Fermentation of Rubus dolichocarpus juice using Lactobacillus gasseri and Lacticaseibacillus casei and protecting phenolic compounds by Stevia extract during cold storage.

This study aimed to investigate the biological activities of Lactobacillus gasseri SM 05 (L. gasseri) and Lacticaseibacillus casei subsp. casei PTCC 1608 (L. casei) in the black raspberry (Rubus dolichocarpus) juice (BRJ) environment, and also the anti-adhesion activity against Salmonella typhimurium (S. typhimurium) in fermented black raspberry juice (FBRJ). Results showed significant anti-adhesion activity in Caco-2 epithelial cells. In the anti-adhesion process, lactic acid bacteria (LAB) improve intestinal health by preventing the adhesion of pathogens. Adding LAB to BRJ produces metabolites with bacteriocin properties. Major findings of this research include improved intestinal health, improved antidiabetic properties, inhibition of degradation of amino acids, and increase in the nutritional value of foods that have been subjected to heat processing by preventing Maillard inhibition, and inhibition of oxidation of foodstuff by increased antioxidant activity of BRJ. Both species of Lactobacillus effectively controlled the growth of S. typhimurium during BRJ fermentation. Moreover, in all tests, as well as Maillard's and α-amylase inhibition, L. gasseri was more effective than L. casei. The phenolic and flavonoid compounds increased significantly after fermentation by both LAB (p < 0.05). Adding Stevia extract to FBRJ and performing the HHP process showed convenient protection of phenolic compounds compared to heat processing.

Effects of stevia extract on production performance, serum biochemistry, antioxidant capacity, and gut health of laying hens.

In the present study, we aimed to elucidate the effects of stevia extract on production performance, serum immune indexes, intestinal structure, and cecum microbial structure. We randomly divided eight hundred 46-wk-old Roman hens into 5 groups, with 8 replicates in each group and 20 chickens in each replicate. The control group was fed a basal diet, whereas the 4 experimental groups were fed 50, 100, 200, and 400 mg/kg stevia extracts. The study period was 24 wk. The addition of different concentrations of the stevia extract to the diet resulted in significant secondary changes in the egg production rate at 1 to 12 wk (P < 0.05). Furthermore, the addition of 50 and 100 mg/kg stevia extract to the diet significantly increased serum IgM and IgG levels in laying hens (P < 0.05) but linearly decreased serum IL-1ß levels (P < 0.05). Serum T-SOD activity linearly increased (P = 0.057); however, serum biochemical indexes showed no significant differences. Stevia extract tended to increase the ratio of the duodenal villi height to the depth of the crypt (P = 0.067), with no obvious lesions in the duodenum, jejunum, and ileum. In addition, stevia extract increased the relative abundance of species at the phylum level, with the abundance of Bacteroides and Firmicutes exhibiting significant secondary changes (P < 0.05). The ACE and Chao1 indexes suggested that stevia extract addition significantly increased the alpha diversity of cecum microorganisms in laying hens. Furthermore, NMDS analysis based on operational taxonomic units revealed that stevia extract addition increased the beta diversity of cecum microorganisms in laying hens. Adding a certain amount of stevia extract to feed can improve the production performance, immune ability, and intestinal health of laying hens to some extent, and we recommend an effective level of 200mg/kg of stevia extract for laying hen diets.

Improving gut functions and egg nutrition with stevia residue in laying hens.

