rebaudioside-a and Hypertension

Stevia rebaudiana Bertoni is a sweet and nutrient-rich plant belonging to the Asteraceae family. Stevia leaves contain steviol glycosides including stevioside, rebaudioside (A to F), steviolbioside, and isosteviol, which are responsible for the plant's sweet taste, and have commercial value all over the world as a sugar substitute in foods, beverages and medicines. Among the various steviol glycosides, stevioside, rebaudioside A and rebaudioside C are the major metabolites and these compounds are on average 250-300 times sweeter than sucrose. Steviol is the final product of Stevia metabolism. The metabolized components essentially leave the body and there is no accumulation. Beyond their value as sweeteners, Stevia and its glycosdies possess therapeutic effects against several diseases such as cancer, diabetes mellitus, hypertension, inflammation, cystic fibrosis, obesity and tooth decay. Studies have shown that steviol glycosides found in Stevia are not teratogenic, mutagenic or carcinogenic and cause no acute and subacute toxicity. The present review provides a summary on the biological and pharmacological properties of steviol glycosides that might be relevant for the treatment of human diseases.

Topics: Cystic Fibrosis; Dental Caries; Diabetes Mellitus; Diterpenes, Kaurane; Glycosides; Humans; Hypertension; Inflammation; Neoplasms; Obesity; Plant Extracts; Stevia

Many different dietary supplements are currently marketed for the management of hypertension and diabetes, but the evidence for effectiveness is mixed. The objective of this systematic review was to critically appraise and evaluate the evidence for effectiveness of steviol glycosides (stevioside and rebaudioside A) on cardiovascular risk factors, using data from randomised clinical trials (RCTs).. Electronic searches were conducted in Medline, Embase, Amed, Cinahl and The Cochrane Library. We also searched Google Scholar, and hand searched the bibliography of retrieved full texts. The reporting quality of included studies was assessed using the Cochrane criteria. Two reviewers independently determined the eligibility, assessed the reporting quality, and extracted the data.. Nine studies with a total of 756 participants were included. There was a variation in the reporting quality of included studies. Meta-analysis revealed a non-significant difference in systolic blood pressure between steviol glycoside and placebo, mean difference (MD): -2.98 mm Hg (-6.23 to 0.27). Significant reductions in diastolic blood pressure and fasting blood glucose were observed. There was no significant effect on blood lipid profile. Heterogeneity was significant. Adverse events included abdominal fullness, epigastric pain, and dizziness.. The evidence from published RCTs suggests that stevioside may generate reductions in blood pressure and fasting blood glucose. The sizes of the effects are small, and the substantial heterogeneity limits the robustness of any conclusions. Rebaudioside A does not appear to have any significant effects on blood pressure or cardiovascular risk factors. Available clinical trials vary in design and reporting quality, and some are characterised by inadequate sample sizes. In addition, the participants in most of the trials have high cardiovascular risk. Further clinical trials and regulatory assessments are warranted.

Topics: Blood Glucose; Blood Pressure; Cardiovascular Diseases; Chi-Square Distribution; Diabetes Mellitus; Dietary Supplements; Diterpenes, Kaurane; Glucosides; Humans; Hypertension; Protective Factors; Randomized Controlled Trials as Topic; Risk Assessment; Risk Factors; Sweetening Agents

The objective of this study was to evaluate the scientific evidence on stevia, including expert opinion, folkloric precedent, history, pharmacology, kinetics/dynamics, interactions, adverse effects, toxicology, and dosing. This review serves as a clinical support tool. Electronic searches were conducted in 10 databases, 20 additional journals (not indexed in common databases), and bibliographies from 50 selected secondary references. No restrictions were placed on the language or quality of the publications. All literature collected pertained to efficacy in humans, dosing, precautions, adverse effects, use in pregnancy and lactation, interactions, alteration of laboratory assays, and mechanisms of action. Standardized inclusion and exclusion criteria were used for selection. Grades were assigned using an evidence-based grading rationale. Based on the availability of scientific data, two indications are discussed in this review: hypertension and hyperglycemia. Evaluation of two long-term studies (1 and 2 years in length, respectively) indicates that stevia may be effective in lowering blood pressure in hypertensive patients, although data from shorter studies (1-3 months) did not support these findings. A pair of small studies also report positive results with respect to glucose tolerance and response, although the relatively low methodological rigor of these experiments limits the strength of these findings. Further investigation is warranted in both indications.

