Functional foods and the immune system: a review

The association between interest of nutritional supplements and COVID-19 pandemic - evidence from Google Trends

BACKGROUND

Due to the spread of the coronavirus disease 2019 (COVID-19) pandemic in 2020, the interest of nutritional supplements has emerged. Limited data are available on how the COVID-19 pandemic affects the search interest in nutritional supplements in Taiwan and worldwide. The study aims to investigate changes in public search interest of nutritional supplements pre- and during the COVID-19 pandemic.

METHODS

Our World in Data dataset was used to collect both global and local (Taiwan) number of COVID-19 newly confirmed cases and deaths. Google Trends search query was being used to obtain relative search volumes (RSVs) covering a timeframe between 2019 to 2022. Spearman's rank-order correlation coefficients were used to measure relationships between confirmed new cases and deaths and RSVs of nutritional supplements. Multivariate analysis was conducted to examine the effect of domestic and global new cases and deaths on the RSVs of nutritional supplements.

RESULTS

The mean RSVs for nutritional supplements were higher during the COVID-19 pandemic period (between 2020 to 2022) compared to the pre-pandemic period (year of 2019) for both Taiwan and worldwide. In terms of seasonal variations, except for vitamin D, the mean RSVs of probiotics, vitamin B complex, and vitamin C in winter were significantly lower compared to other seasons in Taiwan. The RSVs of nutritional supplements were not only affected by domestic cases and deaths but also by global new cases and deaths.

CONCLUSIONS

The interests in nutritional supplements had substantially increased in response to the COVID-19 pandemic. The RSVs of nutritional supplements in Taiwan were not only influenced by global and domestic pandemic severity but also by seasons.

Relationship among Dietary Intake of Vitamin E, Lipid Peroxidation Markers, and C-Reactive Protein in Flu-Like Patients Diagnosed with COVID-19

Objective

This research aimed to assess the intake of vitamin E and its relationship with lipid peroxidation markers and C-reactive protein levels in patients with flu symptoms and COVID-19 diagnosis.

Methods

A cross-sectional study with 121 patients of both sexes assisted at two basic health units in the city of Teresina, Piauí, with COVID-19 diagnosis confirmed through real-time reverse transcription polymerase chain reaction, was performed between the 3rd and 7th days of flu symptoms. The global nutritional status and the measurement of waist circumference were assessed according to the World Health Organization recommendations. The dietary energy intake, macronutrients, and vitamin E consumption were assessed through the 24 hr food recall method. The malondialdehyde plasmatic concentration (MDA) was measured through the method of thiobarbituric acid-reactive substances. Myeloperoxidase (MPO) was assessed through the oxidation speed of the o-dianisidine substrate in the presence of hydrogen peroxide. C-reactive protein (CRP) levels were measured by a high-sensitivity immunoturbidimetry method.

Results

The most common symptoms reported by the participants were sore throat, fever, and cough. Regarding the global nutritional status evaluation, the majority of the sample had overweight. The dietary intake of vitamin E was 100% inadequate and presented a mild correlation (r = 0.197) with MDA, a redox status marker. No correlation was observed among MPO, CRP, and the dietary intake of vitamin E.

Conclusion

The dietary intake of vitamin E was related to MDA as the marker of redox status.

Coping with the COVID-19 pandemic by strengthening immunity as a nonpharmaceutical intervention: A major public health challenge

Background and Aims

The global Coronavirus-2 outbreak has emerged as a significant threat to majority of individuals around the world. The most effective solution for addressing this viral outbreak is through vaccination. Simultaneously, the virus's mutation capabilities pose a potential risk to the effectiveness of both vaccines and, in certain instances, newly developed drugs. Conversely, the human body's immune system exhibits a robust ability to combat viral outbreaks with substantial confidence, as evidenced by the ratio of fatalities to affected individuals worldwide. Hence, an alternative strategy to mitigate this pandemic could involve enhancing the immune system's resilience.

Methods

The research objective of the review is to acquire a comprehensive understanding of the role of inflammation and immunity in COVID-19. The pertinent literature concerning immune system functions, the impact of inflammation against viruses like SARS-CoV-2, and the connection between nutritional interventions, inflammation, and immunity was systematically explored.

Results

Enhancing immune function involves mitigating the impact of key factors that negatively influence the immune response. Strengthening the immune system against emerging diseases can be achieved through nonpharmaceutical measures such as maintaining a balanced nutrition, engaging in regular exercise, ensuring adequate sleep, and managing stress.

Conclusion

This review aims to convey the significance of and provide recommendations for immune-strengthening strategies amidst the ongoing COVID-19 pandemic.

Flavocytochrome b2-Mediated Electroactive Nanoparticles for Developing Amperometric L-Lactate Biosensors

L-Lactate is an indicator of food quality, so its monitoring is essential. Enzymes of L-Lactate metabolism are promising tools for this aim. We describe here some highly sensitive biosensors for L-Lactate determination which were developed using flavocytochrome b2 (Fcb2) as a bio-recognition element, and electroactive nanoparticles (NPs) for enzyme immobilization. The enzyme was isolated from cells of the thermotolerant yeast Ogataea polymorpha. The possibility of direct electron transfer from the reduced form of Fcb2 to graphite electrodes has been confirmed, and the amplification of the electrochemical communication between the immobilized Fcb2 and the electrode surface was demonstrated to be achieved using redox nanomediators, both bound and freely diffusing. The fabricated biosensors exhibited high sensitivity (up to 1436 A·M-1·m-2), fast responses, and low limits of detection. One of the most effective biosensors, which contained co-immobilized Fcb2 and the hexacyanoferrate of gold, having a sensitivity of 253 A·M-1·m-2 without freely diffusing redox mediators, was used for L-Lactate analysis in samples of yogurts. A high correlation was observed between the values of analyte content determined using the biosensor and referenced enzymatic-chemical photometric methods. The developed biosensors based on Fcb2-mediated electroactive nanoparticles can be promising for applications in laboratories of food control.

