Immunomodulatory and antiviral activity of almond skins

Chemical and Sensory Properties of Waffles Supplemented with Almond Skins

Almonds are one of the most produced nuts worldwide and numerous studies have shown that they have nutritional and medicinal characteristics, which gives them the possibility of being applied in various products. However, several by-products are generated during their production, which have characteristics of interest but remain underutilised, namely, the almond skins. This work aimed to study samples of waffles supplemented with almond skins. The waffles were evaluated for their total polyphenol content, antioxidant capacity, total flavonoids, ortho-diphenols, soluble sugars, starch, texture, and colour. They were also sensorially evaluated using a panel of tasters specialised in this type of evaluation and a quantitative descriptive analysis test (QDA) sensory test. The results showed that the waffles with the highest levels of phenolic compounds as well as the highest antioxidant activity (by the ABTS, DPPH, and FRAP methods) were the waffles supplemented with 10% almond skin. The total phenol contents obtained for the prepared extracts varied between 0.127 mg GAE/g and 0.415 mg GAE/g, the flavonoid contents ranged from 0.067 mg CAE/g to 0.339 mg CAE/g and the ortho-diphenol contents varied between 0.163 mg ACE /g and 0.303 mg ACE/g. Regarding the quantification of soluble sugars, the values were presented in percentage of fresh weight, and ranged from 30.148 to 38.054%; regarding the quantification of starch, the percentages varied from 14.488 to 21.982%. Sensorially, we verified that the samples were statistically different in terms of the descriptors "colour", "roasted aroma", and "dissolubility", with a higher score in these descriptors for the waffles with 10% of almond skin. This process of obtaining waffles, which can be industrialised, is interesting from both a nutritional point of view and for the possibility of creating new, differentiated, and innovative products.

Gut microbiota and Autism Spectrum Disorder: From pathogenesis to potential therapeutic perspectives

Autism is a complex neurodevelopmental disorder which disrupts communication, social and interactive skills followed by appearance of repetitive behavior. The underlying etiology remains incomprehensible but genetic and environmental factors play a key role. Accumulated evidence shows that alteration in level of gut microbes and their metabolites are not only linked to gastrointestinal problems but also to autism. So far the mix of microbes that is present in the gut affects human health in numerous ways through extensive bacterial-mammalian cometabolism and has a marked influence over health via gut-brain-microbial interactions. Healthy microbiota may even ease the symptoms of autism, as microbial balance influences brain development through the neuroendocrine, neuroimmune, and autonomic nervous systems. In this article, we focused on reviewing the correlation between gut microbiota and their metabolites on symptoms of autism by utilizing prebiotics, probiotics and herbal remedies to target gut microflora hence autism.

Herbal plants as immunity modulators against COVID-19: A primary preventive measure during home quarantine

The novel coronavirus or severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) is a deadly virus which has spread globally and claimed millions of lives. This novel virus transmits mainly through droplets and close human contact. It’s impact in different countries varies depending on geographical location, climatic conditions, food habits, and cultural activities. Several precautionary measures, as well as many medicines, are applied in different combinations to limit the spread of infection. This results in a preliminary relief of people infected in the first stage of infection. An alternative approach has been introduced which proposes natural herbs, which have minimal or no side effects, and improve overall immunity. Some essential herbs with their immunomodulatory effects are mentioned in this article along with suggestions for improved immunity and protection.

Edible fruit extracts and fruit juices as potential source of antiviral agents: a review

Fruits have been widely consumed since the beginning of human evolution and are important source of a healthy being and helpful in treating various diseases as immunity boosters with the presence of a rich amount of health-promoting bioactives. Therapeutic efficacies of fruit extracts are reported to have immune-modulatory properties and influence greatly on the immune system of human body. Given the facts of the efficacy of edible fruits in improving the immunity of body as immune-stimulants, we have tried to consolidate the previously published data on edible fruits and its juices with antiviral potential. The objective of this review was to gather information on edible fruits with antiviral properties and the efforts to obtain their efficient delivery. Online bibliographical databases like PubMed, Scopus, and Web of Science were used to search literature on the antiviral effect of edible fruit extracts and fruit juices. The edible fruits like almond, apple, bael, blackberry, black currants, crane berry, citrus, grapes, Japanese cherry, mango, mulberry, pistachios, pomegranate, and strawberry showed promising antiviral properties against the different pathogenic viruses. The review provided an overview of likely effects of the intake of edible fruit extracts/fruit juices to strengthen the immune cells by reducing the oxidative stress in host body system which in turn inhibits the viral attachment and replication on the host cell. Hence these fruits can also be exploited in combating COVID-19 in the current pandemic situation. To validate the present hypothesis, the proposed edible fruit extracts can be evaluated against the SARS-CoV-2 via in vitro and in vivo models to confirm the fact.

