Comparative effects of Stevia rebaudiana leaves and stevioside on glycaemia and hepatic gluconeogenesis

Effects of early-life stress followed by access to stevia or sucralose during adolescence on weight gain, glycemia, and anxiety-related behaviors in male and female rats

Early-life stress and subsequent high-calorie diets during adolescence are known to be risk factors for developing metabolic and psychological disorders. Although non-nutritive sweeteners such as stevia and sucralose have been a useful alternative to reduce sugar consumption, the effects of prolonged consumption of these sweeteners on metabolism and behavior in adolescents remain unclear. Here, we evaluated the effects of early-stress followed by access to stevia or sucralose during adolescence on weight gain, glycemia, and anxiety-related behaviors in male and female rats. During postnatal days (PNDs) 1-21, pups were separated twice a day, for 180 min each time, from their dam nest while non-separated pups served as controls. The pups were weaned, separated by sex and randomly distributed into the stevia, sucralose and water conditions. During PNDs 26-50, two bottles containing water and stevia or sucralose were placed in the animal home-cages, and body weight and blood glucose measures were scored. On PNDs 50 and 51, behavioral measures were obtained in the open-field test. Results showed that male rats consuming stevia reduced body weight gain, blood glucose and increased locomotion. Early-stress led to low blood glucose and alterations in anxiety and locomotion-related behaviors in a sex-dependent manner. Moreover, sucralose access during adolescence reversed the effects of early-stress on anxiety-related behaviors in female rats. The results suggest that the consumption of stevia and sucralose could be an alternative for the replacement of sugar-sweetened beverages, especially in adolescents who have had adverse early-life experiences.

Stevia rebaudiana Bertoni, an American plant used as sweetener: Study of its effects on body mass control and glycemia reduction in Wistar male and female rats

Stevia rebaudiana Bertoni water extracts have been used as a natural sweetener and customary medicine by the indigenous inhabitants of South America for several hundred years. This plant was sent to Europe in the 16th century and was described by Peter Jacob Esteve in Spain. Recently the food industry has started to employ S. rebaudiana as sweetener using its glycosides after purification. Advertisement claims that Stevia glycosides is good for controling body mass and reducing glycemia. This study's objective was to evaluate the effect of S. rebaudiana leaf extract on Wistar rats as animal model to prove its effectiveness on body mass control, glycemia reduction, and other biochemical parameters. Three groups were randomly formed with 24 males and 24 females: A blank group without any sweetener, a control group drinking water with 10% glucose, and the test group ingesting a 0.94% water extract of S. rebaudiana. Body mass measurements as well as food and drink consumption were daily performed. The experiment lasted 120 days after the specimens were weaned and got used to eating solid food. Euthanasia was done and blood serum was collected to evaluate the following biochemical parameters: Glucose, triglycerides, cholesterol, insulin, glucagon, leptin, ghrelin, and glucose-dependent insulinotropic peptide, GIP. Results indicated that only female rats had statistical differences in body mass gain. No relevant effects either positive or negative were found in the biochemical parameters measured. The crude extracts of S. rebaudiana did not show any relevant changes in biochemical and hormonal profiles, changes nor body mass with respect to the blank and control groups of young and healthy rats in the age range of infancy to youth. According to the results obtained, the therapeutic properties that have been associated to S. rebaudiana consumption especially for body mass control and glycemia reduction, did not occur in young and healthy male and female rats in equivalent age to infants, young children, and youths.

Steviol Glycosides from Stevia rebaudiana: An Updated Overview of Their Sweetening Activity, Pharmacological Properties, and Safety Aspects

This literature-based review synthesizes the available scientific information about steviol glycosides as natural sweeteners and molecules with therapeutic potential. In addition, it discusses the safety concerns regarding human consumption. Steviol glycosides exhibit a superior sweetener proficiency to that of sucrose and are noncaloric, noncariogenic, and nonfermentative. Scientific evidence encourages stevioside and rebaudioside A as sweetener alternatives to sucrose and supports their use based on their absences of harmful effects on human health. Moreover, these active compounds isolated from Stevia rebaudiana possess interesting medicinal activities, including antidiabetic, antihypertensive, anti-inflammatory, antioxidant, anticancer, and antidiarrheal activity. The described bioactivities of steviol glycosides deserve special attention based on their dose dependence and specific pathological situations. Further clinical research is needed to understand underlying mechanisms of action, therapeutic indexes, and pharmacological applications.

