Optimization of Extraction Conditions of Pomegranate Peel Polyphenols and Its Protective Effect on Acute Alcoholic Liver Injury in Mice

[Objectives]This study was conducted to explore the optimization of ultrasonic-assisted organic solvent extraction of pomegranate peel polyphenols(PPPs),and to study the protective effect of PPPs on acute alcoholic liver injury in mice.[Methods]The optimal extraction conditions of PPPs were determined by single factor and orthogonal experiments,and an acute alcoholic liver injury model in mice was established.Bifendate was used as the positive control group to investigate the protective effect of low,medium and high doses of PPPs on acute alcoholic liver injury.[Results]The optimum extraction process parameters were followed as 60%ethanol concentration,solid-liquid ratio of 1:40(w/v),extraction temperature of 50℃,and extraction time of 1.5 h,and the yield was 1.42%.The results of animal experiments showed that PPPs could effectively reduce the degree of alcoholic liver injury in mice,reduce the levels of serum alanine aminotransferase(ALT)and aspartate aminotransferase(AST),and reduce the inflammation and necrosis of liver tissue in mice.Meanwhile,the total polyphenols from pomegranate peel also significantly reduced the expression levels of malondialdehyde(MDA),tumor necrosis factor(TNF-α)and interleukin-6(IL-6)in mice,and increased the levels of superoxide dismutase(SOD)and reduced glutathione(GSH)in liver tissue of mice,indicating its antioxidant and anti-inflammatory effects,further illustrating its protective effect on alcoholic liver injury.[Conclusions]PPPs could reduce the expression levels of TNF-α,IL-6 and MDA in mice,and increase the expression levels of SOD and GSH to achieve the protective effect on acute alcoholic liver injury in mice.This study will provide new ideas for the development of new anti-alcoholic liver injury drug resources.

Pomegranate peel polyphenols alleviate insulin resistance through the promotion of insulin signaling pathway in skeletal muscle of metabolic syndrome rats

Insulin resistance(IR) has been considered to be an important causative factor of metabolic syndrome(Met S). The present study investigated whether pomegranate peel polyphenols(PPPs) could prevent the development of Met S by improving IR in rats. Male Sprague-Dawley(SD) rats were fed high fat diet(HFD) to induce Met S and supplemented with different dosages of PPPs for 12 weeks. The results showed that HFD-induced insulin resistant rats had disordered metabolism of blood glucose, blood lipid, and terrible muscle fiber morphology when compared with normal diet-fed rats, but PPPs treatment at a dosage of 300 mg/kg·day significantly reversed these negative effects. Moreover, in skeletal muscle tissue of insulin resistant rats, PPPs treatments significantly increased the protein expressions of insulin receptor(Ins R) and phosphorylated insulin receptor substrate 1(IRS-1), stimulated peroxisome proliferator activated receptor gamma(PPARγ) and phosphoinositide 3-kinase(PI3K)/protein kinase B(AKT/PKB) signaling pathway, and aggrandized the protein levels of phosphorylated glycogen synthase kinase-3β(GSK-3β) and glucose transporter 4(GLUT4). Our results suggest that PPPs possess of the beneficial effects on alleviating IR by enhancing insulin sensitivity and regulating glucose metabolism.

Extraction of Effective Ingredient from Pomegranate Peels and Its Whitening Effect

