Antiviral and antibacterial properties of phloroglucinols: a review on naturally occurring and (semi)synthetic derivatives with potential therapeutic interest.

Phloroglucinol and derived compounds comprise a huge class of secondary metabolites widely distributed in plants and brown algae. A vast array of biological activities, including antioxidant, anti-inflammatory, antimicrobial, and anticancer has been associated to this class of compounds. In this review, the available data on the antiviral and antibacterial capacity of phloroglucinols have been analyzed. Some of these compounds and derivatives show important antimicrobial properties in vitro. Phloroglucinols have been shown to be effective against viruses, such as human immunodeficiency virus (HIV), herpes or enterovirus, and preliminary data through docking analysis suggest that they can be effective against SARS-CoV-19. Also, some phloroglucinols derivatives have shown antibacterial effects against diverse bacteria strains, including Bacillus subtilis and Staphylococcus aureus, and (semi)synthetic development of novel compounds have led to phloroglucinols with a significantly increased biological activity. However, therapeutic use of these compounds is hindered by the absence of in vivo studies and scarcity of information on their mechanisms of action, and hence further research efforts are required. On the basis of this consideration, our work aims to gather data regarding the efficacy of natural-occurring and synthetic phloroglucinol derivatives as antiviral and antibacterial agents against human pathogens, which have been published during the last three decades. The recollection of results reported in this review represents a valuable source of updated information that will potentially help researchers in the development of novel antimicrobial agents.

Nanoformulations of curcumin and quercetin with silver nanoparticles for inactivation of bacteria.

Antibiotic resistance in pathogenic bacteria to various types of antibiotics has resulted in the necessity of new effective strategies to get around this problem. In recent investigations, metal or metal oxide nanoparticles specifically silver nanoparticles (AgNPs) have been employed successfully to hinder antibiotic-resistant Gram-negative and Gram-positive bacteria. However, AgNPs at high concentrations have cytotoxicity for eukaryotic cells which, application of other biocompatible materials particularly plant secondary metabolites of curcumin and quercetin to reduce cytotoxicity is a critical affair. These compounds may be used directly or indirectly to produce AgNPs. In this regard, modified NPs by curcumin and quercetin have shown an increased therapeutic effect and biocompatibility and biodegredibility properties. Therefore, here, recent advances and challenges about antibacterial and biocompatibility properties of nanoformulation of AgNPs with curcumin and quercetin are presented.

Tinospora cordifolia (Willd.) Miers: phytochemical composition, cytotoxicity, proximate analysis and their biological activities.

The present research work has been performed to evaluate the phenolic content, flavonoids content, and cytotoxicity of a multidimensional medicinal plant; Tinospora cordifolia and as well as to determine nutritive value by proximate analysis. The total phenolic and flavonoids contents of Tinospora cordifolia were found to be significantly greater in methanol extract as compared to corresponding hexane extract. Brine shrimp bioassay indicated Tinospora cordifolia is pharmacologically active. The percentage composition of different nutrition parameters namely moisture, total ash, crude fat, protein, fibre, carbohydrate, and vitamin C were assessed. The nutritive values of fresh and dried stem samples were evaluated as 156.44 Kcal/100g and 232.61 Kcal/100g respectively. From Gas column mass spectrometry analysis, it can be reported that inositol, 1-deoxy-, trans-sinapyl alcohol, n-hexadecanoic acid were present in the major amount in methanol stem extract. The findings from this study reveal Tinospora cordifolia contains an adequate amount of phenolic and flavonoids content, vital bioactive antioxidant compounds, and a good source of carbohydrates and fibers which potentially adds to the overall value of the plant.

Reinwardtia indica: phytochemical screening and evaluation of wound healing activity of the extracts in experimental model rats.