Anti-inflammatory potential of stevia residue extract against uric acid-associated renal injury in mice

Abnormal uric acid level result in the development of hyperuricemia and hallmark of various diseases, including renal injury, gout, cardiovascular disorders, and non-alcoholic fatty liver. This study was designed to explore the anti-inflammatory potential of stevia residue extract (STR) against hyperuricemia-associated renal injury in mice. The results revealed that STR at dosages of 150 and 300 mg/kg bw and allopurinol markedly modulated serum uric acid, blood urea nitrogen, and creatinine in hyperuricemic mice. Serum and renal cytokine levels (IL-18, IL-6, IL-1Β, and TNF-α) were also restored by STR treatments. Furthermore, mRNA and immunohistochemistry (IHC) analysis revealed that STR ameliorates UA (uric acid)-associated renal inflammation, fibrosis, and EMT (epithelial-mesenchymal transition) via MMPS (matrix metalloproteinases), inhibiting NF-κB/NLRP3 activation by the AMPK/SIRT1 pathway and modulating the JAK2-STAT3 and Nrf2 signaling pathways. In summary, the present study provided experimental evidence that STR is an ideal candidate for the treatment of hyperuricemia-mediated renal inflammation. PRACTICAL APPLICATIONS: The higher uric acid results in hyperuricemia and gout. The available options for the treatment of hyperuricemia and gout are the use of allopurinol, and colchicine drugs, etc. These drugs possess several undesirable side effect. The polyphenolic compounds are abundantly present in plants, for example, stevia residue extract (STR) exert a positive effect on human health. From this study results, we can recommend that polyphenolic compounds enrich STR could be applied to develop treatment options for the treatment of hyperuricemia and gout.

Potential of Diterpenes as Antidiabetic Agents: Evidence from Clinical and Pre-Clinical Studies

Diterpenes are a diverse group of structurally complex natural products with a wide spectrum of biological activities, including antidiabetic potential. In the last 25 years, numerous diterpenes have been investigated for antidiabetic activity, with some of them reaching the stage of clinical trials. However, these studies have not been comprehensively reviewed in any previous publication. Herein, we critically discussed the literature on the potential of diterpenes as antidiabetic agents, published from 1995 to September, 2021. In the period under review, 427 diterpenes were reported to have varying degrees of antidiabetic activity. Steviol glycosides, stevioside (1) and rebaudioside A (2), were the most investigated diterpenes with promising antidiabetic property using in vitro and in vivo models, as well as human subjects. All the tested pimaranes consistently showed good activity in preclinical evaluations against diabetes. Inhibitions of α-glucosidase and protein tyrosine phosphatase 1B (PTP 1B) activities and peroxisome proliferator-activated receptors gamma (PPAR-γ) agonistic property, were the most frequently used assays for studying the antidiabetic activity of diterpenes. The molecular mechanisms of action of the diterpenes include increased GLUT4 translocation, and activation of phosphoinositide 3-kinase (PI3K) and AMP-activated protein kinase (AMPK)-dependent signaling pathways. Our data revealed that diterpenes hold promising antidiabetic potential. Stevioside (1) and rebaudioside A (2) are the only diterpenes that were advanced to the clinical trial stage of the drug discovery pipeline. Diterpenes belonging to the abietane, labdane, pimarane and kaurane class have shown promising activity in in vitro and in vivo models of diabetes and should be further investigated.

