Radiant Heat Tail-flick Method Research Articles

Etodolac nanosuspension based gel for enhanced dermal delivery: in vitro and in vivo evaluation

Aim The objective of this study was to develop dermal nanosuspension (NS) based gel formulation of etodolac (ETD). Methods Etodolac nanosuspension (ETD-NS) was prepared by wet milling method and dispersed in hydroxypropyl methylcellulose (NS-HPMC) or hydroxyethyl cellulose (NS-HEC) gels. Rheologic and mechanical properties were investigated. In vitro and ex vivo permeability studies were performed. Topical anti-inflammatory and analgesic activity were evaluated in regard to carrageenan-induced inflammatory paw oedema and radiant heat tail-flick method, respectively. Results The ETD-NS with approximately 190 nm particle size (PS), 0.16 polydispersity index (PDI), and −15 mV zeta potential (ZP) values were obtained. The work of bioadhesion values of NS-HEC and NS-HPMC gels were 0.229 mJ/cm2 for both gels. Dermal permeation of ETD from NS-HEC gel (7.18%) was found significantly higher than the NS-HPMC gel (4.56%). Enhanced anti-inflammatory and analgesic activity of NS-HEC gels were observed in comparison with micronised ETD. Conclusions ETD-NS based gel formulation is promising for topical delivery of ETD.

Let-7b-5p promotes electroacupuncture tolerance by downregulating Penk1 gene in CFA-induced inflammatory nociception rats.

Studies showed that increased let-7b-5p microRNA during repeated electroacupuncture (EA) treatment was associated the formation of EA tolerance, which manifested as gradually decreased nociceptive threshold. Proenkephalin (PENK) is the precursor of enkephalin which is a pivot neuropeptide responsible for the decreased nociceptive threshold in EA. The aim of this study was to evaluate the relationship between let-7b-5p and PENK in EA tolerance. The target gene of let-7b-5p microRNA was determined through the dual-luciferase reporter assay in cortical neurons. Seventy-two Sprague Dawley rats received a combination of EA and intracerebroventricular injection of microRNA (let-7b-5p agomir, antagomir or their controls). The nociceptive thresholds were assessed with radiant heat tail-flick method. PENK and let-7b-5p were measured with Western Blot and qPCR, respectively, after administration of let-7b-5p agomir, antagomir, and their controls at day 1, 4 and 7. Let-7b-5p targeted the 3' untranslated region of Penk1. The nociceptive thresholds in Let-7b-5p agomir+EA group were decreased (p<0.05) compared with those in Let-7b-5p antagomir+EA group at day 1 to 7. Compared with Let-7b-5p agomir+EA group, the expression level of PENK in Let-7b-5p antagomir+EA group was increased at days 1, 4, and 7 (p<0.05) CONCLUSION: Let-7b-5p may be a new potential target for decreasing the EA tolerance effect and facilitating the application of EA in treating chronic nociception of patients.

Antioxidant, Antimicrobial, Anti-diarrheal and Analgesic Activities of Diospyros malabarica (Desr.) Kostel

The present study was designed to evaluate the antioxidant, antimicrobial, antidiarrheal and analgesic activities of methanol extract of Diospyros malabarica (Desr.) Kostel buds growing in Bangladesh. The total phenolic content of methanol extract of D. malabarica and its Kupchan fractions was determined and expressed in gallic acid equivalent (GAE). In the DPPH free radical scavenging assay, the aqueous soluble fraction of the methanol extract of D. malabarica revealed maximum free radical scavenging activity having IC50 value of 6.17 μg/ml. In antimicrobial assay, all the test samples displayed prominent antimicrobial activity against the test organisms under in vitro conditions. Among these, the carbon tetrachloride soluble fraction was found to exhibit the highest activity against Bacillus cereus, Salmonella Typhi, Salmonella Paratyphi, and Candida albicans with the zone of inhibition as 32, 30, 28 and 30 mm, respectively. In evaluation of antidiarrheal activity, the D. malabarica extracts showed significant anti-diarrheal potential in a dose dependent manner. During the evaluation of analgesic activity by radiant heat tail-flick method, the plant extract at 400 mg/kg b.w. exhibited highest elongation (373.04%) as compared to morphine (472.48%). On the other hand, in acetic acid-induced writhing test, the extract at 200- and 400-mg/kg b.w. showed 61.11 and 66.67% inhibition of writhing in mice model, respectively as compared to 68.06% inhibition produced by the standard diclofenac-Na. The findings of this study justify some of the traditional uses of D. malabarica and reveal the bioactivity of the plants. Further studies are required to isolate and identify the bioactive compounds. Bangladesh Pharmaceutical Journal 22(1): 27-33, 2019

Aceclofenac cocrystal nanoliposomes for rheumatoid arthritis with better dermatokinetic attributes: a preclinical study.

