Dose Of Glycerol Research Articles

Alpha-Mangostin ameliorates acute kidney injury via modifying levels of circulating TNF-α and IL-6 in glycerol-induced rhabdomyolysis animal model.

Alpha mangostin (AM), isolated from G. mangostana, showed beneficial effects in several disorders due to its antioxidant and anti-inflammatory properties. Acute kidney injury (AKI) due to different etiologies can develop into severe complications, resulting in high mortality rates. In this work, AM is tested for its ability to alleviate AKI in glycerol-induced AKI rat model, where 30 Male Sprague-Dawley rats were assigned to a healthy group, glycerol-treated group and AM-treated group. Glycerol- and AM groups received a single dose of glycerol (per IM, 50% glycerol in saline, 8 ml/kg), whereas control group was injected with saline. AM treatment (a single daily dose, per IP, 175mg/kg) was accomplished for three days. Animals were executed to collect blood samples and kidney tissue for biochemical and histological examination. It was found that glycerol induced increase in serum creatinine, blood urea nitrogen (BUN), lipid peroxidation, serum magnesium, TNF-α and IL-6. It also induced renal edema and hypocalcemia along with histopathological renal damage. AM treatment improved renal histological features and alleviated increase in serum creatinine, BUN, serum magnesium, TNF-α and IL-6 levels, as well as renal edema and lipid peroxidation but did not affect serum calcium levels. This suggests AM as a potential therapeutic agent for treating AKI mainly via its antioxidant and anti-inflammatory properties.

Administration of a single dose of lithium ameliorates rhabdomyolysis-associated acute kidney injury in rats.

Rhabdomyolysis is characterized by muscle damage and leads to acute kidney injury (AKI). Clinical and experimental studies suggest that glycogen synthase kinase 3β (GSK3β) inhibition protects against AKI basically through its critical role in tubular epithelial cell apoptosis, inflammation and fibrosis. Treatment with a single dose of lithium, an inhibitor of GSK3β, accelerated recovery of renal function in cisplatin and ischemic/reperfusion-induced AKI models. We aimed to evaluate the efficacy of a single dose of lithium in the treatment of rhabdomyolysis-induced AKI. Male Wistar rats were allocated to four groups: Sham, received saline 0.9% intraperitoneally (IP); lithium (Li), received a single IP injection of lithium chloride (LiCl) 80 mg/kg body weight (BW); glycerol (Gly), received a single dose of glycerol 50% 5 mL/kg BW intramuscular (IM); glycerol plus lithium (Gly+Li), received a single dose of glycerol 50% IM plus LiCl IP injected 2 hours after glycerol administration. After 24 hours, we performed inulin clearance experiments and collected blood / kidney / muscle samples. Gly rats exhibited renal function impairment accompanied by kidney injury, inflammation and alterations in signaling pathways for apoptosis and redox state balance. Gly+Li rats showed a remarkable improvement in renal function as well as kidney injury score, diminished CPK levels and an overstated decrease of renal and muscle GSK3β protein expression. Furthermore, administration of lithium lowered the amount of macrophage infiltrate, reduced NFκB and caspase renal protein expression and increased the antioxidant component MnSOD. Lithium treatment attenuated renal dysfunction in rhabdomyolysis-associated AKI by improving inulin clearance and reducing CPK levels, inflammation, apoptosis and oxidative stress. These therapeutic effects were due to the inhibition of GSK3β and possibly associated with a decrease in muscle injury.

Methane production test of the anaerobic sludge from rice parboiling industries with the addition of biodiesel glycerol from rice bran oil in Brazil

Experimental research and energy plans show that the residues of rice parboiling industries in Brazil have the energy potential to promote the sector's self-sufficiency. The studies investigate the production of biogas from the anaerobic digestion of wastewater and its anaerobic sludge. There are no reports of the investigation to optimize such production by adding glycerol. This addition can increase methane production; however, high proportions of crude glycerol can cause inhibition of microbial activity. Considering that anaerobic sludge acts as inoculum in the digestion of effluent in treatment plants, the main goal of this study was to test the feasibility of adding crude glycerol from the production of rice bran biodiesel in anaerobic digestion with sludge. The reactors operated with different proportions of crude glycerol (0%, 1%, 2%, and 3%). The highest methane production occurred in the system with 1% glycerol, 945.23 ± 5.34 mL, in 168 h – a production 539.45% higher when compared to the system without glycerol. Higher doses of glycerol resulted in fast interruption of methanogenic activity. The study determined that the addition of 1% glycerol was able to prolong the duration of the stationary phase of methanogenic microorganisms. Thus, the high energy potential of the sector can be significantly increased with the addition of the biodiesel by-product in anaerobic digestion. Such a possibility could guarantee greater security, energy autonomy, the possibility of generating revenue from the sale of surplus methane or electricity, and an environmentally proper destination for crude glycerol.

