Compendium of the most significant studies with reference to properties, intake, effects.

Di Sotto A, Locatelli M, Macone A, Toniolo C, Cesa S, Carradori S, Eufemi M, Mazzanti G, Di Giacomo S. Hypoglycemic, Antiglycation, and Cytoprotective Properties of a Phenol-Rich Extract From Waste Peel of Punica granatum L. var. Dente di Cavallo DC2. Molecules. 2019 Aug 27;24(17):3103. doi: 10.3390/molecules24173103. 

Abstract. Pomegranate peel is a natural source of phenolics, claimed to possess healing properties, among which are antioxidant and antidiabetic. In the present study, an ethyl acetate extract, obtained by Soxhlet from the peel of Dente di Cavallo DC2 pomegranate (PGE) and characterized to contain 4% w/w of ellagic acid, has been evaluated for its hypoglycemic, antiglycation, and antioxidative cytoprotective properties, in order to provide possible evidence for future nutraceutical applications. The α-amylase and α-glucosidase enzyme inhibition, interference with advanced glycation end-products (AGE) formation, and metal chelating abilities were studied. Moreover, the possible antioxidant cytoprotective properties of PGE under hyperglycemic conditions were assayed. Phenolic profile of the extract was characterized by integrated chromatographic and spectrophotometric methods. PGE resulted able to strongly inhibit the tested enzymes, especially α-glucosidase, and exerted chelating and antiglycation properties. Also, it counteracted the intracellular oxidative stress under hyperglycemic conditions, by reducing the levels of reactive oxygen species and total glutathione. Among the identified phenolics, rutin was the most abundant flavonoid (about 4 % w/w). Present results suggest PGE to be a possible remedy for hyperglycemia management and encourage further studies to exploit its promising properties.

El Deeb KS, Eid HH, Ali ZY, Shams MM, Elfiky AM. Bioassay-guided fractionation and identification of antidiabetic compounds from the rind of Punica Granatum Var. nana. Nat Prod Res. 2021 Jun;35(12):2103-2106. doi: 10.1080/14786419.2019.1655411. 

Abstract. This study aimed to evaluate the antidiabetic potential of the rind of Punica granatum var. nana. Acute oral toxicity test revealed the safety profile of its ethanolic extract. The extract was administered at 200 mg/kg b.wt to streptozotocin-induced diabetic rats. Serum diagnostic markers of diabetes (insulin, glucose and glycated hemoglobin), inflammatory mediators (tumor necrosis factor-α, interleukin-6, and nitric oxide), and oxidative stress (total antioxidant capacity and reduced glutathione and malondialdehyde) were assayed. The ethanolic extract was further fractionated and assessed for the aforementioned bioactivities at two different doses (100 and 200 mg/kg b.wt). The results revealed that the ethyl acetate fraction of rind exhibited the highest activities. Using different chromatographic techniques, four compounds were isolated and identified as rutin, gallic acid, nictoflorin, and tulipanin. In conclusion: The ethyl acetate fraction of the rind of Punica granatum var. nana may provide a potential therapeutic approach for hyperglycemia.

Gharib E, Montasser Kouhsari S. Study of the Antidiabetic Activity of Punica granatum L. Fruits Aqueous Extract on the Alloxan-Diabetic Wistar Rats. Iran J Pharm Res. 2019 Winter;18(1):358-368. 

