A comprehensive review on phytochemistry, bioactivity and medicinal value of bioactive compounds of pomegranate (Punica granatum)

Unlocking the therapeutic treasure of pomegranate leaf: A comprehensive review on phytochemical compounds, health benefits, and future prospects

The exploration of sustainable and valuable by-products from industrial and agricultural processes is increasingly recognized for its economic, environmental and health advantages. This review examines the phytochemical constituents, biological properties, current applications and future directions of pomegranate (Punica granatum L.) leaf (PGL). PGL exhibits broad biological activities, aiding in managing health conditions like chronic diseases, cancer, diabetes, obesity, and neurological disorders. Anti-cancer and anti-diabetic effects are demonstrated in vitro and in vivo using animal models. Anti-inflammatory and neuroprotective properties are also observed in cell cultures and animal studies. Its anti-microbial properties show efficacy against pathogens. However, variability in phytochemical composition due to different extraction methods and environmental conditions poses challenges for standardization. The review underscores the urgent need for comprehensive human clinical trials to confirm PGL's therapeutic benefits and safety, calling for future research to fully harness PGL's potential as a sustainable and bioactive compound in various industrial applications.

Developmental landscape of computational techniques to explore the potential phytochemicals from Punica granatum peels for their antioxidant activity in Alzheimer's disease

Alzheimer's disease (AD) is more commonly found in women than in men as the risk increases with age. Phytochemicals are screened in silico from Punica granatum peels for their antioxidant activity to be utilized for Alzheimer's disease. Alzheimer's disease is inhibited by the hormone estrogen, which protects the brain from the bad effects of amyloid beta and acetylcholine (ACh), and is important for memory processing. For the purpose, a library of about 1,000 compounds from P. granatum were prepared and studied by applying integrated computational calculations like 3D-QSAR, molecular docking, MD simulation, ADMET, and density functional theory (DFT). The 3D-QSAR model screened the active compounds B25, B29, B35, B40, B45, B46, B48, B61, and B66 by the field points and activity atlas model from the prepared library. At the molecular level, docking was performed on active compounds for leading hit compounds such as B25 and B35 that displayed a high MolDock score, efficacy, and compatibility with drug delivery against the antioxidant activity. Optimization of the structure and chemical reactivity parameter of the hit compound was calculated by DFT. Moreover, ADMET prediction was evaluated to check the bioavailability and toxicity of the hit compound. Hesperidin (B25) is found to be a hit compound after the whole study and can be synthesized for potent drug discovery in the future.

Antioxidant Phytocomplexes Extracted from Pomegranate (Punica granatum L.) Using Hydrodynamic Cavitation Show Potential Anticancer Activity In Vitro

Hydrodynamic cavitation (HC), as an effective, efficient, and scalable extraction technique for natural products, could enable the affordable production of valuable antioxidant extracts from plant resources. For the first time, whole pomegranate (Punica granatum L.) fruits, rich in bioactive phytochemicals endowed with anti-cancer properties, were extracted in water using HC. Aqueous fractions sequentially collected during the process (M1-M5) were lyophilized (L), filtered (A), or used as such, i.e., crude (C), and analyzed for their biochemical profile and in vitro antioxidant power. The fractions M3 and M4 from the L and C series showed the highest antiradical activity and phytochemical content. While the lyophilized form is preferable for application purposes, sample L-M3, which was produced faster and with lower energy consumption than M4, was used to assess the potential antiproliferative effect on human breast cancer line (AU565-PAR) and peripheral blood mononuclear (PBMC) cells from healthy donors. In a pilot study, cell growth, death, and redox state were assessed, showing that L-M3 significantly reduced tumor cell proliferation and intracellular oxygen reactive species. No effect on PBMCs was detected. Thus, the antioxidant phytocomplex extracted from pomegranate quickly (15 min), at room temperature (30 °C), and efficiently showed potential anticancer activity without harming healthy cells.