Effect of Media with Different Glycerol Concentrations on Sheep Red Blood Cells' Viability In Vitro.

Simple SummaryGlycerol is widely used as a feed supplement in ruminant nutrition. However, its administration at moderate and high doses results in an increase in plasma osmolality and in an alteration of red blood cell (RBC) indices. The present study aimed at further elucidating the effect of glycerol on RBCs’ functionality by evaluating the effect of different glycerol concentrations on RBC homeostasis under in vitro conditions. Obtained results showed that glycerol permeates the RBC membrane and leads to hemolysis when glycerol concentration exceeds 200 mg/dL. However, RBCs’ antioxidant defenses appear to protect cell membranes without causing an increase of oxidative stress markers. Moreover, no alteration in RBCs’ intracellular Ca2+ ion concentrations and metabolic activity were found. In conclusion, glycerol-based nutritional treatment should be designed in sheep to avoid exceeding 200 mg/dL glycerol circulating concentration to prevent RBC osmotic stress.The use of high doses of glycerol as a livestock feed supplement is followed by a rapid increase in plasma concentrations and consequently in plasma osmolality. Moreover, glycerol is a highly diffusible molecule that can readily permeate the red blood cell (RBC) membrane following a concentration gradient. A rise in glycerol plasma concentrations can thus alter RBC homeostasis. The present study aimed at investigating both glycerol osmotic effects on sheep RBCs and their oxidative response under in vitro conditions. Sheep blood samples were suspended in media supplemented with increasing glycerol concentrations (0, 25, 50, 100, 150, 200, 250, 300, 350, 400 mg/dL), which reflected those found in vivo in previous studies, and incubated at 37 °C for 4h. Thereafter, osmolality and hemolysis were determined in spent media, while cell extracts were used to assay intracellular concentration of glycerol, ATP, Ca2+ ions, oxidative stress markers and reactive oxygen species (ROS).The study confirmed that glycerol intracellular concentrations are directly related with its concentration in the incubation media, as well as hemolysis (p < 0.001) which increased significantly at glycerol concentrations higher form 200 mg/dL. ROS intracellular level increased at all glycerol concentration tested (p < 0.01) and total thiols decreased at the highest concentrations. However, RBCs proved to be able to cope by activating their antioxidant defense system. Superoxide dismutase activity indeed increased at the highest glycerol concentrations (p < 0.001), while total antioxidant capacity and malonyldialdehyde, a typical product of lipid peroxidation by ROS, did not show significant changes. Moreover, no alterations in intracellular Ca2+ ions and ATP concentrations were found. In conclusion, glycerol-induced hemolysis can be related to the induced osmotic stress. In sheep, nutritional treatments should be designed to avoid reaching glycerol circulating concentrations higher than 200 mg/dL.

Thalidomide reduces glycerol‐induced acute kidney injury by inhibition of NF-κB, NLRP3 inflammasome, COX-2 and inflammatory cytokines