This study aimed to investigate the effect of stevia residue (STER) on the production performance, egg quality and nutrition, antioxidant ability, immune responses, gut morphology and microbiota of laying hens during the peak laying period. A total of 270 Yikoujingfen NO. 8 laying hens (35 wk of age) were randomly divided into 5 treatments. The control group fed a basal diet and groups supplemented with 2, 4, 6, and 8% STER. The results showed that STER significantly increased egg production, the content of amino acids (alanine, proline, valine, ornithine, asparagine, aspartic acid, and cysteine) in egg whites, and decreased the yolk color (P < 0.05). Additionally, STER significantly increased acetate, HOMOγ linolenic acid and cis-13, 16-docosadienoic acid levels in egg yolk (P < 0.05). IL-2, IL-4, and IL-10 levels in serum significantly increased by STER (P < 0.05), while IL-1ß significantly decreased (P < 0.05). STER also increased total antioxidant activity (T-AOC) in the liver and estradiol level in the oviduct (P < 0.05), but decreased the cortisol level in the oviduct (P < 0.05). For the intestinal morphology, the jejunal villus height and crypt-to-villus (V:C) significantly increased by STER (P < 0.05). STER increased the relative abundance of Actinobacteriota (P < 0.05), while deceased Proteobacteria, Desulfobacterota, and Synergistota (P < 0.05). In conclusion, STER improved egg production, quality and nutrition, improved the immune responses, antioxidant capabilities, estrogen level, gut morphology, and increased the relative abundance of beneficial bacteria while decreased the harmful bacteria. Among all treatments, 4 and 6% STER supplementation yielded the most favorable results in terms of enhancing production performance, egg nutrition, gut health, and immune capabilities in laying hens.

Stevia as a natural additive on gut health and cecal microbiota in broilers.

Stevia mash (SM), leaves of Stevia rebaudiana Bertoni plant, is an additive used in poultry that enhances growth and health. Objective: to determine the effect of 1 % SM on productive parameters, gut health, and the cecal microbiome in broilers between the first 15 and 21 days old. One hundred sixty male, 1-day-old broilers (48.5 ± 2.5 g) were divided into Control (C) without SM and Treated (T) with 1 % SM on diet, during 15/21 days. Each subgroup had eight broilers/five repetitions/treatment. At day 15 or 21, all broilers were dissected, Fabricius Bursa and Gut removed and processed for histomorphometry, followed by Villi Height/Crypt Deep (VH/CD) ratio. Conversion Index (CI) was determined. The V3-V4 region of 16S rRNA gene was amplified from DNA obtained from pooled cecal contents and sequenced on Illumina Miseq PE 2 × 250 platform. Sequence processing and taxonomic assignments were performed using the SHAMAN pipeline. Both T groups have better VH/CD Ratios than C groups (p ≤ 0.05). In guts, increased plasmatic and goblet cells number and thicker mucus layer were found in T15 and T21. All groups received SM showed early immunological maturity in Fabricius Bursa. IC was similar between all treatments. Faecalibacterium, Ruminococcus torques group, and Bacteroides were the major genera modulated by SM addition. At 15 and 21 days old, SM exerts a impact on diversity and evenness of the cecal microbiome.  Conclusion: SM (1 %) produced early immunologic maturity on Fabricius Bursa, increased intestinal functionality, and modified the microbiota, increasing beneficial microbial genera and microbial diversity.

The use of plant extracts and bacteriophages as an alternative therapy approach in combatting bacterial infections: the study of lytic phages and Stevia rebaudiana.

Introduction: In the light of the problem of antibiotic resistance, the use of combined alternative therapies in combatting bacteria-related disorders has gained popularity. Bacteriophages are one element implemented in new combination therapy. Stevia rebaudiana is known to have antimicrobial activity and regarded as potentially having a synergistic effect with bacteriophages. Therefore, possible interactions of lytic bacteriophages (MS2, T4 and Phi6) with acetone and methanol S. rebaudiana extracts (SRa and SRm) in the bacterial environment were examined. Material and Methods: The interactions were tested using a microdilution method, phage-extract co-incubation assay, static interaction (synography) and dynamic growth profile experiments in a bioreactor. Results: The interactions of the tested factors in a static environment differed from those in a dynamic environment. Dynamic conditions altered the effect of the extracts in a concentration-dependent manner. How different the effect of the SRa extract was to that of the SRm extract on bacterial growth in a dynamic environment depended on the species of the phage and bacterial host. The greatest differences were observed for E. coli strains and their phages, whereas Pseudomonas syringae and the Phi6 phage reacted very similarly to both extracts. Differences also emerged for the same extract in different E. coli strains and their phages. Conclusion: Every extract type should be tested on a case-by-case basis and experiment outcomes should not be generalised before gathering data. Moreover, many varied experiments should be performed, especially when examining such multifactorial mixtures. The tested mixtures could potentially be used in multidrug-resistant bacterial infection treatments.

