Recent Advances in Nanoencapsulation of Phytochemicals to Combat Obesity and Its Comorbidities

Development of polysaccharide-coated layered double hydroxide nanocomposites for enhanced oral insulin delivery

Oral insulin (INS) is predicted to have the most therapeutic advantages in treating diabetes to repress hepatic glucose production through its potential to mimic the endogenous insulin pathway. Many oral insulin delivery systems have been investigated. Layered double hydroxide (LDH) as an inorganic material has been widely used in drug delivery thanks to its appealing features such as good biocompatibility, low toxicity, and excellent loading capability. However, when used in oral drug delivery, the effectiveness of LDH is limited due to the acidic degradation in the stomach. In this study, to overcome these challenges, chitosan (Chi) and alginate (Alg) dual-coated LDH nanocomposites with the loading of insulin (Alg-Chi-LDH@INS) were developed by the layered-by-layered method for oral insulin delivery with dynamic size of ~ 350.8 nm, negative charge of ~  - 13.0 mV, and dispersity index 0.228. The insulin release profile was evaluated by ultraviolet-visible spectroscopy. The drug release profiles evidenced that alginate and chitosan coating partially protect insulin release from a burst release in acidic conditions. The analysis using flow cytometry showed that chitosan coating significantly enhanced the uptake of LDH@INS by Caco-2 cells compared to unmodified LDH and free insulin. Further in the in vivo study in streptozocin-induced diabetic mice, a significant hypoglycemic effect was maintained following oral administration with great biocompatibility (~ 50% blood glucose level reduction at 4 h). This research has thus provided a potential nanocomposite system for oral delivery of insulin.

Development of polysaccharide-coated layered double hydroxide nanocomposites for enhanced oral insulin delivery

Oral insulin (INS) is predicted to have the most therapeutic advantages in treating diabetes to repress hepatic glucose production through its potential to mimic the endogenous insulin pathway. Many oral insulin delivery systems have been investigated. Layered double hydroxide (LDH) as an inorganic material has been widely used in drug delivery thanks to its appealing features such as good biocompatibility, low toxicity, and excellent loading capability. However, when used in oral drug delivery, the effectiveness of LDH is limited due to the acidic degradation in the stomach. In this study, to overcome these challenges, chitosan (Chi) and alginate (Alg) dual-coated LDH nanocomposites with the loading of insulin (Alg-Chi-LDH@INS) were developed by the layered-by-layered method for oral insulin delivery with dynamic size of ~ 350.8 nm, negative charge of ~  − 13.0 mV, and dispersity index 0.228. The insulin release profile was evaluated by ultraviolet–visible spectroscopy. The drug release profiles evidenced that alginate and chitosan coating partially protect insulin release from a burst release in acidic conditions. The analysis using flow cytometry showed that chitosan coating significantly enhanced the uptake of LDH@INS by Caco-2 cells compared to unmodified LDH and free insulin. Further in the in vivo study in streptozocin-induced diabetic mice, a significant hypoglycemic effect was maintained following oral administration with great biocompatibility (~ 50% blood glucose level reduction at 4 h). This research has thus provided a potential nanocomposite system for oral delivery of insulin.

Graphical Abstract

Development of "Smart Foods" for health by nanoencapsulation: Novel technologies and challenges

Importance of nanotechnology may be seen by penetration of its application in diverse areas including the food sector. With investigations and advancements in nanotechnology, based on feedback from these diverse areas, ease, and efficacy are also increasing. The food sector may use nanotechnology to encapsulate smart foods for increased health, wellness, illness prevention, and effective targeted delivery. Such nanoencapsulated targeted delivery systems may further add to the economic and nutritional properties of smart foods like stability, solubility, effectiveness, safeguard against disintegration, permeability, and bioavailability of smart/bioactive substances. But in the way of application, the fabrication of nanomaterials/nanostructures has several challenges which range from figuring out the optimal technique for obtaining them to determining the most suitable form of nanostructure for a bioactive molecule of interest. This review precisely addresses concepts, recent advances in fabrication techniques as well as current challenges/glitches of nanoencapsulation with special reference to smart foods/bioactive components. Since dealing with food materials also raises the quest for safety and regulatory norms a brief overview of the safety and regulatory aspects of nanomaterials/nanoencapsulation is also presented.

