Standardization of the conditions for extraction of polyphenols from pomegranate peel

Anticancer effect of polyphenolic acid enriched fractions from Grewia bracteata Roth on tumor cells and their p53 gene independent ROS mediated apoptosis in colon cancer cells

It is the first report on leaves of Grewia bracteata Roth for its anticancer effect. In this study, three polarity-guided solvent extracts of Grewia bracteata leaves from n-hexane (GLH), ethyl acetate (GLE), and methanol (GLM) were screened for anticancer effects on HeLa, HCT-116, MCF-7, HCT-116 p53-/- and PC-3 cells via methyl thiazoldiphenyltetrazolium bromide (MTT) assay. Based on the results, GLM was fractionated, and the obtained fractions were tested on HCT-116 cells. Further, FT-IR, HPLC analysis, clonogenic assay, wound healing assay, DCFDA, and cell cycle experiments were conducted on HCT-116 cells. The extracts from methanol (GLM) and ethyl-acetate (GLE) demonstrated a more selective and promising inhibition on HCT-116 cells than others. Notably, GLM recorded superior inhibition on HCT-116 p53-/- than GLE. Amongst, the methanol column fraction (GMCF) showed prominent inhibition on HCT-116 (IC50:63.55 ± 0.61 μg/ml) and HCT-116 p53-/- (IC50: 84.51 ± 0.58 μg/ml) cells. Further, the test on normal cells (NKE) revealed minimal toxicity of GMCF. The phytochemical test, FT-IR, HPLC, and LC-HRMS analyses confirmed the high abundance of polyphenolic acid/polyphenols in GMCF. Further, the clonogenic and wound healing assays on HCT-116 cells were also performed. Later, the probable cell death mechanism was identified using DCFDA and cell cycle experiments. These experiments disclosed that GMCF induced HCT-116 cell death was probably due to reactive oxygen species (ROS) upregulation and cells cycle arrest at SubG0 phase. It inferred that the activity is most probably p53 independent, a tumor suppressor gene responsible for drug resistance in colon cancer.

Pomegranate (Punica granatum L.) peel extract ameliorates metabolic syndrome risk factors in patients with non-alcoholic fatty liver disease: a randomized double-blind clinical trial

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) is a metabolic syndrome (MS)-related liver disorder that has an increasing prevalence. Thus, the aim of our study is to evaluate the effects of pomegranate peel extract (PP) supplementation on hepatic status and metabolic syndrome risk factors.

METHODS

In phase one, the hydro-alcoholic extraction of the peel of 750 kg of pomegranate (Punica granatum L.) was performed by the soaking method. Then, in phase two, NAFLD patients received 1500 mg of placebo (n = 37) or pomegranate peel capsules (n = 39) with a 500-kcal deficit diet for 8 weeks. Gastrointestinal intolerance, dietary intake, lipid and glycemic profiles, systolic and diastolic blood pressure, body composition, insulin resistance indexes, and elastography-evaluated NAFLD changes were followed.

RESULTS

The mean age of participants was 43.1 ± 8.6 years (51.3% female). Following the intervention, the mean body weight (mean changes: -5.10 ± 2.30 kg), waist circumference (-7.57 ± 2.97 cm), body mass index (-1.82 ± 0.85 kg/m2), body fat index (-1.49 ± 0.86), and trunk fat (- 3.93 ± 3.07%), systolic (-0.63 ± 0.29 cmHg) and diastolic (-0.39 ± 0.19 cmHg) blood pressure, total cholesterol (-10.51 ± 0.77 mg/dl), triglyceride (-16.02 ± 1.7 mg/dl), low-density lipoprotein cholesterol (-9.33 ± 6.66 mg/dl; all P < 0.001), fat free mass (- 0.92 ± 0.90 kg; P < 0.003), and fasting blood sugar (-5.28 ± 1.36 mg/dl; P = 0.02) decreased significantly in PP in contrast to the placebo group in the raw model and when adjusted for confounders. Also, high-density lipoprotein cholesterol (5.10 ± 0.36 mg/dl), liver steatosis and stiffness (- 0.30 ± 0.17 and - 0.72 ± 0.35 kPa, respectively, all P < 0.001) improved in the PP group. However, fasting insulin (P = 0.81) and homeostatic model assessment for insulin resistance (HOMA-IR) (P = 0.93) were not significantly different when comparing two groups during the study in the raw and even adjusted models.

