Ayahuasca drinking using a two-bottle choice procedure in male mice.

Ayahuasca has been proposed as a treatment for substance use disorders. However, because of its hallucinogenic properties, studies investigating its abuse potential are needed. The aim of the present study was to investigate voluntary ayahuasca drinking in male mice using a two-bottle choice procedure. Male mice were exposed to two bottles, one of water and one of ayahuasca (0.01, 0.03 or 0.1 mg/ml), for 15 h/day, under 3 protocols (acquisition): (1) every other day access; (2) access every 3 days; (3) access every 5 days. Animals were then submitted to a 14-day drug-free period, followed by 3 re-exposure phases (same conditions as during acquisition), with 7 drug-free days between each. Regardless of the ayahuasca concentration, animals showed a preference for ayahuasca over water when exposed to ayahuasca every other day during the acquisition and re-exposure phases. Extending the period between ayahuasca exposures changed the expression of ayahuasca preference, with the longest break (every 5 days) being associated with preference for water over ayahuasca (i.e., ayahuasca aversion), an effect that was more predominantly observed at higher ayahuasca concentrations. A significant interaction was observed between frequency of exposure to ayahuasca and ayahuasca concentration for total ayahuasca intake during the later re-exposure phase. Our findings show that both the frequency of exposure and the ayahuasca concentration are critical when determining ayahuasca preference in a two-bottle choice model in mice, which can help guide therapeutic/ritualistic ayahuasca use.

Impact of excessive sucrose intake on mouse behavior across different developmental stages.

This study aimed to elucidate the effects of sucrose (SUC) consumption on neurodevelopmental processes through behavioral changes in rodents and determine whether these effects could be because of sweet taste, energy supply, or both. Mice were divided into five groups based on the time of SUC or sucralose (SUR, a noncaloric sweetener) administration: for 6 days from gestation day (GTD) 7, to birth from GTD13 and for 15 days from postnatal day (PND) 21, PND38, and PND56. SUC and SUR administration did not impact body weight. However, food intake in the PND56 group and water intake in the GTD13 and PND56 groups were increased by SUC and SUR administration. Amphetamine (0.5, 1, 2, and 3 mg/kg), a dopamine reuptake inhibitor, administration to assess alterations in the dopaminergic system induced increases in distance traveled after SUC administration in the GTD13 and PND21 groups compared with that in the control (vehicle administration) group. In contrast, the SUR group showed a decrease in the distance traveled in the PND56 group. Although there were no differences in locomotor activity and foraging behavior, SUC preference increased in the SUC group regarding the GTD13 and PND38 groups. The correlations between SUC preference and foraging behavior and between SUC preference and amphetamine response varied in both groups according to the developmental stage. Excessive SUC consumption might affect neural function at different developmental stages, as it could affect brain function through complex mechanisms involving sweet taste and energy supply and influence the dopaminergic system.

The growth hormone secretagogue receptor 1a agonists, anamorelin and ipamorelin, inhibit cisplatin-induced weight loss in ferrets: Anamorelin also exhibits anti-emetic effects via a central mechanism.