Almond By-Products: Valorization for Sustainability and Competitiveness of the Industry

The search for waste minimization and the valorization of by-products are key practices for good management and improved sustainability in the food industry. The production of almonds generates a large amount of waste, most of which is not used. Until now, almonds have been used for their high nutritional value as food, especially almond meat. The other remaining parts (skin, shell, hulls, etc.) are still little explored, even though they have been used as fuel by burning or as livestock feed. However, interest in these by-products has been increasing as they possess beneficial properties (caused mainly by polyphenols and unsaturated fatty acids) and can be used as new ingredients for the food, cosmetic, and pharmaceutical industries. Therefore, it is important to explore almond’s valorization of by-products for the development of new added-value products that would contribute to the reduction of environmental impact and an improvement in the sustainability and competitiveness of the almond industry.

Immunomodulatory role and potential utility of various nutrients and dietary components in SARS-CoV-2 infection

Recently, the outbreak of severe acute respiratory syndrome cornoavirus-2 (SARS-CoV-2), causing coronavirus disease 2019 (COVID-19), has become a great perturbation all around the globe and has many devastating effects on every aspect of life. Apart from the oxygen therapy and extracorporeal membrane oxygenation, Remdesivir and Dexamethasone have been proven to be efficacious against COVID-19, along with various vaccine candidates and monoclonal antibody cocktail therapy for Regeneron. All of these are currently at different stages of clinical trials. People with weak immunity are more prone to a severe infection of SARS-CoV-2. Therefore, early and judicious nutritional supplementation along with pharmacological treatment and clinician collaborations are critical in restituting the current situation. Nutritional supplements help in acquiring strong immunity to prevent the progression of disease any further. Vitamin C, vitamin D, selenium, zinc and many other nutritional and dietary supplements inhibit the production of inflammatory cytokines during a viral infection and prevents several unwanted symptoms of infection. Many dietary components like citrus fruits, black elderberry, ginger, and probiotics have the ability to attack viral replication. These supplements can also tame the overriding immune system during coronavirus infection. Keeping in view these facts, nutritional and dietary supplements can be used along with other management modalities. These nutritional and dietary supplements are potential candidates to curb the convulsive unfolding of novel COVID-19, in combination with other standard treatment protocols. In this review, various search engines were used to exploit available literature in order to provide a comprehensive review on nutritional and dietary supplements with respect to the viral infections. It will also provide a brief overview on some of the clinical trials that are in progress to assess the role of nutritional supplements, either alone or in combination with other pharmacological drugs, in fight against COVID-19.

Use of Almond Skins to Improve Nutritional and Functional Properties of Biscuits: An Example of Upcycling

Upcycling food industry by-products has become a topic of interest within the framework of the circular economy, to minimize environmental impact and the waste of resources. This research aimed at verifying the effectiveness of using almond skins, a by-product of the confectionery industry, in the preparation of functional biscuits with improved nutritional properties. Almond skins were added at 10 g/100 g (AS10) and 20 g/100 g (AS20) to a wheat flour basis. The protein content was not influenced, whereas lipids and dietary fiber significantly increased (p < 0.05), the latter meeting the requirements for applying "source of fiber" and "high in fiber" claims to AS10 and AS20 biscuits, respectively. The addition of almond skins altered biscuit color, lowering L* and b* and increasing a*, but improved friability. The biscuits showed sensory differences in color, odor and textural descriptors. The total sum of single phenolic compounds, determined by HPLC, was higher (p < 0.05) in AS10 (97.84 µg/g) and AS20 (132.18 µg/g) than in control (73.97 µg/g). The antioxidant activity showed the same trend as the phenolic. The p-hydroxy benzoic and protocatechuic acids showed the largest increase. The suggested strategy is a practical example of upcycling when preparing a health-oriented food product.

Adaptogenic and immunomodulatory activity of Virgozest Avaleha – An ayurvedic proprietary formulation

Introduction:

Rasayana (rejuvenator) or adaptogenic drugs have been proved to produce the complete potential to prevent diseases and degenerative changes that leads to diseases and promote longevity by providing strength and immunity. Virgozest Avaleha is a poly-herbal formulation claimed to serve as adaptogenic, and immunomodulatory, as a health tonic, enriched with dry fruits, and ingredients containing natural supplements of Vitamin E and proteins.