Floret Biofortification of Broccoli Using Amino Acids Coupled with Selenium under Different Surfactants: A Case Study of Cultivating Functional Foods

Broccoli serves as a functional food because it can accumulate selenium (Se), well-known bioactive amino-acid-derived secondary metabolites, and polyphenols. The chemical and physical properties of Se are very similar to those of sulfur (S), and competition between sulfate and selenate for uptake and assimilation has been demonstrated. Towards an efficient agronomic fortification of broccoli florets, the working questions were whether we could overcome this competition by exogenously applying the S-containing amino acids cysteine (Cys) or/and methionine (Met), or/and the precursors of Glucosinolate (GSL) types along with Se application. Broccoli plants were cultivated in a greenhouse and at the beginning of floret growth, we exogenously applied sodium selenate in the concentration gradient of 0, 0.2, 1.5, and 3.0 mM to study the impact of increased Se concentration on the organic S (S_org) content of the floret. The Se concentration of 0.2 mM (Se0.2) was coupled with the application of Cys, Met, their combination, or a mixture of phenylalanine, tryptophane, and Met. The application took place through fertigation or foliar application (FA) by adding isodecyl alcohol ethoxylate (IAE) or a silicon ethoxylate (SiE) surfactant. Fresh biomass, dry mass, and Se accumulation in florets were evaluated, along with their contents of S_org, chlorophylls (Chl), carotenoids (Car), glucoraphanin (GlRa), glucobrassicin (GlBra), glucoiberin (GlIb), and polyphenols (PPs), for the biofortification efficiency of the three application modes. From the studied selenium concentration gradient, the foliar application of 0.2 mM Se using silicon ethoxylate (SiE) as a surfactant provided the lowest commercially acceptable Se content in florets (239 μg or 0.3 μmol g^-1 DM); it reduced S_org (-45%), GlIb (-31%), and GlBr (-27%); and it increased Car (21%) and GlRa (27%). Coupled with amino acids, 0.2 mM Se provided commercially acceptable Se contents per floret only via foliar application. From the studied combinations, that of Met,Se0.2/FA,IAE provided the lowest Se content per floret (183 μg or 0.2 μmol g^-1 DM) and increased S_org (35%), Car (45%), and total Chl (27%), with no effect on PPs or GSLs. Cys,Met,Se0.2/FA,IAE and amino acid mix,Se0.2/FA,IAE increased S_org content, too, by 36% and 16%, respectively. Thus, the foliar application with the IAE surfactant was able to increase S_org, and methionine was the amino acid in common in these treatments, with varying positive effects on carotenoids and chlorophylls. Only the Cys,Met,Se0.2 combination presented positive effects on GSLs, especially GlRa, but it reduced the fresh mass of the floret. The foliar application with SiE as a surfactant failed to positively affect the organic S content. However, in all studied combinations of Se 0.2 mM with amino acids, the Se content per floret was commercially acceptable, the yield was not affected, the content of GSLs was increased (especially that of GlRa and GlIb), and PPs were not affected. The content of GlBr decreased except for the treatment with methionine (Met,Se0.2/FA,SiE) where GlBr remained unaffected. Hence, the combination of Se with the used amino acids and surfactants can provide enhanced biofortification efficiency in broccoli by providing florets as functional foods with enhanced functional properties.

Associations between sampling characteristics, nutritional supplemental taking and the SARS-CoV-2 infection onset in a cohort of Italian nurses

Background: The aim of the present study was to analyze any relations existed between sampling characteristics and the onset of the SARS-CoV-2 infection, also by considering the number of times that it occurred in a cohort of Italian nurses interviewed. Additionally, by considering the nutritional supplemental taking, this research wanted to assess any differences both in the onset and in the number of times which the infection occurred among participants. Method: An observational cohort study was carried out thorough all Italian nurses by advertising the questionnaire through some professional internet pages. Results: Work typology (p=0.021), ward Covid-19 (p=0.002) and regular meal assumption (p=0.019) significantly associated to the onset of the SARS-CoV-2 infection. Most of nurses who contracted the SARS-CoV-2 infection worked during the night shift (53.7%), 44.3% worked in a no-Covid-19 ward and 53% declared to have a regular meals’ assumption. Ward typology significantly associated to the times of the SARS-CoV-2 onset (p=0.003), as most of nurses who contracted almost one time the SARS-CoV-2 infection were employed in a no-Covid-19 ward (55.5%) and 54.1% of them declared to have a regular meals’ assumption. The onset of the Sars-CoV-2 infection seemed to be more present in the most part of the sample collect. Conclusion: The present study could be considered as pilot in this sense and also more studies will be performed in order to better relate the function of supplemental food intakes with a better functioning of the immune system.

Assessment of Association Between the Potential Immunomodulatory Activity and Drinking Olive Leaf Tea in the Coronavirus Disease-2019 Pandemic: An Observational Study

Objective: During the Coronavirus Disease-2019 (COVID-19) pandemic, in addition to the current measures, the healthy immune system plays an essential role and various natural agents have been recommended to boost innate immunity. The aim of this study was to investigate any association between the potential immunomodulatory activity and drinking olive leaf tea (OLT) in the COVID-19 pandemic. Design: The study was conducted among the workers in a tractor factory where OLT was served in routine. Drinking at least one cup of OLT per day for a minimum of 1 month was the inclusion criteria used in the study. The workers who had a history of vaccination and COVID-19 were excluded from the study, and lymphocyte subsets, interleukin (IL)-2, IFN-γ, COVID-19-specific IgM and IgG levels were analyzed in all the participants to determine the asymptomatic individuals among the participants and compare the immunological parameters. Results: The study was conducted among 336 workers, 183 of them were OLT drinkers and 153 were OLT nondrinkers. The results showed higher values of CD3^-/CD16/56 (natural killer [NK]) cells, CD3⁺/CD16/56 (natural killer T [NKT]) cells, total NK (NK+NKT) cells, and serum IFN-γ, and IL-2 levels in OLT drinkers compared to the nondrinkers. Although all the OLT drinkers and nondrinkers included in the study reported no history of COVID-19, specific COVID-19 IgG levels were found positive in 60% of OLT drinkers and 38% OLT nondrinkers. Conclusions: Peripheral NK and NKT cell values and IL-2 and IFN-γ secretion levels were found higher in the OLT drinking group. There were positive correlations between the OLT drinking frequency and NK cell counts. Moreover, the number of individuals who had "asymptomatic" COVID-19 infection was higher in the OLT drinking group than in the nondrinking cohort. Clinical Trial Registration Number: The trial has been registered in the ClinicalTrials.gov database (CTR NCT05222347).

Nutraceuticals: A Promising Therapeutic Approach in Ophthalmology

Oxidative stress represents one of the main factors driving the pathophysiology of multiple ophthalmic conditions including presbyopia, cataracts, dry eye disease (DED), glaucoma, age-related macular degeneration (AMD) and diabetic retinopathy (DR). Currently, different studies have demonstrated the role of orally administered nutraceuticals in these diseases. For instance, they have demonstrated to improve lens accommodation in presbyopia, reduce protein aggregation in cataracts, ameliorate tear film stability, break up time, and tear production in dry eye, and participate in the avoidance of retinal neuronal damage and a decrease in intraocular pressure in glaucoma, contribute to the delayed progression of AMD, or in the prevention or treatment of neuronal death in diabetic retinopathy. In this review, we summarized the nutraceuticals which have presented a positive impact in ocular disorders, emphasizing the clinical assays. The characteristics of the different types of nutraceuticals are specified along with the nutraceutical concentration used to achieve a therapeutic outcome in ocular diseases.