Reinwardtia indica is traditionally used for wound healing. The main aim of this study was to evaluate the wound healing activity of leaves extracts of R. indica using the excision wound model in rats. The leaves of R. indica were collected from Gondrang, Chitwan, Nepal.  Leaves were shade dried, extracted by double maceration and subjected to phytochemical screening. Then, the fusion method was used for the formulation of ointment and evaluated. Rats (n=24) were divided into four groups with 6 in each. Excision wound model was used, 2 cm diameter (314 mm2), 2 mm depth wound was created. The treatment was given daily topically to all groups and the % mean wound contraction rate was calculated on days 4, 8, 12 and 16.  The result was analyzed statistically using Graph pad prism version 5. Phytochemical test revealed the presence of alkaloid, flavonoid, tannin, phenol, terpenoid, carbohydrate, etc.  All the evaluation parameters showed satisfactory results. The extract of R. indica ointment (2% w/w and 5% w/w) increased the wound contraction rate day by day. The % means wound contraction rate, on day 12, (80% and 88%), and on day 16, (97% and 100%) and statistically significant difference was at p<0.0001. The R. indica extract ointment showed an increased wound contraction rate. So, in further R. indica could be used for commercial production of wound healing ointment.

Antimicrobial and antibiofilm potential of Curcuma longa Linn. Rhizome extract against biofilm producing Staphylococcus aureus and Pseudomonas aeruginosa isolates.

More than 65% of all human bacterial infection are associated with biofilm. Bacteria in such biofilms are 10 to 1000-fold more resistant to antibiotics than free living bacteria cells. Organisms such as S. aureus and P. aeruginosa are responsible for a significant number of biofilm related infections. In this study, we investigated the antimicrobial and anti-biofilm activity of C. longa L. rhizome extract against biofilm producing S. aureus and P. aeruginosa isolates. The results of MIC and MBC demonstrated promising antibacterial activity of the rhizome extract. TLC and column chromatography detected various curcuminoids while phytochemical analysis also reveals presence of number of bioactive compounds such as alkaloids, flavonoids, phenolics, terpenoids, etc. Micro titer plate assay indicated significant inhibition of biofilm formation in clinical isolates treated with turmeric extract. Thus, on basis of our results turmeric extracts can be considered as natural antibiofilm and antibacterial agent.

Vitex negundo Linn.: phytochemical composition, nutritional analysis, and antioxidant and antimicrobial activity.

Vitex negundo (VN) is a widely used plant in folk medicine, namely for the treatment of jaundice, wounds, body ache, toothache, asthma, eye pain, and migraine. These effects have been increasingly attributed to its chemical composition. Here, we assessed the VN chemical and nutritional composition and biological activity, with particular emphasis on antioxidant and antimicrobial effects. VN methanol and hexane extracts revealed the presence of important phytochemical, such as terpenoids, polyphenol, steroids, saponins, phenolic compound and flavonoids. Total phenolic content of VN methanol extract from bark was 1082.473 mg/g GAE and that of leaves was 1382.984 mg/g GAE. The total flavonoids content in VN methanol extract from VN bark was 127.744 mg/g QE and that of leaves was 123.776 mg/g QE. VN methanol extract from bark exhibited high antioxidant effects (IC50=38.47 ppm). The content (%) of ash, moisture, crude fiber, crude protein and fat in VN leaves was, respectively, 7.86%, 18.35%, 6.52%, 9.687% and 6.19%. VN leaves methanol extract revealed antimicrobial activity against Bacillus subtilis and Staphylococcus aureus, with inhibition halos being, respectively, 13 mm and 14 mm, and the MBC values were found to be 1.562 mg/mL and 6.25 mg/mL, respectively. Similarly, VN bark methanol extract led to inhibition halos of 18 mm and 15 mm for B. subtilis and S. aureus, respectively, and the MBC values were found to be 2.372 mg/mL and 0.245 mg/mL. GC-MS analysis of the VN bark methanol extract revealed that monoolein was the major compounds, with an area of 0.57%. Thus, our results encourage the potential use of VN as a medicinal product, with high protein contents, and prominent antioxidant and anti-bacterial effects.

Biological activities and health-promoting effects of Pyracantha genus: a key approach to the phytochemical's potential.

Pyracantha spp. are commonly called firethorn, and attract human attention due to their colorful berries. These berries are eaten globally as a traditional remedy for treating different stomach abnormalities, and as a cooking ingredient for folk diets. The present review aims to provide an overview on Pyracantha genus' geographical distribution and botanical description, traditional uses, phytochemical composition, biological activities and safety issues. Several biological activities have been reported to Pyracantha species, namely antioxidant, anti-inflammatory, antimicrobial, larvicidal and cytotoxic properties, most of them attributed to the use of their fruits. Pyracantha species phytochemical composition reveal the presence of interesting bioactive molecules, such as pyracrenic acid and fortuneanosides. The currently reported biological activities to these plants derive from in vitro and in vivo studies, so that clinical trials are needed to confirm these preclinical results. Nonetheless, Pyracantha species can be suggested as a safe herb useful to develop future drug formulations and functional foods.

Screening and Optimization of Newly Isolated Thermotolerant Lysinibacillus fusiformis Strain SK for Protease and Antifungal Activity.

The current study was designed to isolate, identify and characterize a Bacillus sp. capable of producing protease and exhibiting antifungal activity. A highly potent bacterium capable of producing protease abundantly was isolated from the soil collected from the waste pit near Microbiology Laboratory of Birendra Multiple Campus, Bharatpur and later on identified as Lysinibacillus fusiformis strain SK on the basis of morphological, physiological, biochemical and 16S rDNA gene sequencing techniques. The strain SK showed 98.36% similarity with L. fusiformis strain NBRC 15717. Using R-programming statistical analysis tool, the optimum incubation time for the highest average protease production (APP) (47.2 U/mL) was found to be 22 h at 50 °C and both incubation time and temperature showed a significant impact on the production of protease (P < 0.01). The maximum average relative protease activity (ARPA) was observed at pH 7.8 and 48 °C, whereas the least ARPA was observed in the presence of 80 g/L NaCl and 10 g/L HgCl2 (P < 0.01). The newly isolated bacterial strain also exhibited strong antifungal activity against aflatoxigenic Aspergillus flavus and Aspergillus parasiticus suggesting that it can be a potential candidate for protease production and activity over a wider range of temperature and pH as well as for synthesizing effective antifungal compounds.

Metabolic engineering of Escherichia coli for the production of isoflavonoid-4'-O-methoxides and their biological activities.

Isoflavonoid representatives such as genistein and daidzein are highly potent anticancer, antibacterial, and antioxidant agents. It have been demonstrated that methylation of flavonoids enhanced the transporting ability, which lead to facilitated absorption and greatly increased bioavailability. In this paper, genetically engineered Escherichia coli was reconstructed by harboring E. coli K12-derived metK encoding S-adenosine-l-methionine (SAM) synthase (accession number: K02129) for enhancement of SAM as a precursor and Streptomyces avermitilis originated SaOMT2 (O-methyltransferase, accession number: NP_823558) for methylation of daidzein and genistein as preferred substrates. The formation of desired products via biotransformation including 4'-O-methyl-genistein and 4'-O-methyl-daidzein was confirmed individually by using chromatographical methods such as high-performance liquid chromatography, liquid chromatography/time-of-flight/mass spectrometry (LC-TOF-MS), and nuclear magnetic resonance (NMR), and NMR (1 H and 13 C). Furthermore, substrates concentration, incubation time, and media parameters were optimized using flask culture. Finally, the most fit conditions were applied for fed-batch fermentation with scale-up to 3 L (working volume) to obtain the maximum yield of the products including 164.25 µM (46.81 mg/L) and 382.50 µM (102.88 mg/L) for 4'-O-methyl genistein and 4'-O-methyl daidzein, respectively. In particular, potent inhibitory activities of those isoflavonoid methoxides against the growth of cancer line (B16F10, AGS, and HepG2) and human umbilical vein endothelial cells were investigated and demonstrated. Taken together, this research work described the production of isoflavonoid-4'-O-methoxides by E. coli engineering, improvement of production, characterization of produced compounds, and preliminary in vitro biological activities of the flavonoids being manufactured.

Interplay between carbon, nitrogen and phosphate utilization in the control of secondary metabolite production in Streptomyces.

Streptomyces species are a wide and diverse source of many therapeutic agents (antimicrobials, antineoplastic and antioxidants, to name a few) and represent an important source of compounds with potential applications in medicine. The effect of nitrogen, phosphate and carbon on the production of secondary metabolites has long been observed, but it was not until recently that the molecular mechanisms on which these effects rely were ascertained. In addition to the specific macronutrient regulatory mechanisms, there is a complex network of interactions between these mechanisms influencing secondary metabolism. In this article, we review the recent advances in our understanding of the molecular mechanisms of regulation exerted by nitrogen, phosphate and carbon sources, as well as the effects of their interconnections, on the synthesis of secondary metabolites by members of the genus Streptomyces.