This study investigated whether ghrelin mimetics, namely anamorelin and ipamorelin, can alleviate weight loss and inhibition of feeding observed during acute and delayed phases of cisplatin-induced emesis in ferrets. The potential of anamorelin to inhibit electrical field stimulation (EFS)-induced contractions of isolated ferret ileum was compared with ipamorelin. In other experiments, ferrets were administered anamorelin (1-3 mg/kg), ipamorelin (1-3 mg/kg), or vehicle intraperitoneally (i.p.) 30 s before cisplatin (5 mg/kg, i.p.) and then every 24 h, and their behaviour was recorded for up to 72 h. Food and water consumption was measured every 24 h. The effect of anamorelin (10 µg) was also assessed following intracerebroventricular administration. Anamorelin and ipamorelin inhibited EFS-induced contractions of isolated ileum by 94.4 % (half-maximal inhibitory concentration [IC50]=14.0 µM) and 54.4 % (IC50=11.7 µM), respectively. Neither of compounds administered i.p. had any effect on cisplatin-induced acute or delayed emesis, but both inhibited associated cisplatin-induced weight loss on the last day of delayed phase (48-72 h) by approximately 24 %. Anamorelin (10 µg) administered intracerebroventricularly reduced cisplatin-induced acute emesis by 60 % but did not affect delayed emesis. It also improved food and water consumption by approximately 20 %-40 % during acute phase, but not delayed phase, and reduced associated cisplatin-induced weight loss during delayed phase by ∼23 %. In conclusion, anamorelin and ipamorelin administered i.p. had beneficial effects in alleviating cisplatin-induced weight loss during delayed phase, and these effects were seen when centrally administered anamorelin. Anamorelin inhibited cisplatin-induced acute emesis following intracerebroventricular but not intraperitoneal administration, suggesting that brain penetration is important for its anti-emetic mechanism of action.

Optical perturbation of Agtr1a-containing neurons and afferents within the caudal nucleus of the solitary tract modulates sodium intake.

Angiotensin-II (Ang-II) production is driven by deviations in blood volume and osmolality, and serves the role of regulating blood pressure and fluid intake to maintain cardiovascular and hydromineral homeostasis. These actions are mediated by Ang-II acting on its type 1a receptor (AT1aR) within the central nervous system and periphery. Of relevance, AT1aR are expressed on sensory afferents responsible for conveying cardiovascular information to the nucleus of the solitary tract (NTS). We have previously determined that optical excitation of neurons and vagal afferents within the NTS that express AT1aR (referred to as NTSAT1aR) mimics the perception of increased vascular stretch and induces compensatory responses to restore blood pressure. Here, we test whether NTSAT1aR are also involved in the modulation of water and sodium intake. We directed the light-sensitive excitatory channelrhodopsin-2 (ChR2) or inhibitory halorhodopsin (Halo) to Agtr1a-containing neurons and measured water and sodium chloride (NaCl) intake in the presence and absence of optical stimulation within the NTS during various challenges to fluid homeostasis. Optical perturbation of NTSAT1aR modulates NaCl intake, such that excitation attenuates, whereas inhibition increases intake. This effect is only observed in the water-deprived condition, suggesting that NTSAT1aR are involved in the regulation of sodium intake during an imbalance in both the intracellular and extracellular fluid compartments. Furthermore, optical excitation of NTSAT1aR increases c-Fos expression within oxytocinergic neurons of the paraventricular nucleus of the hypothalamus (PVN), indicating that the regulation of sodium intake by NTSAT1aR may be mediated by oxytocin. Collectively, these results reveal that NTSAT1aR are sufficient and necessary to modulate sodium intake relative to perceived changes in vascular stretch.

Intracerebroventricular prokineticin 2 infusion may play a role on the hypothalamus-pituitary-thyroid axis and energy metabolism.

AIM: The hypothesis of this study is to determine the effects of intracerebroventricular (icv) prokineticin 2 infusion on food consumption and body weight and to elucidate whether it has effects on energy expenditure via the hypothalamus-pituitary-thyroid (HPT) axis in adipose tissue. MATERIAL AND METHODS: A total of 40 rats were used in the study and 4 groups were established: Control, Sham, Prokineticin 1.5 and Prokineticin 4.5 (n=10). Except for the Control group, rats were treated intracerebroventricularly via osmotic minipumps, the Sham group was infused with aCSF (vehicle), and the Prokineticin 1.5 and Prokineticin 4.5 groups were infused with 1.5 nMol and 4.5 nMol prokineticin 2, respectively. Food and water consumption and body weight were monitored during 7-day infusion in all groups. At the end of the infusion, the rats were decapitated and serum TSH, fT4 and fT3 levels were determined by ELISA. In addition, PGC-1α and UCP1 gene expression levels in white adipose tissue (WAT) and brown adipose tissue (BAT), TRH from rat hypothalamic tissue were determined by real-time PCR. RESULTS: Icv prokineticin 2 (4.5 nMol) infusion had no effect on water consumption but reduced daily food consumption and body weight (p<0.05). Icv prokineticin 2 (4.5 nMol) infusion significantly increased serum TSH, fT4 and fT3 levels when compared to Control and Sham groups (p<0.05). Also, icv prokineticin 2 (4.5 nMol) infusion increased the expression of TRH in the hypothalamus tissue and expression of PGC-1α UCP1 in the WAT and BAT (p<0.05). CONCLUSION: Icv prokineticin 2 (4.5 nMol) infusion may suppress food consumption via its receptors in the hypothalamus and reduce body weight by stimulating energy expenditure and thermogenesis in adipose tissue through the HPT axis.