CONCLUSION

In conclusion, 1500 mg pomegranate peel extract along with a weight-loss diet improved metabolic syndrome risk factors and reduced hepatic steatosis in patients with NAFLD after 8 weeks.

Anticancer Effect of Pomegranate Peel Polyphenols against Cervical Cancer

Polyphenols are a broad group of bioactive phytochemicals with powerful antioxidant, anti-inflammatory, immunomodulatory, and antiviral activities. Numerous studies have demonstrated that polyphenol extracts obtained from natural sources can be used for the prevention and treatment of cancer. Pomegranate peel extract is an excellent source of polyphenols, such as punicalagin, punicalin, ellagic acid, and caffeic acid, among others. These phenolic compounds have antineoplastic activity in in vitro models of cervical cancer through the regulation of cellular redox balance, induction of apoptosis, cell cycle arrest, and modulation of different signaling pathways. The current review summarizes recent data from scientific reports that address the anticancer activity of the predominant polyphenol compounds present in PPE and their different mechanisms of action in cervical cancer models.

Response Surface Methodology Applied to the Optimization of the Preparation of Antioxidant and Antidiabetic Extracts from Phragmanthera capitata (Spreng.) Balle: Effect of Particle Size, Powder-to-Solvent Ratio, and Temperature

Phragmanthera capitata is a medicinal plant used in traditional medicine to treat several diseases, including diabetes. Its antioxidant properties and inhibitory effects on enzyme-carbohydrate digestion activities have been demonstrated. The present study aimed to provide data that can contribute to rationalizing the preparation of antioxidant and antidiabetic extracts from this plant. P. capitata (whole plant) growing on Persea americana was harvested at the fruiting stage. A response surface design-type central composite was applied to maximize the extraction yield, phenolic contents, and antioxidant and antidiabetic properties of the ethyl acetate extract of P. capitata. The influencing extraction factors were temperature, powder particle size, and solvent-to-powder ratio. The total phenolic content, total antioxidant capacity (TAC), DPPH scavenging ability, ferric reducing antioxidant power (FRAP), and antidiabetic (α-amylase and α-glucosidase inhibitory) effects of the extracts were determined using conventional methods. A temperature above 55°C contributed to the degradation of the extract, which was reflected in the GC-MS profile by a significant reduction in the number of compounds it contained. The optimal conditions were defined as 24.42°C for temperature, 250 µm powder particle size, and 8.30 (v:w) solvent-to-powder ratio. This extraction protocol resulted in more than twice the extraction yield (3.05%), TTC (62.30 mg TAE/g), TAC (41.41 mg AAE/g), FRAP (186.56 mg AAE/g), and α-amylase (IC₅₀ 15.05 µg/mL) and α-glucosidase (IC₅₀ 21.14 µg/mL) inhibitory activities compared to our previous results. Additionally, these optimal conditions led experimentally to the extraction of higher phenolic content and to the attainment of higher antioxidant and antidiabetic activity, which closely matched the predicted values. Using these conditions, it is possible to prepare an antidiabetic phytomedicine from P. capitatathat can prevent oxidative stress complications. However, further complementary studies should be carried out considering other factors that influence the composition and pharmacological properties of the extract.