Pomegranate: A Source of Multifunctional Bioactive Compounds Potentially Beneficial in Alzheimer's Disease

Pomegranate fruit (PF) is a fruit rich in nutraceuticals. Nonedible parts of the fruit, especially peels, contain high amounts of bioactive components that have been largely used in traditional medicine, such as the Chinese, Unani, and Ayurvedic ones, for treating several diseases. Polyphenols such as anthocyanins, tannins, flavonoids, phenolic acids, and lignans are the major bioactive molecules present in PF. Therefore, PF is considered a source of natural multifunctional agents that exert simultaneously antioxidant, anti-inflammatory, antitumor, antidiabetic, cardiovascular, and neuroprotective activities. Recently, several studies have reported that the nutraceuticals contained in PF (seed, peel, and juice) have a potential beneficial role in Alzheimer's disease (AD). Research suggests that the neuroprotective effect of PF is mostly due to its potent antioxidant and anti-inflammatory activities which contribute to attenuate the neuroinflammation associated with AD. Despite the numerous works conducted on PF, to date the mechanism by which PF acts in combatting AD is not completely known. Here, we summarize all the recent findings (in vitro and in vivo studies) related to the positive effects that PF and its bioactive components can have in the neurodegeneration processes occurring during AD. Moreover, considering the high biotransformation characteristics of the nutraceuticals present in PF, we propose to consider the chemical structure of its active metabolites as a source of inspiration to design new molecules with the same beneficial effects but less prone to be affected by the metabolic degradation process.

Punica granatum L. Extract Shows Cardioprotective Effects Measured by Oxidative Stress Markers and Biomarkers of Heart Failure in an Animal Model of Metabolic Syndrome

Metabolic syndrome (MetS) significantly increases the risk of cardiovascular diseases (CVD), a leading cause of death globally. The presented study investigated the cardioprotective role of dietary polyphenols found in pomegranate peels in an animal model of metabolic syndrome. Zucker diabetic fatty rats (ZDF, MetS rats, fa/fa) were supplemented with polyphenol-rich pomegranate peel extract (EPP) at two dosages: 100 mg/kg BW and 200 mg/kg BW. The extract was administered for 8 weeks. The effect of ethanolic peel extract on the concentration of oxidative stress markers (CAT, SOD, MnSOD, GR, GST, GPx, TOS, SH, and MDA), biomarkers of heart failure (cTnI, GAL-3), and alternations in tissue architecture was assessed. The results showed a significant increase in SH concentration mediated via EPP supplementation (p < 0.001). Treatment with a 100 mg/kg BW dosage reduced the TOS level more efficiently than the higher dose. Interestingly, the CAT and GST activities were relevantly higher in the MetS 100 group (p < 0.001) compared to the MetS control. The rats administered EPP at a dose of 200 mg/kg BW did not follow a similar trend. No differences in the GR (p = 0.063), SOD (p = 0.455), MnSOD (p = 0.155), and MDA (p = 0.790) concentration were observed after exposure to the pomegranate peel extract. The administration of EPP did not influence the cTnI and GAL-3 levels. Histology analysis of the heart and aorta sections revealed no toxic changes in phenolic-treated rats. The findings of this study prove that the extract from pomegranate peels possesses free radical scavenging properties in the myocardium. The effect on alleviating ventricular remodeling and cardiomyocyte necrosis was not confirmed and requires further investigation.

Role and mechanism of fruit waste polyphenols in diabetes management

Among various diseases in humans, diabetes is one of the most complicated disorders resulting either from the malfunctioning of β cells, causing a poor discharge of insulin from them, or poor functioning of the liberated insulin. A wide array of chemical compounds so-called secondary metabolites are present in plants. These phytochemicals are produced as by-products of metabolism and play a key role in plant protection. However, in humans, they offer several beneficial functions. Polyphenols are an important class of phytochemicals and apart from fruits, they are also found in their major wastes mainly including the peel, pomace, and seed. The current review is aimed to focus on the potential sources, distribution, and extraction/isolation of polyphenols from major fruit wastes along with highlighting their medicinal and therapeutic benefits, especially in the management of diabetes.

Immunomodulatory Activity of Punicalagin, Punicalin, and Ellagic Acid Differs from the Effect of Pomegranate Peel Extract

BACKGROUND

Our recent study has shown that pomegranate peel extract (PEx) showed significant immunomodulatory activity, which might be caused by ellagitannins. The aim of this work was to test the hypothesis that ellagitannin components act synergistically in the modulation of cytokine production.