Quercetin decreases fructose drinking in model of fructose-induced insulin resistance. Unexpected uric acid and TBARS lowering effect of methyl cellulose vehicle and fructose combination.

The aim of this study was to improve insulin sensitivity in fructose-treated animals by ingestion of flavonoid quercetin. Several signs of insulin resistance have been developed in rats by drinking 10% fructose solution for 9 weeks. The effect of 6-week-gavage-administrated quercetin (20 mg/kg/day in 1% methyl cellulose solution) was monitored. Rats of the control groups received methyl cellulose vehicle as well. The most striking result of the quercetin treatment was the normalization of the fructose solution drinking to the level of drinking water intake. In addition, quercetin supplementation considerably decreased the plasma glucose and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) index in rats consuming fructose. Surprisingly, fructose ingestion did not elevate plasma uric acid, thiobarbituric acid reactive substances, nitrotyrosine, or advanced glycation end products fluorescence. Instead, a reduction of the above parameters was observed. In summary, these results indicate that quercetin supplementation reduces fructose drinking and decreases plasma glucose and the HOMA-IR index. Furthermore, methyl cellulose, in combination with fructose, causes uric acid - lowering, antioxidant and anti-glycation effects. Thus, methyl cellulose possibly shifts fructose metabolism in favor of the utilization of antioxidant features of fructose. Our results call for using methyl cellulose in sweetened beverages and other sweetened food.

The estrogenic reduction in water intake stimulated by dehydration involves estrogen receptor alpha and a potential role for GLP-1.

It is well documented that estrogens inhibit fluid intake. Most of this research, however, has focused on fluid intake in response to dipsogenic hormone and/or drug treatments in euhydrated rats. Additional research is needed to fully characterize the fluid intake effects of estradiol in response to true hypovolemia. As such, the goals of this series of experiments were to provide a detailed analysis of water intake in response to water deprivation in ovariectomized female rats treated with estradiol. In addition, these experiments also tested if activation of estrogen receptor alpha is sufficient to reduce water intake stimulated by water deprivation and tested for a role of glucagon like peptide-1 in the estrogenic control of water intake. As expected, estradiol reduced water intake in response to 24 and 48 h of water deprivation. The reduction in water intake was associated with a reduction in drinking burst number, with no change in drinking burst size. Pharmacological activation of estrogen receptor alpha reduced intake. Finally, estradiol-treatment caused a leftward shift in the behavioral dose response curve of exendin-4, the glucagon like peptide-1 agonist. While the highest dose of exendin-4 reduced 10 min intake in both oil and estradiol-treated rats, the intermediate dose only reduced intake in rats treated with estradiol. Together, this series of experiments extends previous research by providing a more thorough behavioral analysis of the anti-dipsogenic effect of estradiol in dehydrated rats, in addition to identifying the glucagon like peptide-1 system as a potential bioregulator involved in the underlying mechanisms by which estradiol reduces water intake in the female rat.

Role of Ang1-7 in renal haemodynamics and excretion in streptozotocin diabetic rats.