Pomegranate Peels and Seeds as a Source of Phenolic Compounds: Effect of Cultivar, By-Product, and Extraction Solvent

The nutraceutical properties of Punica granatum L. are not restricted to the edible portion of the fruit but also to the peels and seeds, flowers, leaves, and tree bark. The recovery and valorization of the peel and seeds (ca. 50% of the whole fruit), besides the positive environmental impact, can be viewed as a source of natural bioactive compounds. Thus, the bioactive properties of extracts of pomegranate peel and seeds from Acco and Wonderful known cultivars, as well as of the novel Big Full cultivar, were evaluated. The dried and ground pomegranate by-products were submitted to a conventional solid/liquid extraction with ethanol/water mixtures (0%, 25%, 50%, and 75% of EtOH, v/v). The obtained extracts were characterized in terms of total phenolic compounds (TPC), total flavonoids (TF), and antioxidant activity (AA), determined by the DPPH radical scavenging activity and expressed as IC50 (half maximum inhibitory concentration). With the exception of the Acco cultivar, the extraction yield (EY) was higher for peels, whose extracts showed higher TPC, TF, and IC50 (lower AA). The extracts obtained from the by-products of the Big Full cultivar had a statistically higher overall bioactive potential (TPC: 0.36 mg GAE/mg extract; TF: 0.031 mg CATE/mg extract; IC50: 0.51 mg/mL) compared to the other two studied cultivars. Furthermore, the EY was enhanced by solvents richer in ethanol (50-75%), allowing obtaining extracts richer in TPC and TF with higher AA. Finally, it was shown that EY combined with bioactive data allowed a satisfactory principal component unsupervised differentiation of the pomegranate extracts according to the type of by-product used.

Effects of drying methods and solvent extraction on quantification of major bioactive compounds in pomegranate peel waste using HPLC

Bioactive compound characterization is an essential step for utilizing pomegranate peel waste as food and nutraceuticals ingredients. In the present investigation, the effects of different drying methods (freeze, tray-oven, and sun) and extraction solvents such as methanol, ethanol, water, acetone, and hexane were investigated on the extraction and recovery of major bioactive compounds (ellagic acid, gallic acid, quercetin, and punicalagin) of pomegranate peel for two pomegranate varieties (i.e., Bhagwa and Ganesh) using high-performance liquid chromatography (HPLC). The results indicated that the freeze dried pomegranate peel powder of both pomegranate varities potential to extraction higher amount of bioactive compounds with methanol as extraction solvent as compared to other drying methods and solvents. Freeze-dried peel powder of Bhagwa pomegranate showed a higher amount of gallic acid (32.2 mg/g), ellagic acid (13.6 mg/g), punicalagin (15.2 mg/g), and quercetin (2.5 mg/g) with methanol solvent as compared to the other extract of Bhagwa and Ganesh varieties. The basis on the results of the current study, it can be concluded that the freeze-drying method of drying pomegranate peel powder and methanol as an extraction solvent are effective to recover higher amounts of bioactive compounds that can be utilized in food and pharmaceutical sectors at commercial scale.

Enhanced Skin Permeation of Punicalagin after Topical Application of Pluronic Micelles or Vesicles Loaded with Lafoensia pacari Extract

Punicalagin, the principal ellagitannin of Lafoensia pacari leaves, has proven antioxidant activity, and standardized extracts of L. pacari can be topically used for skin aging management. We hypothesized that Pluronic nanomicelles or vesicles could solubilize sufficiently large amounts of the standardized extracts of L. pacari and provide chemical stability to punicalagin. The standardized extracts of L. pacari were obtained with an optimized extraction procedure, and the antioxidant activity was characterized. Formulations containing Pluronic at 25% and 35% were obtained with or without Span 80. They were characterized by average diameter, polydispersity index, punicalagin content, physicochemical stability, and rheology. A release and skin permeation study was carried out in vertical diffusion cells. The extraction procedure allowed quantifying high punicalagin content (i.e., 141.61 ± 3.87 mg/g). The standardized extracts of L. pacari showed antioxidant activity for all evaluated methods. Pluronic at 25 and Pluronic at 35 with standardized extracts of L. pacari showed an average diameter of about 25 nm. The addition of Span 80 significantly increased the mean diameter by 15-fold (p < 0.05), indicating the spontaneous formation of vesicles. Pluronic formulations significantly protected punicalagin from chemical degradation (p < 0.05). Pluronic at 25 formulations presented as free-flowing liquid-like systems, while Pluronic at 35 resulted in an increase of about 44-fold in |ƞ*|. The addition of Span 80 significantly reduced the Pluronic sol-gel transition temperature (p < 0.05), indicating the formation of vesicles. Formulations with Span 80 significantly enhanced punicalagin skin permeation compared to formulations without Span 80 (p < 0.05). Formulations with Span 80 were demonstrated to be the most promising formulations, as they allowed significant permeation of punicalagin (about 80 to 315 µg/cm²), which has been shown to have antioxidant activity.