Effect of Cocoa Bean Shell Addition on Metabolite Profile and Antioxidant Activity of Herbal Infusions

Cocoa bean shell (CBS) is a by-product with aromatic characteristics that can enhance the aroma and bioactivity of herbal infusions. This study was aimed to determine the effect of the addition of cocoa bean shell on the metabolite profile and antioxidant activity of infusions made with Ilex guayusa and Vernonanthura patens and their mixtures. Metabolite profile was analyzed by gas chromatography–mass spectrometry combined with multivariate analysis. Total polyphenol content and flavonoids were determined by the Folin-Ciocalteu method and by the flavonoid-AlCl3 complex, respectively. Antioxidant activities were measured by the decolorization assay of the 2,2-diphenyl-1-picrylhydrazyl radical and the ferric reducing antioxidant power. The results revealed that the addition of CBS increases the content of phenolic acids in the infusions (caffeic acid, 4-hydroxybenzoic acid, and pyrocatechol). Nonetheless, the antioxidant activity of the infusions decreased with the addition of CBS (16.21 to 2.74 TEAC). Carboxylic acids and derivatives, major compounds present in the infusions prepared with V. patens, were the metabolites that showed the highest correlation with the antioxidant activity. This study suggests that the infusions made with CBS present a profile of metabolites different from the infusions of I. guayusa, V. patens, and their mixtures.

Diabetes and plant-derived natural products: From ethnopharmacological approaches to their potential for modern drug discovery and development

Diabetes is a disease of serious concern faced by the health care industry today. Primary diabetes mellitus and its complications are still costly to manage with modern drugs. Extensive research on the screening of anti-diabetic agents in past decades established natural products as one of the major potential sources of drug discovery. However, only a few drugs of plant origin have been scientifically validated. Therefore, the development of new anti-diabetic drugs is of great demand. Hence, natural products could be explored as potential anti-diabetic drugs. Natural plants derived extracts and molecules like berberine, ginsenosides, curcumin, stevioside, gingerols, capsaicin, catechins, simple phenolic compounds, anthocyanins, resveratrol, genistein and hesperidin obtained from different species are used for curing diabetes and found to possess different action mechanisms. In this review, the importance of medicinal plants and their active constituents for anti-diabetic agents are described. The present study also emphasized the importance of diabetes control, reduction in its complications and use of the anti-diabetic agents. The detailed action mechanism of these extracts/compounds for their activities are also described. However, the anti-diabetic drugs from plant origin require scientific validation through animal and clinical studies to exploit in terms of modern commercial medicines.

An aqueous extract of Stevia rebaudiana variety Morita II prevents liver damage in a rat model of cirrhosis that mimics the human disease

INTRODUCTION AND AIM

Stevia has exhibited antioxidant, antihyperglycemic, antihypertensive and anti-inflammatory properties in several in vivo and in vitro models. The objective of this study was to investigate the ability of an aqueous extract of stevia (AES) to prevent experimental cirrhosis in rats and to explore its mechanism of action.

MATERIALS AND METHODS

Liver cirrhosis was induced by administering carbon tetrachloride (CCl₄) (400mg/kg by i.p. injection 3 times a week for 12 weeks); AES was administered (100mg/kg by gavage daily) during the CCl₄ treatment. Fibrosis was evaluated with histological, biochemical and molecular approaches, and liver damage was assessed with standardized procedures. The profibrotic pathways were analyzed by western blotting, qRT-PCR and immunohistochemistry.

RESULTS AND CONCLUSIONS

Chronic CCl₄ administration increased nuclear factor kappa B (NF-κB) and proinflammatory cytokine production as well as oxidative parameters such as lipid peroxidation and 4-hydroxynonenal levels, whereas GSH and nuclear factor-E2-related factor 2 (Nrf2) levels were decreased. CCl₄ induced profibrogenic mediator expression, hepatic stellate cell (HSC) activation and, consequently, extracellular matrix production. AES exhibited antioxidant, anti-inflammatory and antifibrotic properties, probably because of its capacity to induce Nrf2 expression, reduce NF-κB expression and block several profibrogenic signaling pathways, subsequently inhibiting HSC activation and preventing fibrosis induced by chronic CCl₄ administration.