Modification of emodin and aloe-emodin by glycosylation in engineered Escherihia coli.

Glycosyltransferase from Bacillus licheniformis DSM13 (YjiC) was used for enzymatic modification of emodin and aloe-emodin in vitro and in vivo. In order to increase the availability of UDP-glucose, three genes involved in the production of precursors of NDP-sugar in Escherichia coli BL21 (DE3) viz. D-glucose phosphate isomerase (pgi), D-glucose-6-phosphate dehydrogenase (zwf), and UDP-sugar hydrolase (ushA) were deleted and glucose-1-phosphate urididyltransferase (galU) gene was over expressed. To improve the yield of the products; substrate, time and media parameters were optimized, and the production was scaled up using a 3 L fermentor. The maximum yield of glycosylated products of emodin (emodin-O-ß-D-glucoside) and aloe-emodin (aloe-emodin-O-ß-D-glucoside) were approximately 144 µM (38 mg/L) and 168 µM (45 mg/L) respectively, representing almost 72 % and 84 % bioconversion of emodin and aloe-emodin when 200 µM of emodin and aloe-emodin were supplemented in the culture. Additionally, the emodin and aloe emodin major glycosylated products exhibited the highest stability at pH 8.0 and the stability of products was up to 70 °C and 60 °C respectively. Furthermore, the biological activities of emodin and its major glucoside (P1) were compared and their anti-cancer activities were assayed in several cancer cell lines. The results demonstrate that YjiC has the capacity to catalyze the glycosylation of these aromatic compounds and that glycosylation of anthraquinones enhances their aqueous solubility while retaining their biological activities.

Glycosylation and subsequent malonylation of isoflavonoids in E. coli: strain development, production and insights into future metabolic perspectives.

Genistin and daidzein exhibit a protective effect on DNA damage and inhibit cell proliferation. Glycosylation and malonylation of the compounds increase water solubility and stability. Constructed pET15b-GmIF7GT and pET28a-GmIF7MAT were used for the transformation of Escherichia coli and bioconversion of genistein and daidzein. To increase the availability of malonyl-CoA, a critical precursor of GmIF7MAT, genes for the acyl-CoA carboxylase α and ß subunits (nfa9890 and nfa9940), biotin ligase (nfa9950), and acetyl-CoA synthetase (nfa3550) from Nocardia farcinia were also introduced. Thus, the isoflavonoids were glycosylated at position 7 by 7-O-glycosyltranferase and were further malonylated at position 6(″) of glucose by malonyl-CoA: isoflavone 7-O-glucoside-6(″)-O-malonyltransferase both from Glycine max. Engineered E. coli produced 175.7 µM (75.90 mg/L) of genistin and 14.2 µM (7.37 mg/L) genistin 6''-O-malonate. Similar conditions produced 162.2 µM (67.65 mg/L) daidzin and 12.4 µM (6.23 mg/L) daidzin 6''-O-malonate when 200 µM of each substrate was supplemented in the culture. Based on our findings, we speculate that isoflavonoids and their glycosides may prove useful as anticancer drugs with added advantage of increased solubility, stability and bioavailability.

Probing 3-hydroxyflavone for in vitro glycorandomization of flavonols by YjiC.

The glycosylation of five different flavonols, fisetin, quercetin, myricetin, kaempferol, and 3-hydroxyflavone, was achieved by applying YjiC. 3-Hydroxyflavone was selected as a probe for in vitro glycorandomization of all flavonols using diverse nucleotide diphosphate-d/l-sugars. This study unlocked the possibilities of the glycodiversification of flavonols and the generation of novel compounds as future therapeutics.

Attitude sustains longer than subjective norm and perceived behavioral control: Results of breast cancer screening educational intervention.