The shelf life of buffalo meat marinated with pomegranate (Punica granatum) peel extract

Objective:

The purpose of this study was to investigate how pomegranate peel extract (PPE) can prevent lipid oxidation, peroxide value, and pathogenic bacteria growth in buffalo meat.

Materials and Methods:

PPE and buffalo meat were employed in this investigation. The buffalo meat marinated with PPE was evaluated by refrigerating it at a temperature of 5°C ± 1°C on days 0, 4, 8, 12, and 16. PPE was added to buffalo meat at a rate of 0% as a control (K0), 0.50% (K1), 1.00% (K2), 1.50% (K3), and 2.00% (K4).

Results:

The addition of PPE lowered the total plate count, peroxide value, lipid, and pH between treatments and storage period (p < 0.05). PPE’s high concentration of polyphenols, flavonoids, antioxidants, and antibacterial substances may decrease lipid oxidation, peroxide production, and bacterial growth rate.

Conclusions:

Marinating buffalo meat in PPE may help maintain the meat’s freshness while being stored at a refrigerator temperature (5°C ± 1°C).

The Antimicrobial Effect of Pomegranate Peel Extract versus Chlorhexidine in High Caries Risk Individuals Using Quantitative Real-Time Polymerase Chain Reaction: A Randomized Triple-Blind Controlled Clinical Trial

The aim of the present study was to compare the antibacterial effectiveness of chlorhexidine and PPE oral rinse on S. mutans, Lactobacilli, and Veillonella, in clinical salivary samples of patients with advanced stages of dental caries at baseline and two and four weeks with PCR technique. This triple-blind randomized clinical trial involved 60 high caries risk adult patients, 19–59 years of age, randomly allocated into two groups of 30 subjects each. The intervention group received pomegranate peel extract mouthwash, whereas the control group received chlorhexidine mouthwash. Unstimulated pooled saliva was collected from the floor of the mouth before and after the intervention. The quantitative real-time polymerase chain reaction was employed to analyze the bacterial copies of each salivary sample at baseline and two and four weeks. The significance level was fixed at 5% (α = 0.05). Overall comparison of antimicrobial effectiveness across both groups revealed insignificant outcomes. The control group evinced a significant reduction in S. mutans between a specific time, i.e., baseline and 4 weeks (p=0.043). PPE oral rinse as a natural product or ecological alternative was effective in disrupting activity across all microorganisms tested in this triple-blind RCT; however, the nutraceutical, when compared to chlorhexidine, was not as effective against S. mutans.