[ Objective] This study aimed to extract the effective ingredient of pomegranate peels and explore its whitening effect. [ Method] Pomegranate peels were used as materials for single factor experiment to determine the optimal technique for effective ingredient extraction from pomegranate peels and explore the inhibition of the extracts on tyrosinase and whitening effect of the effective ingredient of pomegranate peels. [ Result] The optimal conditions for ultrasound-assisted extraction of effective ingredient in pomegranate peels were： liquid-to-solid ratio of 1：20 with 60% ethanol, extraction temperature of 60℃, ultrasonic intensity of 7 and pro- cessing time of 40 min, which led to relatively strong inhibition effect of pomegranate peel extracts on tyrosinase. The inhibition rate of extracts obtained with com- mon solvent reflux extraction method was only around 60%, while the inhibition rate of extracts obtained with ultrasound-assisted extraction method on tyrosinase ac- tivity had achieved around 90%, showing a very significant the difference, which indicated that during the process of extraction of effective ingredient from pome- granate peels, appropriate ultrasound-assistance was advantageous to the extraction of active ingredients; in addition, the inhibition effect of extracts on tyrosinase had increased with the increasing concentration of extracts, and the inhibition rate could achieve 100%. [ Condusion] This study provided a certain theoretical ba- sis for the utilization of pomegranate peels as natural green materials to develop whitening cosmetics.

Growth Performance and Digestibility in Karadi Lambs Receiving Different Levels of Pomegranate Peels

The objective of current study was to determine the effect of different ratios of pomegranate peel in diets of Karadi lambs (0%, 1%, 2% or 4% as control, T1, T2 and T3, respectively) on body weight, total body gain, average daily gain, daily feed intake and apparent digestibility of nutrients. Sixteen Karadi male lambs weighing 23.29 ± 0.42 kg and 4.5-5 months old randomly divided into equally four treatment groups and individually penned for the period of 63 days. Results indicated that final body weight was significantly (P < 0.05) higher in lambs fed 1% or 2% pomegranate peel (PP) as compared to lambs fed 4% PP. The best improvements in total feed intake, total gain, average daily gain and feed conversion ratio (FCR) in lambs fed 1% PP. The total dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), ash, nitrogen free extract (NFE) and metabolizable energy (ME) intake per (body weight0.75) increased (P < 0.05) significantly in lambs fed 1% pomegranate peel (PP);however, the crude fiber (CF) intake decreased in lambs fed 1% PP as compared to other treatments. While, the dry matter digestibility (DMD), crude protein digestibility (CPD), crude fiber digestibility (CFD) and nitrogen free extract digestibility (NFED) were significantly (P < 0.05) higher in lambs fed 1% PP as compared to T2, T3 and control groups. In addition, EED increased significantly in T3 compared to other treatments. In conclusion, it was indicated that addition of pomegranate peel in diet at the rate of 1% or 2% had significant effect on Karadi lambs performance and digestibility.

Methanolic pomegranate dried peel extract improves cryopreserved semen quality and antioxidant capacity of rams

Objective:To select the appropriate concentrations of methanolic pomegranate extract supplemented in rams’semen extender for obtaining the best-cryopreserved semen quality.Methods:Tris-based semen extender was supplemented with 0.0,0.40,0.48,and 0.56 mg/mL pomegranate peel methanolic extract to extend semen collected from five native rams twice weekly for two months(n=80).Pooled(n=16)post-thaw semen characteristics were determined.Thawed seminal plasma of all supplemented and control groups were used to measure malondialdehyde(MDA),nitric oxide(NO),glutathione peroxidase(GPx),superoxide dismutase(SOD),ascorbic acid,zinc,copper,total cholesterol,low-density lipoproteins(LDL),lactate dehydrogenase(LDH),and alkaline phosphatase(ALP).Results:The supplementation of Tris-based semen extender with 0.48 mg/mL semen extender resulted in the highest post-thaw sperm total motility(P<0.001),sperm progressive motility(P<0.001),live sperm(P<0.001),sperm plasma membrane integrity(P<0.001),acrosome integrity(P<0.001),SOD(P<0.05),zinc(P<0.001),total cholesterol(P<0.001),and LDL(P<0.001)with the lowest percentage of abnormal sperm morphology(P<0.001),the lowest lipid peroxidation(MDA,P<0.01),ascorbic acid(P>0.05),and LDH(P>0.05).Conclusions:Pomegranate peel methanolic extract 0.48 mg/mL supplemented to Tris-based semen extender of rams is the best enrichment in preserving the sperm post-thaw characteristics via improving biochemical profiles and antioxidant capacity.