The aim of present research was to complex aceclofenac with lysine (LYS) and the developed aceclofenac-LYS cocrystal was encapsulated in lipid bilayers of liposomes by employing dual carrier approach for the treatment of pain-related disorders in rheumatoid arthritis (RA). The developed carriers were characterized for particle size, drug release, ex vivo and in vivo studies, dermatokinetic modeling, complete freund's adjuvant (CFA)-induced RA rat model, radiant heat tail-flick method, formalin-induced paw-licking model, paw edema model and xylene-induced ear edema model in mice. The developed nanoliposomes offered nanometric size, controlled drug release and enhanced drug permeation. Further, hydrogel incorporated nanoproduct was found to be rheologically acceptable and substantially compatible with rodent skin. The studies indicated the superiority of LYS-conjugated liposome-entrapped nanocarriers for improved management of conditions like RA over the marketed product.

Ethnopharmacological investigation of the aerial part of Phragmites karka (Poaceae).

In this ethnopharmacological study, methanolic extract of the aerial plant parts of Phragmites karka (Family: Poaceae) and its petroleum ether and carbon tetrachloride fractions were investigated for bioactivities in Swiss-albino mice, namely, analgesic, central nervous system (CNS) depressant, hypoglycemic, and antidiarrheal activity. The cold methanolic extract of the aerial plant parts of Phragmites karka (MEPK) was first prepared, and it was then further fractionated as petroleum ether (PEFMEPK) and carbon tetrachloride (CTFMEPK) fractions. Analgesic activity was performed employing acidic acid-induced writhing test, central analgesic effect by radiant heat tail-flick method. CNS depressant activity was evaluated by phenobarbitone-induced sleeping time test. Hypoglycemic activity was tested by glucose tolerance test (GTT). Antidiarrheal activity was evaluated by castor oil-induced diarrhea method. For all in vivo tests, doses of 200 and 400 mg/kg body weight were used. In the mice model, the MEPK, PEFMEPK, and CTFMEPK fractions showed significant peripheral analgesic activity at a dose of 400 mg/kg body weight with percentage of inhibition of acetic acid-induced writhing 77.67 (p<0.001), 33.50 (p<0.001), and 40.29 (p<0.001), respectively, compared to the standard dichlofenac (60.68%, p<0.001) group. The hypoglycemic properties of MEPK, PEFMEPK, and CTFMEPK extracts were evaluated in normoglycemic mice where the reduction of blood glucose level after 30 min of glucose load were 69.85%, 78.91%, and 72.73%, respectively, and for standard glibenclamide, the reduction was 72.85%. All results were significant (p<0.05). In the case of the CNS depressant activity by phenobarbitone-induced sleeping time test, the crude ME significantly reduced sleep latency by 57.14% and increased the duration of sleep by 63.29% compared to the control, which were comparable to that of standard diazepam (65.71% and 77.62%, respectively). Among all the extract and fractions, methanolic extract showed the maximum antidiarrheal effect. The methanolic extract at 200 mg/kg dose induced a significant decrease in the total number of defecation in 4 h (69.05% of inhibition, p<0.001) and at 400 mg/kg dose showed 76.19% of inhibition (p<0.001). In light of the available literature, these findings represent the first experimental investigation of biological activities of P. karka in the perspective of their traditional use.