The contribution of angiotensin (1-7) (Ang1-7) to control of extrarenal and renal function may be modified in diabetes. We investigated the effects of Ang1-7 supplementation on blood pressure, renal circulation and intrarenal reactivity (IVR) to vasoactive agents in normoglycaemic (NG) and streptozotocin diabetic rats (DM). In Sprague Dawley DM and NG rats, 3 weeks after streptozotocin (60 mg/kg i.p.) or solvent injection, Ang1-7 was administered (400 ng/min) over the next 2 weeks using subcutaneously implanted osmotic minipumps. For a period of 5 weeks, blood pressure (BP), 24 h water intake and diuresis were determined weekly. In anaesthetised rats, BP, renal total and cortical (CBF), outer (OMBF) and inner medullary (IMBF) perfusion and urine excretion were determined. To check IVR, a short-time infusion of acetylcholine or norepinephrine was randomly given to the renal artery. Unexpectedly, BP did not differ between NG and DM, and this was not modified by Ang-1-7 supplementation. Baseline IMBF was higher in NG vs. DM, and Ang1-7 treatment did not change it in NG but decreased it in DM. In the latter, Ang1-7 increased cortical IVR to vasoconstrictor and vasodilator stimuli. IMBF decrease after high acetylcholine dose seen in untreated NG was reverted to an increase in Ang1-7 treated rats. Irrespective of the glycaemia level, Ang1-7 did not modify BP. However, it impaired medullary circulation in DM, whereas in NG it rendered the medullary vasculature more sensitive to vasodilators. Possibly, the medullary hypoperfusion in DM was mediated by Ang1-7 activation of angiotensin AT-1 receptors which are upregulated by hyperglycaemia.

Suppression of ventral hippocampal CA1 pyramidal neuronal activities enhances water intake.

Thirst is an important interoceptive response and drives water consumption. The hippocampus actively modulates food intake and energy metabolism, but direct evidence for the exact role of the hippocampus in modulating drinking behaviors is lacking. We observed decreased number of c-Fos-positive neurons in the ventral hippocampal CA1 (vCA1) after water restriction or hypertonic saline injection in rats. Suppressed vCA1 neuronal activities under the hypertonic state were further confirmed with in vivo electrophysiological recording, and the level of suppression paralleled both the duration and the total amount of water consumption. Chemogenetic inhibition of vCA1 pyramidal neurons increased water consumption in rats injected with both normal and hypertonic saline. These findings suggest that suppression of vCA1 pyramidal neuronal activities enhances water intake.

A randomized controlled trial of the GLP-1 receptor agonist dulaglutide in primary polydipsia.

BackgroundPrimary polydipsia, characterized by excessive fluid intake, carries the risk of water intoxication and hyponatremia, but treatment options are scarce. Glucagon-like peptide 1 (GLP-1) reduces appetite and food intake. In experimental models, GLP-1 has also been shown to play a role in thirst and drinking behavior. The aim of this trial was to investigate whether GLP-1 receptor agonists reduce fluid intake in patients with primary polydipsia.MethodsIn this randomized, double-blind, placebo-controlled, 3-week crossover trial, 34 patients with primary polydipsia received weekly dulaglutide (1.5 mg, Trulicity) in one treatment segment and placebo (0.9% sodium chloride) in the other. During the last treatment week, patients attended an 8-hour evaluation visit with free access to water. The primary endpoint was total fluid intake during the evaluation visits. Treatment effects were estimated using linear mixed-effects models. In a subset of 15 patients and an additional 15 matched controls, thirst perception and neuronal activity in response to beverage pictures were assessed by functional MRI.RESULTsPatients on dulaglutide reduced their fluid intake by 490 mL (95% CI: -780, -199; P = 0.002), from 2950 mL (95% CI: 2435, 3465) on placebo to 2460 mL (95% CI: 1946, 2475) on dulaglutide (model estimates), corresponding to a relative reduction of 17%. Twenty-four-hour urinary output was reduced by -943 mL (95% CI: -1473, -413; P = 0.001). Thirst perception in response to beverage pictures was higher for patients with primary polydipsia than for controls, and lower for patients on dulaglutide versus placebo, but functional activity was similar among groups and treatments.CONCLUSIONSGLP-1 receptor agonists reduce fluid intake and thirst perception in patients with primary polydipsia and could therefore be a treatment option for these patients.Trial registrationClinicaltrials.gov NCT02770885.FundingSwiss National Science Foundation (grant 32473B_162608); University Hospital and University of Basel; Young Talents in Clinical Research grant from the Swiss Academy of Medical Sciences and the Gottfried & Julia Bangerter-Rhyner Foundation; Top-up Grant from the PhD Programme in Health Sciences, University of Basel.