Stevia Polyphenols, Their Antimicrobial and Anti-Inflammatory Properties, and Inhibitory Effect on Digestive Enzymes.

Polyphenols from stevia leaves (PPSs) are abundant byproducts from steviol glycoside production, which have been often studied as raw extracts from stevia extracts for their bioactivities. Herein, the PPSs rich in isochlorogenic acids were studied for their antimicrobial and anti-inflammatory properties, as well as their inhibitory effects on digestive enzymes. The PPSs presented stronger antibacterial activity against E. coli, S. aureus, P. aeruginosa, and B. subtilis than their antifungal activity against M. furfur and A. niger. Meanwhile, the PPSs inhibited four cancer cells by more than 60% based on their viability, in a dose-dependent manner. The PPSs presented similar IC50 values on the inhibition of digestive enzyme activities compared to epigallocatechin gallate (EGCG), but had weaker anti-inflammatory activity. Therefore, PPSs could be a potential natural alternative to antimicrobial agents. This is the first report on the bioactivity of polyphenols from stevia rebaudiana (Bertoni) leaves excluding flavonoids, and will be of benefit for understanding the role of PPSs and their application.

The protective effect of aqueous extract of Stevia rebaudiana against tartrazine toxicity in male Wistar rat.

Tartrazine is a yellow colouring agent that is commonly used in foods; however, high dosages of Tartrazine affect fertility and create oxidative stress by generating free radicals. A plant species known as Stevia rebaudiana has natural antioxidants that show promise for protecting testicular tissue. Consequently, this study was intended to examine the ameliorative effect of the aqueous extract of S. rebaudiana (Stevia) on the fertility of male Wistar rats induced by the daily oral intake of Tartrazine. Utilizing gas chromatography-mass spectrometry, phytochemical identification was accomplished for Stevia extract. Study groups were separated into several groups: the first group (the control) got distilled water for up to 56 days; the Stevia group (1000 mg/kg), the Tartrazine group (300 mg/kg) and the Stevia and Tartrazine group (the group was given Tartrazine after 1 h of Stevia extract intake). Also, the oxidative damage in testicular tissues was assessed by measuring the levels of malondialdehyde (MDA) and antioxidants (catalase [CAT], superoxide dismutase [SOD] and glutathione reductase [GSH]). Further, histological alterations were examined. In addition, cyclic AMP-responsive element modulator (Crem) gene expression levels and their relative proteins were measured in the testicular tissues using quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assays, respectively. Sperm analysis and testosterone concentration were also performed. SPSS version 25 was used for the analysis of results while (p < .05) was regarded as significant. Compared with the control group, the results demonstrated that Tartrazine caused a significant reduction (p < .05) in the testosterone hormone level (0.70 ± 0.21) and the Crem protein quantity (1.21 ± 0.23) in the treated Tartrazine group. Also, it had a significant decrease (p < .05) in sperm motility, viability, count and antioxidant levels. Moreover, there was a significant increase (p < .05) in sperm abnormalities, MDA level (7.40 ± 1.10), kidney and liver function parameters, and DNA degradation in the treated Tartrazine group compared with the control group. On the contrary, the Stevia extract intake enhanced the testosterone (2.50 ± 0.60), antioxidants and Crem protein levels (2.33 ± 0.10) with an improvement in sperm quality in the Stevia and Tartrazine-treated group compared with the Tartrazine group. Stevia also caused a significant decrease (p < .05) in the MDA level (3.20 ± 0.20), and sperm abnormalities with an enhancement of the liver and kidney function parameters in the Stevia and Tartrazine-treated group compared to the Tartrazine group. Stevia administration has a protective effect on the testicular tissues and sperm quality against toxicity induced by Tartrazine exposure, so it will be a good antioxidant drug to be administered daily before daily administration of Tartrazine.