Role of phytocompounds as the potential anti-viral agent: an overview

Viral diseases are the most notorious infective agent(s) causing morbidity and mortality in every nook and corner for ages; viruses are active in host cells, and specific anti-virus medicines' developments remain uncanny. In this century of the biological era, human viruses act predominantly as versatile spreaders. The infection of the present COVID-19 virus is up in the air; blithely, the integument of medicinal chemistry approaches, particularly bioactive derived phytocompounds could be helpful to control those human viruses, recognized in the last 100 years. Indeed, natural products are being used for various therapeutic purposes. The major bioactive phytocompounds are chemically containing coumarin, thiosulfonate, steroid, polysaccharide, tannin, lignin, proanthocyanidin, terpene, quinone, saponin, flavonoid, alkaloid, and polyphenol, that are documented for inhibitory action against several viral infections. Mostly, about 20-30% of plants from tropical or temperate regions are known to have some antiviral activity. This comprehensive analysis of bioactive-derived phytocompounds would represent a significant impact and might be helpful for antiviral research and the current state of viral treatments.

A Comprehensive Review of Phytonutrients as a Dietary Therapy for Obesity

Obesity is a complex medical condition mainly caused by eating habits, genetics, lifestyle, and medicine. The present study deals with traditional diets like the Mediterranean diet, Nordic diet, African Heritage diet, Asian diet, and DASH, as these are considered to be sustainable diets for curing obesity. However, the bioavailability of phytonutrients consumed in the diet may vary, depending on several factors such as digestion and absorption of phytonutrients, interaction with other substances, cooking processes, and individual differences. Hence, several phytochemicals, like polyphenols, alkaloids, saponins, terpenoids, etc., have been investigated to assess their efficiencies and safety in the prevention and treatment of obesity. These phytochemicals have anti-obesity effects, mediated via modulation of many pathways, such as decreased lipogenesis, lipid absorption, accelerated lipolysis, energy intake, expenditure, and preadipocyte differentiation and proliferation. Owing to these anti-obesity effects, new food formulations incorporating these phytonutrients were introduced that can be beneficial in reducing the prevalence of obesity and promoting public health.

The Antioxidant and In Vitro Wound Healing Activity of Cotyledon orbiculata Aqueous Extract and the Synthesized Biogenic Silver Nanoparticles

The synthesis of silver nanoparticles using biogenic methods, particularly plants, has led to the discovery of several effective nanoparticles. In many instances, plant-derived silver nanoparticles have been shown to have more activity than the plant extract which was used to synthesize the nanoparticles. Silver nanoparticles have been successfully synthesized using the medicinal plant, Cotyledon orbiculata. This is a shrub found in the Western Cape province of South Africa. It has a long history of use in traditional medicine in the treatment of wounds and skin infections. The C. orbiculata synthesized silver nanoparticles (Cotyledon-AgNPs) were reported to have good antimicrobial and anti-inflammatory activities; however, their wound-healing properties have not been determined. This study aimed to determine the wound healing activity of Cotyledon-AgNPs using the scratch assay. Gene expression studies were also done to determine the nanoparticles' mechanism of action. The Cotyledon-AgNPs showed good antioxidant, growth-promoting and cell migration properties. Gene expression studies showed that the C. orbiculata water extract and Cotyledon-AgNPs promoted wound healing by upregulating genes involved in cell proliferation, migration and growth while downregulating pro-inflammatory genes. This confirms, for the first time that a water extract of C. orbiculata and silver nanoparticles synthesized from this extract are good wound-healing agents.

In Silico Study: Combination of α-Mangostin and Chitosan Conjugated with Trastuzumab against Human Epidermal Growth Factor Receptor 2

Breast cancer is a type of cancer with the highest prevalence worldwide. Almost 10–30% of breast cancer cases are diagnosed as positive for HER2 (human epidermal growth factor receptor 2). The currently available treatment methods still exhibit many shortcomings such as a high incidence of side effects and treatment failure due to resistance. This in silico study aims to simulate α-mangostin and chitosan combination conjugated to trastuzumab formulation against HER2 as an effort to improve breast cancer patient therapy. This molecular docking simulation was done through using PatchDock Server. The materials used including the two-dimensional structure of α-mangostin, chitosan, and sodium tripolyphosphate from the PubChem database; trastuzumab FASTA sequence from the DrugBank database; and HER2 structure obtained from a crystal complex with PDB ID: 1N8Z. The results indicated that the particle of α-mangostin and chitosan combinations interacted mostly with the crystallizable fragment (Fc region) of trastuzumab in the conjugation process. The conjugation of trastuzumab to the particle of a combination of α-mangostin and chitosan resulted in the greatest increase in the binding score of the smallest-sized particles (50 Å) with an increase in the score of 3828 and also gave the most similar mode of interaction with trastuzumab. However, the conjugation of trastuzumab eliminated the similarity of the mode of interaction and increased the value of atomic contact energy. Thus, a cominbation of α-mangostin and chitosan conjugated to a trastuzumab formulation was predicted can increase the effectiveness of breast cancer therapy at a relatively small particle size but with the consequence of decreasing atomic contact energy.