Stevia residue extract increases intestinal uric acid excretion via interactions with intestinal urate transporters in hyperuricemic mice

The supplementation of STVRE significantly attenuated hyperuricemia and oxidative stress, upregulated ABCG2 and downregulated GLUT9 (protein and mRNA) expression in hyperuricemic mice.

Effect of Incorporating Stevia and Moringa in Cookies on Postprandial Glycemia, Appetite, Palatability, and Gastrointestinal Well-Being

BACKGROUND

Medicinal plants including stevia and moringa constitute an important source of health-beneficial bioactive components, and hence their intake may beneficially modulate biomarkers of chronic diseases.

OBJECTIVE

The objective of the present study was to investigate the effect of incorporating stevia and moringa leaf powder in cookies on postprandial glycemia, appetite, palatability, and gastrointestinal well-being in humans.

METHOD

In a randomized crossover design, 20 healthy subjects consumed 3 isocaloric test foods (each providing 50 g available carbohydrates) of control cookies (CC) made from 100% wheat flour, cookies containing stevia leaf powder (SC, 3% w/w), and cookies containing moringa leaf powder (MC, 5% w/w) as breakfast. Blood glucose and subjective appetite were measured at fasting and at 15, 30, 45, 60, 90, and 120 min after the consumption of the cookies. Palatability and gastrointestinal well-being were measured using standard questionnaires.

RESULTS

Compared to CC, MC resulted in a significant decrease in postprandial blood glucose concentration at 30 and 45 min (p = 0.002 and p = 0.003, respectively) and showed a tendency (p = 0.077) for lower blood glucose incremental area under the curve (iAUC). Subjects were significantly less hungry after SC and MC intake (p = 0.035 and p = 0.041, respectively) compared to CC. All the cookies were liked by the subjects without any reported gastrointestinal discomfort.

CONCLUSION

The results showed that compared to CC, MC improved postprandial glycemia and reduced hunger, while SC reduced hunger only. Future studies are now warranted to explore the mechanisms responsible for these observed effects.

Stevia rebaudiana Bertoni: A Natural Alternative for Treating Diseases Associated with Metabolic Syndrome

Stevia rebaudiana (SR) is often used by the food industry due to its steviol glycoside content, which is a suitable calorie-free sweetener. Further, both in vitro and in vivo studies indicate that these glycosides and the extracts from SR have pharmacological and therapeutic properties, including antioxidant, antimicrobial, antihypertensive, antidiabetic, and anticancer. This work reviews the antiobesity, antihyperglycemic, antihypertensive, and antihyperlipidemic effects of the majority of glycosides and aqueous/alcoholic extracts from the leaves, flowers, and roots of the SR. These compounds can serve as a natural and alternative treatment for diseases that are associated with metabolic syndrome, thus contributing to health promotion.

Antihyperglycemic and Antihyperlipidemic Activity of Hydroponic Stevia rebaudiana Aqueous Extract in Hyperglycemia Induced by Immobilization Stress in Rabbits

Diabetes mellitus (DM) is a serious worldwide problem related to human hyperglycemia. Thus, herbal preparations with antihyperglycemic properties especially leaf extracts of hydroponic Stevia rebaudiana (SR) would be useful in hyperglycemia treatment. The antihyperglycemic potential of this medicinal plant grown using hydroponics methods has been evaluated. Significant reduction of some biochemical characteristics for sugars and fatty acids in blood, liver, and muscle especially fasting glucose levels, serum triglycerides, LDL-cholesterol, total cholesterol levels, and increased HDL-cholesterol ones was shown with SR aqueous extract treatment. Therefore, the aqueous extract of SR is suggested to have antihyperglycemic and antihyperlipidemic activity and to restore liver and muscle glycogen levels (hepatoprotective effects) in hyperglycemia induced by immobilization stress in rabbits and might be recommended for treatment of DM (hyperglycemia).