Chronic Antidiabetic Actions of Leptin: Evidence From Parabiosis Studies for a CNS-Derived Circulating Antidiabetic Factor.

We used parabiosis to determine whether the central nervous system (CNS)-mediated antidiabetic effects of leptin are mediated by release of brain-derived circulating factors. Parabiosis was surgically induced at 4 weeks of age, and an intracerebroventricular (ICV) cannula was placed in the lateral cerebral ventricle at 12 weeks of age for ICV infusion of leptin or saline vehicle. Ten days after surgery, food intake, body weight, and blood glucose were measured for 5 consecutive days, and insulin-deficiency diabetes was induced in all rats by a single streptozotocin (STZ) injection (40 mg/kg). Five days after STZ injection, leptin or vehicle was infused ICV for 7 days, followed by 5-day recovery period. STZ increased blood glucose and food intake. Chronic ICV leptin infusion restored normoglycemia in leptin-infused rats while reducing blood glucose by ∼27% in conjoined vehicle-infused rats. This glucose reduction was caused mainly by decreased hepatic gluconeogenesis. Chronic ICV leptin infusion also reduced net cumulative food intake and increased GLUT4 expression in skeletal muscle in leptin/vehicle compared with vehicle/vehicle conjoined rats. These results indicate that leptin's CNS-mediated antidiabetic effects are mediated, in part, by release into the systemic circulation of leptin-stimulated factors that enhance glucose utilization and reduce liver gluconeogenesis.

The anti-dipsogenic and anti-natriorexigenic effects of estradiol, but not the anti-pressor effect, are lost in aged female rats.

Estradiol (E2) inhibits fluid intake in several species, which may help to defend fluid homeostasis by preventing excessive extracellular fluid volume. Although this phenomenon is well established using the rat model, it has only been studied directly in young adults. Because aging influences the neuronal sensitivity to E2 and the fluid intake effects of E2 are mediated in the brain, we tested the hypothesis that aging influences the fluid intake effects of E2 in female rats. To do so, we examined water and NaCl intake in addition to the pressor effect after central angiotensin II treatment in young (3-4 months), middle-aged (10-12 months), and old (16-18 months) ovariectomized rats treated with estradiol benzoate (EB). As expected, EB treatment reduced water and NaCl intake in young rats. EB treatment, however, did not reduce water intake in old rats, nor did it reduce NaCl intake in middle-aged or old rats. The ability of EB to reduce blood pressure was, in contrast, observed in all three age groups. Next, we also measured the gene expression of estrogen receptors (ERs) and the angiotensin type 1 receptor (AT1R) in the areas of the brain that control fluid balance. ERß, G protein estrogen receptor (GPER), and AT1R were reduced in the paraventricular nucleus of the hypothalamus in middle-aged and old rats, compared to young rats. These results suggest the estrogenic control of fluid intake is modified by age. Older animals lost the fluid intake effects of E2, which correlated with decreased ER and AT1R expression in the hypothalamus.

Voiding behavior in awake unrestrained untethered spontaneously hypertensive and Wistar control rats.