METHODS

Human peripheral blood mononuclear cells (PBMCs) from healthy donors were stimulated with phytohemagglutinin and treated with different concentrations of PEx or punicalagin (PG), punicalin (PN), and ellagic acid (EA), alone or with their combinations. Cytotoxicity, cell proliferation, and cytokine production were determined.

RESULTS

Non-cytotoxic concentrations of all compounds significantly inhibited cell proliferation. IC50 values (μg/mL) were: EA (7.56), PG (38.52), PEx (49.05), and PN (69.95). PEx and all ellagitannins inhibited the levels of TNF-α, IL-6, and IL-8, dose-dependently, and their combinations acted synergistically. PEx and all ellagitannins inhibited Th1 and Th17 responses, whereas the lower concentrations of PEx stimulated the production of IL-10, a Treg cytokine, as did lower concentrations of EA. However, neither component of ellagitannins increased Th2 response, as was observed with PEx.

CONCLUSIONS

The combination of PG, PN, and EA potentiated the anti-inflammatory response without any significant synergistic down-modulatory effect on T-cell cytokines. The increased production of IL-10 observed with PEx could be attributable to EA, but the examined ellagitannins are not associated with the stimulatory effect of PEx on Th2 response.

Dietary anthocyanins balance immune signs in osteoarthritis and obesity - update of human in vitro studies and clinical trials

Anthocyanins are known to change ligand-receptor bindings, cell membrane permeability, and intracellular signaling pathways. The beneficial effects of dietary anthocyanins have been chronologically demonstrated in interventional and observational studies, including fourteen human chondrocyte studies and related cell culture assays, nineteen human clinical trials in osteoarthritis patients, seven in vivo obesity assays, nineteen in vitro assays in preadipocytes and related cells, and twenty-two clinical trials in overweight/obese subjects, which are critically discussed in this update. Strawberries, cherries, berries, pomegranate, tropical fruits, rosehip, purple rice, purple corn, red beans, and black soybean, together with cyanidin, delphinidin, malvidin, peonidin, some 3-O-glycosides, metabolites, and acylated anthocyanins from a potato cultivar have shown the best outcomes. The set of these five key tests and clinical trials, taken together, contributes to the understanding of the underlying mechanisms and pathways involved. Furthermore, this set shows the value of anthocyanins in counteracting the progression of osteoarthritis/obesity. The interplay between the inflammation of osteoarthritis and obesity, and the subsequent regulation/immunomodulation was performed through isolated and food anthocyanins. The antioxidant, anti-inflammatory, and immunomodulatory properties of anthocyanins explain the findings of the studies analyzed. However, further interventional studies should be conducted to finally establish the appropriate doses for anthocyanin supplementation, dose-response, and length of consumption, to include dietary recommendations for osteoarthritis/obese patients for preventive and management purposes.

Antioxidant Activity and Phenolic Content of Sonication- and Maceration-Assisted Ethanol and Acetone Extracts of Cymbopogon citratus Leaves

Cymbopogon citratus is a medicinal and well-known aromatic plant which is usually used as a substitute for green-tea with extraordinary phytomedicinal potential. It is of great importance because it offers several promising health effects. The objective of the study was to investigate the antioxidant activity and total phenolic content of lemongrass leaves extracted by maceration and ultrasound-assisted extraction techniques. Different concentrations of both acetone and ethanol (50% and 70%) as solvents were tested for their radical scavenging activity against the stable free radical DPPH in quantization using a spectrophotometric assay. The ultrasound-assisted extraction technique had advantageous results in the polyphenols extraction yield (26.68%), TPC (61 mg GAE/g of extract) and DPPH (73.85%) compared to the maceration technique. Overall, the results were significant from 50% ethanol and the DPPH results were more significant from 70% ethanol than other concentrations. It is concluded that the ultrasound-assisted extraction is a better extraction technique for polyphenols than other conventional techniques.

Chemopreventive Potential of Dietary Nanonutraceuticals for Prostate Cancer: An Extensive Review

There are more than two hundred fifty different types of cancers, that are diagnosed around the world. Prostate cancer is one of the suspicious type of cancer spreading very fast around the world, it is reported that in 2018, 29430 patients died of prostate cancer in the United State of America (USA), and hence it is expected that one out of nine men diagnosed with this severe disease during their lives. Medical science has identified cancer at several stages and indicated genes mutations involved in the cancer cell progressions. Genetic implications have been studied extensively in cancer cell growth. So most efficacious drug for prostate cancer is highly required just like other severe diseases for men. So nutraceutical companies are playing major role to manage cancer disease by the recommendation of best natural products around the world, most of these natural products are isolated from plant and mushrooms because they contain several chemoprotective agents, which could reduce the chances of development of cancer and protect the cells for further progression. Some nutraceutical supplements might activate the cytotoxic chemotherapeutic effects by the mechanism of cell cycle arrest, cell differentiation procedures and changes in the redox states, but in other, it also elevate the levels of effectiveness of chemotherapeutic mechanism and in results, cancer cell becomes less reactive to chemotherapy. In this review, we have highlighted the prostate cancer and importance of nutraceuticals for the control and management of prostate cancer, and the significance of nutraceuticals to cancer patients during chemotherapy.

Extraction and Evaluation of the Antimicrobial Activity of Polyphenols from Banana Peels Employing Different Extraction Techniques

Polyphenols are natural antioxidants and play a vital role in inhibiting oxidative stress induced by the body’s free radicals. Banana peels are a significant agro-industrial waste. This waste could be utilized to extract polyphenols to process various functional foods and nutraceuticals. An investigation was executed to extract polyphenols from banana peel using the sonication and maceration techniques. Three different polar solvents, methanol, ethanol and acetone, were used at four different concentrations: 25%, 50%, 75% and 100%. Yield (%), Total Polyphenolic Content (TPC), Total Flavonoid Content (TFC) and 1,1-diphenyl-2-picryl-hydrazyl (DPPH) Radical Scavenging assays were performed. The results from the current study articulate that extraction by sonication yields a higher quantity of polyphenols than the maceration technique. The study also concludes that ethanol leads to better extraction than other solvents used in this study.

Polynesian medicine used to treat diarrhea and ciguatera: An ethnobotanical survey in six islands from French Polynesia

ETHNOPHARMACOLOGICAL RELEVANCE

In French Polynesia, many pathologies common or endemic to the territory cause diarrhea. This is the case for rotavirus gastroenteritis, salmonella food poisoning, ingestion of water contaminated by bacteria, and ciguatera. To treat these ailments, the population may employ traditional medicine for cultural reasons, geographical isolation, and poor health coverage. Polynesian remedies are often used without medical consultation and there is no data on their benefit-risk balance. A few ethnobotanical studies have been carried out in order to identify the traditional remedies used for various ailments, but few studies have focused on gastrointestinal pathologies. In this context, an ethnobotanical survey was carried out to identify treatments used for diarrhea and ciguatera, inventory the plants used, better understand the local representation of these remedies, and provide efficacy and safety data on these uses.

MATERIALS AND METHODS

From February to April 2021, a semi-structured survey was conducted on six islands in French Polynesia, including one island in the Windward Islands archipelago (Tahiti), three islands in the Marquesas archipelago (Hiva Oa, Nuku Hiva, Tahuata), and two islands in the Leeward Islands archipelago (Raiatea, Tahaa). A total of 133 people was interviewed including 34 specialists (of which 29 experts in herbalism).

RESULTS

These people mentioned the use of 27 plants for the treatment of diarrhea, and 24 for the treatment of ciguatera. Citrus aurantiifolia, Psidium guajava and Cordyline fruticosa were the three most cited plant species used for treating diarrhea, while Cocos nucifera, Punica granatum and Barringtonia asiatica were the most cited for ciguatera. A large majority of plants are widespread and introduced plants, which is congruent with the history of Polynesian people. While some plants are well known for similar uses (e.g. Psidium guajava for diarrhea, Heliotropium arboreum for ciguatera), others are less well known and may present toxicity risks (e.g. Barringtonia asiatica for ciguatera).

CONCLUSION

Traditional Polynesian medicine is an integral part of the local culture so important to be preserved and valued. However, more pharmacological and toxicological studies are still needed to determine the benefit-risk balance of some of these remedies and to allow their official integration into the Polynesian health system.

Applications of Innovative Non-Thermal Pulsed Electric Field Technology in Developing Safer and Healthier Fruit Juices

The deactivation of degrading and pectinolytic enzymes is crucial in the fruit juice industry. In commercial fruit juice production, a variety of approaches are applied to inactivate degradative enzymes. One of the most extensively utilized traditional procedures for improving the general acceptability of juice is thermal heat treatment. The utilization of a non-thermal pulsed electric field (PEF) as a promising technology for retaining the fresh-like qualities of juice by efficiently inactivating enzymes and bacteria will be discussed in this review. Induced structural alteration provides for energy savings, reduced raw material waste, and the development of new products. PEF alters the α-helix conformation and changes the active site of enzymes. Furthermore, PEF-treated juices restore enzymatic activity during storage due to either partial enzyme inactivation or the presence of PEF-resistant isozymes. The increase in activity sites caused by structural changes causes the enzymes to be hyperactivated. PEF pretreatments or their combination with other nonthermal techniques improve enzyme activation. For endogenous enzyme inactivation, a clean-label hurdle technology based on PEF and mild temperature could be utilized instead of harsh heat treatments. Furthermore, by substituting or combining conventional pasteurization with PEF technology for improved preservation of both fruit and vegetable juices, PEF technology has enormous economic potential. PEF treatment has advantages not only in terms of product quality but also in terms of manufacturing. Extending the shelf life simplifies production planning and broadens the product range significantly. Supermarkets can be served from the warehouse by increasing storage stability. As storage stability improves, set-up and cleaning durations decrease, and flexibility increases, with only minor product adjustments required throughout the manufacturing process.

Nutritional Value, Phytochemical Potential, and Therapeutic Benefits of Pumpkin (Cucurbita sp.)

Pumpkin is a well-known multifunctional ingredient in the diet, full of nutrients, and has opened new vistas for scientists during the past years. The fruit of pumpkin including the flesh, seed, and peel are a rich source of primary and secondary metabolites, including proteins, carbohydrates, monounsaturated fatty acids, polyunsaturated fatty acids, carotenoids, tocopherols, tryptophan, delta-7-sterols, and many other phytochemicals. This climber is traditionally used in many countries, such as Austria, Hungary, Mexico, Slovenia, China, Spain, and several Asian and African countries as a functional food and provides health promising properties. Other benefits of pumpkin, such as improving spermatogenesis, wound healing, antimicrobial, anti-inflammatory, antioxidative, anti-ulcerative properties, and treatment of benign prostatic hyperplasia have also been confirmed by researchers. For better drug delivery, nanoemulsions and niosomes made from pumpkin seeds have also been reported as a health promising tool, but further research is still required in this field. This review mainly focuses on compiling and summarizing the most relevant literature to highlight the nutritional value, phytochemical potential, and therapeutic benefits of pumpkin.

Effect of Co-Encapsulated Natural Antioxidants with Modified Starch on the Oxidative Stability of β-Carotene Loaded within Nanoemulsions

β-Carotene (vitamin A precursor) and α-tocopherol, the utmost energetic form of vitamin E (VE), are known to be fat-soluble vitamins (FSVs) and essential nutrients needed to enhance the growth and metabolic functions of the human body. Their deficiencies are linked to numerous chronic disorders. Loading of FSVs within nanoemulsions could increase their oxidative stability and solubility. In this research, VE and β-Carotene (BC) were successfully co-entrapped within oil-in-water nanoemulsions of carrier oils, including tuna fish oil (TFO) and medium-chain triglycerides (MCTs), stabilized by modified starch and Tween-80. These nanoemulsions and free carrier oils loaded with vitamins were stored for over one month to investigate the impact of storage circumstances on their physiochemical characteristics. Entrapped bioactive compounds inside the nanoemulsions and bare oil systems showed a diverse behavior in terms of oxidation. A more deficiency of FSVs was found at higher temperatures that were more noticeable in the case of BC. VE behaved like an antioxidant to protect BC in MCT-based nanoemulsions, whereas it could not protect BC perfectly inside the TFO-loaded nanoemulsions. However, cinnamaldehyde (CIN) loading significantly enhanced the oxidative stability and FSVs retention in each nanoemulsion. Purity gum ultra (PGU)-based nanoemulsions comprising FSVs and CIN presented a greater BC retention (42.3%) and VE retention (90.1%) over one-month storage at 40 °C than Twee 80. The superior stability of PGU is accredited to the OSA-MS capabilities to produce denser interfacial coatings that can protect the entrapped compounds from the aqueous phase. This study delivers valuable evidence about the simultaneous loading of lipophilic bioactive compounds to enrich functional foods.