Acute kidney injury (AKI) is an important clinical complication of rhabdomyolysis. The inflammatory processes are involved in the pathogenesis of AKI induced by rhabdomyolysis. Thalidomide is an anti-inflammatory agent that has been used in the treatment of inflammatory disorders. The aim of this study was to investigate the therapeutic effect of thalidomide and its underlying mechanisms on a mouse model of rhabdomyolysis-induced AKI. Mice were injected with a single dose of glycerol (50%, 10 ml/kg, im) to induce AKI, and treated with thalidomide (40 and 80 mg/kg/day, orally) for 2 days. Renal tissue and blood samples were collected for histological and biochemical analysis. In thalidomide treated mice, blood urea nitrogen (BUN) (59.3 ± 19.6 vs. 223 ± 33 mg/dl), plasma creatinine (0.58 ± 0.3 vs. 1.28 ± 0.3 mg/dl), relative kidney weight (0.93 ± 0.13% vs. 1.22 ± 0.1%) and histopathological damage (1.5 ± 0.8 vs. 3.3 ± 1.1 score) were significantly lower as compared to the glycerol group. The results also showed that the levels of malondialdehyde (MDA) (0.13 ± 0.02 vs. 0.2 ± 0.01 µM/mg), myeloperoxidase (MPO) (0.1 ± 0.05 vs. 0.25 ± 0.02 U/mg) and the expression of nuclear factor kappa B (NF-κB) (1.7-fold), NLRP3 inflammasome (1.4-fold) and cyclooxygenase (COX)-2 (3-fold) in renal tissue were significantly lower in thalidomide treated group than those in the glycerol group. Thalidomide treatment resulted in lower renal pro-inflammatory cytokines tumor necrosis factor (TNF)-α (6.7 ± 0.8 vs. 12.3 ± 1.2 ng/ml), interleukin (IL)-1β (3.2 ± 0.5 vs. 5.1 ± 0.3 pg/mg), IL-6 (24.7 ± 2.4 vs. 33 ± 3 pg/mg) and transforming growth factor (TGF)-β1 (0.6 ± 0.17 vs. 1.56 ± 0.24 ng/ml) than those in the glycerol treated mice. In addition the levels of monocyte chemoattractant protein (MCP)-1 (9.5 ± 1 vs. 12.8 ± 1.1 pg/mg) and intercellular adhesion molecule (ICAM)-1 (22.8 ± 7.8 vs. 53.3 ± 5.5 pg/mg) were significantly lower in renal tissue of mice treated with thalidomide as compared to the glycerol treated mice. In conclusion these data revealed that thalidomide may be a potential therapeutic approach against rhabdomyolysis-induced AKI through inhibition of inflammatory responses.

Mixotrophic cultivation of Thalassiosira pseudonana with pure and crude glycerol: Impact on lipid profile

The mixotrophic cultivation of microalgae often couples high biomass production with lipid accumulation, and thus it is considered a useful approach to obtain high quantities of added value microalgal biomass. In this study, the marine diatom Thalassiosira pseudonana was supplied with glycerol to determine the potential of the mixotrophic alga for the accumulation of lipids. In preliminarily experiments, T. pseudonana was cultivated in the presence of increasing concentrations of glucose, acetate and glycerol in order to select the best organic carbon source for growth promotion, and glycerol was selected for further experiments. The best glycerol dose for both biomass productivity and lipid production was 2.5 g L−1. To overcome the costs of the pure glycerol supply, the crude glycerol derived from a biodiesel production plant was also tested, as a low-cost alternative. Beside growth and photosynthetic parameters useful to monitor the algal conditions, lipid amount and profile were compared between autotrophic and pure/crude glycerol-treated algae. Interestingly, an almost doubled lipid content was accumulated in mixotrophic algae compared to the autotrophic ones. Moreover, an evident increase in a relatively short-chain fatty acid (C14:0, myristic acid), potentially useful for bio-jet fuels, and in a long-chain omega3-polyunsaturated fatty acid (C18:4; stearidonic acid), interesting for nutritional purposes, was highlighted in mixotrophic samples, especially when cultivated with crude glycerol. Differently, the fatty acid profile obtained from the autotrophic cultures suggested a preferable employment of the algal biomass for biodiesel production, owing to the prevalence of palmitic and palmitoleic acids. This study highlights that the mixotrophic cultivation of T. pseudonana drives the algal metabolism towards the production of different lipids, suitable for diversified applications. Moreover, the use of biodiesel-derived crude glycerol could make mixotrophy economically advantageous, in particular considering a bio-refinery approach.

The Possible Nephroprotective Effect of Roflumilast Ameliorating Glycerol -Induced Myoglobinuric Acute Renal Injury in Rabbits Model

urther leads to tissue necrosis and inflammation. While, roflumilast N-oxide is an active metabolite ofroflumilast that rising the cyclic adenosine-3?, 5?-monophosphate by inhibiting PDE4.Thirty rabbits were divided into three groups, control group was received normal saline intra-muscularly anddrived from water for eighteen hours before. Second group was received a single dose glycerol injected intramuscularly after drived from water for eighteen hours .Third group was received roflumilast intraperitonealdaily for three days after received a single dose of glycerol .All animals were sacrificed after 72 hour, and then blood collected by cardiac puncture for evaluation thechanges in the levels of renal function tests and histopathological study of rabbit’s kidneys tissues areevaluated evaluation and scoring the changes of tested agents. The numerical data are expressed as means ±standard error means and analyzed by using SPSS version 20.The results of the levels serum urea and creatinine found to be significantly reduced by roflumilast usingANOVA test. Besides, the histopathological changes showed ameliorative effects of roflumilast in comparedto glycerol group. From this study, one could be concluded the protective effect of roflumilast in case ofrenal failure induction by glycerol.