Evaluation of antinociceptive and antidiarrhoeal properties of Manilkara zapota leaves in Swiss albino mice

Context Manilkara zapota (L.). P. Royen. (Sapotaceae) has been used in folk medicine to treat pain, diarrhoea, inflammation, arthralgia, and other disorders.Objective Screening of Manilkara zapota leaves ethanol extract and its different solvent soluble fractions for possible antinociceptive and antidiarrhoeal activities in Swiss albino mice.Materials and methods The extract and various fractions (200 and 400 mg/kg body weight; p.o.) were tested for peripheral and central antinociceptive activity by acetic acid-induced writhing and radiant heat tail-flick method, respectively; castor oil-induced diarrhoeal model was used to evaluate antidiarrhoeal activity at both doses. All the samples were administered once in a day and the duration of study was approximately 5 h.Results Ethanol extract (400 mg/kg), petroleum ether fraction (400 mg/kg), and ethyl acetate fraction (400 mg/kg) showed significant peripheral antinociceptive activity having 59.89, 58.24, and 46.7% (p < 0.001) of writhing inhibition, respectively, which is comparable with that of standard diclofenac (59.34% inhibition). The ethanol extract (400 mg/kg) and petroleum ether fraction (400 mg/kg) also showed promising central analgesic activity having 74.15 and 82.15% (p < 0.001) elongation of reaction time, respectively, at 90 min after administration of sample which is also similar to that obtained by morphine (85.84% elongation). In antidiarrhoeal activity screening, ethanol extract (200 and 400 mg/kg) showed significant inhibition of defecation by 53.57 and 60.71%, respectively (p < 0.001) compared with that of loperamide (71.42%).Discussion and conclusion The findings of the studies demonstrated antinociceptive and antidiarrhoeal activities of M. zapota leaves which could be the therapeutic option against pain and diarrhoeal disease.

Analgesic and Antipyretic Activities of Methanol Extract and Its Fraction from the Root of Schoenoplectus grossus.

The study aims to evaluate analgesic and antipyretic activities of the methanol extract and its different fractions from root of Schoenoplectus grossus using acetic acid induced writhing and radiant heat tail flick method of pain models in mice and yeast induced pyrexia in rats at the doses of 400 and 200 mg/kg. In acetic acid writhing test, the methanol extract, petroleum ether, and carbon tetrachloride fractions produced significant (P < 0.001 and P < 0.05) inhibition of writhing responses in dose dependent manner. The methanol extract at 400 and 200 mg/kg being more protective with 54% and 45.45% of inhibition compared to diclofenac sodium of 56% followed by petroleum ether fractions of 49.69% and 39.39% at the same doses. The extracts did not produce any significant antinociceptive activity in tail flick test except standard morphine. When studied on yeast induced pyrexia, methanol and petroleum ether fractions significantly lowered the rectal temperature time dependently in a manner similar to standard drug paracetamol and distinctly more significant (P < 0.001) after second hour. These findings suggest that the root extracts of S. grossus possess significant peripherally acting analgesic potential and antipyretic property. The phytochemical screening showed the presence of flavonoids, alkaloids, and tannins.

Pharmacological Evaluation of Naproxen Metal Complexes on Antinociceptive, Anxiolytic, CNS Depressant, and Hypoglycemic Properties.

Purpose. The present study was designed to investigate the antinociceptive, anxiolytic, CNS depressant, and hypoglycemic effects of the naproxen metal complexes. Methods. The antinociceptive activity was evaluated by acetic acid-induced writhing method and radiant heat tail-flick method while anxiolytic activity was evaluated by elevated plus maze model. The CNS depressant activity of naproxen metal complexes was assessed using phenobarbitone-induced sleeping time test and the hypoglycemic test was performed using oral glucose tolerance test. Results. Metal complexes significantly (P < 0.001) reduced the number of abdominal muscle contractions induced by 0.7% acetic acid solution in a dose dependent manner. At the dose of 25 mg/kg body weight p.o. copper, cobalt, and zinc complexes exhibited higher antinociceptive activity having 59.15%, 60.56%, and 57.75% of writhing inhibition, respectively, than the parent ligand naproxen (54.93%). In tail-flick test, at both doses of 25 and 50 mg/kg, the copper, cobalt, silver, and zinc complexes showed higher antinociceptive activity after 90 minutes than the parent drug naproxen. In elevated plus maze (EPM) model the cobalt and zinc complexes of naproxen showed significant anxiolytic effects in dose dependent manner, while the copper, cobalt, and zinc complexes showed significant CNS depressant and hypoglycemic activity. Conclusion. The present study demonstrated that copper, cobalt, and zinc complexes possess higher antinociceptive, anxiolytic, CNS depressant, and hypoglycemic properties than the parent ligand.