Aim:

To evaluate the adaptogenic activity and humoral immune activity of virgozest Avaleha in Wistar albino rats.

Materials and methods:

Virgozest Avaleha was evaluated for adaptogenic activity against swimming stress-induced changes and hypothermia in albino rats. The humoral immune activity of virgozest Avaleha was evaluated against sheep red blood cells (SRBCs)-induced response in albino rats with the inclusion of cyclophosphamide as immune suppressant agent.

Results:

In adaptogenic activity, virgozest Avaleha (450 and 900 mg/kg) exhibited an increase in physical activity, decrease in stress-induced hypothermia, and serum cortisol level when compared to the stress control group of albino rats. In humoral immune activity, virgozest Avaleha reversed the effects of cyclophosphamide-induced adverse changes on spleen and lymph node, and produced a significant increase in serum antibody titer in SRBCs-sensitized rats.

Conclusion:

The present study concluded that virgozest Avaleha has adaptogenic and humoral immune activity in Wistar albino rats, which may suggest the Rasayana like properties of Ayurvedic formulation.

The Antimicrobial and Antiviral Activity of Polyphenols from Almond (Prunus dulcis L.) Skin

Due to their antimicrobial and antiviral activity potential in vitro, polyphenols are gaining a lot of attention from the pharmaceutical and healthcare industries. A novel antiviral and antimicrobial approach could be based on the use of polyphenols obtained from natural sources. Here, we tested the antibacterial and antiviral effect of a mix of polyphenols present in natural almond skin (NS MIX). The antimicrobial potential was evaluated against the standard American Type Culture Collection (ATCC) and clinical strains of Staphylococcus aureus, including methicillin-resistant (MRSA) strains, by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Herpes simplex virus type I was used for the antiviral assessment of NS MIX by plaque assay. Furthermore, we evaluated the expression of viral cascade antigens. NS MIX exhibited antimicrobial (MIC values of 0.31–1.25 mg/ml) and antiviral activity (decrease in the viral titer ** p < 0.01, and viral DNA accumulation * p < 0.05) against Staphylococcus aureus and HSV-1, respectively. Amongst the isolated compounds, the aglycones epicatechin and catechin showed the greatest activity against S. aureus ATCC 6538P (MIC values of 0.078–0.15 and 0.15 mg/ml, respectively), but were not active against all the other strains. These results could be used to develop novel products for topical use.

Polyphenols in Almond Skins after Blanching Modulate Plasma Biomarkers of Oxidative Stress in Healthy Humans

Almond skins are a waste byproduct of blanched almond production. Polyphenols extracted from almond skins possess antioxidant activities in vitro and in vivo. Thus, we examined the pharmacokinetic profile of almond skin polyphenols (ASP) and their effect on measures of oxidative stress. In a randomized crossover trial, seven adults consumed two acute ASP doses (225 mg (low, L) or 450 mg (high, H) total phenols) in skim milk or milk alone. Plasma flavonoids, glutathione peroxidase (GPx), glutathione (GSH), oxidized GSH (GSSG), and resistance of low- density lipoprotein (LDL) to oxidation were measured over 10 h. The H dose increased catechin and naringenin in plasma, with maximum concentrations of 44.3 and 19.3 ng/mL, respectively. The GSH/GSSG ratio at 3 h after the H doses was 212% of the baseline value, as compared to 82% after milk (p = 0.003). Both ASP doses upregulated GPx activity by 26-35% from the baseline at 15, 30, 45, and 120 min after consumption. The in vitro addition of α-tocopherol extended the lag time of LDL oxidation at 3 h after L and H consumption by 144.7% and 165.2% of that at 0 h compared to no change after milk (p ≤ 0.05). In conclusion, ASP are bioavailable and modulate GSH status, GPx activity, and the resistance of LDL to oxidation.

Protein Hydrolyzates from Changbai Mountain Walnut (Juglans mandshurica Maxim.) Boost Mouse Immune System and Exhibit Immunoregulatory Activities

The Changbai Mountain walnut (Juglans mandshurica Maxim.) is a rich source of essential amino acids. Walnut dregs are byproducts of edible oil production and primarily used as fodder and fertilizers. We systematically examined the effect of three types of walnut protein hydrolyzates—albumin, glutelin, and globin—on the immune system of mice and aimed to provide the theoretical basis for developing and utilizing J. mandshurica Maxim. protein resources. In comparison with the normal control mice, those treated with different doses of walnut proteins showed improved immune indices, including organ index, spleen lymphocyte proliferation, macrophage activity, number of CD4⁺ and CD8⁺ T cells, immunoglobulin A (IgA) and secretory IgA content, and mRNA and protein expression levels of cytokine factors. Our results indicated that these walnut proteins may have positive effects on the immune system and perform their immunomodulatory functions by inducing splenic enlargement. These findings support the use of walnut proteins as nutritional sources to boost the immune system.