Unlocking the Therapeutic Potential of Stevia rebaudiana Bertoni: A Natural Antiglycating Agent and Non-Toxic Support for HDF Cell Health.

Sugar carbonyl groups interact with protein amino groups, forming toxic components referred to as advanced glycation end products (AGEs). The glycation system (BSA, a model protein, and fructose) was incubated for five weeks at 37 °C in the presence and absence of Stevia leaf extract. The results indicated that the leaf extract (0.5 mg/mL) decreased the incidence of browning (70.84 ± 0.08%), fructosamine (67.27 ± 0.08%), and carbonyl content (64.04 ± 0.09%). Moreover, we observed an 81 ± 8.49% reduction in total AGEs. The inhibition of individual AGE (argpyrimidine, vesper lysine, and pentosidine) was ~80%. The decrease in the protein aggregation was observed with Congo red (46.88 ± 0.078%) and the Thioflavin T (31.25 ± 1.18%) methods in the presence of Stevia leaf extract. The repercussion of Stevia leaf extract on DNA glycation was examined using agarose gel electrophoresis, wherein the DNA damage was reversed in the presence of 1 mg/mL of leaf extract. When the HDF cell line was treated with 0.5 mg/mL of extract, the viability of cells decreased by only ~20% along with the same cytokine IL-10 production, and glucose uptake decreased by 28 ± 1.90% compared to the control. In conclusion, Stevia extract emerges as a promising natural agent for mitigating glycation-associated challenges, holding potential for novel therapeutic interventions and enhanced management of its related conditions.

Fermented Stevia Improves Alcohol Poisoning Symptoms Associated with Changes in Mouse Gut Microbiota.

We previously found that the continuous feeding of ethanol caused mice dysbiosis, in which the cecal microbiota were significantly altered, as compared with those in the non-feeding control group, especially in some bacterial genera involved in gut inflammation. In the present study, we have found that the fermented extract of stevia (Stevia rebaudiana) leaves with plant-derived lactic acid bacteria (LABs), Pediococcus pentosaceus LY45, improves the trimethylamine (TMA) productivity of cecal content, which can be used as an indicator of dysbiosis. The following animal experiment also shows that the LY45-fermented stevia extract represses the typical increase in serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, which decreased from 1106 to 210 IU/L (p < 0.05) and from 591 to 100 IU/L (p < 0.05), respectively, together with the simultaneously latent TMA productivity (from 1356 to 745 µM, p < 0.05) of cecal content in the ethanol-fed mice. The microbiota analyses have shown that the observed increased alterations in pro-inflammatory genera putative SMB53 (family Clostridiaceae) and Dorea are restored by the fermented stevia extract. Our result indicates that the preliminary bioconversion of herbal medicinal precursors by fermentation with safe microorganisms like LABs is expected to be a hopeful method of producing specific metabolites that may contribute to the reconstruction of gut microbiota.

Antimicrobial and Cytotoxic Activity of Ocimum tenuiflorum and Stevia rebaudiana-Mediated Silver Nanoparticles - An In vitro Study.

Background: Silver nanoparticles (AgNPs) are the nanoparticles of silver between 1 nm and 100 nm in size. In this study, AgNPs were extracted from Ocimum tenuiflorum and Stevia rebaudiana which is a medicinal plant of Indian origin, worshipped by the Hindus and used in Ayurvedic medicine since ancient times. Aim: The aim of the study was to assess the antimicrobial and cytotoxic effect of AgNPs reinforced with the herb O. tenuiflorum and S. rebaudiana against oral pathogens. Materials and Methods: In this in vitro study, the organisms used were Streptococcus mutans, Staphylococcus aureus, Lactobacillus sp., and Candida albicans. Agar well-diffusion method was used to assess the antimicrobial efficacy of the nanoparticles at 25 mL, 50 mL, and 100 mL. To assess the cytotoxic effect, brine shrimp lethality assay was used. Results: Zone of inhibition was found to be highest at 100 mL against S. mutans, S. aureus, Lactobacillus sp., and C. albicans. The cytotoxic activity at 5 mL and 10 mL was 0%. The maximum cytotoxicity was seen at 80 mL where 30% of the Nauplii's died. Conclusion: The findings from this study suggest that AgNPs reinforced with O. tenuiflorum and S. rebaudiana extracts has the potential as an antimicrobial agent and has less cytotoxic effect on brime shrimp and can be used as an alternative to commercially available antimicrobial agents.