Evaluation of analgesic, anti-inflammatory, thrombolytic and hepatoprotective activities of roots of Premna esculenta (Roxb).

The objective of this study was to investigate the antinociceptive, anti-inflammatory, thrombolytic and hepatoprotective activities of root extracts of Premna esculenta (family: Verbenaceae). The analgesic activity was evaluated using the acetic-acid-induced writhing test in mice and radiant heat tail-flick method in rats. The anti-inflammatory activity was investigated by carrageenan-induced rat's paw edema, while the thrombolytic activity was evaluated by in vitro clot lysis model. The hepatoprotective activity was investigated against carbon-tetrachloride-induced liver damage in rats. In acetic-acid-induced writhing test, chloroform and ethyl acetate fraction of ethanolic extract at a dose of 200 mg/kg showed a significant (p<0.001) reduction in the number of writhes with 85.96% and 61.98% of inhibition, respectively. In radiant heat tail-flick method, the ethanolic extract produced 88.49% (p<0.001) elongation of tail-flicking time at 90 min after oral administration at same dose level. In the carrageenan-induced edema test, the ethanolic extract at a dose of 200 mg/kg showed a significant inhibition of paw edema with 22.68% and 17.24% inhibition after the first and third hours of the study period, respectively. In clot lysis model, the ethanolic extract at 5 mg/mL induced a significant clot lysis activity (37.69%, p<0.001). Oral administration of ethanolic extract at the dose of 400 mg/kg/day for 7 days significantly (p<0.001) reduced the elevated levels of serum glutamic pyruvic transaminase, serum glutamyl oxaloacetate transaminase and alkaline phosphatase compared to the CCl4-treated control group. The results of the study demonstrated the antinociceptive, anti-inflammatory, thrombolytic and hepatoprotective activities of roots of P. esculenta.

Evaluation of antinociceptive, anti-inflammatory and anxiolytic activities of methanolic extract of Terminalia citrina leaves

ObjectiveTo investigate the antinociceptive, anti-inflammatory and anxiolytic effects of methanolic extracts of Terminalia citrina (T. citrina) leaves (Family: Combretaceae). MethodsThe antinociceptive activity was evaluated by acetic acid induced writhing method and radiant heat tail flick method while anti-inflammatory activity was evaluated by human red blood cell membrane stabilization method and anxiolytic activity by elevated plus maze model. ResultsThe methanolic extract of T. citrina leaves showed significant antinociceptive, anti-inflammatory and anxiolytic effects in dose dependent manner compared to their respective standard drugs. ConclusionsThe present study demonstrated that T. citrina possesses antinociceptive, anti-inflammatory and anxiolytic effects.

Evaluation of Analgesic activity of Sterculia villosa Roxb. (Sterculiaceae) Bark in Swiss-Albino mice

The methanolic crude extract and different fractions of Sterculia villosa bark were investigated for their possible analgesic activity in experimental animal models. Analgesic activity was evaluated using acetic acid induced writhing inhibition and radiant heat tail-flick methods in swiss albino mice. In peripheral method of antinociception, the methanolic crude extract (400 mg/kg) and petroleum ether fraction (400 mg/kg) showed significant analgesic activity having 50.76% and 51.72% (P &lt; 0.001) of writhing inhibition, respectively compared to standard aspirin (71.03% inhibition). In the radiant heat tail-flick method of central anti-nociception, the methanolic crude extract (400 mg/kg) and petroleum ether fraction (400 mg/kg) of S. villosa showed significant analgesic activity having 71.25% (P &lt; 0.001) and 66.77% (P &lt; 0.001) elongation of reaction time, respectively at 30 minutes after administration of sample compared to the standard morphine (144.4% elongation). The findings of the studies demonstrated analgesic activity of the bark of S. villosa which could be the therapeutic option against pain. Dhaka Univ. J. Pharm. Sci. 12(2): 125-129, 2013 (December) DOI: http://dx.doi.org/10.3329/dujps.v12i2.17622

Analgesic and Anti-inflammatory activity of leaves of Rivea hypocrateriformis

The ethanolic extract of the leaves of Rivea hypocrateriformis obtained by soxhlet extraction method was evaluated for analgesic action by Radiant Heat Tail Flick method and was tested for anti-inflammatory action by carrageenan induced paw edema. The ethanolic extract in doses of 200 and 400 mg/kg of Body weight showed 64.83 and 100% inhibition of paw edema, respectively at the end of three hours compared to that of standard Ibuprofen (87.04%). In the Radiant Heat Tail Flick model, the ethanolic extract at high dose 400 mg/kg of Body weight increased the pain threshold significantly after 30 min, 1, 2 and 4 h of administration. The ethanolic extract showed dose-dependent action in all the experimental models. The results were analyzed for statistical significance using two-way ANOVA followed by Dunnel’s test. A P value < 0.05 is considered significant. Key words: Carrageenan induced paw edema, ethanolic extract Rivea hypocrateriformis, Tail flick method.