Effect of pomegranate peel extract on the reduction of heterocyclic amines and quality characteristics of mutton meatballs

Pomegranate peel extract(PPE),rich in phenolic compounds,is an undervalued byproduct derived from processing pomegranates.However,there are very few studies on the inhibitory effect of PPE on harmful substances during meat processing.This study was intended to investigate the influence of different concentrations of PPE(0.50%,1%,and 1.50%)on the generation of heterocyclic amines(HCAs)and some quality attributes in mutton meatballs.All samples with the addition of PPE(0,0.50%,1%,and 1.50%)were fried for different lengths of time(2.5 min and 5 min)at 175±5 C,and the contents of fourteen HCAs,color,thiobarbituric acid reactive substances,and carbonyl values of fried mutton meatballs were evaluated.The results showed that samples fried at 2.5 min had a low HCA content,and the HCA content enhanced signifi-cantly when the frying time was increased from 2.5 to 5 min(P<0.05).In comparison with the control group,PPE could significantly inhibit the generation of total HCAs in fried mutton meatballs(P<0.05),and the total HCAs content decreased with increasing PPE concentration.PPE significantly reduced carbonyl andTBARS values in fried mutton meatballs(P<0.05).Moreover,PPE resulted in a significant increase in a*and b*values as well as a decrease in L*values in fried mutton meatballs(P<0.05).In conclusion,PPE could inhibit the formation of HCAs and improve the quality of mutton meatballs,and could be considered as a natural inhibitor of HCAs in fried meat products.

Optimization of enzyme assisted extraction of polysaccharides from pomegranate peel by response surface methodology and their anti-oxidant potential

Objective： To optimize the enzymatic extraction conditions of polysaccharides from pomegranate peel using response surface methodology（RSM）, and invest the anti-oxidant activity of pomegranate peel polysaccharide in vitro for seeking novel biological components used as pharmaceutical products and functional foods.Methods： Effects of enzymolysis time, ratio of water to raw material, and the dosage of cellulase on the extraction yield of pomegranate peel polysaccharide were fully examined by Box-Behnken design of RSM. DPPH radical scavenging activity, hydroxyl radicals scavenging activity, superoxide anion radical scavenging activity, and reducing power assay were measured by microplate reader.Results： The optimal extraction conditions were as follows： enzymolysis temperature 55 °C, pH 5.0,enzymolysis time 88 min, ratio of water to raw material 22：1 mL/g, and dosage of cellulose 0.93%. Under the optimal extraction conditions, the yield of pomegranate peel polysaccharide was（22.31 ± 0.07）%,which was well matched with the predicted value 22.35% of the Box-Behnken design model. Also,pomegranate peel polysaccharide demonstrated appreciable anti-oxidant potential on DPPH（1,1-diphenyl-2-picrylhydrazyl） radical scavenging, hydroxyl radical scavenging, superoxide anion radical scavenging and reducing power in vitro.Conclusions： An optimized enzymolysis assisted method was proposed for the extraction of pomegranate peel polysaccharide, which can be used as a good anti-oxidant.

Adsorptive removal of phosphate by the bimetallic hydroxide nanocomposites embedded in pomegranate peel

This study aimed to fabricate new and effective material for the efficiency of phosphate adsorption.Two types of adsorbent materials,the zirconium hydroxides embedded in pomegranate peel(Zr/Peel)and zirconium-lanthanum hydroxides embedded in pomegranate peel(Zr-La/Peel)were developed.Scanning electronic microscopy(SEM),x-ray photoelectron spectroscopy(XPS)and x-ray diffraction(XRD)were evaluated to give insight into the physicochemical properties of these adsorbents.Zr-La/Peel exceeded the adsorption efficiency of Zr/Peel adsorbents in batch adsorption experiments at the same pH level.The peel as a host can strive to have a strong"shielding effect"to increase the steadiness of the entrenched Zr and La elements.La and Zr are hydroxide metals that emit many hydrogen ions during the hydrolysis reaction,which contribute to protonation and electrostatic attraction.The highest adsorption capacity of La-Zr/Peel for phosphate was calculated to be40.21 mg/g,and pseudo second-order equation is very well fitted for kinetic adsorption.Phosphate adsorption efficiency was reduced by an increase of pH.With the background of coexisting Cl-,little effect on adsorption efficiency was observed,while adsorption capacities were reduced by almost 20-30%with the coexistence of SO42-,NO3-and humic acid(HA).