Abstract. Pancreatic β-cells dysfunction and impairment of insulin action usually leads to hyperglycemia. Punica granatum L. is a well-known traditional herbal remedy in Iran due to its positive effects on ameliorating blood glucose homeostasis. In this study, Alloxan-diabetic male Wistar rats were administrated with pomegranate fruits aqueous extract (PE) in different doses of 100, 200, and 350 mg/kg bw (PE+Da, PE+Db and PE+Dc, respectively), and the effects of PE polyphenols content on glucose metabolism in treated groups were examined using oral glucose tolerance test (OGTT), short-term and long-term PE consumption periods models followed by evaluation of plasma insulin, free fatty acids, and triglycerides levels and tissues contents of glycogen and triglycerides; compared with diabetic control (DC) and healthy control (NC) groups. By using Real-time PCR, the possibility of modulations of the Insulin receptor substrate 1 (IRS-1), Protein kinase B (Akt), Glucose transporter 2 and 4 (Glut-2, 4) mRNAs expression levels in PE treated rats were investigated. The obtained data showed noticeable reduction in fasting blood glucose (FBG) by 28.1% and 67.9% in short-term and long-term treatment models, respectively, in PE + Dc group. Also, there existed marked increase in the mRNAs expression levels of IRS-1, Akt, Glut-2, and Glut-4, which results in improvement of glucose uptake and promotes its storage. Taking together, it is suggested that PE administration contributes to the modulation of both hyperglycemia and hyperlipidemia in Alloxan-diabetic Wistar rats.

Joshi C, Patel P, Kothari V. Anti-infective potential of hydroalcoholic extract of Punica  granatum peel against gram-negative bacterial pathogens. F1000Res. 2019 Jan 18;8:70. doi: 10.12688/f1000research.17430.2. 

Abstract. Background:Punica granatum extracts have been prescribed in traditional medicine for management of a variety of disease conditions including microbial infections. Generation of scientific evidence for validation of P. granatum peel extract's anti-pathogenic efficacy is required. Methods: Hydroalcoholic extract of P. granatum peel (PGPE), prepared by microwave assisted extraction method was evaluated for its quorum-modulatory potential against two different human-pathogenic bacteria viz. Chromobacterium violaceum and Pseudomonas aeruginosa. Results: This extract was able to modulate in vitro production of quorum sensing-regulated pigments in both these test bacteria at ≥5 μg/ml. Virulence traits of P. aeruginosa like haemolytic activity, and biofilm formation were negatively affected by the test extract, and it also made P. aeruginosa more susceptible to lysis by human serum. Antibiotic susceptibility of both test bacteria was modulated owing to pre-treatment with PGPE. Exposure of these test pathogens to PGPE (≥0.5 μg/ml) effectively reduced their virulence towards the nematode Caenorhabditis elegans. Repeated subculturing of P. aeruginosa on PGPE-supplemented growth medium did not induce resistance to PGPE in this notorious pathogen, and this extract was also found to exert a post-extract effect on P. aeruginosa. Individual constituent phytocompounds of PGPE were found to be less efficacious than the whole extract. PGPE seemed to interfere with the signal-response machinery of P. aeruginosa and C. violaceum. PGPE also exhibited notable prebiotic potential by promoting growth of probiotic strains- Bifidobacterium bifidum and Lactobacillus plantarum at ≤50 μg/ml. Conclusions: This study indicates PGPE to be an effective antipathogenic and prebiotic preparation, and validates its therapeutic use mentioned in traditional medicine. This study also emphasizes the need for testing any bioactive extract at broadest possible concentration range, particularly in vivo, so that an accurate picture of dose-response relationship can emerge.

Lavaee F, Motaghi D, Jassbi AR, Jafarian H, Ghasemi F, Badiee P. Antifungal effect of the bark and root extracts of Punica granatum on oral Candida isolates. Curr Med Mycol. 2018 Dec;4(4):20-24. doi: 10.18502/cmm.4.4.382.

Abstract. Background and purpose: Oral candidiasis is one of the most common fungal infections in humans. The treatment and prophylaxis of the patients suffering from this infection require the identification of new anti-Candida agents with no side effects or toxicity like medicinal plants. The present study was conducted to compare the antifungal activities of the aqueous, ethanolic, and methanolic extracts of the bark and roots of P. granatum with those of two routine antifungal agents (i.e., fluconazole and nystatin) on oral Candida strains isolated from liver transplant recipients....Conclusion: As the findings indicated, the methanolic and ethanolic extracts of the bark and root of Punica granatum had anti-Candida activities. Therefore, they can be considered as mouthwash or toothpaste to prevent and treat Candida infections in the oral cavity.