Applications of Biotechnology in Food and Agriculture: a Mini-Review

Biotechnology is a wide-ranging science that uses modern technologies to construct biological processes, organisms, cells or cellular components. The clinical new instruments, industry, and products developed by biotechnologists are useful in research, agriculture and other major fields. The biotechnology is as ancient as civilization. The food you buy, and the pets you love? Using artificial selection for crops, domesticated animals and other species, you may thank our distant ancestors for setting off the agrarian revolution. When Alexander Fleming discovered antibiotics, and when Edward Jenner invented vaccines, the biotechnology potential was harnessed. And, of course, without the mechanisms of fermentation that gave us beer, wine and cheese, it would not be possible to imagine modern society. This article summarizes some of the applications of biotechnology in food & agriculture.

Graphical abstract

Applications of biotechnology in animal and plant sector.

Nutritional and Health Potential of Probiotics: A Review

Several products consist of probiotics that are available in markets, and their potential uses are growing day by day, mainly because some strains of probiotics promote the health of gut microbiota, especially Furmicutes and Bacteroidetes, and may prevent certain gastrointestinal tract (GIT) problems. Some common diseases are inversely linked with the consumption of probiotics, i.e., obesity, type 2 diabetes, autism, osteoporosis, and some immunological disorders, for which the disease progression gets delayed. In addition to disease mitigating properties, these microbes also improve oral, nutritional, and intestinal health, followed by a robust defensive mechanism against particular gut pathogens, specifically by antimicrobial substances and peptides producing probiotics (AMPs). All these positive attributes of probiotics depend upon the type of microbial strains dispensed. Lactic acid bacteria (LAB) and Bifidobacteria are the most common microbes used, but many other microbes are available, and their use depends upon origin and health-promoting properties. This review article focuses on the most common probiotics, their health benefits, and the alleviating mechanisms against chronic kidney diseases (CKD), type 1 diabetes (T1D), type 2 diabetes (T2D), gestational diabetes mellitus (GDM), and obesity.

Sonication, a Potential Technique for Extraction of Phytoconstituents: A Systematic Review

Traditional extraction techniques have lost their optimum performance because of rising consumer demand and novel technologies. In this regard, several techniques were developed by humans for the extraction of plant materials from various indigenous sources, which are no longer in use. Many of the techniques are not efficient enough to extract maximum plant material. By this time, evolution in extraction has led to development of various techniques including microfiltration, pulsed electric fields, high pressure, microwave assistance, enzyme assistance, supercritical fluid, subcritical fluid and ultrasonication. These innovations in food processing/extraction are known as “Green Food Processing”. These technologies were basically developed by focusing on three universal parameters: simplicity, energy efficiency and economy. These green technologies are practical in a number of different food sectors, mostly for preservation, inhibition of microorganisms, inactivation of enzymes and extraction of plant material. Like the others, ultrasonication could also be used for the said purposes. The primary objective of this review is to confine the potential use of ultrasonication for extraction of oils, pectin and phytochemicals by reviewing the literature systematically.