Resveratrol alleviates enterotoxigenic Escherichia coli K88-induced damage by regulating SIRT-1 signaling in intestinal porcine epithelial cells

This study found that resveratrol pretreatment attenuated porcine intestinal epithelial cell damage caused by enterotoxigenic Escherichia coli (ETEC) K88 in vitro and the protective effects of resveratrol were associated with SIRT-1 signaling. ETEC K88 is a main intestinal pathogen for post-weaning diarrhea (PWD) in piglets. With the strict ban on antibiotics in animal feed, people are seeking effective antibiotic substitutes to protect the intestinal system against harmful pathogenic bacteria. This study was conducted to evaluate the effects of resveratrol, a natural plant polyphenol, on ETEC K88-induced cellular damage in porcine enterocytes and underlying mechanisms. Intestinal porcine epithelial cell line 1 (IPEC-1) cells, pretreated with or without resveratrol (30 μM, 4 h), were challenged with ETEC K88 (MOI = 1 : 10) for 3 h. The results showed that ETEC K88 infection induced severe damage and dysfunction in IPEC-1 cells, as evidenced by a reduced cell viability, decreased tight junctions, mitochondrial dysfunction, and autophagy. It is noteworthy that IPEC-1 cells pre-treated with resveratrol improved their capacity for resistance to most of these abnormal phenotypes caused by ETEC K88 infection. Furthermore, we found that the activation of SIRT-1 signaling was associated with the benefits of resveratrol, as demonstrated by EX-527, an inhibitor of SIRT-1, which reversed most of the protective effects of resveratrol. In conclusion, these results indicated that resveratrol could protect intestinal epithelial cells against ETEC K88 infection by activating SIRT-1 signaling. These findings provide new insights into the role of resveratrol in maintaining intestinal physiological functions.

Utilization of Nanotechnology to Improve the Application and Bioavailability of Phytochemicals Derived from Waste Streams

Phytochemicals are relatively small molecular species found in edible plants that may exhibit a diverse range of techno- and biofunctional attributes. In particular, there has been great interest in the identification, isolation, and utilization of dietary phytochemicals that can be used as natural pigments, antioxidants, or antimicrobials or that may improve human health and wellbeing by preventing chronic diseases, such as cardiovascular diseases, diabetes, obesity, and cancer. Relatively high levels of these phytochemicals are often present in the waste streams produced by the food and agriculture industry, such as the peels, stems, roots, or leaves of plants, that are normally discarded or turned into animal foods. From an economic and environmental perspective, it would be advantageous to convert these waste streams into value-added functional ingredients, which is consistent with the creation of a more circular economy. Bioactive phytochemicals can be isolated from agricultural and food waste streams using green extraction methods and then incorporated into plant-based functional foods or biodegradable active packaging materials. The utilization of phytochemicals in the food industry is often challenging. They may chemically degrade in the presence of light, heat, oxygen, and some pH conditions, thereby altering their biological activity. They may have low solubility in aqueous solutions and gastrointestinal fluids, thereby making them difficult to introduce into foods and leading to a low bioavailability. These challenges can sometimes be overcome using nanoencapsulation, which involves trapping the phytochemicals inside tiny food-grade particles. These nanoparticles may be assembled from edible lipids, proteins, carbohydrates, and/or surfactants and include nanoemulsions, solid lipid nanoparticles, nanoliposomes, and biopolymer nanoparticles. In this manuscript, we review a number of important phytochemicals and nanoencapsulation methods used to improve their efficacy.

Current Development of Nano-Drug Delivery to Target Macrophages

Macrophages are the most important innate immune cells that participate in various inflammation-related diseases. Therefore, macrophage-related pathological processes are essential targets in the diagnosis and treatment of diseases. Since nanoparticles (NPs) can be preferentially taken up by macrophages, NPs have attracted most attention for specific macrophage-targeting. In this review, the interactions between NPs and the immune system are introduced to help understand the pharmacokinetics and biodistribution of NPs in immune cells. The current design and strategy of NPs modification for specific macrophage-targeting are investigated and summarized.