Almond Skin Extracts Abrogate HSV-1 Replication by Blocking Virus Binding to the Cell

The aim of the present research was to determine the effect of almond skin extracts on herpes simplex virus 1 (HSV-1) replication. Drug-resistant strains of HSV frequently develop following therapeutic treatment. Therefore, the discovery of novel anti-HSV drugs deserves great effort. Here, we tested both natural (NS) and blanched (BS) polyphenols-rich almond skin extracts against HSV-1. HPLC analysis showed that the prevalent compounds in NS and BS extracts contributing to their antioxidant activity were quercetin, epicatechin and catechin. Results of cell viability indicated that NS and BS extracts were not toxic to cultured Vero cells. Furthermore, NS extracts were more potent inhibitors of HSV-1 than BS extracts, and this trend was in agreement with different concentrations of flavonoids. The plaque forming assay, Western blot and real-time PCR were used to demonstrate that NS extracts were able to block the production of infectious HSV-1 particles. In addition, the viral binding assay demonstrated that NS extracts inhibited HSV-1 adsorption to Vero cells. Our conclusion is that natural products from almond skin extracts are an extraordinary source of antiviral agents and provide a novel treatment against HSV-1 infections.

Role of Bacterial Exopolysaccharides as Agents in Counteracting Immune Disorders Induced by Herpes Virus

Extreme marine environments, such as the submarine shallow vents of the Eolian Islands (Italy), offer an almost unexplored source of microorganisms producing unexploited and promising biomolecules for pharmaceutical applications. Thermophilic and thermotolerant bacilli isolated from Eolian vents are able to produce exopolysaccharides (EPSs) with antiviral and immunomodulatory effects against Herpes simplex virus type 2 (HSV-2). HSV-2 is responsible for the most common and continuously increasing viral infections in humans. Due to the appearance of resistance to the available treatments, new biomolecules exhibiting different mechanisms of action could provide novel agents for treating viral infections. The EPSs hinder the HSV-2 replication in human peripheral blood mononuclear cells (PBMC) but not in WISH (Wistar Institute Susan Hayflic) cells line, indicating that cell-mediated immunity was involved in the antiviral activity. High levels of Th1-type cytokines were detected in PBMC treated with all EPSs, while Th2-type cytokines were not induced. These EPSs are water soluble exopolymers able to stimulate the immune response and thus contribute to the antiviral immune defense, acting as immunomodulators. As stimulants of Th1 cell-mediated immunity, they could lead to the development of novel drugs as alternative in the treatment of herpes virus infections, as well as in immunocompromised host.

Almond Skin Inhibits HSV-2 Replication in Peripheral Blood Mononuclear Cells by Modulating the Cytokine Network

We have investigated the effect of almond skin extracts on the production of pro-inflammatory and anti-inflammatory cytokines in human peripheral blood mononuclear cells (PBMCs). PBMCs were either infected or not by herpes simplex virus type 2 (HSV-2), with and without prior treatment with almond skin extracts. Production of IL-17 induced by HSV-2 was inhibited by natural skins (NS) treatment. NS triggered PBMC in releasing IFN-α, IFN-γ and IL-4 in cellular supernatants. These results may explain the antiviral potential of almond skins.

In vitro antiviral and immunomodulatory activity of arbidol and structurally related derivatives in herpes simplex virus type 1-infected human keratinocytes (HaCat)

Arbidol (ARB) is an antiviral drug that has broad-spectrum activity against a number of viral infections. To date, there are no specific data regarding its effects against a herpesvirus. Here, the in vitro antiviral effect of ARB and structurally related derivatives were evaluated in HaCat cells on different steps of herpes simplex virus type 1 replication: adsorption, entry and post-entry. The simplified pyrrolidine analogue, 9a2, showed the best antiviral activity in vitro by reducing the plaque numbers by about 50% instead of 42% obtained with ARB at the same concentration. Furthermore, we have reported that all tested compounds evaluated for their immunomodulatory activity showed the ability to reduce the viral proteins VP16 and ICP27 and to modify the virus-induced cytokine expression, allowing the host cell a more efficient antiviral response.