Topics: Animals; Blood Pressure; Drug Interactions; Evidence-Based Medicine; Humans; Hypertension; Phytotherapy; Plant Extracts; Plant Preparations; Stevia; Sweetening Agents

The antihypertensive effect of crude stevioside obtained from the leaves of Stevia rebaudiana (Bertoni) Bertoni (Compositae) on previously untreated mild hypertensive patients was examined. Patients with essential hypertension were submitted to a placebo phase for 4 weeks. The volunteers selected in this phase were randomly assigned to receive either capsules containing placebo during 24 weeks or crude stevioside 3.75 mg/kg/day (7 weeks), 7.5 mg/kg/day (11 weeks) and 15.0 mg/kg/day (6 weeks). All capsules were prescribed twice a daily (b.i.d.), i.e. before lunch and before dinner. After the placebo phase and after each dose of crude stevioside, body mass index, electrocardiogram and laboratory tests were performed. During the investigation blood pressure (BP) was measured biweekly and the remaining data were collected at the end of each stevioside dose step. All adverse events were prospectively recorded but no major adverse clinical effects were observed during the trial. Systolic and diastolic BP decreased (p < 0.05) during the treatment with crude stevioside, but a similar effect was observed in the placebo group. Therefore, crude stevioside up to 15.0 mg/kg/day did not show an antihypertensive effect. Moreover, the results suggest that oral crude stevioside is safe and supports the well-established tolerability during long term use as a sweetener in Brazil.

Topics: Adult; Antihypertensive Agents; Diterpenes, Kaurane; Double-Blind Method; Female; Glucosides; Humans; Hypertension; Male; Middle Aged; Phytotherapy; Prospective Studies; Stevia

The objective of this in vivo study is to evaluate in five rat models the pharmacologic effects and toxicity of a commercial hydro-alcoholic extract, GlucoMedix®, derived from Stevia rebaudiana and the pentacyclic chemotype of Uncaria Tomentosa (Willd.) DC, for use as a treatment for metabolic syndrome. The extract contains phytochemicals of Stevia (e.g., steviol glycosides) and Uncaria (e.g., pentacyclic oxindole alkaloids, but lacks tetracyclic oxindole alkaloids).. The pharmacologic assessments in three rat models include reductions in chemically induced hyperglycemia, hyperlipidemia (cholesterol and triglycerides), and hypertension, all of which are comorbidities of metabolic syndrome. Acute toxicity and 28-day subacute toxicity were assessed in rat models at doses higher than those used in the efficacy models.. The five in vivo rat models revealed that the all-natural phytotherapy GlucoMedix® is a safe and effective treatment for hyperglycemia, hyperlipidemia, and hypertension. This extract is expected to affect multiple comorbidities of metabolic syndrome, without any acute or subacute oral toxicity in humans. Although multiple prescription drugs are well known for the treatment of individual comorbidities of metabolic syndrome, no drug monotherapy concurrently treats all three comorbidities.

Topics: Animals; Cat's Claw; Hyperglycemia; Hyperlipidemias; Hypertension; Metabolic Syndrome; Plant Extracts; Rats; Stevia