Citrus junos Tanaka Peel Extract Exerts Antidiabetic Effects via AMPK and PPAR-γ both In Vitro and In Vivo in Mice Fed a High-Fat Diet

The antidiabetic effect of the Citrus junos Tanaka (also known as yuja or yuzu) was examined. Ethanol extract of yuja peel (YPEE) significantly stimulated 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-D-glucose (2-NBDG) uptake in C2C12 myotubes. However, ethanol extract of yuja pulp (YpEE) and water extract of yuja peel (YPWE) or pulp (YpWE) did not stimulate glucose uptake. In addition, peroxisome proliferator-activated receptor gamma (PPAR-γ) and AMP-activated protein kinase (AMPK) activities were increased by YPEE in a dose-dependent manner. Pretreatment of AMPK inhibitor decreased the glucose uptake stimulated by YPEE in C2C12 myotubes. We confirmed the anti-diabetic effect of YPEE in mice fed a high fat-diet (HFD). Compared with control mice on a normal diet (ND), these mice showed increased body weight, liver fat, insulin resistance, triacylglycerol (TG), and total cholesterol content. Addition of 5% YPEE significantly reduced the weight gain and rise in liver fat content, serum triacylglycerol (TG), total cholesterol, and insulin resistance found in mice fed a high-fat diet (HFD). Moreover, YPEE reduced the secretion of HFD-induced adipocytokines such as leptin and resistin. YPEE also resulted in increased phosphorylation of AMPK in muscle tissues. These results suggest that ethanol extract of yuja peel exerts anti-diabetic effects via AMPK and PPAR-γ in both cell culture and mouse models.

Steviol glycosides from Stevia: biosynthesis pathway review and their application in foods and medicine

Stevia rebaudiana, a perennial herb from the Asteraceae family, is known to the scientific world for its sweetness and steviol glycosides (SGs). SGs are the secondary metabolites responsible for the sweetness of Stevia. They are synthesized by SG biosynthesis pathway operating in the leaves. Most of the genes encoding the enzymes of this pathway have been cloned and characterized from Stevia. Out of various SGs, stevioside and rebaudioside A are the major metabolites. SGs including stevioside have also been synthesized by enzymes and microbial agents. These are non-mutagenic, non-toxic, antimicrobial, and do not show any remarkable side-effects upon consumption. Stevioside has many medical applications and its role against diabetes is most important. SGs have made Stevia an important part of the medicinal world as well as the food and beverage industry. This article presents an overview on Stevia and the importance of SGs.

A pharmacological appraisal of medicinal plants with antidiabetic potential

Diabetes mellitus is a complicated metabolic disorder that has gravely troubled the human health and quality of life. Conventional agents are being used to control diabetes along with lifestyle management. However, they are not entirely effective and no one has ever been reported to have fully recovered from diabetes. Numerous medicinal plants have been used for the management of diabetes mellitus in various traditional systems of medicine worldwide as they are a great source of biological constituents and many of them are known to be effective against diabetes. Medicinal plants with antihyperglycemic activities are being more desired, owing to lesser side-effects and low cost. This review focuses on the various plants that have been reported to be effective in diabetes. A record of various medicinal plants with their established antidiabetic and other health benefits has been reported. These include Allium sativa, Eugenia jambolana, Panax ginseng, Gymnema sylvestre, Momrodica charantia, Ocimum sanctum, Phyllanthus amarus, Pterocarpus marsupium, Trigonella foenum graecum and Tinospora cordifolia. All of them have shown a certain degree of antidiabetic activity by different mechanisms of action.