Antibacterial activities of almond skins on cagA-positive and-negative clinical isolates of Helicobacter pylori

BACKGROUND

Helicobacter pylori is known to be a gastric pathogen of humans. Eradication regimens for H. pylori infection have some side effects, compliance problems, relapses, and antibiotic resistance. Therefore, the need for alternative therapies for H. pylori infections is of special interest. We have previously shown that polyphenols from almond skins are active against a range of food-borne pathogens. The aim of this study was to evaluate the antibacterial effects of natural almond skins before and after simulated human digestion and the pure flavonoid compounds epicatechin, naringenin and protocatechuic acid against H. pylori.

RESULTS

H. pylori strains were isolated from gastric biopsy samples following standard microbiology procedures. Also, cagA and vacA genes were identified using PCR. Susceptibility studies on 34 strains of H. pylori, including two reference strains (ATCC 43504, ATCC 49503), were performed by the standard agar dilution method.

CONCLUSIONS

Polyphenols from almond skins were effective in vitro against H. pylori, irrespective of genotype status and could therefore be used in combination with antibiotics as a novel strategy for antibiotic resistance.

Evaluation of sanitizers for inactivating Salmonella on in-shell pecans and pecan nutmeats

Chlorine, organic acids, and water extracts of inedible pecan components were tested for effectiveness in killing Salmonella on pecans. In-shell pecans and nutmeats (U.S. Department of Agriculture medium pieces) were immersion inoculated with a mixture of five Salmonella serotypes, dried to 3.7% moisture, and stored at 4°C for 3 to 6 weeks. In-shell nuts were immersed in chlorinated water (200, 400, and 1,000 μg/ml), lactic acid (0.5, 1, and 2%), and levulinic acid (0.5, 1, and 2%) with and without 0.05% sodium dodecyl sulfate (SDS), and a mixed peroxyacid sanitizer (Tsunami 200, 40 μg/ml) for up to 20 min at 21°C. The rate of reduction of free chlorine in conditioning water decreased as the ratio of in-shell nuts/water was increased. The rate of reduction was more rapid when nuts were not precleaned before treatment. The initial population of Salmonella on in-shell nuts (5.9 to 6.3 log CFU/g) was reduced by 2.8 log CFU/g after treating with chlorinated water (1,000 μg/ml). Treatment with 2% lactic acid plus SDS or 2% levulinic acid plus SDS reduced the pathogen by 3.7 and 3.4 log CFU/g, respectively. Lactic and levulinic acids (2%) without SDS were less effective (3.3- and 2.1-log CFU/g reductions, respectively) than acids with SDS. Treatment with Tsunami 200 resulted in a 2.4-log CFU/g reduction. In-shell nuts and nutmeats were immersed in water extracts of ground pecan shucks (hulls), shells, a mixture of shells and pith, and pith. The general order of lethality of extracts to Salmonella was shuck < shell-pith ≤ shell ≤ pith < chlorine (400 μg/ml) and shuck < shell ≤ pith = shell-pith < chlorine (400 μg/ml). Results emphasize the importance of removing soil and dust on in-shell pecans before conditioning in chlorinated water and the need for sanitizers with increased effectiveness in killing Salmonella on pecans.

Natural almond skin reduced oxidative stress and inflammation in an experimental model of inflammatory bowel disease

The aim of the present study was to examine the effects of natural almond skin (NS) powder in mice subjected to experimental colitis. Colitis was induced in mice by intracolonic instillation of dinitrobenzene sulfonic acid (DNBS). NS powder was administered daily orally (30 mg/kg). Four days after DNBS administration, colon NF-κB and p-JNK activation was increased as well as TNF-α and IL-1β productions. Neutrophil infiltration, by myeloperoxidase (MPO) activity, in the mucosa was associated with up-regulation of ICAM-1 and P-selectin. Immunohistochemistry for i-NOS, nitrotyrosine and poly (ADP-ribose) polymerase (PARP) showed an intense staining in the inflamed colon. Treatment with NS powder significantly reduced the appearance of diarrhea and body weight loss. This was associated with a significant reduction in colonic MPO activity. NS powder also reduced NF-κB and p-JNK activation, the pro-inflammatory cytokines release, the appearance of i-NOS, nitrotyrosine and PARP in the colon and reduced the up-regulation of ICAM-1 and the expression of P-selectin. The results of this study suggested that administration of NS powder may be beneficial for treatment of inflammatory bowel disease.