The quality of crude glycerine influences the fermentation and nutritive value of Piatã grass silage

ABSTRACT We aimed to evaluate the effects of crude glycerine purity and levels of glycerol on the fermentative profile, microorganisms counting, and nutritional value of Piata grass silage. The experiment was carried out in a 3×3+1 completely randomized factorial design using three different types of crude glycerine [low purity (40% of glycerol), medium purity (60% glycerol), and high purity (80% glycerol)], three doses of glycerol (20, 40, and 60 g/kg DM), and a control (no crude glycerine added) as an [...]

Phaeodactylum tricornutum cultivation under mixotrophic conditions with glycerol supplied with ultrafiltered digestate: A simple biorefinery approach recovering C and N

Phaeodactylum tricornutum was cultivated mixotrophically in batch mode providing glycerol as the C source, i.e., 0.02, 0.03 and 0.04 Mol L−1 glycerol, and ultrafiltered digestate (UF) as an N source. Biomass productivity, biomass composition, N efficiency use and total energy balance were recorded and compared to those under autotrophic conditions. Under mixotrophic conditions (0.03 Mol L-1 and 0.04 Mol L-1 glycerol), biomass productivity of P. tricornutum increased by 1.29 and 1.60 times in comparison with autotrophic conditions.Algal protein content declined as glycerol concentration increased, contrary to the case of the carbohydrate content. Lipid content did not change but unexpectedly, a lower unsaturated fatty acid in mixotrophic culture was observed than that from autotrophic culture. Mixotrophic conditions offered a higher energy recovery efficiency (EFt) than autotrophic conditions (5.7 % in 0.04 Mol L−1 glycerol and 4.2 % in autotrophic trial, respectively). Additionally, the efficiency of glycerol conversion into biomass (EFgly) increased with the glycerol dose, achieving 22.8 % for 0.04 Mol L−1 glycerol.

Administration of glycerol-based formulations in sheep results in similar ovulation rate to eCG but red blood cell indices may be affected

BackgroundThe objective of this study was to investigate the metabolic and osmotic effects of different doses of glycerol or a glycerol – propylene glycol mixture in Sarda sheep with the aim to identify those able to beneficially modify ewe’s metabolic status without harmful changes in red blood cell (RBC) indices. Thereafter, the selected doses were tested for their effects on ewe’s ovarian activity during an induced follicular phase and compared to the effects of a hormonal treatment with equine chorionic gonadotrophin (eCG).ResultsGlycerol was administered alone (G groups: 90% glycerol and 10% water; % v/v) or in combination with propylene glycol (M groups: 70% glycerol, 20% propylene glycol, 10% water; % v/v). Treatments were formulated to provide 100, 75, 50 and 25% of the amount of energy supplied in previous experiments. Obtained results showed that the formulations G75 and M75 (22.5 and 18.2% on DM basis, respectively) induce metabolic changes comparable to those induced by M100. The latter dose has been already evaluated for its effects on sheep metabolism and reproductive performance. However, with these high doses, plasma osmolality increased significantly, and RBC indices showed significant alterations. The low dose groups (G25 and M25, 8.6 and 6.9% on DM basis, respectively) did not show any alterations in plasma osmolality and RBC indices, but the metabolic milieu differed markedly from that of M100. Between the medium dose groups, M50 (12.9% on DM basis) showed a more comparable milieu to M100 than G50 (15.9% on DM basis) and no RBC alterations. Therefore, M75, G75 and M50 doses were tested for their effect on ovarian functions and proved to be equally effective as eCG.ConclusionThe results of the present study evidenced an alteration of RBC indices, and possibly of their functions, as a side effect of glycerol administration at high doses in the diet of ewes. Therefore, protocols foreseeing the administration of glycerol should be tested for their effects on RBC indices and functions. In general terms, the medium dose of the glucogenic mixture (12.9% of dietary DM on offer) should be preferred.

The Role of Vaccinium Myrtillus in the Prevention of Renal Injury in an Experimental Model of Ruptured Abdominal Aortic Aneurysm.