Pomegranate peel extract polyphenols attenuate the SARS-CoV-2 S-glycoprotein binding ability to ACE2 Receptor: In silico and in vitro studies

The novel coronavirus disease (Covid-19) has become a major health threat globally. The interaction of SARS-CoV-2 spike (S) glycoprotein receptor-binding domain (RBD) with ACE2 receptor on host cells was recognized as the first step of virus infection and therefore as one of the primary targets for novel therapeutics. Pomegranate extracts are rich sources of bioactive polyphenols that were already recognized for their beneficial health effects. In this study, both in silico and in vitro methods were employed for evaluation of pomegranate peel extract (PoPEx), their major polyphenols, as well as their major metabolite urolithin A, to attenuate the contact of S-glycoprotein RBD and ACE2. Our results showed that PoPEx, punicalin, punicalagin and urolithin A exerted significant potential to block the S-glycoprotein-ACE2 contact. These in vitro results strongly confirm the in silico predictions and provide a valuable insight in the potential of pomegranate polyphenols for application in SARS-CoV-2 infection.

Natural Polyphenols in Metabolic Syndrome: Protective Mechanisms and Clinical Applications

Metabolic syndrome (MetS) is a chronic disease, including abdominal obesity, dyslipidemia, hyperglycemia, and hypertension. It should be noted that the occurrence of MetS is closely related to oxidative stress-induced mitochondrial dysfunction, ectopic fat accumulation, and the impairment of the antioxidant system, which in turn further aggravates the intracellular oxidative imbalance and inflammatory response. As enriched anti-inflammatory and antioxidant components in plants, natural polyphenols exhibit beneficial effects, including improving liver fat accumulation and dyslipidemia, reducing blood pressure. Hence, they are expected to be useful in the prevention and management of MetS. At present, epidemiological studies indicate a negative correlation between polyphenol intake and MetS incidence. In this review, we summarized and discussed the most promising natural polyphenols (including flavonoid and non-flavonoid drugs) in the precaution and treatment of MetS, including their anti-inflammatory and antioxidant properties, as well as their regulatory functions involved in glycolipid homeostasis.

Immunostimulatory Potential of Fruits and Their Extracts in Poultry

The impact of antibiotic use for growth promotion in livestock and poultry production on the rise of antimicrobial resistance (AMR) in bacteria led to the ban of this practice in the European Union in 2006 and a restriction of antimicrobial use (AMU) in animal agriculture in Canada and the United States of America. There is a high risk of infectious diseases such as necrotic enteritis due to Clostridium perfringens, and colibacillosis due to avian pathogenic Escherichia coli in antimicrobial-free broiler chickens. Thus, efficient and cost-effective methods for reducing AMU, maintaining good poultry health and reducing public health risks (food safety) are urgently needed for poultry production. Several alternative agents, including plant-derived polyphenolic compounds, have been investigated for their potential to prevent and control diseases through increasing poultry immunity. Many studies in humans reported that plant flavonoids could modulate the immune system by decreasing production of pro-inflammatory cytokines, T-cell activation, and proliferation. Fruits, especially berries, are excellent sources of flavonoids while being rich in nutrients and other functionally important molecules (vitamins and minerals). Thus, fruit byproducts or wastes could be important resources for value-added applications in poultry production. In the context of the circular economy and waste reduction, this review summarizes observed effects of fruit wastes/extracts on the general health and the immunity of poultry.

Interplay of Biochemical, Genetic, and Immunohistochemical Factors in the Etio-Pathogenesis of Gastric Ulcer in Rats: A Comparative Study of the Effect of Pomegranate Loaded Nanoparticles Versus Pomegranate Peel Extract

Background

Few data are available about the role of herbal extract loaded nanoparticles as an alternative safe medicine for the management of a gastric ulcer.

Aim

This work is targeted at exploring the physiological effects of pomegranate loaded nanoparticles (PLN) against an indomethacin IND-induced gastric ulcer and comparing the results with traditional pomegranate peel extract (PPE).

Methods

Twenty-four rats were equally distributed into four groups: control, IND-treated, PLN-treated, and PPE-treated groups. Gross examination of gastric mucosa, and the calculation of ulcer and inhibition indices were done. Serum malondialdehyde (MDA), total antioxidant capacity (TAC), interleukin 2 (IL-2), IL-6, IL-10, gastric homogenate prostaglandin E₂ (PGE₂), and nitric oxide (NO) were estimated. Mucosal endothelial nitric oxide synthase (eNOS mRNA) expression was identified by qPCR. Histological and immuno-histochemical staining of Tumor necrosis factor-α (TNF-α) and eNOS of stomach mucosa were performed.