Rios-Corripio G, Guerrero-Beltrán JÁ. Antioxidant and physicochemical characteristics of unfermented and fermented pomegranate (Punica granatum L.) beverages. J Food Sci Technol. 2019 Jan;56(1):132-139. doi: 10.1007/s13197-018-3466-6. 

Abstract. The aim of this study was to evaluate the physicochemical, antioxidant (antioxidant activity, total phenolic compounds, flavonoids, anthocyanins), and sensory characteristics of fresh (FRJ) and fermented (FEB) pomegranate beverages. Three fermentation conditions were tested based on the total soluble solids (TSS: °Bx) content in pomegranate juice: (a) natural TSS (13.9 °Bx) in fresh juice (FEB1), (b) adjusted to 17.5 °Bx (FEB2) and (c) adjusted to 25 °Bx (FEB3). The antioxidant activity, total phenolic compounds, flavonoids and anthocyanins after fermentation in FEB3 were 262.61 ± 0.12 mg Trolox, 188.60 ± 0.20 mg Gallic acid, 64.35 ± 0.09 mg quercetin and 1.92 ± 0.15 cyanidin-3-O-glucoside (C3OG)/100 mL, respectively. The final amounts of ethanol in FEB1, FEB2, and FEB3 were 6.82 ± 0.01, 9.73 ± 0.01, and 12.88 ± 0.01% (v/v), similar to that in wines. In general, the sensory characteristics of both FRJ and FEB beverages were well sensory accepted by consumers.

Tang D, Liu L, Ajiakber D, Ye J, Xu J, Xin X, Aisa HA. Anti-diabetic Effect of Punica granatum Flower Polyphenols Extract in Type 2 Diabetic Rats: Activation of Akt/GSK-3β and Inhibition of IRE1α-XBP1 Pathways. Front Endocrinol (Lausanne). 2018 Oct 15;9:586. doi: 10.3389/fendo.2018.00586.

Abstract. Type 2 diabetes mellitus (T2DM) is the most common type of diabetes with more than hundreds of millions of patients worldwide. However, the medicines for treatment of T2DM are very limited. In China, Punica granatum L. flower (PGF) has been used as an anti-diabetic herb in the herbal medicine. The activity involves in improvement of insulin sensitivity. However, the underlying mechanism of action is elusive. The current study was designed to address this issue by investigating the effect of polyphenols extract of PGF in diabetic rats. A rat model was orally administrated with PGF polyphenols extract at doses of 50 and 100 mg/kg for 4 weeks. Insulin sensitivity was improved as indicated by oral glucose tolerance test (OGTT), insulin tolerance test (ITT) and homeostasis model assessment of insulin resistance (HOMA-IR). At the molecular level, insulin signaling activity was improved with an elevation in insulin-stimulated phosphorylation of insulin receptor substrate (IRS-1), Akt and GSK-3β. Endoplasmic reticulum (ER) stress signals including phosphorylation of inositol-requiring kinase1 (IRE1) and activation of X box binding protein (XBP-1) splicing were decreased by the PGF treatment. Expressions of IRE1α, XBPs, and CHOP were all decreased by PGF. Blood lipid profile, liver glycogen content and antioxidant status were improved by PGF in the rats. The observations suggest that PGF is able to lower glucose levels in T2DM rats by improving the insulin resistance. The mechanism is likely related to the activation of Akt-GSK3β signaling pathway and inhibition of ER stress.

Devanesan S, AlSalhi MS, Balaji RV, Ranjitsingh AJA, Ahamed A, Alfuraydi AA, AlQahtani FY, Aleanizy FS, Othman AH. Antimicrobial and Cytotoxicity Effects of Synthesized Silver Nanoparticles from Punica granatum Peel Extract. Nanoscale Res Lett. 2018 Oct 4;13(1):315. doi: 10.1186/s11671-018-2731-y. 