Tolerance to Morphine-Induced Antinociception Is Decreased by Chronic Sucrose or Polycose Intake

D’ANCI, K. E. Tolerance to morphine-induced antinociception is decreased by chronic sucrose or Polycose intake. PHARMACOL BIOCHEM BEHAV 63(1) 1–11, 1999.—Chronic intake of palatable fluids alters morphine-induced antinociception. Two experiments were conducted to evaluate how long-term access to palatable fluids alters the development of tolerance to morphine-induced antinociception. In Experiment 1, 40 adult male Long–Evans rats were used. In addition to ad lib chow and water, 10 rats were given a 0.15% saccharin solution, 10 were given a 32% sucrose solution, and 10 were given a 32% Polycose solution to drink for 3 weeks. Ten rats were given chow and water alone, and served as dietary controls. Morphine-induced antinociception was assessed using the radiant-heat tail-flick method (TF). Half of the animals in each dietary condition were given preexposure to 7.5 mg/kg morphine; the other half received saline. All rats were given a TF 30-min postinjection. To determine whether tolerance developed, a cumulative dose paradigm (0.625, 1.25, 2.5, 5.0, 10.0 mg/kg) was employed 1 week after initial morphine injections, and was repeated at weekly intervals for 3 weeks. Antinociception was significantly lower in rats preexposed to morphine relative to rats preexposed to saline. Although all rats displayed decreased antinociception relative to the first morphine injection, rats that drank saccharin showed greater reductions in morphine-induced antinociception relative to rats that drank sucrose or Polycose. Experiment 2 was conducted to determine whether initial pairing of the TF with morphine preexposure produced differences in the development of opioid tolerance. All conditions and procedures were identical to Experiment 1, except that the initial morphine and saline injections were not followed by TF. As in Experiment 1, rats that drank saccharin showed less antinociception than rats that drank sucrose or Polycose. The present results suggest that long-term intake of palatable nutritive solutions curbs tolerance to morphine-induced antinociception, whereas long-term intake of a nonnutritive, sweet saccharin solution does not.

Analgesic effects of the neurosteroid 3α-androstanediol

The efficacy of 5α-androstane-3α,17β-diol (3α-Androstanediol; 3α-Diol) and 4-pregnen-3,20-dione (progesterone; P) in promoting analgesia was investigated. Ovariectomized rats received daily injections of 3α-Diol (0.6, 3.0, 6.0 and 7.5 mg/kg) or vehicle and twice daily injections of estradiol-17β (E 2: 1 μg) for 2 days. Progesterone (0.5, 1.0, 2.0 and 4.0 mg/kg) or its vehicle was given on the third day and nociceptive testing using the radiant heat tailflick method was carried out 4 h later. In Expt. 1, P and 3α-Diol both produced analgesia and had biphasic dose-response effects when administered singly. 3α-Diol (3.0 mg/kg) elevated tailflick latencies in E 2 -primed animals above those following vehicle, 6.0 or 7.5 mg/kg 3α-Diol; 6.0 and 7.5 mg/kg produced elevations that were greater than vehicle but less than 3.0 mg/kg. Progesterone (0.5 and 1.0 mg/kg) also elevated tailflick latencies above vehicle controls, while 2.0 and 4.0 mg/kg produced intermediate effects. In Expt. 2, 3α-Diol (3α-Diol:BSA) and P (P:BSA) conjugated to bovine serum albumin (BSA) were applied to the medial basal hypothalamus (MBH) and preoptic area (POA) to ascertain whether the steroids' analgesic actions were mediated by membrane actions in these sites. Free P and P:BSA both increased tailflick latencies when applied to the MBH, while 3 α-Diol and 3α-Diol:BSA elevated latencies when applied to the POA, suggesting the steroids' effects occur in part at the neuronal membrane. In Expt. 3, free P or P:BSA applied to the MBH did not increase tailflick latencies if systemic P was given concurrently. Similarly, free 3α-Diol and 3α-Diol:BSA implants into the POA failed to increase tailflick latencies if s.c. 3α-Diol was co-administered. These data indicate that P and 3α-Diol at moderate doses have analgesic effects in part via membrane actions within the MBH and POA, respectively.