Results

In comparison with the control group, IND-treated rats showed visible multiple ulcers with ulcer index, serum MDA, IL-2 and IL-6 were elevated while IL-10, PGE₂, NO, and eNOS mRNA expression were significantly reduced. Damaged surface epithelium with disrupted glandular architecture and heavy leucocyte infiltration of lamina propria was noticed. Immunohistochemical staining of stomach mucosa revealed marked increased TNF-α and reduced eNOS. Oral administration of PLN and PPE succeeded in improving the gross mucosal picture, and all biochemical, histological, and immunohistochemical alterations.

Conclusion

Both PLN and PPE potently alleviated IND-induced gastric ulceration via increasing TAC, PGE₂, NO, eNOS mRNA, and protein expression. However, the healing effect of PLN was obviously greater than PPE-treated rats.

Characterization of pomegranate peel extracts obtained using different solvents and their effects on cell cycle and apoptosis in leukemia cells

Pomegranate (Punica granatum L.) has been used in traditional herbal medicine by several cultures as an anti-inflammatory, antioxidant, antihyperglycemic, and for treatment and prevention of cancer and other diseases. Different parts of the fruit, extraction methods, and solvents can define the chemical profile of the obtained extracts and their biological activities. This study aimed to characterize the chemical profile of peel extracts collected using different extraction solvents and their biological effects on the cell cycle and apoptosis of THP-1 leukemic cells. Aqueous extract presented the highest content of punicalagins (α pun = 562.26 ± 47.14 mg/L and β pun = 1,251.13 ± 22.21 mg/L) and the lowest content of ellagic acid (66.38 ± 0.21 mg/L), and it promoted a significant impairment of the cell cycle S phase. In fact, punicalagin-enriched fraction, but not an ellagic acid-enriched fraction, caused an S phase cell cycle arrest. All extracts increased the number of apoptotic cells. Punicalagin-enriched fraction increased the percentage of cells with fragmented DNA, which was intensified by ellagic acid combination. The treatment combining punicalagin and ellagic acid fractions increased the apoptotic cleaved PARP1 protein and reduced the activation of the growth-related mTOR pathway. Thus, these results evidence that solvent choice is critical for the phenolic compounds profile of pomegranate peel extracts and their biological activities.

Rheological, physico-sensory and antioxidant properties of punicic acid rich wheat bread

Punicic acid (PA), a predominant fatty acid (85%) in pomegranate seeds, also called as an ω-5 fatty acid, is known to render various health beneficial effects to humans. The objective of this study was to prepare and observe the effect of replacement of wheat flour with 5-12.5% punicic acid rich pomegranate seed powder (PSP, 9XXX fraction) on rheological, physico-sensory and antioxidant properties of bread. The increasing amount of PSP caused decrease in farinograph water absorption capacity, dough stability; amylograph peak viscosity; bread volume and overall quality score, whereas crumb hardness was increased. The combination of additives (CA) showed significant improvement in dough strength, texture and quality of bread with 10% PSP. The total polyphenol content (TPP) and radical scavenging activity (RSA) increased by 10- to 30-fold while PA was increased to 60-fold when compared to control. The recovery of PA from bread samples was in range of 45-60% and further increased by the addition of CA (65%). Hence, 10% PSP bread having 60% recovery of PA can be successfully considered for formulations without altering the rheological and sensory quality of bread. These results reveal that PA rich PSP prepared from a fruit industry by-product can be utilized for preparing antioxidant rich functional bread which also helps in overall improvement of bone health.