Antioxidant Activity of Leaf Extracts from Stevia rebaudiana Bertoni Exerts Attenuating Effect on Diseased Experimental Rats: A Systematic Review and Meta-Analysis.

Stevia (Stevia rebaudiana Bertoni) is an aromatic plant known for its high sweetening power ascribed to its glycosides. Stevia also contains several bioactive compounds showing antioxidant, antiproliferative, antimicrobial, and anti-inflammatory activities. Since inflammation and oxidative stress play critical roles in the pathogenesis of many diseases, stevia emerges as a promising natural product that could support human health. In this study we set out to investigate the way stevia affects oxidative stress markers (e.g., SOD, CAT, GPx, GSH, MDA) in diseased rats administered stevia leaf extracts or glycosides. To this end, we performed an inclusive literature search, following PRISMA guidelines, and recruited multivariate meta-analysis and meta-regression to synthesize all available data on experimental animal models encountering (a) healthy, (b) diseased, and (c) stevia-treated diseased rats. From the 184 articles initially retrieved, 24 satisfied the eligibility criteria, containing 104 studies. Our results demonstrate that regardless of the assay employed, stevia leaf extracts restored all oxidative stress markers to a higher extent compared to pure glycosides. Meta-regression analysis revealed that results from SOD, CAT, GSH, and TAC assays are not statistically significantly different (p = 0.184) and can be combined in meta-analysis. Organic extracts from stevia leaves showed more robust antioxidant properties compared to aqueous or hydroalcoholic ones. The restoration of oxidative markers ranged from 65% to 85% and was exhibited in all tested tissues. Rats with diabetes mellitus were found to have the highest restorative response to stevia leaf extract administration. Our results suggest that stevia leaf extract can act protectively against various diseases through its antioxidant properties. However, which of each of the multitude of stevia compounds contribute to this effect, and to what extent, awaits further investigation.

Genome-wide identification of SrbHLH transcription factors highlights its potential role in rebaudioside A (RA) biosynthesis in Stevia rebaudiana.

Stevia rebaudiana Bertoni is a valuable medicinal plant and an essential source of natural sweetener, steviol glycosides (SGs), with rebaudioside A (RA) being one of the main components of SGs. bHLH transcription factors play a crucial role in plant development and secondary metabolism. In this study, 159 SrbHLH genes were identified from the S. rebaudiana genome, and each gene was named based on its chromosome location. The SrbHLH proteins were then clustered into 18 subfamilies through phylogenetic analysis. The analysis of conserved motifs and gene structure further supported the classification of the SrbHLH family. Chromosomal location and gene duplication events of SrbHLH genes were also studied. Moreover, based on the RNA-Seq data of different tissues of S. rebaudiana, 28 SrbHLHs were co-expressed with structural genes involved in RA biosynthesis. The expression pattern of candidate SrbHLH genes were confirmed by qPCR. Finally, dual luciferase reporter assays (DLAs) and subcellular localization analysis verified SrbHLH22, SrbHLH111, SrbHLH126, SrbHLH142, and SrbHLH152 are critical regulators of RA biosynthesis. This study provides new insights into the function of SrbHLHs in regulating SGs biosynthesis and lays the foundation for future applications of SrbHLH genes in molecular breeding of S. rebaudiana.