The spontaneously hypertensive rat (SHR), a genetic model of high blood pressure, has also been studied as a potential model of overactive bladder. In vivo studies have confirmed the presence of surrogate markers of overactive bladder, including detrusor overactivity, increased urinary frequency, decreased bladder capacity and voided volume (VV), and afferent hypersensitivity to bladder irritation. However, these observations were during awake cystometry using implanted bladder catheters tethered to an infusion pump and artificially filled. We conducted experiments in awake unrestrained untethered age-matched female SHRs and Wistar rats to quantify naïve consumption and voiding behavior and the effect of capsaicin desensitization on consumption and voiding behavior. Food and water consumption, body weight, voiding frequency, and VV were recorded. Rats were placed in metabolism cages for 24 h, up to twice a week, from 17 to 37 wk of age. Compared with Wistar rats, SHRs exhibited decrease in VV and did not exhibit diurnal variation in VV between light and dark periods, suggesting that SHRs may have bladder hypersensitivity. Furthermore, SHRs may also have smaller bladder capacities, as they consumed less water, voided less volume (regardless of light cycle), and had equal urinary frequencies compared with age-matched Wistar rats. We detected no change in SHR voiding behavior following capsaicin desensitization, which was in contrast to a prior awake in vivo cystometry study describing increased VV and micturition interval in SHRs and suggests that C-fiber activity may not contribute to bladder hypersensitivity in SHRs.NEW & NOTEWORTHY We characterized the long-term (20 wk) voiding, defecation, and consumption behavior of age-matched spontaneously hypertensive and Wistar rats without the influence of anesthesia or catheters. Spontaneously hypertensive rats exhibited bladder hypersensitiviy that persisted for the 20-wk duration and was unaffected by capsacin desensitization.

Chemogenetic activation of endogenous arginine vasopressin exerts anorexigenic effects via central nesfatin-1/NucB2 pathway.

We examined whether the chemogenetic activation of endogenous arginine vasopressin (AVP) affects central nesfatin-1/NucB2 neurons, using a transgenic rat line that was previously generated. Saline (1 mL/kg) or clozapine-N-oxide (CNO, 1 mg/mL/kg), an agonist for hM3Dq, was subcutaneously administered in adult male AVP-hM3Dq-mCherry transgenic rats (300-370 g). Food and water intake were significantly suppressed after subcutaneous (s.c.) injection of CNO, with aberrant circadian rhythmicity. The percentages of Fos expression in nesfatin-1/NucB2-immunoreactive neurons were significantly increased in the hypothalamus and brainstem at 120 min after s.c. injection of CNO. Suppressed food intake that was induced by chemogenetic activation of endogenous AVP was ablated after intracerebroventricularly administered nesfatin-1/NucB2-neutralizing antibody in comparison with vehicle, without any alteration of water intake nor circadian rhythmicity. These results suggest that chemogenetic activation of endogenous AVP affects, at least in part, central nesfatin-1/NucB2 neurons and may exert anorexigenic effects in the transgenic rats.

Ferulic acid, a phytochemical with transient anorexigenic effects in birds.

Ferulic acid (FA) is a phenolic acid found within the plant cell wall that has physiological benefits as an antioxidant. Although metabolic benefits of FA supplementation are described, lacking are reports of effects on appetite regulation. Thus, our objective was to determine if FA affects food or water intake, using chicks as a model. At 4 days post-hatch, broiler chicks were intraperitoneally injected with 0 (vehicle), 12.5, 25, or 50 mg/kg of FA. Chicks treated with 50 mg/kg of FA consumed 70% less food than controls at 30 min post-injection, and the effect dissipated thereafter. Water intake was not affected at any time. In a behavior analysis, FA-treated chicks defecated fewer times than vehicle-injected chicks, while other behaviors were not affected. There was an increase in c-Fos immunoreactivity within the hypothalamic arcuate nucleus (ARC) of FA-treated chicks, and no differences were detected in other nuclei. mRNA abundance was measured in the whole hypothalamus and the ARC. There was decreased hypothalamic galanin, ghrelin, melanocortin receptor 3, and pro-opiomelanocortin (POMC) mRNA in FA-treated chicks. Within the ARC, there was an increase in c-Fos mRNA and a decrease in POMC mRNA in response to FA. It is likely that the mechanism responsible for mediating FA's transient effects on food intake originates within the ARC, possibly involving POMC. A greater understanding of the short-term, mild appetite-suppressive effects of FA may have applications to treating eating disorders and modulating food intake in animal models of obesity.