Cherries and Blueberries-Based Beverages: Functional Foods with Antidiabetic and Immune Booster Properties

Nowadays, it is largely accepted that the daily intake of fruits, vegetables, herbal products and derivatives is an added value in promoting human health, given their capacity to counteract oxidative stress markers and suppress uncontrolled pro-inflammatory responses. Given that, natural-based products seem to be a promising strategy to attenuate, or even mitigate, the development of chronic diseases, such as diabetes, and to boost the immune system. Among fruits, cherries and blueberries are nutrient-dense fruits that have been a target of many studies and interest given their richness in phenolic compounds and notable biological potential. In fact, research has already demonstrated that these fruits can be considered functional foods, and hence, their use in functional beverages, whose popularity is increasing worldwide, is not surprising and seem to be a promising and useful strategy. Therefore, the present review reinforces the idea that cherries and blueberries can be incorporated into new pharmaceutical products, smart foods, functional beverages, and nutraceuticals and be effective in preventing and/or treating diseases mediated by inflammatory mediators, reactive species, and free radicals.

A Review on the Antiviral Activity of Functional Foods Against COVID-19 and Viral Respiratory Tract Infections

Due to the absence of successful therapy, vaccines for protection are continuously being developed. Since vaccines must be thoroughly tested, viral respiratory tract infections (VRTIs), mainly coronaviruses, have seriously affected human health worldwide in recent years. In this review, we presented the relevant data which originated from trusted publishers regarding the practical benefits of functional foods (FFs) and their dietary sources, in addition to natural plant products, in viral respiratory and COVID-19 prevention and immune-boosting activities. As a result, FFs were confirmed to be functionally active ingredients for preventing COVID-19 and VRTIs. Furthermore, the antiviral activity and immunological effects of FFs against VRTIs and COVID-19 and their potential main mechanisms of action are also being reviewed. Therefore, to prevent COVID-19 and VRTIs, it is critical to identify controlling the activities and immune-enhancing functional food constituents as early as possible. We further aimed to summarize functional food constituents as a dietary supplement that aids in immune system boosting and may effectively reduce VRTIs and COVID-19 and promote therapeutic efficacy.

Immunonutrition and SARS-CoV-2 Infection in Children with Obesity

Since the beginning of the SARS-CoV-2 pandemic, there has been much discussion about the role of diet and antiviral immunity in the context of SARS-CoV-2 infection. Intake levels of vitamins D, C, B12, and iron have been demonstrated to be correlated with lower COVID-19 incidence and mortality. Obesity has been demonstrated to be an independent risk for the severity of COVID-19 infection in adults and also in children. This may be due to different mechanisms, mainly including the gut dysbiosis status observed in obese children. Moreover, the existence of a gut-lung axis added new knowledge to on the potential mechanisms by which diet and dietary substances may affect immune function. The aim of this narrative review is to address the intricate inter-relationship between COVID-19, immune function, and obesity-related inflammation and to describe the role of nutrients and dietary patterns in enhancing the immune system. Two ways to fight against COVID-19 disease exist: one with an antiviral response through immune system boosting and another with antioxidants with an anti-inflammatory effect. In the current pandemic situation, the intake of a varied and balanced diet, rich in micronutrients and bioactive compounds including fibers, should be recommended. However, clinical studies conducted on children affected by SARS-CoV-2 infection and comorbidity are warranted.

Evaluating the Nutritional and Immune Potentiating Characteristics of Unfermented and Fermented Turmeric Camel Milk in Cyclophosphamide-Induced Immunosuppression in Rats

Antioxidative, nutritional, and immune-boosting characteristics of turmeric-camel milk (TCM) and fermented turmeric-camel milk (FTCM) were investigated. A cyclophosphamide-induced immunosuppression rat model consisting of six experimental groups was carried out to study the effects of TCM and FTCM on weight gain, antioxidant status, immunoglobulin (Igs), pro-inflammatory and anti-inflammatory cytokines, and oxidative stress biomarkers. TCM or FTCM were orally administrated at 10 or 20 mL Kg^-1 rat weight to CYP-immunosuppressed rats for 2 weeks in the presence of negative (NR) and positive (CYP) control groups. The phytochemical analysis and antioxidant capacity results indicated that TCM and FTCM contained considerable phenolic content with super antioxidant activities. CYP injection affected the rats' weight directly during the first week and then, a low weight gain percentage was recorded in treated groups at the end of the experiment. The most efficient treatment for recovering rats' weight was administering TCM and FTCM at 20 mL kg^-1. Feed efficiency significantly increased with feeding TCM and FTCM in a dose-dependent manner. A significant improvement was found in WBCs, lymphocytes, and neutrophils count, suggesting that both TCM and FTCM alleviated the CYP-induced immunity suppression in a dose-dependent manner. IgG, IgA, and IgM concentrations in the CYP + TCM at 10 or 20 mL kg^-1 and CYP + FTCM at 10 or 20 mL kg^-1 groups were increased significantly. Concentrations of IL-1 beta, IL-6, IL-10, IL-13, and IL-TNF-α in the CYP group were significantly lower than in the NR group. Interestingly, both TCM and FTCM, especially with high doses, significantly enhanced cytokines production. Administrating FTCM was more potent than TCM, indicating that TCM with probiotics fermentation potentiated the immunological activity in immunosuppressed rats. Treated rats with TCM and FTCM can reverse CYP inhibition of antioxidant enzyme activities, significantly increase GSH, CAT, and SOD, and decrease MDA levels in a dose-dependent manner. In conclusion, these observations indicated that FTCM exhibits better improvements in weight gain, increased immune biomarkers in terms of WBCs, enhanced pro-inflammation and anti-inflammation responses, and accelerated antioxidant activity in immunosuppressed rats compared with TCM. It could be beneficial and profitable for boosting immunity and protecting against oxidative stress.