Abstract. To address the growing challenges from drug-resistant microbes and tumor incidence, approaches are being undertaken to phytosynthesize metal nanoparticles, particularly silver nanoparticles, to get remedial measure. In this study, an attempt has been made to utilize a major biowaste product, pomegranate fruit peel (Punica granatum), to synthesize silver nanoparticles. The silver nanoparticles (AgNPs) were synthesized using the aqueous extract of pomegranate peel. The formation of synthesized AgNPs was confirmed through UV-Vis spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX) as well as through the change of the colorless aqueous solution to a dark brown solution. Using UV-Vis spectroscopy, the dark brown solution showed a Plasmon resonance band peak at 378 nm in UV-Vis spectroscopy after reacting for 24, 48, and 72 h. The XRD report revealed that the AgNPs had a cubic structure. The TEM and SEM report showed the nanoparticles were equally distributed in the solution, with a spherical shape and size ranging from 20 to 40 nm and with an average particle size of 26.95 nm. EDX imaging also confirmed the presence of AgNPs. The synthesized AgNPs were found to exhibit good antimicrobial effects on Gram-negative and Gram-positive bacteria, particularly the pathogens Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27584), Proteus vulgaris (ATCC 8427), Salmonella typhi (ATCC 14028), Staphylococcus aureus (ATCC 29213), Staphylococcus epidermidis (MTCC 3615), and Klebsiella pneumonia. The cytotoxic effects of AgNPs were also tested against a colon cancer cell line (RKO: ATCC® CRL-2577™), and it was observed that the viabilities were 56% and 61% on days 3 and 5, respectively, with exposure to 12.5 μg of AgNPs. This simple, economic, and eco-friendly method suggests that the AgNPs biosynthesized using pomegranate peel extract may be a novel, potent solution for the development of a drug for colon cancer that also has antibacterial activity.

Pomegranate comes from the pomegranate tree (Punicum granatum), which can grow up to 5 metres and is more of a berry than a fruit.

The pomegranate ripens exclusively on the plant so the unripe pomegranates are used only for decoration.

Punica granatum, commonly known as pomegranate, is a deciduous shrub or small tree known for its distinctive, vibrant red fruits and ornamental flowers. Native to the Mediterranean region and parts of Asia, the pomegranate has been cultivated for centuries for its sweet and tangy fruit, which is rich in nutrients and has various culinary, medicinal, and cultural uses.

Botanical Classification:

• Kingdom: Plantae
• Order: Myrtales
• Family: Lythraceae
• Genus: Punica
• Species: Punica granatum

Plant Characteristics:

Growth Form: Punica granatum is a deciduous shrub or small tree that typically reaches a height of 5-10 meters (16-33 feet). It has a bushy appearance with multiple branches.

Leaves: The leaves are simple, lanceolate to oblong, and shiny green. They are usually about 3-7 cm long and turn yellow in the fall.

Flowers: The plant produces striking, trumpet-shaped flowers that can be orange, red, or pink. The flowers appear in late spring to early summer and are followed by the fruit.

Fruit: The fruit is a large, round berry with a tough, leathery rind that ranges from yellow to red. Inside, it contains numerous arils (seed-filled sacs) that are juicy and edible. The fruit typically measures 7-12 cm in diameter.

Chemical Composition and Structure:

• Polyphenols: The fruit is rich in polyphenols, including ellagic acid, punicalagins, and anthocyanins. These compounds are known for their strong antioxidant properties.
• Vitamins: Pomegranate is a good source of vitamins, particularly vitamin C, vitamin K, and some B vitamins.
• Minerals: It contains essential minerals such as potassium, calcium, and magnesium.
• Organic Acids: The fruit has high levels of citric acid and other organic acids that contribute to its tart flavor.

How to Cultivate It:

• Soil: Punica granatum thrives in well-drained, loamy soils with a slightly acidic to neutral pH (6.0-7.0). It is tolerant of poor soil conditions but performs best in fertile soils.
• Climate: The plant prefers a temperate to subtropical climate with hot, dry summers and cool winters. It is not frost-tolerant and requires a warm climate to produce fruit.
• Watering: Regular watering is necessary, particularly during dry periods. However, the plant should not be overwatered as it is susceptible to root rot. The soil should be kept moderately moist.
• Fertilization: Fertilize in early spring with a balanced fertilizer to promote healthy growth and fruit production. Avoid excessive nitrogen, which can lead to excessive foliage growth at the expense of fruit.
• Pruning: Pruning helps to maintain the plant’s shape and remove dead or diseased branches. It also improves air circulation and light penetration, which can enhance fruit production. Prune in late winter or early spring before new growth starts.