Hypoglycaemic action of stevioside and а barley and brewer's yeast based preparation in the experimental model on mice

The aim of this study was to investigate influence of the preparation based on barley and brewer's yeast extracts with chromium (BBCr) and stevioside (S) on fasting glycaemia and glycaemia in mice after glucose, adrenalin and alloxan application. The animals were divided into three groups: glucose 500 mgkg(-1) (I); adrenalin 0.2 mgkg(-1)(II) and alloxan 100 mg kg(-1) (III) and into subgroups according to the substance they received: stevioside 20 mg kg(-1) (I-S, II-S, III-S); BBCr 750 mg kg(-1)(I-BBCr, II-BBCr, III-BBCr) and saline 1 ml/100g (III-placebo). Glycaemia was measured before and after 7-day treatment with stevioside or BBCr in the following conditions: fasting, 30 min after glucose load (I) or 45 min after adrenaline load (II). In group III glycaemia was measured before and after 12-day treatment with S, BBCr or placebo and alloxan application (7th, 8th and 10th days of treatment ). BBCr significantly reduced fasting glycaemia in I and II groups and glycaemia values after the glucose load (I-BBCr: 9.20 ± 0.61 vs. 7.42 ± 0.59 mmol/L, p = 0.01). Stevioside significantly reduced glycaemia after the adrenalin load (II-S: 13.45 ± 0.71 vs. 11.65 ± 1.19 mmol/L; p = 0.03). In the III-BBCr glycaemia values did not indicate the development of alloxan-induced diabetes and were significantly lower than in the III-placebo (8.6 ± 3.16 vs. 18.8 ± 5.53 mmol/L; p < 0.05). In conclusion, BBCr caused a significant decrease of fasting glycaemia, significant reduction of glycaemia after glucose load and prevented onset of alloxan-induced diabetes. Stevioside caused the decrease of adrenalin-induced hyperglycaemia.

Advances in the treatment of type 2 diabetes mellitus

There is a rising worldwide prevalence of diabetes, especially type 2 diabetes mellitus (T2DM), which is one of the most challenging health problems in the 21st century. The associated complications of diabetes, such as cardiovascular disease, peripheral vascular disease, stroke, diabetic neuropathy, amputations, renal failure, and blindness result in increasing disability, reduced life expectancy, and enormous health costs. T2DM is a polygenic disease characterized by multiple defects in insulin action in tissues and defects in pancreatic insulin secretion, which eventually leads to loss of pancreatic insulin-secreting cells. The treatment goals for T2DM patients are effective control of blood glucose, blood pressure, and lipids (if elevated) and, ultimately, to avert the serious complications associated with sustained tissue exposure to excessively high glucose concentrations. Prevention and control of diabetes with diet, weight control, and physical activity has been difficult. Treatment of T2DM has centered on increasing insulin levels, either by direct insulin administration or oral agents that promote insulin secretion, improving sensitivity to insulin in tissues, or reducing the rate of carbohydrate absorption from the gastrointestinal tract. This review presents comprehensive and up-to-date information on the mechanism(s) of action, efficacy, pharmacokinetics, pleiotropic effects, drug interactions, and adverse effects of the newer antidiabetic drugs, including (1) peroxisome proliferator-activated-receptor-γ agonists (thiazolidinediones, pioglitazone, and rosiglitazone); (2) the incretin, glucagon-like peptide-) receptor agonists (incretin-mimetics, exenatide. and liraglutide), (3) inhibitors of dipeptidyl-peptidase-4 (incretin enhancers, sitagliptin, and vildagliptin), (4) short-acting, nonsulfonylurea secretagogue, meglitinides (repaglinide and nateglinide), (5) amylin anlog-pramlintide, (6) α-glucosidase inhibitors (miglitol and voglibose), and (7) colesevelam (a bile acid sequestrant). In addition, information is presented on drug candidates in clinical trials, experimental compounds, and some plants used in the traditional treatment of diabetes based on experimental evidence. In the opinion of this reviewer, therapy based on orally active incretins and incretin mimetics with long duration of action that will be efficacious, preserve the β-cell number/function, and block the progression of diabetes will be highly desirable. However, major changes in lifestyle factors such as diet and, especially, exercise will also be needed if the growing burden of diabetes is to be contained.

Antidiabetic activity of medium-polar extract from the leaves of Stevia rebaudiana Bert. (Bertoni) on alloxan-induced diabetic rats

OBJECTIVE

To investigate the medicative effects of medium-polar (benzene:acetone, 1:1, v/v) extract of leaves from Stevia rebaudiana (family Asteraceae) on alloxan-induced diabetic rats.