Exploring the impact of daily food habit and modification of lifestyle for boosting immunity against COVID-19

The lockdown crisis due to novel coronavirus (COVID-19) mainly affected people who live under economic despair. Since boosting the immune system against the virus depends on a variety of food intake and lifestyle approaches; hence, it is crucial to know how daily food habits and lifestyle modification protect from pathogenic viral infections. This study focused on the benefit of plant-based foods, functional foods and the modified lifestyle which enhance the immunity of all aged groups against COVID-19 in Bangladesh. An online close-ended randomly selected structured multiple-choice questionnaire survey was conducted for people of different parts of Bangladesh (n = 161; male 51.55%, female 48.45%). The total percentage was counted for all variables. We found that plant-based foods, functional foods, and physical exercise played a vital role in enhancing people's immunity to control COVID-19. Plant-based micronutrients, nutraceuticals and antioxidants mainly took part to boost the immune system against the virus. Furthermore, physical activity had a vital role in improving people's immunity to manage COVID-19. Literature suggested that food habits, body immunity, awareness, stress and weight variation were affected by the COVID-19 pandemic. The vaccine or proper medication of COVID-19 still remains in an enigma. In this situation, boosting immunity to combat Coronavirus is the only way to survive.

Supplementation with a Natural Source of Amino Acids, Sil-Q1 (Silk Peptide), Enhances Natural Killer Cell Activity: A Redesigned Clinical Trial with a Reduced Supplementation Dose and Minimized Seasonal Effects in a Larger Population

The aim of this study was to re-validate the changes in natural killer (NK) cell cytotoxicity and cytokines related to T cells after Sil-Q1 (SQ; silk peptide) supplementation in a larger pool of Korean adults with minimized daily dose of SQ and controlling seasonal influence compared to the previous study. A total of 130 subjects were randomly assigned (1:1) to consume either 7.5 g of SQ or placebo for 8 weeks. NK cell cytotoxicity and cytokines were measured at T0 (baseline) and T8 (follow-up). Comparing the NK cell cytotoxicity values at T0 and T8 within each group, the cytotoxicity at all effector cell (E) to target cell (T) ratios of 10:1, 5:1, 2.5:1, and 1.25:1 was significantly increased in the SQ group at T8. Additionally, significant differences in the changed value (Δ, subtract baseline values from follow-up values) comparison between the groups at E:T = 10:1, 5:1, and 2.5:1 were found. As a secondary endpoint, the interleukin (IL)-12 level in the SQ group was significantly increased for 8 weeks, and Δ IL-12 in the SQ group was greater than in the placebo group. In conclusion, the present study showed considerable practical implications of SQ supplementation. Thus, SQ is an effective and safe functional food supplement for enhancing immune function.

Therapeutic potential of phytoconstituents of edible fruits in combating emerging viral infections

Plant-derived bioactive molecules display potential antiviral activity against various viral targets including mode of viral entry and its replication in host cells. Considering the challenges and search for antiviral agents, this review provides substantiated data on chemical constituents of edible fruits with promising antiviral activity. The bioactive constituents like naringenin, mangiferin, α-mangostin, geraniin, punicalagin, and lectins of edible fruits exhibit antiviral effect by inhibiting viral replication against IFV, DENV, polio, CHIKV, Zika, HIV, HSV, HBV, HCV, and SARS-CoV. The significance of edible fruit phytochemicals to block the virulence of various deadly viruses through their inhibitory action against the entry and replication of viral genetic makeup and proteins are discussed. In view of the antiviral property of active constituents of edible fruits which can strengthen the immune system and reduce oxidative stress, they are suggested to be diet supplements to combat various viral diseases including COVID-19. PRACTICAL APPLICATIONS: Considering the increasing threat of COVID-19, it is suggested to examine the therapeutic efficacy of existing antiviral molecules of edible fruits which may provide prophylactic and adjuvant therapy with their potential antioxidant, anti-inflammatory, and immune-modulatory effects. Several active molecules like geraniin, naringenin, (2R,4R)-1,2,4-trihydroxyheptadec-16-one, betacyanins, mangiferin, punicalagin, isomangiferin, procyanidin B2, quercetin, marmelide, jacalin lectin, banana lectin, and α-mangostin isolated from various edible fruits have showed promising antiviral properties against different pathogenic viruses. Especially flavonoid compounds extracted from edible fruits possess potential antiviral activity against a wide array of viruses like HIV-1, HSV-1 and 2, HCV, INF, dengue, yellow fever, NSV, and Zika virus infection. Hence taking such fruits or edible fruits and their constituents/compounds as dietary supplements could deliver adequate plasma levels in the body to optimize the cell and tissue levels and could lead to possible benefits for the preventive measures for this pandemic COVID-19 situation.

Actinidia arguta Leaf as a Donor of Potentially Healthful Bioactive Compounds: Implications of Cultivar, Time of Sampling and Soil N Level

The aim of this study was to assess the enzymatic and non-enzymatic antioxidant status of kiwiberry (Actinidia arguta) leaf under different N regimes tested three times in field conditions during the 2015 growing season in two cultivars (‘Weiki’ and ‘Geneva’). Leaf total antioxidant capacity using ABTS, DPPH and FRAP tests was evaluated in the years 2015 to 2017, which experienced different weather conditions. Both cultivars exhibited a significant fall in leaf L-ascorbic acid (L-AA) and reduced glutathione (GSH) as well as global content of these compounds during the growing season, while total phenolic contents slightly (‘Weiki’) or significantly (‘Geneva’) increased. There was a large fluctuation in antioxidative enzyme activity during the season. The correlation between individual antioxidants and trolox equivalent antioxidant capacity (TEAC) depended on the plant development phase. The study revealed two peaks of an increase in TEAC at the start and end of the growing season. Leaf L-AA, global phenolics, APX, CAT and TEAC depended on the N level, but thiol compounds were not affected. Over the three years, TEAC decreased as soil N fertility increased, and the strength of the N effect was year dependent. The relationship between leaf N content and ABTS and FRAP tests was highly negative. The antioxidant properties of kiwiberry leaves were found to be closely related to the plant development phase and affected by soil N fertility.

The Biological Effects of Novel Nutraceuticals with Curcuminoids and Other Plant-Derived Immunomodulators and Pre-Probiotics

An effective and well-balanced immune system is pivotal for maintaining health. Diet and nutrition can affect the functioning of numerous immune parameters, with direct repercussions on homeostasis. Since our immune functions are indispensable in defending the body against pathogens and thus play a vital role in maintaining health, modulating immune response may well serve as the basis for the development of plant-based functional foods and novel nutraceuticals. This concept is currently utilized in attempts to prevent or mitigate inflammatory reactions via the development of targeted food products or active ingredients since an extended number of phytoconstituents (such as curcuminoids) are associated with beneficial effects on immunity. Immunomodulatory plant-based dietary supplements are considered effective in improving immune functions and reducing the incidence of immunological disorders or imbalances. Therefore, the main focus of this study was to evidence the beneficial biological effects such as antioxidant and antimicrobial, as well as nutritional status, biocompatibility and cell proliferation capacity and immunomodulation of two novel nutraceuticals. The first nutraceutic was based on curcuminoids and other actives from Trigonella foenum- graecum (seeds), Chelidonium majus L. (aerial parts), Taraxacum officinale L. (roots), vitamins (C, D3, A, E) and minerals (zinc) whereas the second one was made of probiotics such as Lactobacillus acidophilus and Bifidobacterium animalis subsp. Lactis combined with actives from Helianthus tuberosus (tubers) and Psyllium/Plantago ovata (husk) as herbal prebiotics.

