Extract of Glycyrrhiza glabra root attenuates nociception in experimental pain models: the role of BKCa channels / Extracto de raíz de Glycyrrhiza glabra atenúa la nocicepción en modelos experimentales de dolor: el rol de los canales BKCa

Abstract: The aim of this study was to evaluate the functional interaction of Glycyrrhiza glabra root extract (GGRE) on the large conductance Ca 2+ - activated K + (BKCa) channels expressed in the peripheral nervo us system by using nociception and inflammation models in rodents in vivo . Besides toxicity studies and open field tests, nociception and inflammation tests were performed on rodents. Different doses of GGRE were given orally to rats and mice. Naloxone, in domethacin, morphine, NS1619 and iberiotoxin (IbTX) were administered. GGRE had both anti - nociceptive and anti - inflammatory activity in rats and mice. GGRE exhibited an analgesic effect by decreasing the time - course of the pain threshold or reaction time i n some nociceptive tests. Furthermore, GGRE reduced level of pro - inflammatory cytokines, including TNF - α and IL - 1ß. As a conclusion, GGRE can alleviate the pain sensation of the afferent nerves and can reduce inflammation and associated pain by activating B KCa channels and reducing the levels of TNF - α, IL1ß

Resumen: El objetivo de este estudio fue evaluar la interacción funcional del extracto de raíz de Glycyrr hiza glabra (GGRE) en los canales de K + (BKCa) activados por Ca 2+ de gran conductancia expresados en el sistema nervioso periférico mediante el uso de modelos de nocicepción e inflamación en roedores in vivo . Además de los estudios de toxicidad y las prueb as de campo abierto, se realizaron pruebas de nocicepción e inflamación en roedores. Se administraron por vía oral diferentes dosis de GGRE a ratas y ratones. Se administraron naloxona, indometacina, morfina, NS1619 e iberiotoxina (IbTX). GGRE tenía activi dad tanto antinociceptiva como antiinflamatoria en ratas y ratones. GGRE mostró un efecto analgésico al disminuir la evolución temporal del umbral del dolor o el tiempo de reacción en algunas pruebas nociceptivas. Además, GGRE redujo el nivel de citocinas proinflamatorias, incluidas TNF - α e IL - 1ß. Como conclusión, GGRE puede aliviar la sensación de dolor de los nervios aferentes y puede reducir la inflamación y el dolor asociado activando los canales BKCa y reduciendo los niveles de TNF - α, IL1ß.

Glabridin Alleviates Inflammation and Nociception in Rodents by Activating BKCa Channels and Reducing NO Levels.

Inflammation, and the pain that accompanies it, is a natural response of the body. The licorice plant (Glycyrrhiza glabra) have demonstrated anti-inflammatory, anti-edematous, and anti-nociceptive effects of its extracts. The effective ingredient remains unidentified; however, one possibility is the unique isoflavone glabridin. The anti-nociceptive, and anti-inflammatory effects of glabridin and its possible mechanism with focus on the large conductance Ca2+-activated K+ (BKCa) channels and L-arginine-nitric oxide (NO) pathway were examined by using different tests. In order to determine the anti-edematous, anti-nociceptive, and anti-oxidative effects of glabradin, some tests such as the tail flick, hotplate, carrageenan-induced paw edema, air pouch, acetic-acid-induced writhing, formalin, and capsaicin tests, as well as toxicity and open field tests were made. Glabridin was administered to rats (n = 8) or mice (n = 8) for 3 d at 3 doses (10, 20, and 40 mg/kg). Glabridin inhibited cytokine production and showed an anti-nociceptive response via the activating of BKCa channels and downregulating NO level and partially transient receptor potential vanilloid-1 pathways. It also demonstrated anti-inflammatory effects by inhibiting cyclooxygenase (COX) activity, while showing no cytotoxicity. Glabridin, however, showed no anti-nociceptive effect in the neurogenic phase. Glabridin is a promising substance in terms of its anti-nociceptive and anti-inflammatory effects by disrupting peripheral NO production, inhibiting cyclic guanosine monophosphate (cGMP) activation and activating BKCa channels and its lack of acute and subacute toxic effects.

Hepatoprotective properties for Salvia cryptantha extract on carbon tetrachloride-induced liver injury.

The present study was designed to determine the possible hepatoprotective effects of Salvia cryptantha (black weed) plant extract against carbon tetrachloride (CCl4)-induced hepatic injury in rats. Animals were grouped as follows: control group (Group I), CCl4 group (Group II), olive oil group (Group III), CCl4 + S. cryphantha 200 mg/kg group (Group IV), and CCl4 + S. cryptantha 400mg/kg group (Group V). Rats were injected intraperitoneally with CCl4 diluted in olive oil (50% v/v) at a dose of 1ml/kg body weight.  Bax and Caspase3 were determined by immunohistochemical staining, while apoptotic index was evaluated using TUNEL assay. Total mRNA was isolated from liver tissues, and the levels of BCL2, Caspase3, SOD, CAT, and glutathione peroxidase (GPx) were determined by using PCR, while MDA level were determined using a colorimetric assay. The antioxidant and anti-apoptotic gene transcripts were decreased in all of the control and treatment groups, while Caspase3 levels were not statistically different. The S. cryptantha plant extract treatment was also found to improve SOD, GPx, and catalase levels, while reducing the serum levels of MDA. The extract of S. cryptantha supplementation had a protective effect against CCl4-induced liver damage. S. cryptantha extract as a supplement may be useful as a hepato-protective agent to combat the toxic effects caused by CCl4 and other chemicals.

L-Carnitine Supplementation Reduces Short-Term Neutrophil-Lymphocyte Ratio in Patients Undergoing Coronary Artery Bypass Grafting.

This study aims to investigate whether preoperative L-carnitine supplementation affects the neutrophil-to-lymphocyte ratio (NLR) in patients undergoing coronary artery bypass grafting surgery. The neutrophil-to-lymphocyte ratio is an inflammatory marker that has proven usefulness for predicting postoperative complications in coronary artery bypass surgery. A lot of studies concerning the role of L-carnitine in the immune system have been performed, contradictory results have been reported on its effects on absolute numbers of WBC subtypes. This randomized, double-blinded, placebo-controlled study was conducted among patients scheduled for coronary artery bypass grafting surgery between June 2012 and December 2013 in our cardiovascular surgery clinic. A total of 60 consecutive patients were randomized and divided into 2 groups. The first group received 2 g of L-carnitine in 1000 mL of 0.9% saline solution infused over 24 hours for each of the 3 preoperative days (L-carnitine group, n = 30), or only 1000 mL of 0.9% saline solution for the same time period (placebo group, n = 30). The basal values of leukocyte, neutrophil, lymphocyte counts, and neutrophil to lymphocyte ratio were similar in the 2 groups. After L-carnitine supplementation (just before surgery), leukocyte and neutrophil counts of the L-carnitine group were significantly lower than those of the placebo group (7.7 ± 1.5 versus 9.7 ± 2.6, P < 0.001 and 4.6 ± 1.3 versus 6.5 ± 2.2, P < 0.001). On postoperative day 1, lymphocyte counts were significantly higher in the L-carnitine group (1.1 ± 0.6 versus 0.8 ± 0.9, P < 0.001). Moreover, the increase in NLR was significantly lower in the L-carnitine group at postoperative day 1 (20.7 ± 13.8 versus 10.8 ± 4.1, P < 0.001). Preoperative L-carnitine supplementation may reduce neutrophil-lymphocyte ratio during the early postoperative period of coronary artery bypass grafting surgery.