Multiresponse Optimization of Pomegranate Peel Extraction by Statistical versus Artificial Intelligence: Predictive Approach for Foodborne Bacterial Pathogen Inactivation

Pomegranate (Punica granatum L.) peel is a potential source of polyphenols known for their activity against foodborne pathogen bacteria. In this study, the effects of pomegranate peel extraction time (10–60 min), agitation speed (120–180 rpm), and solvent/solid ratio (10–30) on phytochemical content and antibacterial activity were determined. Response surface methodology (RSM) and artificial neural network (ANN) methods were used, respectively, for multiresponse optimization and predictive modelling. Compared with the original conditions, the total phenolic content (TPC), the total flavonoid content (TFC), and the total anthocyanin content (TAC) increased by 56.22, 63.47, and 64.6%, respectively. Defined by minimal inhibitory concentration (MIC), the maximum of antibacterial activity was higher than that from preoptimized conditions. With an extraction time of 11 min, an agitation speed 125 rpm, and a solvent/solid ratio of 12, anti-S. aureus activity remarkably decreased from 1.56 to 0.171 mg/mL. Model comparisons through the coefficient of determination (R²) and mean square error (MSE) showed that ANN models were better than the RSM model in predicting the photochemical content and antibacterial activity. To explore the mode of action of the pomegranate peel extract (PPE) at optimal conditions against S. aureus and S. enterica, Chapman and Xylose Lysine Deoxycholate broth media were artificially contaminated at 10⁴ CFU/mL. By using statistical approach, linear (ANOVA), and general (ANCOVA) models, PPE was demonstrated to control the two dominant foodborne pathogens by suppressing bacterial growth.

Punicalagin Content and Antifungal Activity of Different Pomegranate (Punica ganatum L.) Genotypes

This study investigated the antifungal activity of a number of pomegranate genotypes. Since the main compound of pomegranate extract is punicalagin, an important substance involved in antifungal and antimicrobial activity, we analyzed the contents of punicalagin (α and β) in 21 different pomegranate genotypes. Ellagic acid content, total phenolic content, acidity and pH were also determined. This work allowed us to determine which genotypes of pomegranate can be used to obtain extracts with the highest content of punicalagin, with the goal of developing a green alternative to synthetic pesticides. To improve the extraction system from pomegranate peel fruits, several different solvents were tested. All the pomegranate genotypes tested showed antifungal activity; some genotypes were able to almost completely inhibit the fungus, while others had very low inhibitory activity. Research results also showed that the use of water as a solvent for extraction is very effective, especially when it is combined with ethanol. This is very important for the practical use of the extracts since water is economical and environmentally friendly. The research showed that among the genotypes there is also great variability regarding the chemical parameters. Genotypes with a high phenolic and punicalagin content were significantly correlated with antifungal activity. All the other chemical parameters (pH, titratable acidity and ellagic acid content) were not correlated with antifungal activity. The results obtained indicate that the fruits of some pomegranate genotypes could be used to obtain extracts very rich in punicalagins and that these substances could be used as an alternative to synthetic products to control plant disease and improve the quality of the plant products, avoiding the impact of synthetic chemicals on the environment.

Transcriptomic Analysis of Orange Fruit Treated with Pomegranate Peel Extract (PGE)

A Pomegranate Peel Extract (PGE) has been proposed as a natural antifungal substance with a wide range of activity against plant diseases. Previous studies showed that the extract has a direct antimicrobial activity and can elicit resistance responses in plant host tissues. In the present study, the transcriptomic response of orange fruit toward PGE treatments was evaluated. RNA-seq analyses, conducted on wounded fruits 0, 6, and 24 h after PGE applications, showed a significantly different transcriptome in treated oranges as compared to control samples. The majority (273) of the deferentially expressed genes (DEGs) were highly up-regulated compared to only 8 genes that were down-regulated. Gene Ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis showed the involvement of 1233 gene ontology (GO) terms and 35 KEGG metabolic pathways. Among these, important defense pathways were induced and antibiotic biosynthesis was the most enriched one. These findings may explain the underlying preventive and curative activity of PGE against plant diseases.