COVID-19: Role of Nutrition and Supplementation

At the end of 2019, a new coronavirus (COVID-19) appeared on the world scene, which mainly affects the respiratory system, causing pneumonia and multi-organ failure, and, although it starts with common symptoms such as shortness of breath and fever, in about 2-3% of cases it leads to death. Unfortunately, to date, no specific treatments have been found for the cure of this virus and, therefore, it is advisable to implement all possible strategies in order to prevent infection. In this context, it is important to better define the role of all behaviors, in particular nutrition, in order to establish whether these can both prevent infection and improve the outcome of the disease in patients with COVID-19. In the literature, it is widely shown that states of malnutrition, overweight, and obesity negatively affect the immune system, leading to viral infections, and several studies have shown that nutritional interventions can act as immunostimulators, helping to prevent viral infections. Even if several measures, such as the assumption of a specific diet regimen, the use of dietary supplements, and other similar interventions, are promising for the prevention, management, and recovery of COVID-19 patients, it is important to highlight that strong data from randomized clinical trials are needed to support any such assumption. Considering this particular scenario, we present a literature review addressing several important aspects related to diet and SARS-CoV-2 infection, in order to highlight the importance of diet and supplementation in prevention and management of, as well as recovery from COVID-19.

Polyphenols as promising biologically active substances for preventing SARS-CoV-2: A review with research evidence and underlying mechanisms

Currently, antiviral drugs and/or vaccines are not yet available to treat or prevent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this review, we narrated the available data, from credible publishers, regarding the possible role of polyphenols and natural extracts-containing polyphenols in the prevention of coronavirus disease 2019 (COVID-19), and their immune-boosting properties. It was revealed that polyphenols could be considered as promising biologically active substances for the prevention of COVID-19. The underlying potential mechanism behind this action is mostly due to the antiviral activities and the immune-regulation functions of polyphenols against COVID-19-infections. Antivirus polyphenolic-based medications can mitigate SARS-CoV-2-enzymes, which are vital for virus duplication and infection. It was also found that triterpenoid, anthraquinone, flavonoids, and tannins are possible keys to scheming antiviral therapies for inhibiting SARS-CoV-2-proteases. The identified pharmacophore structures of polyphenols could be utilized in the explanation of novel anti-COVID-19 designs. The advantage of using mixtures containing polyphenols is related to the high-safety profile without having major side-effects, but further randomized controlled trials are required in the upcoming studies.

Traditional foods with their constituent's antiviral and immune system modulating properties

Background

Viruses are responsible for several diseases, including severe acute respiratory syndrome, a condition caused by today's pandemic coronavirus disease (COVID-19). A negotiated immune system is a common risk factor for all viral infections, including COVID-19. To date, no specific therapies or vaccines have been approved for coronavirus. In these circumstances, antiviral and immune boosting foods may ensure protection against viral infections, especially SARS-CoV-2 by reducing risk and ensuring fast healing of SARS-CoV-2 illness.

Scope and approach

In this review, we have conducted an online search using several search engines (Google Scholar, PubMed, Web of Science and Science Direct) to find out some traditional foods (plant, animal and fungi species), which have antiviral and immune-boosting properties against numerous viral infections, particularly coronaviruses (CoVs) and others RNA-virus infections. Our review indicated some foods to be considered as potential immune enhancers, which may help individuals to overcome viral infections like COVID-19 by modulating immune systems and reducing respiratory problems. Furthermore, this review will provide information regarding biological properties of conventional foods and their ingredients to uphold general health.

Key Findings and Conclusions

We observed some foods with antiviral and immune-boosting properties, which possess bioactive compounds that showed significant antiviral properties against different viruses, particularly RNA viruses such as CoVs. Interestingly, some antiviral and immune-boosting mechanisms were very much similar to the antiviral drug of COVID-19 homologous SARS (Severe Acute Respiratory Syndrome Coronavirus) and MERS (Middle East Respiratory Syndrome Coronavirus). The transient nature and the devastating spreading capability of COVID-19 lead to ineffectiveness of many curative therapies. Therefore, body shielding and immune-modulating foods, which have previous scientific recognition, have been discussed in this review to discern the efficacy of these foods against viral infections, especially SARS-CoV-2.

Functionality of Food Components and Emerging Technologies

This review article introduces nutrition and functional food ingredients, explaining the widely cited terms of bioactivity, bioaccessibility, and bioavailability. The factors affecting these critical properties of food components are analyzed together with their interaction and preservation during processing. Ultimately, the effect of emerging (non-thermal) technologies on different food components (proteins, carbohydrates, lipids, minerals, vitamins, polyphenols, glucosinolates, polyphenols, aroma compounds, and enzymes) is discussed in spite of preserving their functional properties. Non-thermal technologies can maintain the bioavailability of food components, improve their functional and technological properties, and increase the recovery yields from agricultural products. However, the optimization of operational parameters is vital to avoid degradation of macromolecules and the oxidation of labile compounds.

Present Status and Future Trends of Natural-Derived Compounds Targeting T Helper (Th) 17 and Microsomal Prostaglandin E Synthase-1 (mPGES-1) as Alternative Therapies for Autoimmune and Inflammatory-Based Diseases

Several natural-based compounds and products are reported to possess anti-inflammatory and immunomodulatory activity both in vitro and in vivo. The primary target for these activities is the inhibition of eicosanoid-generating enzymes, including phospholipase A2, cyclooxygenases (COXs), and lipoxygenases, leading to reduced prostanoids and leukotrienes. Other mechanisms include modulation of protein kinases and activation of transcriptases. However, only a limited number of studies and reviews highlight the potential modulation of the coupling enzymatic pathway COX-2/mPGES-1 and Th17/Treg circulating cells. Here, we provide a brief overview of natural products/compounds, currently included in the Italian list of botanicals and the BELFRIT, in different fields of interest such as inflammation and immunity. In this context, we focus our opinion on novel therapeutic targets such as COX-2/mPGES-1 coupling enzymes and Th17/Treg circulating repertoire. This paper is dedicated to the scientific career of Professor Nicola Mascolo for his profound dedication to the study of natural compounds.