Period1 gene expression in the olfactory bulb and liver of freely moving streptozotocin-treated diabetic mouse.

Clock genes express circadian rhythms in most organs. These rhythms are organized throughout the whole body, regulated by the suprachiasmatic nucleus (SCN) in the brain. Disturbance of these clock gene expression rhythms is a risk factor for diseases such as obesity. In the present study, to explore the role of clock genes in developing diabetes, we examined the effect of streptozotocin (STZ)-induced high glucose on Period1 (Per1) gene expression rhythm in the liver and the olfactory bub (OB) in the brain. We found a drastic increase of Per1 expression in both tissues after STZ injection while blood glucose content was low. After a rapid expression peak, Per1 expression showed no rhythm. Associated with an increase of glucose content, behavior became arrhythmic. Finally, we succeeded in detecting an increase of Per1 expression in mice hair follicles on day 1 after STZ administration, before the onset of symptoms. These results show that elevated Per1 expression by STZ plays an important role in the aggravation of diabetes.

The anorexigenic effect of neuropeptide AF in Japanese quail, Coturnix japonica, is associated with activation of the melanocortin system.

Neuropeptide AF (NPAF) decreases food and water intake in birds and food intake in mammals. In this study, the objective was to determine the effects of centrally administered NPAF on food and water intake, hypothalamic c-Fos immunoreactivity and hypothalamic mRNA abundance of appetite-regulating factors in Japanese quail (Coturnix japonica). Seven days post hatch, 6 h fasted quail were intracerebroventricularly (ICV) injected with 0 (vehicle), 4, 8, or 16 nmol of NPAF and food and water intake were measured at 30 min intervals for 180 min. In Experiment 1, chicks which received 4, 8, and 16 nmol ICV NPAF had reduced food intake for 120, 60 and 180 min following injection, respectively, and reduced water intake during the entire 180 min observation. In Experiment 2, there was increased c-Fos immunoreactivity in the paraventricular nucleus, the ventromedial nucleus of the hypothalamus, and the dorsomedial hypothalamic nucleus in NPAF-injected quail. In Experiment 3, ICV NPAF was associated with decreased corticotropin-releasing factor mRNA, and an increase in hypothalamic proopiomelanocortin and melanocortin receptor 4 mRNA. These results demonstrate that central NPAF suppresses food and water intake in quail, effects that are likely mediated via the melanocortin system in the hypothalamus.

Antidepressant-like effects of water extract of Cordyceps militaris (Linn.) Link by modulation of ROCK2/PTEN/Akt signaling in an unpredictable chronic mild stress-induced animal model.

ETHNOPHARMACOLOGY RELEVANCE: Cordyceps militaris (Linn.) Link (CM) is a medicinal mushroom traditionally used in tonics for treating several neurological disorders, including epilepsy and anxiety, in Asia. Reports have shown that CM has anti-inflammatory and anti-oxidative effects and may be beneficial for depression management. AIM OF THE STUDY: This study aimed to investigate the potential of CM as an antidepressant for a long-term unpredictable chronic mild stress (UCMS) rodent models and explore its underlying mechanisms. MATERIALS AND METHODS: Rats were orally administered with 125 (low, L), 250 (medium, M), and 500 (high, H) mg/kg bodyweight (bw) of the water extract of CM (WCM) for 35 consecutive days in the UCMS protocol. The levels of cerebral serotonin (5-HT), dopamine (DA), and metabolites in the frontal cortex of the rats were measured. Blood was collected to investigate the levels of proinflammatory cytokines, and the brain was dissected to assay the stress-associated ROCK2/PTEN/Akt signaling. RESULTS: All doses of the WCM prevented abnormal behaviors induced by UCMS, including anhedonia and hypoactivity. The LWCM treatment reduced the turnover rate of 5-HT, and all doses of the WCM reduced the turnover rate of DA in the frontal cortex. The LWCM also attenuated the elevation of serum IL-1ß induced by chronic stress. All doses of the WCM attenuated the ROCK2 protein hyperactivation, and the LWCM further increased the down-regulation of p-Akt/Akt signaling. CONCLUSION: The WCM has antidepressant-like effects, which may result from the regulation of the stress-related ROCK2/PTEN/Akt pathway. Therefore, the WCM may be developed and used for the complementary treatment of depression.

