reactivity, vessels in which important circulatory alterations are known to occur.

Pharmacological screening of species from the Lippia genus, content in terpenes and phenylpropanoids, and their vasorelaxing effects on human umbilical artery.

BACKGROUND: Naturally occurring bioactive compounds have a plethora of biological effects. OBJECTIVE: In this study, we examined a pharmacological screening of natural products on the human umbilical artery (HUA). METHODS: HUA preparations were used to follow contractions by KCl (60 mM) and tested at different concentrations (1-5000 µg/mL and µM) of the Lippia alba (EOLa) and Lippia origanoides (EOLo) essential oils, terpenes (citral, limonene perilic alcohol) and phenylpropanoids (eugenol, methyl eugenol). Discussion/Results: The reduction corresponded to approximately 100%, except for limonene (80±1.2 %). When evaluating the concentration of the natural product that promotes 50 % relaxation of the HUA contracted by KCL, EC50 values were: 424.3 µg/mL (EOLa); 468.7±6.7 µg/mL (EOLo); 264.2 ± 8.2 µM (citral); 677.8±5.4 µM (limonene); 186.3±6.4 µM (peryl alcohol); 986.4±7.9 µM (eugenol); and 279.1±4.4 µM (methyl-eugenol). Perillyl alcohol had a lower EC50 (consequently it has a higher pharmacological potency). CONCLUSION: The plant extracts have a promising vasorelaxing effect in HUAs, paving the way for future investigations: as applications in diseases related to these vessels, such as preeclampsia.

Effect of Lippia alba (Mill.) N.E. Brown Essential Oil on the Human Umbilical Artery.

Lippia alba is popularly known as lemon balm, with its essential oil (EO) cited for displaying antimicrobial, sedative, and vasorelaxant effects. Yet, its action on isolated human vessels has not been described in the literature. Thus, we evaluated the vasorelaxant effect of essential oil of L. alba (EOLa) on human umbilical arteries (HUA) isolated in organ baths. HUA rings were isolated, subjected to contractions induced by potassium chloride (KCl), serotonin (5-HT), or histamine (HIST) to record the isometric tension, and then treated with EOLa (30-1000 µg/mL). The EOLa showed a more prominent inhibitory effect on the pharmacomechanical coupling contraction via HIST with an EC50 value of 277.1 ± 8.5 µg/mL and maximum relaxant effect at 600 µg/mL. The addition of tetraethylammonium (TEA) or 4-aminopyridine (4-AP) in HUA preparations did not inhibit EOLa total relaxant effect at 1000 µg/mL. In the presence of gliblenclamide (GLI), the oil relaxed the HUA rings by 90.8% at maximum concentration. The EOLa was also investigated for its effects on voltage-operated calcium channels (VOCCs), where the HUA preincubation with this oil at 1000 µg/mL inhibited BaCl2 (0.1-30 mM)-induced contractions. This study demonstrates for the first time that EOla has a vasorelaxant effect on HUA and its particular blockade of VOCCs.

Characterization of the vasodilator effect of eugenol in isolated human umbilical cord arteries.

Eugenol (EUG) is a phenylpropanoid widely used in the food and cosmetic industries. It is commonly referred to in the literature by its biological activities such as antioxidant, anti-inflammatory, antimicrobial, and relaxing in organs of laboratory animals, especially in rodent vessels. However, its vasorelaxant potential in human tissue, has not been investigated. Thus, this study characterizes the vasodilatory effect of EUG in the human umbilical artery (HUA). HUAs were isolated, cleaned, sectioned (3-4 mm) and placed in an organ bath (10 mL Krebs Henseleit, 37 °C; and carbogenic mixture). EUG (100-1400 µM), obtained total relaxation of electromechanical contractions induced by KCl (60 mM), and pharmacomechanical contractions (30-1200 µM), induced by serotonin (10 µM) and by histamine (10 µM), showing statistically significant concentrations: 600 µM, 400 µM and 200 µM, and EC50 values: 759.8 ± 6.5 µM, 229.9 ± 7.9 and 279.0 ± 3.4 µM, respectively. EUG (1200 and 1400 µM) prevented the contraction promoted by BaCl2 (0.1-30 mM), similar to the effects of nifedipine (10 µM), sugesting the involvement of EUG in blocking VOCCs. In the presence of tetraethylammonium (10 µM), EUG (30-1200 µM) did not produce a total relaxation (88.6%), suggesting that an alternative pathway where potassium channels, may partially mediate EUG effect. In the presence of 4-aminopyridine (1 mM), glibenclamide (10 µM), and tetraethylammonium (1 mM), EUG relaxed HUAs 100%, although the pharmacological potency was statistically altered, demonstrating the participation of K+ channels (Kv, KATP, BKCa). Our data indicates that EUG has a vasorelaxant effect on HUAs, had a greater pharmacological potency in the serotoninergic pathway, showing effective participation of VOCCs and a partial modulation of K+ channels. These data suggest new possibilities for the use of EUG in human vascular dysfunctions, such as preeclampsia. More studies are necessary to confirm the safety and effectivity in future treatments.

Dúvidas sobre infecções sexualmente transmissíveis de adolescentes: revisão integrativa da literatura / Doubts about sexually transmitted infections in adolescents: integrative literature review / Dudas sobre las infecciones de transmisión sexual en los adolescentes: revisión bibliográfica integradora

Objetivo: Identificar as principais dúvidas sobre infecções sexualmente transmissíveis em adolescentes. Método: Revisão integrativa da literatura realizada no período de janeiro a março de 2020, nas bases de dados MEDLINE, LILACS, BDENF, CINAHL, IBECS e na biblioteca virtual SciELO, utilizando os Descritores em Ciências da Saúde: Adolescentes, Infecções Sexualmente Transmissíveis e Conhecimentos. Resultados: Foram identificadas 3455 publicações, sendo 16 incluídas para análise, considerandose os critérios de inclusão e exclusão. Identificou-se que grande parte dos adolescentes possuíam conhecimentos concernentes a algumas Infecções Sexualmente Transmissíveis, sobretudo HIV, mas superficiais, obtidos em conversas com amigos, sem embasamento teórico. Suas dúvidas eram relativas ao modo de transmissão, à prevenção, à identificação dos sinais e sintomas e aos riscos de contágio. Conclusão: As evidências apontadas na revisão integrativa apresentam subsídios para a elaboração de materiais educativos destinados à educação e promoção da saúde sexual, como também, poderá subsidiar conhecimentos a se trabalhar com os adolescentes.(AU)

Objective: To identify the main doubts about sexually transmitted infections in adolescents. Method: Integrative literature review conducted from January to March 2020, in the MEDLINE, LILACS, BDENF, CINAHL, IBECS databases and in the SciELO virtual library, using the Health Sciences Descriptors: Adolescents, Sexually Transmitted Infections and Knowledge. Results: 3455 publications were identified, of which were included for analysis, considering the inclusion and exclusion criteria. It was identified that most adolescents had knowledge concerning some Sexually Transmitted Infections, especially HIV, but superficial, obtained from conversations with friends, without theoretical basis. Their doubts were related to the mode of transmission, prevention, identification of signs and symptoms, and the risks of infection. Conclusion: The evidence pointed out in the integrative review presents subsidies for the development of educational materials for education and promotion of sexual health, as well as can subsidize knowledge to work with adolescents.(AU)

Objetivo: Identificar las principales dudas sobre las infecciones de transmisión sexual en los adolescentes. Método: Revisión bibliográfica integrativa realizada entre enero y marzo de 2020, en las bases de datos MEDLINE, LILACS, BDENF, CINAHL, IBECS y biblioteca virtual SciELO, utilizando los descriptores de Ciencias de la Salud: Adolescentes, Infecciones de Transmisión Sexual y Conocimiento. Resultados: Se identificaron 3455 publicaciones, de las cuales se incluyeron 16 para el análisis, teniendo en cuenta los criterios de inclusión y exclusión. Se identificó que una gran parte de los adolescentes tiene conocimientos relacionados con algunas infecciones de transmisión sexual, sobre todo el VIH, pero de forma superficial, obtenidos en conversaciones con amigos, sin que haya un análisis teórico. Sus dudas estaban relacionadas con el modo de transmisión, la prevención, la identificación de signos y síntomas y los riesgos de contagio. Conclusión: Las evidencias presentadas en la revisión integradora son fundamentales para la elaboración de materiales didácticos destinados a la educación y promoción de la salud sexual, así como también pueden ayudar a mejorar los conocimientos para trabajar con los adolescentes.(AU)

Myorelaxant Effect of the Dysphania ambrosioides Essential Oil on Sus scrofa domesticus Coronary Artery and Its Toxicity in the Drosophila melanogaster Model.

PURPOSE: Alternative methods for the use of animals in research have gained increasing importance, due to assessments evaluating the real need for their use and the development of legislation that regulates the subject. The principle of the 3R's (replacement, reduction and refinement) has been an important reference, such that in vitro, ex vivo and cord replacement methods have achieved a prominent place in research. METHODS: Therefore, due to successful results from studies developed with these methods, the present study aimed to evaluate the myorelaxant effect of the Dysphania ambrosioides essential oil (EODa) using a Sus scrofa domesticus coronary artery model, and the toxicity of both the Dysphania ambrosioides essential oil and its major constituent, α-terpinene, against Drosophila melanogaster in toxicity and negative geotaxis assays. RESULTS: The EODa relaxed the smooth muscle of swine coronary arteries precontracted with K+ and 5-HT in assays using Sus scrofa domesticus coronary arteries. The toxicity results presented LC50 values of 1.546 mg/mL and 2.282 mg/mL for the EODa and α-terpinene, respectively, thus showing the EODa and α-terpinene presented toxicity to these dipterans, with the EODa being more toxic. CONCLUSIONS: Moreover, the results reveal the possibility of using the EODa in vascular disease studies since it promoted the relaxation of the Sus scrofa domesticus coronary smooth muscle.

Pharmacological screening of the phenolic compound caffeic acid using rat aorta, uterus and ileum smooth muscle.

Caffeic acid is a phenolic compound widely found in commonly consumed foods such as pears, apples and coffee, and is pharmacologically known for its antioxidant, anti-inflammatory and anti-asthmatic properties. However, its relaxant activity in the aorta, uterus and ileum smooth muscle has not been investigated. This study aimed to comparatively evaluate the effect of caffeic acid on smooth muscle from different organs (aorta, uterus and ileum), and the contractions of this different organ were induced by different agonists. The organ bath technique was used, where the organs were placed in different cuvettes with 10 mL of Tyrode solution for 1 h to stabilize, then, myometrial, intestinal strip and aortic ring contractions were evoked using different contractile agonists (KCl 60 mM, PHE 0.1 µM, OT 10-2 IU/mL, CCh 10-6 M and BaCl2 0.1-30 mM); increasing concentrations of caffeic acid (0.03-7 mM) were administered in the experimental preparations. In the presence of KCl (60 mM), caffeic acid caused relaxations with the following EC50 values: 2.7 ± 0.26 mM/mL (aorta), 5.7 ± 0.71 mM/mL (uterus) and 2.1 ± 0.39 mM/mL (ileum). When in the presence of different agonists, PHE (0.1 µM) for the aorta, OT (10-2 IU/mL) for the uterus and CCh (10-6 M) for the ileum, caffeic acid caused relaxations with EC50 values of: 2.7 ± 0.31 mM/mL; 2.2 ± 0.34 mM/mL and 2.0 ± 0.28 mM/mL, respectively. The inhibitory effect of caffeic acid on serotonergic (aorta and uterus) and muscarinic receptors (uterus and ileum), as well as its possible involvement with L-type Ca2+ channels, was also observed. This study reports the pharmacological characterization of caffeic acid on smooth muscle from different organs, for which caffeic acid was more potent in the ileum. A diverse understanding of its performance as a possible therapeutic product is attributed to its relaxant effect.

Relaxant Effect of Monoterpene (-)-Carveol on Isolated Human Umbilical Cord Arteries and the Involvement of Ion Channels.

Carveol is a monoterpene present in the structure of many plant products. It has a variety of biological activities: antioxidant, anticancer and vasorelaxation. However, studies investigating the effect of monoterpenoids on human vessels have not yet been described. Thus, the present study aimed to characterize the effect of (-)-carveol on human umbilical arteries (HUAs). HUA ring preparations were isolated and subjected to isometric tension recordings of umbilical artery smooth muscle contractions. (-)-Carveol exhibited a significant vasorelaxant effect on KCl and 5-HT-induced contractions, obtaining EC50 values of 344.25 ± 8.4 and 175.82 ± 4.05 µM, respectively. The participation of calcium channels in the relaxation produced by (-)-carveol was analyzed using vessels pre-incubated with (-)-carveol (2000 µM) in a calcium-free medium, where the induction of contractions was abolished. The vasorelaxant effect of (-)-carveol on HUAs was reduced by tetraethylammonium (TEA), which increased the (-)-carveol EC50 to 484.87 ± 6.55 µM. The present study revealed that (-)-carveol possesses a vasorelaxant activity in HUAs, which was dependent on the opening of calcium and potassium channels. These results pave the way for further studies involving the use of monoterpenoids for the vasodilatation of HUAs. These molecules have the potential to treat diseases such as pre-eclampsia, which is characterized by resistance in umbilical arteries.

Myorelaxant action of the Dysphania ambrosioides (L.) Mosyakin & Clemants essential oil and its major constituent α-terpinene in isolated rat trachea.

This study aimed to investigate the myorelaxant action of the Dysphania ambrosioides essential oil (EODa) and its major constituent α-terpinene on tracheal smooth muscle isolated from rats. In tracheal smooth muscle ex vivo, in organ baths, isometric contractions recordings were done in order to evaluated the effect of EODa (1-1000 µg/mL) and α-terpinene (1-3000 µg/mL) on the following parameters: basal tone, contractions evoked by potassium (KCl 60 mM), acetylcholine (ACh 10 µM) or serotonin (5-HT 10 µM). The EODa and its major constituent α-terpinene, did not statistically alter basal tone; however, they induced myorelaxant effects on top of contractions induced by KCl, ACh and 5-HT. EODa and α-terpinene also inhibited the contractions induced by barium in presence of High [K+] (80 mM). The data suggest that the relaxation induced by these agents is caused by the inhibition of L-type VGCC, inhibiting the inward Ca2+ current through these channels, but does not exclude the possibility of participation of other mechanisms. Results from this study also suggest the EODa, due to their efficacy on relaxation of the respiratory tract, posses a therapeutic potential as a antispasmodic agent for respiratory tract.

Anxiolytic and antidepressant-like effects of Annona coriacea (Mart.) and caffeic acid in mice.

This research evaluated the anxiolytic and antidepressant-like effects of a hydroethanolic extract from the leaves of Annona coriacea (EHFAC) and caffeic acid (CA). Mice were intraperitoneally treated with saline, EHFAC (1, 10, 20 mg/kg) or CA (0.15 mg/kg) and subject to the elevated plus-maze, open field, rota-rod, forced swimming and reserpine-induced akinesia tests. Pro-convulsant and anticholinergic effects were also evaluated. EHFAC presented anxiolytic-like effect on the elevated plus-maze, which was partially reversed by flumazenil. A similar effect was observed with CA. In the forced swimming test, EHFAC and CA reduced the immobility time of mice; such effect was potentiated when EHFAC or CA were associated with imipramine, bupropion and fluoxetine. The antidepressant-like effect was reinforced as EHFAC partially reversed the reserpine-induced akinesia. In addition, a pre-treatment with EHFAC and CA did not decrease the latency to 1st seizure of animals that received a sub-convulsive dose of PTZ, nor reduced the intensity of oxotremorine-induced tremors. Taken together, the results indicate that EHFAC and CA have anxiolytic and antidepressant-like effects, which involve important neurotransmitter systems, such as GABAergic and monoaminergic ones, being devoid of side effects, commonly associated with classical psychotropic drugs.

Tocolytic activity of the Lippia alba essential oil and its major constituents, citral and limonene, on the isolated uterus of rats.

The species Lippia alba (Mill.) N. E. Brown belongs to the Verbenaceae family. It is abundant and grows spontaneously throughout the Brazilian territory. Popularly known as "erva-cidreira", it is widely used because of its sedative, carminative and analgesic properties. The objective of this study was to investigate the mechanism of action of the L. alba essential oil (EOLa) and its major constituents citral and limonene, on isolated rat uterus muscle. To evaluate the EOLa, citral and limonene effect, cumulative concentrations curves for EOLa and citral (1-600 µg/mL) and for limonene (1-1200 µg/mL) were constructed from contractions of rat uterine strips under a 1 g tension. EOLa, citral and limonene dose-dependently relaxed myometrial preparations pre-contracted with 60 mM KCl, 10-2 IU/mL oxytocin, serotonin (10 µM), or ACh (10 µM). The results demonstrate that the EOLa, citral and limonene cause relaxation of the uterine smooth muscle. These results suggest that the relaxation induced by EOLa, citral and limonene is caused by inhibition of L-type VOCC, inhibiting the Ca2+ current through these channels, although other mechanisms of action are likely to contributing to relaxant activity. There was no involvement of K+ channels (BKca, KATP, KV) or cyclooxygenase on the relaxation promoted by EOLa. Then studies of the tocolytic effects of EOLa, citral and limonene may yield new insights into their therapeutic use.