Breast malignancy is the most frequent carcinoma among females across the world and third-most in Nepal. Early diagnosis of breast cancer through breast health awareness and self-examination, in addition to mammography screening, is a highly feasible and useful technique in poorly resourced settings. However, their intentions, whether to modify behaviors or actions, remain debatable and less explained in the literature. So, we aimed to assess how long an educational intervention affects women's intention to do a breast self-examination (BSE) and mammography screening. After assessing feasibility, one ward was assigned to the intervention (IG; ward number 30) and control group (CG; ward number 33), and then with inclusion criteria, a total of 360 females (180 each in IG and CG) aged 40-75 years enrolled in the study. After the baseline assessment, participants in the IG were delivered an hour-long breast cancer screening-related lecture-discussion- demonstration session that included BSE and mammography, aided with a silicone dummy. The session was carried out by the female trained nurses. Outcome data were obtained at the baseline, 4, 8, and 12 months following the intervention. Attitudes, perceived behavioral controls (PBCs) and behavioral intents (BIs) of both mammography and BSE at baseline were similar in both IG and CG except in case of subjective norms (SNs). Intents of BSE remained effective for 4 months, whereas for mammography, it was effective only at 4 and 12 months. Moreover, attitudes toward both tests remained intact for 4, 8, and 12 months (p = < .05) consistently. With regards to PBCs, women having good control remained only for 4 months in both screening tests. Further, regarding SN, significant mean changes were observed at 4 and 12 months in BSE, and only at 4 months in mammography screening. The session was effective in sustaining BSE and mammography intentions for at least 4 months. To retain the effects longer (up to 12 months), additional educational strategies focusing on subjective norms and perceived behavioral controls of both tests are highly warranted.

Ethnobotany, Phytochemistry, Biological Activities, and Health-Promoting Effects of the Genus Bulbophyllum.

The genus Bulbophyllum is of scientific interest due to the phytochemical components and diverse biological activities found across species of the genus. Most Bulbophyllum species are epiphytic and located in habitats that range from subtropical dry forests to wet montane cloud forests. In many cultures, the genus Bulbophyllum has a religious, protective, ornamenting, cosmetic, and medicinal role. Detailed investigations into the molecular pharmacological mechanisms and numerous biological effects of Bulbophyllum spp. remain ambiguous. The review focuses on an in-depth discussion of studies containing data on phytochemistry and preclinical pharmacology. Thus, the purpose of this review was to summarize the therapeutic potential of Bulbophyllum spp. biocompounds. Data were collected from several scientific databases such as PubMed and ScienceDirect, other professional websites, and traditional medicine books to obtain the necessary information. Evidence from pharmacological studies has shown that various phytoconstituents in some Bulbophyllum species have different biological health-promoting activities such as antimicrobial, antifungal, antioxidant, anti-inflammatory, anticancer, and neuroprotective. No toxicological effects have been reported to date. Future clinical trials are needed for the clinical confirmation of biological activities proven in preclinical studies. Although orchid species are cultivated for ornamental purposes and have a wide traditional use, the novelty of this review is a summary of biological actions from preclinical studies, thus supporting ethnopharmacological data.

Bioactive Effects of Curcumin in Human Immunodeficiency Virus Infection Along with the Most Effective Isolation Techniques and Type of Nanoformulations.

Human immunodeficiency virus (HIV) is one of the leading causes of death worldwide, with African countries being the worst affected by this deadly virus. Curcumin (CUR) is a Curcuma longa-derived polyphenol that has attracted the attention of researchers due to its antimicrobial, anti-inflammatory, antioxidant, immunomodulatory and antiviral effects. CUR also demonstrates anti-HIV effects by acting as a possible inhibitor of gp120 binding, integrase, protease, and topoisomerase II activities, besides also exerting a protective action against HIV-associated diseases. However, its effectiveness is limited due to its poor water solubility, rapid metabolism, and systemic elimination. Nanoformulations have been shown to be useful to enhance curcumin's bioavailability and its effectiveness as an anti-HIV agent. In this sense, bioactive effects of CUR in HIV infection are carefully reviewed, along with the most effective isolation techniques and type of nanoformulations available.

Hyssopus Essential Oil: An Update of Its Phytochemistry, Biological Activities, and Safety Profile.