Ameliorative effect of Stevia rebaudiana Bertoni on sperm parameters, in vitro fertilization, and early embryo development in a streptozotocin-induced mouse model of diabetes.

Diabetes mellitus (DM) is a common metabolic disease characterized by high blood sugar levels. It is well known that men with diabetes frequently experience reproductive disorders and sexual dysfunction. In fact, sperm quality has a significant effect on fertilization success and embryo development. The current study aimed to investigate the effect of Stevia rebaudiana hydroalcoholic extract on serum testosterone levels, sperm parameters, in vitro fertilization (IVF) success, and in vitro embryonic developmental potential to reach the blastocyst stage in a streptozotocin (STZ)-induced mouse model of diabetes. In this research, 30 male mice were distributed randomly into control, diabetic (streptozotocin 150 mg/kg) and diabetic + Stevia (400 mg/kg) groups. The results revealed a decrease in body and testis weight and elevated blood fasting blood sugar (FBS) levels in the diabetic group, compared with the control. However, Stevia treatment significantly increased body and testis weight, while serum FBS levels were decreased compared with the diabetic group. In addition, Stevia significantly increased blood testosterone levels compared with the diabetic group. Moreover, sperm parameters were improved considerably by Stevia treatment compared with the diabetic group. Furthermore, Stevia administration significantly promoted IVF success rate and in vitro development of fertilized oocytes compared with the diabetic group. In summary, our data indicated that Stevia enhanced sperm parameters, IVF success, and in vitro embryonic developmental competency in diabetic mice, probably because of its antioxidant effects. Therefore, Stevia could ameliorate sperm parameters that, in turn, increase fertilization outcomes in experimental-induced diabetes.

Effect of Non-Nutritive Sweeteners on Antibacterial Activity of Black and Green Tea Aqueous Extracts against Salivary Mutans Streptococci (in-vitro Study).

Herbal medicines, such as plants and their constituents, have been used globally to treat and cure disorders since antiquity, long before the discovery of modern drugs. Some of these items require an addition to make them more appealing to consumers. This study is an in vitro evaluation of the antibacterial activity of tea (black and green tea aqueous extracts) against salivary Mutans streptococci, followed by an analysis of the effect of non-nutritive sweeteners on the antibacterial activity of these extracts against salivary Mutans streptococci. The examined bacteria were sensitive to various doses of black and green tea aqueous extract, with the inhibition zone expanding as the concentration of the extracts rose. At a dosage of 225mg/ml for black tea extracts and 200mg/ml for green tea extracts, all Mutans isolates were destroyed. In this trial, 1% stevia or sucralose did not inhibit the antibacterial activity of any tea extract, nor did 5% stevia inhibit the antimicrobial activity of black tea extract. In addition, this concentration inhibits the antimicrobial properties of green tea extracts. In this investigation, it found that increasing the content of nonnutritive sweeteners interfered with the antibacterial activity of black and green tea aqueous extract against salivary Mutans streptococci.

Nano-stevia interaction: Past, present, and future.

Nanotechnology has recently been emerged as a transformative technology that offers efficient and sustainable options for nano-bio interface. There has been a considerable interest in exploring the factors affecting elicitation mechanism and nanomaterials have been emerged as strong elicitors in medicinal plants. Stevia rebaudiana is well-known bio-sweetener and the presence of zero calorie, steviol glycosides (SGs) in the leaves of S. rebaudiana have made it a desirable crop to be cultivated on large scale to obtain its higher yield and maximal content of high quality natural sweeteners. Besides, phenolics, flavonoids, and antioxidants are abundant in stevia which contribute to its medicinal importance. Currently, scientists are trying to increase the market value of stevia by the enhancement in production of its bioactive compounds. As such, various in vitro and cell culture strategies have been adopted. In stevia agronanotechnology, nanoparticles behave as elicitors for the triggering of its secondary metabolites, specifically rebaudioside A. This review article discusses the importance of S. rebaudiana and SGs, conventional approaches that have failed to increase the desired yield and quality of stevia, modern approaches that are currently being applied to obtain utmost benefits of SGs, and future needs of advanced technologies for further exploitation of this wonder of nature.