A Critical Review on Pulsed Electric Field: A Novel Technology for the Extraction of Phytoconstituents

Different parts of a plant (seeds, fruits, flower, leaves, stem, and roots) contain numerous biologically active compounds called “phytoconstituents” that consist of phenolics, minerals, amino acids, and vitamins. The conventional techniques applied to extract these phytoconstituents have several drawbacks including poor performance, low yields, more solvent use, long processing time, and thermally degrading by-products. In contrast, modern and advanced extraction nonthermal technologies such as pulsed electric field (PEF) assist in easier and efficient identification, characterization, and analysis of bioactive ingredients. Other advantages of PEF include cost-efficacy, less time, and solvent consumption with improved yields. This review covers the applications of PEF to obtain bioactive components, essential oils, proteins, pectin, and other important materials from various parts of the plant. Numerous studies compiled in the current evaluation concluded PEF as the best solution to extract phytoconstituents used in the food and pharmaceutical industries. PEF-assisted extraction leads to a higher yield, utilizes less solvents and energy, and it saves a lot of time compared to traditional extraction methods. PEF extraction design should be safe and efficient enough to prevent the degradation of phytoconstituents and oils.

A Comprehensive Study of the Antibacterial Activity of Bioactive Juice and Extracts from Pomegranate (Punica granatum L.) Peels and Seeds

Due to the growing awareness of Punica granatum fruit’s health-promoting properties, the pomegranate is increasingly used for food purposes. This results in the formation of biological waste products such as peels. A biowaste circular bioeconomy strategy holds great prospective for a sustainable economy. Therefore, a sustainable and environmentally friendly way of disposing of waste (e.g., use of biowaste to obtain high-value components (e.g., punicalagins, enzymes)) is crucial for the protection of the environment and human health. In the presented study, the content of total phenols and proanthocyanidins in ten samples of Punica granatum fruit (juice, aqueous (H₂O) and ethanolic (EtOH) extracts of peels and seeds) was determined. Peel extracts were found to be the richest in the content of secondary metabolites and showed extremely high antioxidant potential (approximately 90% inhibition: DPPH radical scavenging activity). To the best of our knowledge, this is the first comparative study to determine the enzymatic activity of α-amylase, lipase, peroxidase, protease, and transglutaminase in different P. granatum samples. Furthermore, the antibacterial efficacy of all P. granatum samples was qualitatively determined against three strains of Gram-negative (Escherichia coli, Pseudomonas aeruginosa, and Pseudomonas fluorescens) and three strains of Gram-positive (Bacillus cereus, Staphylococcus aureus, and Streptococcus pyogenes) bacteria, susceptible to gaining antibiotic resistance. Moreover, the most promising peel extracts were quantified for antibacterial efficacy against tested bacteria at five different concentrations. All samples slowed down and inhibited the growth of all tested bacteria. MIC₉₀ values (2.7 or 0.3 mg/mL) were determined in 18 out of 24 experiments (four samples, six bacteria tested). There is no research in the reviewed literature that is current with such detailed and comprehensive determination of P. granatum peel extracts antibacterial activity. The results of the research showed great potential for the use of P. granatum in the field of antibacterial activity in biomedicine applications and in the cosmetic, food, and pharmaceutical industries.

Heterocyclic Aromatic Amines in Meat: Formation, Isolation, Risk Assessment, and Inhibitory Effect of Plant Extracts

Heterocyclic aromatic amines (HAAs) are potent carcinogenic compounds induced by the Maillard reaction in well-done cooked meats. Free amino acids, protein, creatinine, reducing sugars and nucleosides are major precursors involved in the production of polar and non-polar HAAs. The variety and yield of HAAs are linked with various factors such as meat type, heating time and temperature, cooking method and equipment, fresh meat storage time, raw material and additives, precursor’s presence, water activity, and pH level. For the isolation and identification of HAAs, advanced chromatography and spectroscopy techniques have been employed. These potent mutagens are the etiology of several types of human cancers at the ng/g level and are 100- to 2000-fold stronger than that of aflatoxins and benzopyrene, respectively. This review summarizes previous studies on the formation and types of potent mutagenic and/or carcinogenic HAAs in cooked meats. Furthermore, occurrence, risk assessment, and factors affecting HAA formation are discussed in detail. Additionally, sample extraction procedure and quantification techniques to determine these compounds are analyzed and described. Finally, an overview is presented on the promising strategy to mitigate the risk of HAAs by natural compounds and the effect of plant extracts containing antioxidants to reduce or inhibit the formation of these carcinogenic substances in cooked meats.