Introduction: medicinal plants have demonstrated therapeutic applications for treating different diseases, including chronic and degenerative diseases associated with metabolic syndrome. Objectives: to assess the weight control and the antihypertensive, antihyperglycemic and antioxidant effects of aqueous and ethanolic extracts of Stevia rebaudiana (creole variety INIFAP C01) leaves and stems cultivated in the Muna and Mocochá municipalities (Yucatán, México). Methods: aqueous and ethanolic extracts of leaves (HAMU and HEMU, respectively) and stems (TAMU and TEMU, respectively) from Muna, and aqueous and ethanolic extracts of leaves (HAMO and HEMO, respectively) and stems (TAMO and TEMO, respectively) from Mocochá were orally administered to Wistar male rats induced to metabolic syndrome. Weight, blood pressure, blood sugar levels, malondialdehyde (MDA) levels, and superoxide dismutase (SOD) levels in blood plasma were measured. Results: TAMU and HAMO samples reduced weight by 1.91 % and 1.57 %, respectively. On the other hand, HEMU and HAMU samples reduced systolic (PAS) and diastolic (PAD) blood pressure levels by 29.31-30.47 % and 36.69-36.98 %. In the glucose tolerance test (GTT) HEMU showed a reduction in blood sugar levels of 10.94 % on the first day, and of 14.83 % on day 30. TEMO and TAMO samples showed lower malondialdehyde (MDA) concentrations of 7.0 and 7.3 µM, respectively. HEMU and TEMU showed a higher superoxide dismutase (SOD) concentration of 1.29 and 1.12 U/mL, respectively. Conclusions: extracts of S. rebaudiana can help to control weight gain, to decrease blood pressure and the incidence of diabetes, and to reduce oxidative damage.. Introducción: las plantas medicinales han mostrado tener aplicaciones terapéuticas en el tratamiento de diferentes enfermedades, entre ellas las enfermedades crónicas degenerativas presentes en el síndrome metabólico (SM). Objetivos: evaluar el efecto en el control del peso, así como el efecto antihipertensivo, antihiperglucémico y antioxidante, de extractos acuosos y etanólicos de hojas y tallos de Stevia rebaudiana, variedad criolla INIFAP C01, producidas en los municipios de Muna y Mocochá (Yucatán, México). Métodos: se administraron por vía oral extractos acuosos y etanólicos de hojas (HAMU y HEMU, respectivamente) y tallos procedentes de Muna (TAMU y TEMU, respectivamente), así como extractos acuosos y etanólicos de hojas (HAMO y HEMO, respectivamente) y tallos de Mocochá (TAMO y TEMO, respectivamente), a ratas Wistar macho en las que se indujo un SM. Se registraron los pesos y se midieron los niveles de presión arterial (PA) y glucosa en sangre, así como los niveles de malondialdehído (MDA) y superóxido-dismutasa (SOD) en plasma sanguíneo. Resultados: TAMU y HAMO mostraron porcentajes de reducción del peso del 1,91 % y 1,57 %, respectivamente. HEMU y HAMU mostraron porcentajes de reducción de la presión arterial sistólica (PAS) y diastólica (PAD) del 30,47-29,31 % y 36,98-36,69 %, respectivamente. En el test de tolerancia oral a la glucosa (TTOG), HEMU mostró porcentajes de reducción de la glucosa sanguínea del 10,94 % en el día uno y del 14,83 % en el día 30. TEMO y TAMO mostraron una menor concentración de MDA, de 7,0 y 7,3 µM, respectivamente, y HEMU y TEMU mostraron una mayor concentración de SOD, de 1,29 y 1,12 U/mL, respectivamente. Conclusiones: los extractos de S. rebaudiana pueden ayudar a controlar el aumento de peso, disminuir las cifras de presión arterial y la incidencia de diabetes, y reducir el daño oxidativo.

Topics: Animals; Antioxidants; Hyperglycemia; Hypertension; Male; Metabolic Syndrome; Phytotherapy; Plant Extracts; Rats; Rats, Wistar; Stevia

Efficient treatment of hypertension is vital. The inhibition of angiotensin-converting enzyme activity has been one of the major strategies for treating hypertension. The ethanol extract of stevia leaves, steviol glycosides (with 95% purity; natural sweeteners widely used in the food industry) isolated from the ethanol extract and stevia leaf protein hydrolysates inhibited 26.60%, 59.56% and 74.38% of angiotensin-converting enzyme activities, respectively. Their effect was dose-dependent, which can be beneficial for avoiding hypertension or hypotension just by the proper control of the amount of their intake, and it was found to be superior to that of pharmaceutical drugs. A sensory test indicated that the application of the mixtures of steviol glycosides and stevia protein hydrolysates to decaffeinated coffee or tea as well as a formulated peanut protein drink was found to be well accepted, and an animal test showed that they had a significantly antihypertensive effect in spontaneously hypertensive rats. Steviol glycosides and stevia leaf protein hydrolysates can be good ingredients for making functional or healthy food products or beverages targeted for the prevention or treatment of hypertension.

Topics: Animals; Antihypertensive Agents; Diterpenes, Kaurane; Enzyme Inhibitors; Female; Glucosides; Humans; Hypertension; Male; Peptidyl-Dipeptidase A; Plant Extracts; Plant Leaves; Plant Proteins; Protein Hydrolysates; Rats; Rats, Inbred SHR; Stevia; Taste