Enhancing Stevia rebaudiana growth and yield through exploring beneficial plant-microbe interactions and their impact on the underlying mechanisms and crop sustainability.

Stevia rebaudiana is an important medicinal plant which represents the most important sugar substitute in many countries. Poor seed germination of this plant is a critical problem that affects the final yield and the availability of the products in the market. Continuous cropping without supplying soil nutrients is also a serious issue as it results in declining soil fertility. This review highlights the important use of beneficial bacteria for the enhancement of Stevia rebaudiana growth and its dynamic interactions in the phyllosphere, rhizosphere, and endosphere. Fertilizers can increase crop yield and preserve and improve soil fertility. There is a rising concern that prolonged usage of chemical fertilizers may have negative impacts on the ecosystem of the soil. On the other hand, soil health and fertility are improved by plant growth-promoting bacteria which could eventually increase plant growth and productivity. Accordingly, a biocompatible strategy involving beneficial microorganisms inoculation is applied to boost plant growth and reduce the negative effects of chemical fertilizers. Plants benefit extensively from endophytic bacteria, which promote growth and induce resistance to pathogens and stresses. Additionally, several plant growth-promoting bacteria are able to produce amino acids, polyamines, and hormones that can be used as alternatives to chemicals. Therefore, understanding the dynamic interactions between bacteria and Stevia can help make the favorable bacterial bio-formulations, use them more effectively, and apply them to Stevia to improve yield and quality.

Intra-gastrically administration of Stevia and particularly Nano-Stevia reversed the hyperglycemia, anxiety, and memory impairment in streptozotocin-induced diabetic rats.

Type II diabetes mellitus is a group of metabolic disorders considered chronic hyperglycemia resulting from deficits in insulin secretion or insulin function. This disease usually links with various psychological problems such as anxiety and cognitive dysfunctions. Stevia (Stevia rebaudiana Bertoni) is a natural and healthy substitute sweetener for sugar and artificial sweeteners. It has become essential for human diets and food manufacturers. The aim of this research was to investigate the effects of Stevia and Nano-stevia on the regulation of anxiety and memory processes in male diabetic rats. The elevated plus-maze (EPM) test-retest procedure was used to assess anxiety and memory in male diabetic rats. The findings exhibited that induction of diabetes caused a distorted cellular arrangement in the liver tissue of male rats. On the other hand, intra-gastrically administration of Stevia (1 ml/kg) and nano-Stevia (1 ml/kg) indicated a normal appearance in the liver tissue of male diabetic rats. Moreover, induction of diabetes caused the augmentation of blood glucose, reduction in time spent in%open-arm time (%OAT) on the test day, and enhancement of%OAT on the retest day. Therefore, induction of diabetes in rats produced hyperglycemia, anxiogenic effect, and memory impairment and these responses were reversed by drug treatment. Furthermore, intra-gastrically application of Stevia (1 ml/kg) and nano-Stevia (1 ml/kg) reversed the hyperglycemia, anxiogenic effect, and memory impairment in male diabetic rats. Interestingly, Nano-Stevia exhibited the highest significant response rather than Stevia. In conclusion, the results of this research suggested the beneficial properties of Stevia and particularly Nano-Stevia on inducing anti-diabetic effects, anxiolytic behavior, as well as memory improvement in male diabetic rats.

A New Substrate and Nitrogen Source for Traditional Kombucha Beverage: Stevia rebaudiana Leaves.