Phenolic compounds as beneficial phytochemicals in pomegranate (Punica granatum L.) peel: A review

Pomegranate peel (PoP), a juice byproduct often considered as a waste, comprises nearly around 30-40% portion of the fruit. Phenolic compounds (one class of bioactive phytochemicals) are primarily concentrated in the peel portion of pomegranate fruit. In PoP, the main phenolic compounds reported in the literature include flavonoids (anthocyanins such as pelargonidin, delphinidin, cyanidin along with their derivatives and anthoxanthins such as catechin, epicatechin and quercetin), tannins (ellagitannins and ellagic acid derivatives such as punicalagin, punicalin and pedunculagin) and phenolic acids (such as chlorogenic, caffeic, syringic, sinapic, p-coumaric, ferulic, ellagic, gallic and cinnamic acid). It is generally accepted that phenolic compounds can be more efficiently recovered from PoP by improving the extraction efficiency. The curative relevance of these compounds has been mainly assessed by in vitro experimentation. Therefore, conclusive clinical trials of the phenolic compounds present in PoP are essential for correct validation of their health benefits.

Stimulation of liver IGF-1 expression promotes peak bone mass achievement in growing rats: a study with pomegranate seed oil

Peak bone mass (PBM) achieved at adulthood is a strong determinant of future onset of osteoporosis, and maximizing it is one of the strategies to combat the disease. Recently, pomegranate seed oil (PSO) has been shown to have bone-sparing effect in ovariectomized mice. However, its effect on growing skeleton and its molecular mechanism remain unclear. In the present study, we evaluated the effect of PSO on PBM in growing rats and associated mechanism of action. PSO was given at various doses to 21-day-old growing rats for 90 days by oral gavage. The changes in bone parameters were assessed by micro-computed tomography and histology. Enzyme-linked immunosorbent assay was performed to analyze the levels of serum insulin-like growth factor type 1 (IGF-1). Western blotting from bone and liver tissues was done. Chromatin immunoprecipitation assay was performed to study the histone acetylation levels at IGF-1 gene. The results of the study show that PSO treatment significantly increases bone length, bone formation rate, biomechanical parameters, bone mineral density and bone microarchitecture along with enhancing muscle and brown fat mass. This effect was due to the increased serum levels of IGF-1 and stimulation of its signaling in the bones. Studies focusing on acetylation of histones in the liver, the major site of IGF-1 synthesis, showed enrichment of acetylated H3K9 and H3K14 at IGF-1 gene promoter and body. Further, the increased acetylation at H3K9 and H3K14 was associated with a reduced HDAC1 protein level. Together, our data suggest that PSO promotes the PBM achievement via increased IGF-1 expression in liver and IGF-1 signaling in bone.

Antioxidant properties and phenolic profile characterization by LC-MS/MS of selected Tunisian pomegranate peels

Antioxidant contents and activities of different extracts from four Tunisian pomegranate peels, locally called "Acide", "Gabsi", "Nebli" and "Tounsi", were studied. Peels samples were extracted with three solvents (water, ethanol and acetone). For each extract, the total phenol contents and antioxidant activity were evaluated. The highest values of polyphenol, tannins, flavonoids and anthocyanins were recorded in the acetone extract of Acide ecotype with 304.6 mg gallic acid equivalent/g; 292.23 mg gallic acid equivalent/g; 15.46 mg Quercetin/g and 54.51 mg cy-3-glu/100 g, respectively. The acetone extract of Acide ecotype also showed the highest free radical-scavenging and reducing power activity compared to other extracts. Besides, the phytochemical analysis by LC-MS/MS revealed a high content of ellagitannins with punicalagin and punicalagin derivatives as the major compounds that might be responsible for promising antioxidant activity of pomegranate peel extracts. Two compounds (Castalagin derivative and Galloyl-bis-HHDP-hex derivative) were detected only in "Acide" ecotype in important contents.