Epigallocatechin gallate: Phytochemistry, bioavailability, utilization challenges, and strategies

Epigallocatechin gallate (EGCG), a green tea catechin, has gained the attention of current study due to its excellent health-promoting effects. It possesses anti-obesity, antimicrobial, anticancer, anti-inflammatory activities, and is under extensive investigation in functional foods for improvement. It is susceptible to lower stability, lesser bioavailability, and lower absorption rate due to various environmental, processing, formulations, and gastrointestinal conditions of the human body. Therefore, it is the foremost concern for the researchers to enhance its bioactivity and make it the most suitable therapeutic compound for its clinical applications. In the current review, factors affecting the bioavailability of EGCG and the possible strategies to overcome these issues are reviewed and discussed. This review summarizes structural modifications and delivery through nanoparticle-based approaches including nano-emulsions, encapsulations, and silica-based nanoparticles for effective use of EGCG in functional foods. Moreover, recent advances to enhance EGCG therapeutic efficacy by specifically targeting its molecules to increase its bioavailability and stability are also described. PRACTICAL APPLICATIONS: The main green tea constituent EGCG possesses several health-promoting effects making EGCG a potential therapeutic compound to cure ailments. However, its low stability and bioavailability render its uses in many disorders. Synthesizing EGCG prodrugs by structural modifications helps against its low bioavailability and stability by overcoming premature degradation and lower absorption rate. This review paper summarizes various strategies that benefit EGCG under different physiological conditions. The esterification, nanoparticle approaches, silica-based EGCG-NPs, and EGCG formulations serve as ideal EGCG modification strategies to deliver superior concentrations with lesser toxicity for its efficient penetration and absorption across cells both in vitro and in vivo. As a result of EGCG modifications, its bioactivities would be highly improved at lower doses. The protected or modified EGCG molecule would have enhanced potential effects and stability that would contribute to the clinical applications and expand its use in various food and cosmetic industries.

Lactobacillus paracasei 24 Attenuates Lipid Accumulation in High-Fat Diet-Induced Obese Mice by Regulating the Gut Microbiota

Obesity has become a worldwide public health problem. Lactic acid bacteria have attracted extensive attention for alleviating obesity and fat accumulation. This study aimed to evaluate the alleviating effects of Lactobacillus paracasei 24 (LP24) on lipid accumulation in an obese mouse model induced by a high-fat diet (HFD). The results showed that LP24 treatment significantly reduced body weight and fat deposition in HFD mice, improved blood lipid levels and liver steatosis, reduced liver oxidative stress injury and the inflammatory response, and regulated fat metabolism-related factors. Moreover, LP24 regulated the abundance and diversity of the gut microbiota, reduced the abundance of Firmicutes and the ratio of Firmicutes/Bacteroidetes (F/B), and increased the abundance of Akkermansia. In summary, LP24 regulates lipid metabolism by activating the expression level of related genes and regulating the gut microbiota through the gut-liver axis to attenuate the development of obesity. This study provides a theoretical basis for probiotics to regulate gut microbiota to reduce lipid accumulation.

Nano-Drug Delivery Systems Entrapping Natural Bioactive Compounds for Cancer: Recent Progress and Future Challenges

Cancer is a prominent cause of mortality globally, and it becomes fatal and incurable if it is delayed in diagnosis. Chemotherapy is a type of treatment that is used to eliminate, diminish, or restrict tumor progression. Chemotherapeutic medicines are available in various formulations. Some tumors require just one type of chemotherapy medication, while others may require a combination of surgery and/or radiotherapy. Treatments might last from a few minutes to many hours to several days. Each medication has potential adverse effects associated with it. Researchers have recently become interested in the use of natural bioactive compounds in anticancer therapy. Some phytochemicals have effects on cellular processes and signaling pathways with potential antitumor properties. Beneficial anticancer effects of phytochemicals were observed in both in vivo and in vitro investigations. Encapsulating natural bioactive compounds in different drug delivery methods may improve their anticancer efficacy. Greater in vivo stability and bioavailability, as well as a reduction in undesirable effects and an enhancement in target-specific activity, will increase the effectiveness of bioactive compounds. This review work focuses on a novel drug delivery system that entraps natural bioactive substances. It also provides an idea of the bioavailability of phytochemicals, challenges and limitations of standard cancer therapy. It also encompasses recent patents on nanoparticle formulations containing a natural anti-cancer molecule.