The genus Hyssopus is widespread in central Asia, East Mediterranean, and Mongolian areas. It has six main species which are used as herbal remedies, such as Hyssopus officinalis which is used as a condiment and flavoring agent in food industry. The other five species are H. ambiguus, H. cuspidatus, H. latilabiatus, H. macranthus, and H. seravschanicus. Its species are used in the treatment of various ailments such as cold, cough, loss of appetite, fungal infection, and spasmodic condition. Its constituents especially essential oils are popularly used as an additive in beverages, foods, and cosmetics. The volatile constituents are used for aroma in the food industry, cosmetic industry, and household products. The important active constituents in its essential oils are ß-pinene, pinocamphone, isopinocamphone, and other terpenoids. Hyssopus genus is also bundled with other secondary metabolites including flavonoids luteolin, quercetin, apigenin, and their glucosides, as well as phenolic compounds including ferulic, p-hydroxy-benzoic acid, protocatechuic acid, chlorogenic, and caffeic acid. Combinedly, the extracts of Hyssopus are reported to have potential antiviral and antifungal activities proven using in vitro studies, whereas in vivo investigations have reported the crucial role of Hyssopus extracts in plasma membrane relaxation, cytotoxic, and sedative effects. This plant is believed to be relatively safe at levels commonly used in foods; nevertheless, more studies are needed to determine the safety profile.

Antibiotic resistance in microbes: History, mechanisms, therapeutic strategies and future prospects.

Antibiotics have been used to cure bacterial infections for more than 70 years, and these low-molecular-weight bioactive agents have also been used for a variety of other medicinal applications. In the battle against microbes, antibiotics have certainly been a blessing to human civilization by saving millions of lives. Globally, infections caused by multidrug-resistant (MDR) bacteria are on the rise. Antibiotics are being used to combat diversified bacterial infections. Synthetic biology techniques, in combination with molecular, functional genomic, and metagenomic studies of bacteria, plants, and even marine invertebrates are aimed at unlocking the world's natural products faster than previous methods of antibiotic discovery. There are currently only few viable remedies, potential preventive techniques, and a limited number of antibiotics, thereby necessitating the discovery of innovative medicinal approaches and antimicrobial therapies. MDR is also facilitated by biofilms, which makes infection control more complex. In this review, we have spotlighted comprehensively various aspects of antibiotics viz. overview of antibiotics era, mode of actions of antibiotics, development and mechanisms of antibiotic resistance in bacteria, and future strategies to fight the emerging antimicrobial resistant threat.

Cinnamomum Species: Bridging Phytochemistry Knowledge, Pharmacological Properties and Toxicological Safety for Health Benefits.

The genus Cinnamomum includes a number of plant species largely used as food, food additives and spices for a long time. Different traditional healing systems have used these plants as herbal remedies to cure diverse ailments. The aim of this comprehensive and updated review is to summarize the biodiversity of the genus Cinnamomum, its bioactive compounds, the mechanisms that underlie the pharmacological activities and molecular targets and toxicological safety. All the data in this review have been collected from databases and recent scientific literature including Web of Science, PubMed, ScienceDirect etc. The results showed that the bioactive compounds of Cinnamomum species possess antimicrobial, antidiabetic, antioxidant, anti-inflammatory, anticancer and neuroprotective effects. The preclinical (in vitro/in vivo) studies provided the possible molecular mechanisms of these action. As a novelty, recent clinical studies and toxicological data described in this paper support and confirm the pharmacological importance of the genus Cinnamomum. In conclusion, the obtained results from preclinical studies and clinical trials, as well as reduced side effects provide insights into future research of new drugs based on extracts and bioactive compounds from Cinnamomum plants.

Dairy-Derived and Egg White Proteins in Enhancing Immune System Against COVID-19.

Coronavirus disease (COVID-19) is a global health challenge, caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) triggers a plethora of respiratory disturbances and even multiple organs failure that can be fatal. Nutritional intervention is one of the key components toward to a proper management of COVID-19 patients, especially in those requiring medication, and should thus be considered the first-line treatment. Immuno-modulation and -stimulation are currently being explored in COVID-19 management and are gaining interest by food and pharmaceutical industries. Various dietary combinations, bioactive components, nutrients and fortified foods have been reported to modulate inflammation during disease progression. Dietary combinations of dairy-derived products and eggs are gaining an increasing attention given the huge immunomodulatory and anti-inflammatory properties attributed to some of their chemical constituents. Eggs are complex dietary components containing many essential nutrients and bioactive compounds as well as a high-quality proteins. Similarly, yogurts can replenish beneficial bacteria and contains macronutrients capable of stimulating immunity by enhancing cell immunity, reducing oxidative stress, neutralizing inflammation and regulating the intestinal barriers and gut microbiome. Thus, this review highlights the impact of nutritional intervention on COVID-19 management, focusing on the immunomodulatory and inflammatory effects of immune-enhancing nutrients.