Estradiol benzoate potentiates neuroactive steroids' effects on pain sensitivity

Progesterone (P), its metabolites, and other neuroactive steroids alter pain thresholds consistent with their efficacies at modulating γ-aminobutyric acid (GABA A) receptor complexes. We investigated whether estradiol benzoate (EB) potentiates low dosages of neuroactive steroids' effects on pain. Subcutaneous EB (10 μg) or sesame oil vehicle was administered to ovariectomized Long-Evans rats ( n = 40) 48 h before intracerebroventricular (ICV) infusion of a neuroactive steroid (0.0, 0.1, 0.3, or 0.5 μg) in cyclodextrin vehicle. Neuroactive steroids (listed from greatest to least efficacious at GABA A receptor complexes) were THP [5α-pregnan-3α-ol-20-one], THDOC [5α-pregnan-3α, 21-diol-20-one], DHP [5α-pregnan-3,20-dione], P [4-pregnen-3,20-dione], and DHEAS [5-androsten-3β-ol-17-one sulfate]. Pain sensitivity was assessed using the radiant heat tail-flick method before and 20 and 60 min following infusion. Estradiol benzoate interacted with the neuroactive steroids to alter tail-flick latencies. In particular, EB potentiated the antinociceptive effect of THP and DHP by significantly increasing tail-flick latencies above those of non-EB-treated animals. A similar pattern of increased tail-flick latencies occurred in EB-primed animals that received THDOC. Estradiol benzoate less consistently altered the pain threshold of animals administered P, which is less effective at modulating GABAergic activity. Conversely, EB increased the nociceptive effect of the neurosteroid DHEAS, an allosteric antagonist of GABA A receptor complexes, by significantly decreasing tail-flick latencies of EB- compared to vehicle-primed rats. Thus, EB priming potentiated neuroactive steroids' effects on pain threshold.

Progesterone metabolites, effective at the GABA A receptor complex, attenuate pain sensitivity in rats

To investigate whether progesterone metabolites' antinociceptive effects correlate with their previously established binding efficacies at the GABA receptor complex (GBR), seven progestin metabolites were administered to ovariectomized Long-Evans rats s.c. (Expt. 1), via i.c.v. implantation (Expt. 2) and then i.c.v. infusion (Expt. 3). Progestins, listed from most to least efficacious at the GBR, were THP [5α-pregnan-3α-ol-20-one], THDOC [5α-pregnan-3α,21-diol-20-one], P [4-pregnen-3,20-di-one], DHP [5α-pregnan-3,20-dione],17-OH-P [17-hydroxyprogesterone], DHEAS [5-androsten-3β-ol-17-one sulfate] and PS [5-pregnen-3β-ol-20-one sulfate]. Pain sensitivity was measured via the radiant heat tailflick method 0, 5, 20, 40, 60, 80, 100 and 120 min after weekly progestin administration. Peripheral administration of 0.0, 0.1, 0.4, 1.6, 3.2 or 6.4 mg/kg of potent to moderate agonists of the GBR (THP, THDOC, P and DHP) tended to elevate tailflick latencies above baseline, whereas administration of the non-5α-reduced metabolite (17-OH-P) and GBR antagonists (DHEAS and PS) did not. Intracerebroventricular implantation and infusion (0.0, 0.5, 1.0, 2.0 μg/rat) of THP, THDOC, P and DHP all significantly increased tailflick latencies above baseline and vehicle control, consistent with their GBR efficccies. Central 17-OH-P, DHEAS and PS did not elevate tailflick latencies. These rapid differences were unlikely confounded by stress given that corticosterone levels were not elevated (Expt. 4). As pain sensitivity was attenuated rapidly (0–5 min post-i.c.v.) and consistent with GBR efficacies, this suggests that progestins' modulation of pain may occur via GBR action.