Potential Inhibitors for SARS-CoV-2 and Functional Food Components as Nutritional Supplement for COVID-19: A Review

The severe acute respiratory syndrome is a viral respiratory infection and commonly called as COVID-19, caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). It widely transmitted through direct or indirect contact. Currently, no specific treatment against SARS-CoV-2 are available; only prevention and supportive strategy are the preventive measures. The present review emphasizes the latest research related to COVID-19 and SARS-CoV-2 virus as well as the current status of potential inhibitors identified. Recent interest in SARS-CoV-2 has focused on transmission, symptoms, structure, and its structural proteins that exhibit promising therapeutics targets for rapid identification of potential inhibitors. The quick identification of potential inhibitors and immune-boosting functional food ingredients are crucial to combat this pandemic disease. We also tried to give an overview of the functional food components as a nutritional supplement, which helps in boosting our immune system and could be useful in preventing the COVID-19 and/or to improve the outcome during therapy.

A Comparative Study on the Strategies Adopted by the United Kingdom, India, China, Italy, and Saudi Arabia to Contain the Spread of the COVID-19 Pandemic

Purpose

The objective of this study was to compare the strategies adopted by the United Kingdom, Italy, China, India, and Saudi Arabia to contain the spread of the COVID-19 pandemic.

Materials and Methods

A review of the literature was carried out to collect data on the strategies used by China, Italy, India, the United Kingdom, and Saudi Arabia to contain the spread of the COVID-19 virus. The global analysis of 65 published literature references allowed observing the effectiveness and efficiency of the strategies used by these countries to control the spread of the COVID-19 virus.

Results

Both mitigation and suppression strategies were adopted by the United Kingdom, India, Italy, China, and Saudi Arabia to control the spread of the COVID-19 pandemic. It was observed that China has achieved a greater success in flattening the curve compared to the other countries. In China, few new daily cases have occurred since March, and it has been the only country that has managed to keep the COVID-19 pandemic under control. On the other hand, reductions in the number of daily cases (since May 2020) were detected in the United Kingdom, Italy, and Saudi Arabia (since July 2020). Also, during the last 3 months (June, July and August) India has shown the highest growth in the total number of confirmed cases and in the number of new daily cases, compared to the mentioned countries.

Conclusion

The review of the strategies adopted by China, India, the United Kingdom, Italy and Saudi Arabia to combat the COVID-19 pandemic can guide countries in the design and development of mitigation and suppression approaches to control the spread of the COVID-19 virus. Containment strategies such as lockdowns cannot continue in the long term. Therefore, countries must adopt mitigation and prevention strategies to protect people from infection and learn to live with the virus.

Repositioning Natural Antioxidants for Therapeutic Applications in Tissue Engineering

Although a large panel of natural antioxidants demonstrate a protective effect in preventing cellular oxidative stress, their low bioavailability limits therapeutic activity at the targeted injury site. The importance to deliver drug or cells into oxidative microenvironments can be realized with the development of biocompatible redox-modulating materials. The incorporation of antioxidant compounds within implanted biomaterials should be able to retain the antioxidant activity, while also allowing graft survival and tissue recovery. This review summarizes the recent literature reporting the combined role of natural antioxidants with biomaterials. Our review highlights how such functionalization is a promising strategy in tissue engineering to improve the engraftment and promote tissue healing or regeneration.

Antiviral Functional Foods and Exercise Lifestyle Prevention of Coronavirus

Novel coronavirus (COVID-19) is causing global mortality and lockdown burdens. A compromised immune system is a known risk factor for all viral influenza infections. Functional foods optimize the immune system capacity to prevent and control pathogenic viral infections, while physical activity augments such protective benefits. Exercise enhances innate and adaptive immune systems through acute, transient, and long-term adaptations to physical activity in a dose-response relationship. Functional foods prevention of non-communicable disease can be translated into protecting against respiratory viral infections and COVID-19. Functional foods and nutraceuticals within popular diets contain immune-boosting nutraceuticals, polyphenols, terpenoids, flavonoids, alkaloids, sterols, pigments, unsaturated fatty-acids, micronutrient vitamins and minerals, including vitamin A, B6, B12, C, D, E, and folate, and trace elements, including zinc, iron, selenium, magnesium, and copper. Foods with antiviral properties include fruits, vegetables, fermented foods and probiotics, olive oil, fish, nuts and seeds, herbs, roots, fungi, amino acids, peptides, and cyclotides. Regular moderate exercise may contribute to reduce viral risk and enhance sleep quality during quarantine, in combination with appropriate dietary habits and functional foods. Lifestyle and appropriate nutrition with functional compounds may offer further antiviral approaches for public health.

Choice of Food: A Preventive Measure during Covid-19 Outbreak

As the Covid-19 pandemic has affected communities around the globe, people are facing the fear of being infected by it. It is believed that Coronavirus disease 2019 is directly associated to an individual’s immune response, with no documented research evidence found yet. But, Covid-19 is genetically similar to Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV), therefore the same immune response is expected for Covid-191. It has also been found that individuals having weaker immune functions are more suspected to infect and have a high fatality rate2. Preventive measures such as good personal hygiene, wearing a mask, avoiding crowded places and sick individuals, practicing quarantine, and proper choice of food can help an individual to be safe from the risk of current COVID-19 infection. Research findings state that nutrition influences immune strength thereby protecting our body from the attack of pathogens3. Increasing intake of a nutritious diet can help to enhance the immune system and makes an individual less susceptible to diseases, which is also considered as a key factor for the prevention of viral infection like COVID-19. Therefore, the incorporation of foods rich in nutrients that boosts our immunity is one of the possible essential preventive measures to fight with this global crisis.

Immunosenescence and Its Hallmarks: How to Oppose Aging Strategically? A Review of Potential Options for Therapeutic Intervention

Aging is accompanied by remodeling of the immune system. With time, this leads to a decline in immune efficacy, resulting in increased vulnerability to infectious diseases, diminished responses to vaccination, and a susceptibility to age-related inflammatory diseases. An age-associated immune alteration, extensively reported in previous studies, is the reduction in the number of peripheral blood naïve cells, with a relative increase in the frequency of memory cells. These two alterations, together with inflamm-aging, are considered the hallmarks of immunosenescence. Because aging is a plastic process, it is influenced by both nutritional and pharmacological interventions. Therefore, the role of nutrition and of immunomodulation in immunosenescence is discussed, due to the multifactorial influence on these hallmarks. The close connection between nutrition, intake of bioactive nutrients and supplements, immune function, and inflammation demonstrate the key role of dietary strategies as regulators of immune response and inflammatory status, hence as possible modulators of the rate of immunosenescence. In addition, potential options for therapeutic intervention are clarified. In particular, the use of interleukin-7 as growth factor for naïve T cells, the function of checkpoint inhibitors in improving T cell responses during aging and, the potential of drugs that inhibit mitogen-activated protein kinases and their interaction with nutrient signaling pathways are discussed. Finally, it is suggested that the inclusion of appropriate combinations of toll-like receptor agonists may enhance the efficacy of vaccination in older adults.

Prophylactic Potential of Synbiotic (Lactobacillus casei and Inulin) in Malnourished Murine Giardiasis: an Immunological and Ultrastructural Study

Giardiasis is a re-emerging infectious disease with outbreaks reported globally specially in children and malnourished individuals leading to malabsorption, growth retardation, and severe diarrhea. Thus, in the present study, prophylactic administration of synbiotic as the functional food was used to assess its antigiardial potential in malnourished murine giardiasis. Interestingly, prior administration of synbiotic (Lactobacillus casei + inulin) even to malnourished-Giardia-infected mice led to increased body mass, small intestine mass, lactobacilli counts, and reduced severity of giardiasis as evident by decreased cyst and trophozoite counts. Synbiotic therapy further boosted the innate and acquired immune response resulting into increase in nitric oxide, antigiardial secretory IgA and IgG antibody levels along with IL-6 and IL-10 cytokines, and decreased levels of inflammatory TNF-α cytokine in both serum and intestinal fluid in malnourished-synbiotic-Giardia-infected mice compared with malnourished-Giardia-infected mice. More specifically, histopathological and scanning electron microscopy analysis of the small intestine also confirmed the modulatory potentials of synbiotic in malnourished-synbiotic-Giardia mice which had less cellular and mucosal damage compared with severely damaged, mummified, and blunted villi in malnourished-Giardia-infected mice. Taken together, this is the first experimental study to report that prior supplementation of synbiotic restored the gut morphology and improved the immune status of the malnourished-Giardia-infected mice, and could be considered as the prophylactic adjunct therapy for malnourished individuals.

Green Juice in Human Metabolism: A Randomized Trial

OBJECTIVE

Fruits and vegetables contain many compounds presenting potential antioxidant activity. The objective of this study was to evaluate the effect of a green juice recipe in adult metabolism in order to identify new preventive dietary sources.

METHOD

This was a single-blind randomized controlled clinical trial. Recruitment and data were, respectively, made and collected at the Universidade Federal de Ciências da Saúde de Porto Alegre. Individuals who met all the inclusion criteria during the period of recruitment were included. Green juice (experimental group) or placebo (control group) were consumed from Monday to Friday between 8 and 9 am, in the amount of 300 mL for 60 days (except Saturdays and Sundays). To verify the effect of green juice on metabolism, the following were evaluated: (a) glycemia, plasma lipid profile, renal and liver functions, redox profile, and antioxidant enzymes; (b) anthropometry; and (c) well-being and anxiety.

RESULTS

This study included 14 participants in the test group (juice group) and 13 controls (placebo group), with mean ages of 31.07 and 30.15 years, respectively. We did not observe a significant difference between the treatments. Dietary properties of vegetable and fruit juices are an area of significant interest.

CONCLUSIONS

Together with an analysis of previous works, we suggest that green juice did not cause an improvement in metabolic function and there is a need for further research on this issue, mainly through different interventions and other samples.

A role for whey-derived lactoferrin and immunoglobulins in the attenuation of obesity-related inflammation and disease

Obesity is a strong predictive factor in the development of chronic disease and has now superseded undernutrition as a major public health issue. Chronic inflammation is one mechanism thought to link excess body weight with disease. Increasingly, the gut and its extensive population of commensal microflora are recognized as playing an important role in the development of obesity-related chronic inflammation. Obesity and a high fat diet are associated with altered commensal microbial communities and increased intestinal permeability which contributes to systemic inflammation as a result of the translocation of lipopolysaccharide into the circulation and metabolic endotoxemia. Various milk proteins are showing promise in the prevention and treatment of obesity and chronic low-grade inflammation via reductions in visceral fat, neutralization of bacteria at the mucosa and reduced intestinal permeability. In this review, we focus on evidence supporting the potential antiobesogenic and anti-inflammatory effects of bovine whey-derived lactoferrin and immunoglobulins.

Fat Soluble Vitamins and Immune System: An Overview

The immune system guards against invasion by foreign microrganisms and molecules. In this way, it protects from fatal illnesses and communicable diseases. Its proper functioning is fundamental for survival.

Research has demonstrated that proper nutrition plays a crucial role in the prevention of chronic disease. Protein-energy malnutrition is associated with a significant impairment of cell-mediated immunity, phagocyte function, the complement system, secretory immunoglobulin A antibody concentrations, and cytokine production. Deficiency of single nutrients also results in altered immune responses; this is observed even when the deficiency state is relatively mild. Of the micronutrients, zinc, selenium, iron, copper, vitamins A,C,E and B, and folic acid have important influences on the immune response.

It is now apparent that vitamin E and β-carotene have more subtle roles and that deficient dietary intake of these vitamins increases susceptibility to certain cancers and cardiovascular disease. This reflects, in part, the antioxidant properties of the vitamins and their ability to reduce free radical-mediated damage to DNA, proteins and lipid membranes. These findings have considerable practical and public health significance. The aim of this review is to give an up-to date account of the roles of selected fat-soluble vitamins in health and disease.

Coconut water of different maturity stages ameliorates inflammatory processes in model of inflammation

AIM

Coconut water is a natural beverage that is a part of daily diet of many people. This study was designed to explore the anti-inflammatory activity of coconut water of different maturation stages (young and mature) with rat paw edema model of inflammation using plethysmometer.

METHODOLOGY

For this study, albino rats were selected and divided into four equal groups (10 rats in each group). Group 1 was set as control and administered distilled water 1 ml orally; Groups 2 and 3 were treated with young and mature coconut water, respectively, at 4 ml/100 g dose orally. Group 4 was treated with the standard drug (ibuprofen) at 400 mg/70 kg. 0.1 ml of 1% w/v acetic acid was administered in the subplantar tissue of rat paw 30 min after oral treatments of groups. Plethysmometer was used to measure rat paw edema.