A Nanosized Codelivery System Based on Intracellular Stimuli-Triggered Dual-Drug Release for Multilevel Chemotherapy Amplification in Drug-Resistant Breast Cancer

Lacking nano-systems for precisely codelivering the chemotherapeutics paclitaxel (PTX) and the natural P-glycoprotein (P-gp) inhibitor, quercetin (QU), into cancer cells and controlling their intracellular release extremely decreased the anticancer effects in multidrug resistant (MDR) tumors. To overcome this hurdle, we constructed hybrid polymeric nanoparticles (PNPs) which consist of redox-sensitive PTX/polyethyleneimine-tocopherol hydrogen succinate-dithioglycollic acid PNPs and pH-sensitive hyaluronic acid-QU conjugates. The obtained hybrid PNPs can be internalized into drug-resistant breast cancer cells by the hyaluronic acid/CD44-mediated endocytosis pathway and escape from the lysosome through the “proton sponge effect”. Under the trigger of intracellular stimuli, the nanoplatform used the pH/glutathione dual-sensitive disassembly to release QU and PTX. The PTX diffused into microtubules to induce tumor cell apoptosis, while QU promoted PTX retention by down-regulating P-gp expression. Moreover, tocopherol hydrogen succinate and QU disturbed mitochondrial functions by generating excessive reactive oxygen species, decreasing the mitochondrial membrane potential, and releasing cytochrome c into the cytosol which consequently achieved intracellular multilevel chemotherapy amplification in MDR cancers. Importantly, the PNPs substantially suppressed tumors growth with an average volume 2.54-fold lower than that of the control group in the MCF-7/ADR tumor-bearing nude mice model. These presented PNPs would provide a valuable reference for the coadministration of natural compounds and anticarcinogens for satisfactory combination therapy in MDR cancers.

Food-grade systems for delivery of DHA and EPA: Opportunities, fabrication, characterization and future perspectives

Docosahexaenoic acid (C22: 6n-3, DHA) and eicosapentaenoic acid (C20: 5n-3, EPA) have been shown to provide the opportunity to inhibit onset and escalation of chronic diseases. Nevertheless, their undesirable characteristics including poor water solubility, oxidation sensitivity, high melting point and unpleasant sensory attributes hinder their application in the food industry. In recent years, utilizing food-grade delivery systems to deliver DHA/EPA and improve their biological efficacy has emerged as an attractive approach with fascinating prospects. This review focuses on introducing potential delivery systems for DHA/EPA, including microemulsions, nanoemulsions, Pickering emulsions, hydrogels, lipid particles, oleogels, liposomes, microcapsules and micelles. The opportunities, fabrication and characterization of these delivery systems loaded with DHA/EPA are highlighted. Besides, food sources of DHA/EPA, their benefits to the human body and a series of challenges for effective utilization of DHA/EPA are discussed. Promising future research trends of food-grade systems for delivery of DHA/EPA are also presented. Conducting in vivo experiments, applying DHA/EPA-loaded delivery systems into real food, improving the applicability of such delivery systems in industrial production, co-encapsulating DHA/EPA with other substances, seeking measures to improve the performance of existing delivery systems and developing novel food-grade delivery systems inspired by other fields are various future considerations.

A Review on Obesity Management through Natural Compounds and a Green Nanomedicine-Based Approach

Obesity is a serious health complication in almost every corner of the world. Excessive weight gain results in the onset of several other health issues such as type II diabetes, cancer, respiratory diseases, musculoskeletal disorders (especially osteoarthritis), and cardiovascular diseases. As allopathic medications and derived pharmaceuticals are partially successful in overcoming this health complication, there is an incessant need to develop new alternative anti-obesity strategies with long term efficacy and less side effects. Plants harbor secondary metabolites such as phenolics, flavonoids, terpenoids and other specific compounds that have been shown to have effective anti-obesity properties. Nanoencapsulation of these secondary metabolites enhances the anti-obesity efficacy of these natural compounds due to their speculated property of target specificity and enhanced efficiency. These nanoencapsulated and naive secondary metabolites show anti-obesity properties mainly by inhibiting the lipid and carbohydrate metabolizing enzymes, suppression of adipogenesis and appetite, and enhancing energy metabolism. This review focuses on the plants and their secondary metabolites, along with their nanoencapsulation, that have anti-obesity effects, with their possible acting mechanisms, for better human health.

Nrf2-interacting nutrients and COVID-19: time for research to develop adaptation strategies

There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPARγ:Peroxisome proliferator-activated receptor, NFκB: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2α:Elongation initiation factor 2α). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT₁R axis (AT₁R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity.