Antinociceptive and anti-inflammatory effect of a standardized fraction of Oenothera rosea L'Hér. ex Aiton and its possible mechanism of action in mice.

Objective: This study was conducted to investigate the antinociceptive and anti-inflammatory effect of ethyl acetate fraction of Oenothera rosea (EAOr) and the mechanism involved, in mice. Materials and Methods: The antinociceptive activity was tested using chemical- and heat-induced nociception models. The anti-inflammatory activity was tested using carrageenan-induced edema and inflammatory cytokines were measured. Results: EAOr reduced the licking time on the second phase of the formalin test (100 and 177 mg/kg). The antinociception of EAOr was prevented by L-NAME (10 mg/kg), 1H-[1, 2, 4]-oxadiazolo [4, 3-a]-quinoxalin-1-one (ODQ, 0.1 mg/kg), glibenclamide (10 mg/kg) and bicuculline (1 mg/kg), but not by naloxone (2 mg/kg). Also, EAOr decreased licking time in capsaicin induced-nociception. EAOr did not have effect on withdrawal latency in tail-flick test. Carrageenan-induced paw edema was reduced by EAOr, and TNF-α and IL-1ß levels were reduced in mice treated with EAOr by 72.2 and 32.8%, respectively. Furthermore, EAOr did not present side effects as sedation nor gastric injury. Chemical analysis of this fraction showed the presence of glycosylated quercetin derivatives such as quercetin glucoside and quercetin rhamnoside in a 2.5% concentration. Conclusion: This study demonstrates antinociceptive and anti-inflammatory effect of an organic fraction of O. rosea and its possible interaction with the NO-cGMP-K+ channels and GABAergic system and thus, it could be considered a therapeutic alternative.

Efficacy and safety of the metformin-mazindol anorectic combination in rat.

The current study investigates the anorectic interaction and safety of the mazindol-metformin combination in rats. Isobologram and interaction index were used to determine anorectic interaction between mazindol and metformin in the sweetened milk model. The safety profile of the mazindol-metformin combination was determined by measuring anxiety, blood pressure, hematic biometry and blood chemistry. An acute dose of mazindol and metformin administered per os, individually or as a mixture, has reduced the milk consumption in rats in a dose-dependent manner. Theoretical effective dose 40 (ED40t) did not differ from the experimental effective dose 40 (ED40e) obtained with the mazindol-metformin mixture in the anorexia experiments, by Student's t-test. In addition, the interaction index confirmed the additive anorectic effect between both drugs. A single oral dose of ED40e mazindol-metformin mixture induced anxiolysis in the elevated plus-maze test. Moreover, oral administration of mazindol-metformin combination for 3 months significantly decreased glycemia, but not blood pressure nor other parameters of hematic biometry and blood chemistry. Results suggest that mazindol-metformin combination exerts an additive anorectic effect, as well as anxiolytic and hypoglycemic properties. Mazindol-metformin combination might be useful in obese patients with anxiety disorders or diabetes risk factors.

Supplement consumption in people who makes exercise in Northern Mexico gyms. / Consumo de suplementos nutricionales en personas que se ejercitan en gimnasios del norte de México.

BACKGROUND: Physical activity and sports have acquired great importance in contemporary society, given that they have created trends to improve performance, strength and muscle mass through the consumption of nutritional supplements. OBJECTIVE: To determine the profile of the consumer and the type of nutritional supplements in people attending the gyms of the northern border of Tamaulipas. METHOD: It was carried out a cross-sectional and descriptive study in a sample of 800 people attending gyms in 4 cities in the border area between the United States and Mexico, in the state of Tamaulipas (Reynosa, Rio Bravo, Nuevo Laredo and Matamoros). A survey was applied to determine the profile of the consumer and the type of supplements they consumed. RESULTS: 81% of people who went to a gym consumed nutritional supplements, and both genders used them, regardless of their body mass index. CONCLUSIONS: The most used supplements were proteins, essential amino acids and nitric oxide. Improving sports performance, beauty or aesthetics, health care and finally compensating losses were the reasons selected to justify the consumption of nutritional supplements.

INTRODUCCIÓN: La actividad física y el deporte han adquirido gran importancia en la sociedad actual, pues han generado tendencias para mejorar el rendimiento, la fuerza y la masa muscular mediante el consumo de suplementos alimenticios. OBJETIVO: Determinar el perfil del consumidor y el tipo de suplementos nutricionales en personas que asisten a gimnasios de la frontera norte de Tamaulipas. MÉTODO: Estudio transversal y descriptivo en una muestra de 800 personas que se ejercitaban en gimnasios en cuatro ciudades (Reynosa, Río Bravo, Nuevo Laredo y Matamoros) de la zona fronteriza entre los Estados Unidos de Norteamérica y México, en el estado de Tamaulipas. Se aplicó una encuesta para determinar el perfil del consumidor y el tipo de suplementos que empleaba. RESULTADOS: El 81% de las personas que acudieron a un gimnasio consumían suplementos nutricionales y ambos sexos los utilizaron, independientemente de su índice de masa corporal. CONCLUSIONES: Los suplementos más utilizados fueron proteínas, aminoácidos esenciales y óxido nítrico. Mejorar el rendimiento deportivo, la belleza física o el aspecto estético, el cuidado de salud y, por último, compensar pérdidas, fueron las razones seleccionadas para justificar el consumo de suplementos nutricionales.

Possible involvement of peripheral TRP channels in the hydrogen sulfide-induced hyperalgesia in diabetic rats.

BACKGROUND: Peripheral diabetic neuropathy can be painful and its symptoms include hyperalgesia, allodynia and spontaneous pain. Hydrogen sulfide (H2S) is involved in diabetes-induced hyperalgesia and allodynia. However, the molecular target through which H2S induces hyperalgesia in diabetic animals is unclear. The aim of this study was to determine the possible involvement of transient receptor potential (TRP) channels in H2S-induced hyperalgesia in diabetic rats. RESULTS: Streptozotocin (STZ) injection produced hyperglycemia in rats. Intraplantar injection of NaHS (an exogenous donor of H2S, 3-100 µg/paw) induced hyperalgesia, in a time-dependent manner, in formalin-treated diabetic rats. NaHS-induced hyperalgesia was partially prevented by local intraplantar injection of capsazepine (0.3-3 µg/paw), HC-030031 (100-316 µg/paw) and SKF-96365 (10-30 µg/paw) blockers, at 21 days post-STZ injection. At the doses used, these blockers did not modify formalin-induced nociception. Moreover, capsazepine (0.3-30 µg/paw), HC-030031 (100-1000 µg/paw) and SKF-96365 (10-100 µg/paw) reduced formalin-induced nociception in diabetic rats. Contralateral injection of the highest doses used did not modify formalin-induced flinching behavior. Hyperglycemia, at 21 days, also increased protein expression of cystathionine-ß-synthase enzyme (CBS) and TRPC6, but not TRPA1 nor TRPV1, channels in dorsal root ganglia (DRG). Repeated injection of NaHS enhanced CBS and TRPC6 expression, but hydroxylamine (HA) prevented the STZ-induced increase of CBS protein. In addition, daily administration of SKF-96365 diminished TRPC6 protein expression, whereas NaHS partially prevented the decrease of SKF-96365-induced TRPC6 expression. Concordantly, daily intraplantar injection of NaHS enhanced, and HA prevented STZ-induced intraepidermal fiber loss, respectively. CBS was expressed in small- and medium-sized cells of DRG and co-localized with TRPV1, TRPA1 and TRPC6 in IB4-positive neurons. CONCLUSIONS: Our data suggest that H2S leads to hyperalgesia in diabetic rats through activation of TRPV1, TRPA1 and TRPC channels and, subsequent intraepidermal fibers loss. CBS enzyme inhibitors or TRP-channel blockers could be useful for treatment of painful diabetic neuropathy.

N-(4-Methoxy-2-nitrophenyl)hexadecanamide, a palmitoylethanolamide analogue, reduces formalin-induced nociception.

AIMS: To investigate the local antinociceptive effect as well as the possible mechanisms of action of a novel analogue of palmitoylethanolamide (PEA) N-(4-methoxy-2-nitrophenyl)hexadecanamide (HD) in the rat formalin test. MAIN METHODS: The formalin test was used to assess the antinociceptive activity of HD in vivo. The hydrolysis of anandamide catalyzed by fatty acid amide hydrolase (FAAH) was used to determine the action of HD on FAAH activity in vitro. KEY FINDINGS: Local peripheral ipisilateral, but not contralateral, administration of HD (10-100µg/paw) produced a dose-dependent antinociceptive effect in rats. The CB(1) and CB(2) receptor antagonists AM281 (0.3-30µg/paw) and SR144528 (0.3-30µg/paw), respectively, reduced the antinociceptive effect of HD (100µg/paw). In addition, methiothepin (0.03-0.3µg/paw) and naloxone (5-50µg/paw) significantly reduced HD-induced antinociception (100µg/paw). In vitro, HD reduced only to a minor extent the hydrolysis of anandamide catalyzed by FAAH. SIGNIFICANCE: HD local administration produces antinociception that probably results from an indirect activation of peripheral CB(1) and CB(2) cannabinoid receptors. Data suggest that 5-HT(1) and opioid receptors also participate in the antinociceptive effect of this compound. HD may have potential as analgesic drug.