ObjectiveTo examine the biochemical and histopathological renal effects of ischemia/reperfusion (I/R) injury using a ruptured abdominal aortic aneurysm (RAAA) model in rats and to investigate the potential protective effects of whortleberry (Vaccinium myrtillus).MethodsThirty-two male Sprague-Dawley rats were randomly assigned into four groups - control, sham (I/R+glycerol), I/R, and I/R+whortleberry. Midline laparotomy alone was performed in the control group. Atraumatic abdominal clamps were attached under anesthesia to the abdominal aorta beneath the level of the renal artery in the groups subjected to I/R. Sixty-minute reperfusion was established one hour after ischemia. The sham group received five intraperitoneal doses of glycerol five days before I/R. The I/R+whortleberry group received a single intraperitoneal 50 mg/kg dose diluted with saline solution five days before I/R. All animals were finally euthanized by cervical dislocation following 60-min reperfusion.ResultsIncreases were observed in malondialdehyde (MDA) levels and tubular necrosis scores (TNS) in thin kidney tissues and in numbers of apoptotic renal tubule cells, together with a decrease in glutathione (GSH) levels, in sham and I/R groups. In contrast, we observed a decrease in MDA levels, TNS, and numbers of apoptotic renal tubule cells, and an increase in GSH levels with whortleberry treatment compared to the I/R group.ConclusionOur findings suggest that whortleberry may be effective against acute kidney injury by reducing oxidative stress and apoptosis.

The Role of Glycerol-Containing Drugs in Cerebral Microdialysis: A Retrospective Study on the Effects of Intravenously Administered Glycerol

BackgroundCerebral microdialysis (CMD) is a valuable tool for monitoring compounds in the cerebral extracellular fluid (ECF). Glycerol is one such compound which is regarded as a marker of cell membrane decomposition. Notably, in some acutely brain-injured patients, CMD-glycerol levels rise without any other apparent indication of cerebral deterioration. The aim of this study was to investigate whether this could be due to an association between CMD-glycerol levels and the administration of glycerol-containing drugs.MethodsMicrodialysis data were retrospectively retrieved from the hospital’s intensive care unit patient data management system (PDMS). All patients who were monitored with CMD for ≥ 96 h were included. Administered drug doses were retrieved from the PDMS and converted to exact doses of glycerol. Cross-correlation analyses were performed between the free, metabolized as well as total administered dose of glycerol and the detrended and differenced CMD-glycerol concentration. These analyses were repeated for two sets of subgroups based upon the individual catheter’s graphical trend and its location in relation to the lesion.ResultsThere was no significant correlation between the differenced CMD-glycerol levels and drug-administered glycerol. Furthermore, there was no significant correlation between CMD-glycerol and catheter location or graphical trend. However, if the CMD-glycerol levels were detrended, significant but clinically non-relevant correlations were identified (maximum correlation coefficient of 0.1 (0.04–0.15, 95% CI) at a lag of 7 h using the total administered dose of glycerol).ConclusionsGlycerol-containing drugs routinely administered intravenously in the clinical setting appear to have a minimal and clinically insignificant effect on levels of glycerol in the cerebral ECF.

Enhancing Biodiesel Production Using Green Glycerol-Enriched Calcium Oxide Catalyst: An Optimization Study

The present article demonstrates a superior catalytic performance of glycerol-enriched calcium oxide for biodiesel production than other calcium-based counterparts. The proficiency of glycerol-enriched calcium oxide in catalyzing the methanolysis of crude Jatropha curcas oil containing high free fatty acids content was systematically researched by examining the effects of glycerol dose, temperature, time, methanol-to-oil molar ratio and calcium oxide (CaO) amount on the process. Acid value of oil was lowered by 49 times and the maximum oil conversion of 96.1% was reported after the methanolysis reaction that indicated the improved performance of calcium oxide, after its treatment with glycerol, in accelerating biodiesel production from crude oil with very high free fatty acids amount. An interaction between the reaction variables, their influence on the methanolysis and optimum conditions affecting the process were moreover determined by means of the regression analysis (response surface methodology). The statistical analysis suggested that both CaO amount and mole ratio of methanol-to-oil had a significant impact on the current biodiesel production process.