MATERIALS AND METHODS

Diabetes was induced in adult albino Wistar rats by intraperitoneal (i.p.) injection of alloxan (180 mg/kg). Medium-polar extract was administered orally at daily dose of 200 and 400 mg/kg body wt. basis for 10 days. The control group received normal saline (0.9%) for the same duration. Glibenclamide was used as positive control reference drug against Stevia extract.

RESULTS

Medium-polar leaf extract of S. rebaudiana (200 and 400 mg/kg) produced a delayed but significant (P < 0.01) decrease in the blood glucose level, without producing condition of hypoglycemia after treatment, together with lesser loss in the body weight as compared with standard positive control drug glibenclamide.

CONCLUSIONS

Treatment of diabetes with sulfonylurea drugs (glibenclamide) causes hypoglycemia followed by greater reduction in body weight, which are the most worrisome effects of these drugs. Stevia extract was found to antagonize the necrotic action of alloxan and thus had a re-vitalizing effect on β-cells of pancreas.

Effect of moderate intake of sweeteners on metabolic health in the rat

The rise in prevalence of obesity, diabetes, metabolic syndrome, and fatty liver disease has been linked to increased consumption of fructose-containing foods or beverages. Our aim was to compare the effects of moderate consumption of fructose-containing and non-caloric sweetened beverages on feeding behavior, metabolic and serum lipid profiles, and hepatic histology and serum liver enzymes, in rats. Behavioral tests determined preferred (12.5-15%) concentrations of solutions of agave, fructose, high fructose corn syrup (HFCS), a combination of HFCS and Hoodia (a putative appetite suppressant), or the non-caloric sweetener Stevia (n=5/gp). HFCS intake was highest, in preference and self-administration tests. Groups (n=10/gp) were then assigned to one of the sweetened beverages or water as the sole source of liquid at night (3 nights/wk, 10wks). Although within the normal range, serum cholesterol was higher in the fructose and HFCS groups, and serum triglycerides were higher in the Agave, HFCS, and HFCS/Hoodia groups (vs. water-controls, p<0.05). Liver histology was normal in all groups with no evidence of steatosis, inflammation, or fibrosis; however serum alanine aminotransferase was higher in the fructose and HFCS groups (vs. water-controls, p<0.05). Serum inflammatory marker levels were comparable among Stevia, agave, fructose, HFCS, and water-consuming groups, however levels of IL-6 were significantly lower in association with the ingestion of Hoodia. There were no differences in terminal body weights, or glucose tolerance assessed by 120-min IVGTTs performed at the end of the 10-week regimen. We conclude that even moderate consumption of fructose-containing liquids may lead to the onset of unfavorable changes in the plasma lipid profile and one marker of liver health, independent of significant effects of sweetener consumption on body weight.

Stevioside and related compounds: therapeutic benefits beyond sweetness

Stevioside, an abundant component of Stevia rebaudiana leaf, has become well-known for its intense sweetness (250-300 times sweeter than sucrose) and is used as a non-caloric sweetener in several countries. A number of studies have suggested that, beside sweetness, stevioside along with related compounds, which include rebaudioside A (second most abundant component of S. rebaudiana leaf), steviol and isosteviol (metabolic components of stevioside) may also offer therapeutic benefits, as they have anti-hyperglycemic, anti-hypertensive, anti-inflammatory, anti-tumor, anti-diarrheal, diuretic, and immunomodulatory actions. It is of interest to note that their effects on plasma glucose level and blood pressure are only observed when these parameters are higher than normal. As steviol can interact with drug transporters, its role as a drug modulator is proposed. This review summarizes the current knowledge of the pharmacological actions, therapeutic applications, pharmacokinetics and safety of stevioside and related compounds. Although much progress has been made concerning their biological and pharmacological effects, questions regarding chemical purity and safety remain unsolved. These issues are discussed to help guide future research directions.