RESULTS

Results revealed that both coconut water possess significant anti-inflammatory activity (P < 0.001). In comparison to control, percent inhibition by young coconut water was 20.22%, 35.13%, 42.52%, and 36% at 1, 2, 3, and 4 h of acetic acid administration, respectively. However, maximum percent inhibition (42.52%) was observed in the second phase of the inflammatory process. On the other hand, percent inhibition by mature coconut water was 18.80%, 25.94%, 24.13%, and 18.66% at 1, 2, 3, and 4 h of acetic acid administration, respectively. However, maximum percent inhibition (25.94%) was observed in the first phase of the inflammatory process.

CONCLUSIONS

This study strongly suggests the use of young coconut water for potent anti-inflammatory effect and mature coconut water for moderate anti-inflammatory effect.

Consumption of star fruit juice on pro-inflammatory markers and walking distance in the community dwelling elderly

PURPOSE

This study aimed to evaluate the effect of star fruit juice supplementation on tumor necrosis factor-alpha (TNF-α), interleukin-23 (IL-23) and interleukin-2 (IL-2), nitric oxide (NO), and 6 min walking distance (6MWD) in a group of elderly individuals.

METHODS

Twenty-nine individuals (20 males, 9 females) with a mean age of 72.4±8.3 years completed this study. A two-week control period was followed by four weeks of 100g fresh star fruit juice consumption twice per day after meals.

RESULTS

Plasma TNF-α, IL-23, IL-2, NO and the 6MWD were evaluated twice during the control period (weeks 0 and 2) and once after the star fruit juice consumption (week 6).

RESULTS

The results showed that all parameters in the blood did not change significantly during the control period. After 4 weeks of star fruit juice consumption, a significant reduction in NO, TNF-α and IL-23 was found; however, there was no change in IL-2. Moreover, the 6MWD increased significantly at week 6, when compared to that at week 0 and 2. Furthermore, the results also showed a significantly positive and negative correlation of NO and TNF-α to the 6MWD, but no correlation of IL-23 and IL-2.

CONCLUSION

This preliminary study concluded that consumption of star fruit juice at 100g twice daily for one month can significantly depress the pro-inflammation cytokines: TNF-α, IL-23, and NO, while increasing walking distance. Low TNF-α and high NO also present a significant correlation to walking capacity in elderly individuals.

The good and bad of antioxidant foods: An immunological perspective

Maintenance of redox homeostasis plays a central role in health and disease prevention, and antioxidant foods are thought to exert protective effects by counteracting oxidative stress. The term "dietary antioxidant" implies a classical reducing or radical-scavenging capacity, but more data on the in vivo bioactivity of such compounds are needed. Indeed, several dietary antioxidants activate signaling cascades that lead to effects that extend beyond radical scavenging, such as the induction of endogenous cytoprotective mechanisms and detoxification. Currently, the overall uptake of antioxidants with diet exceeds actual needs, as food additives that include vitamins, colorants, flavoring agents, and preservatives are often also relatively strong antioxidants. Chronic antioxidative stress favors adverse effects, such as the suppression of T helper (Th) type 1 immune responses and consequent activation of Th2 reactions that support the development of asthma, allergies, and obesity. In this context, we discuss the immunoregulatory pathway of tryptophan breakdown by enzyme indoleamine 2,3-dioxygenase (IDO), which represents a central regulatory hub for immune, metabolic, and neuroendocrine processes. Activation of IDO-mediated tryptophan metabolism is strongly redox-sensitive and is therefore susceptible to modulation by dietary components, phytochemicals, preservatives, and drugs.

A systematic review of the safety of probiotics

INTRODUCTION

There is growing evidence on the use of probiotics in various diseases, especially in gastrointestinal (GI) diseases. Although probiotics have been found helpful in many illnesses, they do not always seem to be safe. Through interference with commensal microflora, they can result in opportunistic performances in the host due to bacterimia and fungemia. Since considerable numbers of consumers use probiotic products worldwide, assurance of safety of these products is necessary.

AREAS COVERED

This review evaluates all the existing information about the safety of probiotics in humans and animal models up to May 2013. In all eligible published studies in which adverse effects and tolerability of probiotics were investigated and reported, no language limitations were applied. The main key search terms were 'probiotics,' 'safety,' 'side effects,' 'clinical trial' and 'adverse effects.' The vast majority of trials investigated Bifidobacterium (B) and Lactobacillus (L) species.

EXPERT OPINION

The main observed adverse effects of probiotics were sepsis, fungemia and GI ischemia. Generally, critically ill patients in intensive care units, critically sick infants, postoperative and hospitalized patients and patients with immune-compromised complexity were the most at-risk populations. While the overwhelming existing evidence suggests that probiotics are safe, complete consideration of risk-benefit ratio before prescribing is recommended.

An overview of health-promoting compounds of broccoli (Brassica oleracea var. italica) and the effect of processing

Broccoli offers many heath-promoting properties owing to its content of antioxidant and anticarcinogenic compounds. The concentration and bioavailability of polyphenols, glucosinolates, sulforaphane and selenium depend on plant biochemistry, cultivation strategy and type of processing. In this article, the main biochemical properties of broccoli are reviewed regarding their health-promoting effects. Additionally, the way these properties are affected by processing is discussed. Steaming and drying result in an apparent increment of sulforaphane content as well as antioxidant activity, most likely due to an increase of the extractability of antioxidants and sulforaphane. Freezing and boiling diminish polyphenols concentration, mainly due to volatilization and leaching into the cooking water. In view of these results, the optimization of broccoli processing in order to maximize the content of bioactive compounds should be possible. The effect of processing on selenium compounds has been poorly studied so far, and therefore this topic should be investigated in the future. Finally, the effect of operating conditions in different drying processes on the content of bioactive compounds in broccoli should be investigated in a greater depth.

Antioxidant activities of licorice-derived prenylflavonoids

Glycyrrhiza uralensis (or licorice) is a widely used Oriental herbal medicine from which the phenylflavonoids dehydroglyasperin C (DGC), dehydroglyasperin D (DGD), and isoangustone A (IsoA) are derived. The purpose of the present study was to evaluate the antioxidant properties of DGC, DGD, and IsoA. The three compounds showed strong ferric reducing activities and effectively scavenged DPPH, ABTS⁺, and singlet oxygen radicals. Among the three compounds tested, DGC showed the highest free radical scavenging capacity in human hepatoma HepG2 cells as assessed by oxidant-sensitive fluorescent dyes dichlorofluorescein diacetate and dihydroethidium bromide. In addition, all three compounds effectively suppressed lipid peroxidation in rat tissues as well as H₂O₂-induced ROS production in hepatoma cells. This study demonstrates that among the three phenylflavonoids isolated from licorice, DGC possesses the most potent antioxidant activity, suggesting it has protective effects against chronic diseases caused by reactive oxygen species as well as potential as an antioxidant food additive.