INFLUENCE OF GLICEROL ON FUNCTIONAL-MORPHOLOGICAL INDICATORS OF KIDNEYS AT MODELLING RENAL INSUFFICIENCY IN RATS

It is known, that after acute damage of kidney there is a risk of development of chronic kidney desease and death rate from its complications.&#x0D; Material and methods. Research are spent on 40 not purebred rats at modelling of acute damage of the kidneys caused by toxic doses of glycerol. To evaluate histopathologal changes , we used cuts of fabrics painted gematoksilin- eozinom. Ultrathin preparations analyzed in electronic microscope PЕМ-125К.&#x0D; Results. Administration of glycerol leads to uremia with dystrophic changes in tubular device and glomerular hypertrophy. At a stage of chronic renal insufficiency reduction of the glomerular sizes, tubulointerstitial fibrosis and glomerulosclerosis is observed.&#x0D; Conclusion. At modelling of a nephritic pathology by introduction of 50 % glycerol infringement of function of kidneys has phasic character with probable development of chronic kidney desease in 8 weeks.

World demand for lithium growing rapidly as energy storage needs skyrocket.

Experimental research and energy plans show that the residues of rice parboiling industries in Brazil have the energy potential to promote the sector's self-sufficiency. The studies investigate the production of biogas from the anaerobic digestion of wastewater and its anaerobic sludge. There are no reports of the investigation to optimize such production by adding glycerol. This addition can increase methane production; however, high proportions of crude glycerol can cause inhibition of microbial activity. Considering that anaerobic sludge acts as inoculum in the digestion of effluent in treatment plants, the main goal of this study was to test the feasibility of adding crude glycerol from the production of rice bran biodiesel in anaerobic digestion with sludge. The reactors operated with different proportions of crude glycerol (0%, 1%, 2%, and 3%). The highest methane production occurred in the system with 1% glycerol, 945.23 ± 5.34 mL, in 168 h – a production 539.45% higher when compared to the system without glycerol. Higher doses of glycerol resulted in fast interruption of methanogenic activity. The study determined that the addition of 1% glycerol was able to prolong the duration of the stationary phase of methanogenic microorganisms. Thus, the high energy potential of the sector can be significantly increased with the addition of the biodiesel by-product in anaerobic digestion. Such a possibility could guarantee greater security, energy autonomy, the possibility of generating revenue from the sale of surplus methane or electricity, and an environmentally proper destination for crude glycerol.

Glycerol-enhanced microwave heating for ultra-rapid effective remediation of marine sediments highly contaminated with hydrocarbons

Abstract In this study, a new enhanced MW heating treatment using glycerol was proposed and investigated in the remediation of marine sediments highly contaminated with hydrocarbons. The heating and contaminant removal performance of different treatments using varying glycerol doses were compared. The results showed that the addition of glycerol in sediments largely promoted the MW absorbing performance that corresponded to a large increase in temperature (up to ∼120 °C) with a maximum sediment temperature of 342 °C. This allowed much faster contaminant removal kinetic to be obtained. A glycerol dose of 5% led to drastically lowered contaminant residual concentrations of 6454 (R = ∼81%), 770 (R = ∼98%) and 12 (R > 99%) mg kg −1 after 3, 5 and 10 min, respectively, demonstrating that ∼5 min were sufficient to reach the regulatory remediation target. A further dose increase (10%) led to a required time of 3 min (R > 99%), which corresponded to almost half of the MW energy required respect to the unenhanced MW. The main advantage of MW/glycerol treatment is the possibility to obtain a very rapid and effective decontamination process potentially reducing energy costs, also in the case of a very high initial hydrocarbon concentration, without producing additional by-products (respect to MW alone), which in some cases can be toxic. A comparison with other available clean-up alternatives revealed that literature does not report similar rapid and at the same time effective treatments for hydrocarbon-contaminated sediments.

Re-evaluation of glycerol (E422) as a food additive.