Evaluation of the toxic potential of the aqueous extract from Mangifera indica Linn. (Anacardiaceae) in rats submitted to experimental models of acute and subacute oral toxicity.

ETHNOPHARMACOLOGICAL RELEVANCE: The population has traditionally used the Mangifera indica plant leaves to treat diseases such as Diabetes Mellitus and alleviate signs and symptoms such as inflammation, diarrhea, and dysentery. In a previous study, we demonstrated that the flavonoids present in the aqueous extract from M. indica leaves (EAMI) exhibited a potent hypoglycemic effect in diabetic rats, promoting the widespread use of the plant by the population and highlighting the importance of investigating its oral toxicity. AIM OF THE STUDY: The present study aimed to assess the toxic potential of EAMI in rats submitted to experimental models of acute and subacute (short-term) oral toxicity. MATERIAL AND METHODS: For the acute toxicity test, female Wistar rats received a single oral dose of 2000 mg/kg body weight of EAMI and were observed for 14 days. In the short-term toxicity test, male and female Wistar rats received repeated oral EAMI doses of 125, 250, 500 or 1000 mg/kg body weight and observed for 28 days. RESULTS: The phytochemical analysis of EAMI demonstrated that the extract has high levels of flavonoids. No animals died in the acute toxicity test, and no clinical changes were observed that show signs of toxicity in the animals. There was no significant change in the weight of the organs of the animals submitted to tests with the EAMI, suggesting that LD50 is greater than 2000 mg/kg. In the conditions and doses tested in the short-term toxicity experiments, the treatment did not produce significant changes in the physiological, biochemical, hematological, and histopathological parameters in the animals evaluated. CONCLUSIONS: Our study demonstrated that high doses of EAMI administered acutely, as well as all doses evaluated in the short-term oral toxicity model, should be considered safe during traditional therapeutic use.

Effects of SGLT2 inhibitor ipragliflozin alone and combined with pioglitazone on fluid retention in type 2 diabetic mice with NASH.

Several antidiabetic agents, including thiazolidinediones and sodium-glucose cotransporter (SGLT) 2 inhibitors, attenuate the symptoms of nonalcoholic steatohepatitis (NASH). However, thiazolidinediones have serious side effects such as fluid retention and increased risk of congestive heart failure. We examined the effects of SGLT2 inhibitor ipragliflozin, pioglitazone, and ipragliflozin + pioglitazone on fluid retention in type 2 diabetic mice with NASH. Four-week repeated administration of pioglitazone caused significant increases in heart weight (31% increase in 30 mg/kg pioglitazone-treated group compared to vehicle-treated group) concomitant with fluid retention, as estimated by a decrease in plasma osmolality and increase in water intake/urine volume ratio. In addition, pioglitazone significantly increased (by 1.5 to 2-fold) mRNA expression of α, ß, and γ subtypes of ENaC and AQP2 and 3 subtypes in the renal medulla. Thus, pioglitazone-induced fluid retention may arise from enhanced reabsorption of sodium and water associated with increased expression of these channels in the kidney. In contrast, ipragliflozin alone did not induce these symptoms and did not affect ENaC or AQP expression. Combination treatment with ipragliflozin + pioglitazone attenuated these symptoms by ipragliflozin-induced osmotic diuresis. These findings demonstrate that treatment with ipragliflozin monotherapy or coadministered with pioglitazone may be a potential therapeutic option for the treatment of type 2 diabetes with NASH without fluid retention as a side effect.