Uses and Benefits:

• Culinary Uses: The arils of the pomegranate fruit are used in a variety of culinary applications, including fresh eating, juices, sauces, and as a garnish. The juice is particularly popular for its refreshing taste and health benefits.
• Medicinal Uses: Pomegranate has been used in traditional medicine for its anti-inflammatory, antioxidant, and antimicrobial properties. It is believed to support cardiovascular health, improve memory, and aid digestion.
• Cosmetic Uses: Extracts from pomegranate are used in skincare products for their antioxidant and anti-aging properties. They help to protect the skin from damage caused by free radicals and promote a healthy, youthful appearance.

Applications:

• Food Industry: Pomegranate is widely used in the food industry for its juice, flavoring, and as a functional ingredient in various products such as sauces, dressings, and snacks.
• Pharmaceutical Industry: The fruit and its extracts are included in health supplements and medicinal products aimed at promoting cardiovascular health, improving cognitive function, and supporting overall well-being.
• Cosmetic Industry: Pomegranate extracts are used in skincare products for their antioxidant and anti-aging benefits, contributing to the development of creams, serums, and lotions that promote skin health and reduce signs of aging.

Environmental and Safety Considerations:

• Environmental Impact: Punica granatum is generally non-invasive and does not pose significant environmental risks. It can be grown in garden settings and contributes to biodiversity by attracting pollinators such as bees.
• Safety: The fruit and its extracts are considered safe for consumption and use. However, individuals with allergies to pomegranates or related plants should exercise caution. 

Studies

In the phytochemical composition there are polyphenols, flavonoids, anthocyanins, tannins, ellagic acid, ursolic acid, gallic acid.

Of all the fresh fruit, the pomegranate has the highest antioxidant power and I quote the formula: 3895.9 +/- 241.4 mg/L x kJ(-1). All the remaining fruit has a lower degree and in order: orange, lemon, mandarin, persimmon, kiwi, pear and avocado (1).

It has first-rate antioxidant properties for the human body (2), releasing ellagic acid into the grains and internal cortex, which protects the brain, intestines, prostate (3) and others.

As far as the prostate is concerned, it is an alternative cure for contrasting the tumor (4).

Microscopic observation of the wound healing process on collagen, number of polymorphonuclear cell infiltration, angiogenesis and re-epithelialisation showed that topical administration of 10% Powder of standardized pomegranate extract accelerates the healing of wounds from second-degree burns (5).

Pomegranate studies

References_________________________________________________________________________

(1) Basov AA, Bykov IM. Comparative characteristics of antioxidant capacity and energy content of some foods. Vopr Pitan. 2013;82(3):77-80. Russian. PMID: 24006756.

Abstract. The paper presents a comparative evaluation of antioxidant capacity and energy values of different foods groups in order to identify the most efficient combinations for correction of metabolic disorders associated with an imbalance in antioxidant system. In study integral method for determining of antioxidant and energy indicators (patent No 2,455,703) has been used. It has been revealed that the highest antioxidant-energy capacity (AE) of fresh juices has a pomegranate juice (AE = 3895.9 +/- 241.4 mg/L x kJ(-1)), other fresh juices inferior to him on this indicator: grenade>orange>lemon=apple> pomelo > mandarin > persimmon > kiwi > pears > avocado. Among dairy products the highest AE belongs to boiled fermented milk--"ryazhenka" (AE = 40.9 +/- 2.7 mg/L x kJ(-1)), other dairy products can be placed in line with index AE: ryazhenka ==>kefir > yogurt. Most of fresh juices were significantly superior to antioxidant-energy potential of other foods. Despite the fact that dairy products AE were lower than AE of some juices, they were much superior to AE values of fastfood products (biscuits, potato chips, popcorn). This demonstrates need to reduce the quota of fast foods in the diet to prevent the risk of reduction potential of the endogenous antioxidant system.