The ANS Panel provides a scientific opinion re‐evaluating the safety of glycerol (E 422) used as a food additive. In 1981, the Scientific Committee on Food (SCF) endorsed the conclusion from the Joint FAO/WHO Expert Committee on Food Additives (JECFA) in 1976 of ‘acceptable daily intake (ADI) for man not specified’. The Panel concluded that glycerol has low acute toxicity and that local irritating effects of glycerol in the gastrointestinal tract reported in some gavage studies was likely due to hygroscopic and osmotic effects of glycerol. Glycerol did not raise concern with respect to genotoxicity and was of no concern with regard to carcinogenicity. Reproductive and prenatal developmental studies were limited to conclude on reproductive toxicity but no dose‐related adverse effects were reported. None of the animal studies available identified an adverse effect for glycerol. The Panel conservatively estimated the lowest oral dose of glycerol required for therapeutic effect to be 125 mg/kg bw per hour and noted that infants and toddlers can be exposed to that dose by drinking less than the volume of one can (330 mL) of a flavoured drink. The Panel concluded that there is no need for a numerical ADI and no safety concern regarding the use of glycerol (E 422) as a food additive at the refined exposure assessment for the reported uses. The Panel also concluded that the manufacturing process of glycerol should not allow the production of a food additive, which contains genotoxic and carcinogenic residuals at a level which would result in a margin of exposure below 10,000. The Panel recommended modification of the EU specifications for E 422. The Panel also recommended that more information on uses and use levels and analytical data should be made available to the Panel.

Biodegradation of deproteinized potato wastewater and glycerol during cultivation of Rhodotorula glutinis yeast

Background: Deproteinized potato wastewater and glycerol are two by-products which are difficult to dispose. The objective of this study was to determine the ability of Rhodotorula glutinis to use glycerol and nitrogen compounds present in deproteinized potato wastewater and to evaluate the ability of simultaneous biodegradation of potato wastewater and glycerol via microbiological methods. Results: It has been found that R. glutinis used glycerol and potato wastewater as a source of carbon and nitrogen, respectively. The highest degree of glycerol content (70.6%) reduction was found after cultivation of the investigated strain using a medium with 5% glycerol. In this medium, a significant reduction in the total protein content, estimated at 61%, was observed. The process of 72 h cultivation of yeast in a medium containing potato wastewater and 5% glycerol reduced the chemical oxygen demand (COD) more than 77%. Supplementation of media with high doses of glycerol ( i.e. 20 and 25%) led to decreased metabolic activity in the yeast strain tested. Conclusion: It has been found that there is a possibility of simultaneous biodegradation of potato wastewater and glycerol during the cultivation of R. glutinis .

Nephroprotective effect of ethanolic extract of Azima tetracantha root in glycerol induced acute renal failure in Wistar albino rats

The gravity of the impact of renal failure on human health is well known and as there is no specific pharmacotherapy for renal failure, the current study was undertaken to evaluate the effect of root extract of Azima tetracantha, an ancient medicinal plant used in Siddha and Ayurvedhic systems of medicine.The experiment was done in glycerol-induced acute renal failure in Wistar albino rats. Thirty rats were divided into five groups. Group 1 was given normal saline (10 ml/kg) per oral, group 2 with single dose of hypertonic glycerol (8 ml/kg) by intramuscular injection into the hind limbs, group 3 with glycerol and ethanolic extract of A. tetracantha root (ATR) 250 mg/kg, group 4, glycerol and ATR 500 mg/kg and group 5, 500 mg/kg ATR. Extract was given orally 60 min prior to glycerol injection. 24 h urine output, serum creatinine, blood urea nitrogen, total proteins and albumin were measured for all the groups. Kidneys were examined for histopathological changes.The antioxidant activity of the extract was tested in vitro and in vivo. Rats treated with ATR showed significant improvement in biochemical parameters and histopathological changes compared to glycerol treated group. The protective effect was highly significant at 500 mg/kg. Both in vitro and in vivo assays showed significant antioxidant activity. The in vitro activity was comparable to vitamin-C.The ethanolic extract of ATR has nephroprotective effect in glycerol-induced acute renal failure and the mechanism of action could be the antioxidant effect.

The comparison of propylene glycol and glycerol as feed additives in early lactation of high producing dairy cows

The aim of this study was to compare the antiketogenic effect of glycerol and propylene glycol after parturition. Two experiments were carried out on 36 Holstein cows. In each experiment there were 18 dairy cows receiving daily 300 ml of propylene glycol and either 500 or 1000 ml of glycerol during the first month of lactation. Blood was taken on weeks 1, 2, 3, and rumen fluid, on week 3 after parturition. A similar antiketogenic effect of 300 ml of propylene glycol and 500 ml of glycerol was observed. Although no negative effects of high doses of glycerol (1000 ml · d -1 ) on metabolism, ruminal fermentation, or liver parenchyma were found, there were no additional positive effects over the 500 ml dose. The results indicate that glycerol is an appropriate alternative for cattle to prevent energy deficiency in the early lactation period, while increasing the daily glycerol dose from 500 to 1000 ml has no beneficial effect.