Recently, the use of different herbal products as carbon sources instead of black and green tea in the preparation of traditional kombucha has been investigated. In this study, functional kombucha was prepared by adding Stevia rebaudiana Bertoni leaves, which have special organoleptic properties, to kombucha medium, and some properties of the beverage were analyzed. Tea blends were determined as 100% green tea (control = C), 75% green tea (GT) + 25% Stevia (ST), 50% GT + 50% ST, and 100% ST. On the 15th day of fermentation, gluconic acid (43.12 ± 0.01 g/L) was detected as dominant organic acid in GT75 + ST25 samples compared to group C (p < 0.05). According to physicochemical parameters that determine the drinkability properties of prepared teas, the best results were in GT25 + ST75 compared to group C (p < 0.05). It proved that the highest activity was in GT25 + ST75 on the 10th day in the groups that applied different antioxidant tests (DPPH, MCA, and CUPRAC). The antimicrobial activities of kombucha at 25, 50, 75, and 100% concentrations of GT and ST reached the highest levels in the GT25 + ST75 group in samples after 10 days of fermentation for all selected microorganisms. The results prove that GT25 + ST75 kombucha is a functional product with high drinkability on the 10th day of fermentation and also more beneficial for health due to the phenolic compounds from both green tea and Stevia. Stevia rebaudiana leaves can be suggested that be used as a new substrate and nitrogen source for kombucha production.

Digestive Enzyme Activities, Oxidative Status and Intestinal Histomorphometry of Rats Supplemented with Steviana, A Natural Sweetener.

<b>Background and Objective:</b> Stevia (<i>Stevia rebaudiana</i>), often known as sweet leaf, is a perennial plant and a member of the Asteraceae family. The commercial version of stevia leaf powder, known as Steviana, is one of the most popular natural sweeteners in use today. The current study aimed to analyze the activities of gut digestive enzymes, intestinal oxidative state and intestinal histological structure in stevia-fed rats. <b>Materials and Methods:</b> In this study, male rats were given Steviana and the oxidative condition of the gastrointestinal tract (GIT), the activities of certain digestive enzymes and the histomorphology of the GIT were examined. Animals used in experiments were split into 2 groups: Control and treated groups. For four consecutive weeks, the treatment group received a daily oral intake of 5 mg kg¹ b.wt., of Steviana solution. At the end of the trial, serum, pancreas and intestinal tissue samples were taken. <b>Results:</b> The Steviana sweetener has a strong antioxidative effect on both blood and intestinal tissue. Both sample types showed a decrease in malondialdehyde levels and a marked increase in superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities compared to control samples. In samples of blood, pancreas and intestinal contents, the activities of digestive enzymes including α-amylase, lipase and protease were significantly elevated in Steviana-treated rats. In addition, histological analysis of the small intestine showed that in rats given Steviana sweetener, intestinal glandular crypt depth was more pronounced compared to the control animals. <b>Conclusion:</b> In summary, consumption of Steviana appears to enhance digestion and absorption processes through antioxidative effects, improving the health of the local GIT and subsequently accelerating the rate of synthesis and release of endogenous digestive enzymes. Another aspect that enhances the digestion and absorption process is the change in the histological structure of the intestinal glands, as shown by an increase in the crypt depth.

Thermal and rheological study of artificial and natural powder tabletop sweeteners.

Tabletop sweeteners play an essential role in calorie-restricted and low-sugar diets. Thus, this work aims to characterize by thermal analysis, SEM, and rheology, powder tabletop sweeteners samples based on the most currently consumed: aspartame (A1), saccharin (C1), sucralose (U1), stevia extract (E2) and monk fruit extract (M1). Their physicochemical properties were compared regarding thermal stability, morphology, and viscoelastic behavior. Samples based on artificial sweeteners started to lose mass from 65 °C. On the other hand, natural sweeteners showed greater thermal stability with an initial decomposition temperature of 170 °C. The DSC curves of A1 and C1 samples exhibited similar thermal profiles showing dextrose melting at 150 °C. Both DSC analyses of samples based on natural sweeteners revealed Tm erythritol (121 °C) followed by its decomposition (288 °C). In rheological analysis, except for the U1 sample, all the others presented a slight increase in the storage modulus at 10 and 25 °C, indicating that their granules were not wholly deformed. This aspect could influence the aftertaste of the products in which they will be used.