Effect of pomegranate peel polyphenol gel on cutaneous wound healing in alloxan-induced diabetic rats

Background Pomegranate （punica granatum） belongs to the family Punicaceae, and its peel has been used as a traditional Chinese medicine because of its efficacy in restraining intestine, promoting hemostasis, and killing parasites. Pomegranate peel has been reported to possess wound-healing properties which are mainly attributed to its polyphenol extracts. The purpose of this study was to investigate the effect of pomegranate peel polyphenols （PPP） gel on cutaneous wound healing in diabetic rats. Methods AIIoxan-induced diabetic rats were given incisional wounds on each side of the mid-back and then treated daily with PPP gel （polyphenol mass fraction =30%） post-wounding. Rats were sacrificed on days 4, 7, 14, and 21 post-wounding to assess the rates of wound closure, histological characteristics; and to detect the contents of hydroxyproline, production of nitric oxide （NO）, and activities of NO synthase （NOS）, as well as the expressions of transforming growth factor-β1 （TGF-β1）, vascular endothelial growth factor （VEGF）, and epidermal growth factor （EGF） in wound tissue. Results Wound closure was significantly shortened when PPP gel was applied to the wounds of diabetic rats. Histological examination showed the ability of PPP gel to increase fibroblast infiltration, collagen regeneration, vascularization, and epithelialization in the wound area of diabetic rats. In addition, PPP gel-treated diabetic rats showed increased contents of hydroxyproline, production of NO, and activities of NOS and increased expressions of TGF-β1, VEGF, and EGF in wound tissues. Conclusion PPP gel may be a beneficial method for treating wound disorders associated with diabetes.

Effect of pulsed ultrasound assisted extraction and aqueous acetone mixture on total hydrolysable tannins from pomegranate peel

Pomegranate peels are disposed of as waste even though it is an eminent source of total hydrolysable tannins(THT)and possesses a great worth for recycling.The present study was carried out with the hypothesis that pulsed system ultrasound-assisted extraction(PSUAE)technique optimization would aid in retaining high extract yield and THT recovery yield from pomegranate peel extract(PPE)with enhanced antioxidant potential.The extraction was performed at various conditions regarding solvent concentration(30-90% of acetone),solvent-feed ratio(10-30 mL/g),extraction time(10-20 min),and ultrasound amplitude(40-80%)for maximum extract yield,THT and antioxidant activity(AA).To model and optimize the process conditions tools namely response surface methodology(RSM)and artificial neural network(ANN)were applied.For solvent concentration,solvent-feed ratio,extraction time,and amplitude the optimal conditions attained with aid of RSM and ANN were:56%,26.5 mL/g,15 min,55%,and 45%,23 mL/g,15 min,50% respectively.The extract yield and THT content determined with RSM and ANN optimized values were 51.2%,86.4 mg TAE/g,and 62%,98.1 mg TAE/g,respectively.The mean square error value displayed the minimum and R^(2) exhibited maximum value in case of ANN compared to RSM model.PSUAE significantly augmented the AA of PPE to 77.2±0.50% compared to 49.7±0.35% of conventional extraction.FTIR and HPLC analysis established that PPE produced from PSUAE contains a significant amount of THT compounds(gallic acid and tannic acid derivative).SEM elucidated that the sonication effect resulted in peel cell wall disruptions ensuing in elevated extraction of THT.Therefore,this pulsed mode of ultrasound extraction could be regarded as an easy,cost-effective,and competent technique for the extraction of preferred natural THT from pomegranate peels that possess high prospective to be applied in food and nutraceutical formulations.