(2) Aslan A, Can Mİ, Boydak D. Anti-oxidant effects of pomegranate juice on Saccharomyces cerevisiae cell growth. Afr J Tradit Complement Altern Med. 2014 Jun 4;11(4):14-8. doi: 10.4314/ajtcam.v11i4.3. PMID: 25392575; PMCID: PMC4202391.

Abstract. Background: Pomegranate juice has a number of positive effects on both human and animal subjects....Results: According to our results statistically significant differences have been determined among the study groups in terms of fatty acids and vitamin (p<0,05). Fatty acid synthesis, vitamin control and cell density increased in groups to which PJ was given in comparison with the control group (p<0,05). Pomegranate juice increased vitamins, fatty acids and total protein expression in Saccharomyces cerevisiae in comparison with the control. Conclusion: Pomegranate juice has a positive effect on fatty acid, vitamin and protein synthesis by Saccharomyces cerevisiae. Accordingly, we believe that it has significantly decreased oxidative damage thereby making a positive impact on yeast development.

(3) Naiki-Ito A, Chewonarin T, Tang M, Pitchakarn P, Kuno T, Ogawa K, Asamoto M, Shirai T, Takahashi S. Ellagic acid, a component of pomegranate fruit juice, suppresses androgen-dependent prostate carcinogenesis via induction of apoptosis. Prostate. 2015 Feb;75(2):151-60. doi: 10.1002/pros.22900. Epub 2014 Oct 4. PMID: 25284475.

(4) Wang L, Martins-Green M. Pomegranate and its components as alternative treatment for prostate cancer. Int J Mol Sci. 2014 Aug 25;15(9):14949-66. doi: 10.3390/ijms150914949. PMID: 25158234; PMCID: PMC4200766.

Abstract. Prostate cancer is the second leading cause of cancer deaths in men in the United States. There is a major need for less toxic but yet effective therapies to treat prostate cancer. Pomegranate fruit from the tree Punica granatum has been used for centuries for medicinal purposes and is described as "nature's power fruit". Recent research has shown that pomegranate juice (PJ) and/or pomegranate extracts (PE) significantly inhibit the growth of prostate cancer cells in culture. In preclinical murine models, PJ and/or PE inhibit growth and angiogenesis of prostate tumors. More recently, we have shown that three components of PJ, luteolin, ellagic acid and punicic acid together, have similar inhibitory effects on prostate cancer growth, angiogenesis and metastasis. Results from clinical trials are also promising. PJ and/or PE significantly prolonged the prostate specific antigen (PSA) doubling time in patients with prostate cancer. In this review we discuss data on the effects of PJ and PE on prostate cancer. We also discuss the effects of specific components of the pomegranate fruit and how they have been used to study the mechanisms involved in prostate cancer progression and their potential to be used in deterring prostate cancer metastasis.

(5) Lukiswanto BS, Miranti A, Sudjarwo SA, Primarizky H, Yuniarti WM. Evaluation of wound healing potential of pomegranate (Punica granatum) whole fruit extract on skin burn wound in rats (Rattus norvegicus). J Adv Vet Anim Res. 2019 Apr 14;6(2):202-207. doi: 10.5455/javar.2019.f333. 

Abstract. Objective: This research was conducted to study the wound healing process of whole fruit pomegranate extract (punica granatum) standardized with 40% ellagic acid ointment for deep second-degree burn wound of skin in the rat (Rattus norvegicus)....Results: Microscopic observation on the wound healing process on the collagen, PMN infiltration, angiogenesis, and re-epithelization showed that topical administration of 10% SPE in burns gives the best result. This is characterized by a high density of collagen with a good arrangement, which is accompanied by a complete and mature epithelium, low number of inflammatory cells, and angiogenesis. This may be caused by the compounds in the pomegranate extract, which have the antioxidant, anti-inflammatory, and anti-bacterial effects. Conclusion: This study reveals that 10% SPE accelerates the healing of deep second-degree burn wound. Thus, pomegranate standardized with 40% ellagic acid is a promising herb for the healing of burn wound of skin.