Hibiscus tea
May 14 2016

Hibiscus sabdariffa is commonly known as roselle or hibiscus. Roselle grows native from India to Malaysia, but is now found in many parts of the world. There are more than 300 species of hibiscus, growing in both tropical and subtropical regions. The swollen red calyces of hibiscus are dried and exported to Europe, Australia and the United States, where they are used for culinary and medicinal purposes.

You can buy hibiscus tea and sweeten it with stevia for a delicious tea anytime of day.

Medical uses
Traditionally, hibiscus has been used for the following conditions: abscesses, antiseptic, antispasmodic, astringent, bilious conditions, cancer, cough, digestive problems, diuretic, dyspepsia, fever, hangover, heart ailments, hypertension, liver diseases, neurosis, scurvy, and as a sedative.

Cancer prevention
Ceska Slov Farm. 2016. Antimicrobial, antiparasitic and anticancer properties of Hibiscus sabdariffa and its phytochemicals: in vitro and in vivo studies. In the last few decades, Hibiscus sabdariffa L. (Malvaceae; H. sabdariffa) has gained much attention in research field because of its potentially useful bioactivity as well as a great safety and tolerability. For decades, microbial, parasitic and cancer diseases remain a serious threat to human health and animals as well. To treat such diseases, a search for new sources such as plants that provide various bioactive compounds useful in the treatment of several physiological conditions is urgently needed, since most of the drugs currently used in the therapy have several undesirable side effects, toxicity, and drug resistance. In this paper, we aim to present an updated overview of in vitro and in vivo studies that show the significant therapeutic properties of the crude extracts and phytochemicals derived from H. sabdariffa as antimicrobial, antiparasitic, and anticancer agents.

H. Pylori infection
Pharm Biol. 2016. In vitro synergistic effect of Hibiscus sabdariffa aqueous extract in combination with standard antibiotics against Helicobacter pylori clinical isolates. The increasing problem of drug-resistant strains has led to the failure of current treatment regimens of Helicobacter pylori (HP) infection. Recently, a new treatment strategy has been developed to overcome the problem by using natural products in combination with antibiotics to enhance the treatment efficacy. Objective The antimicrobial combinatory effect of the aqueous extract of Hibiscus sabdariffa (AEHS) with antibiotics (clarithromycin, CLA; amoxicillin, AMX; metronidazole, MTZ) has been evaluated in vitro against HP strains. This study presents AEHS as a potent therapeutic candidate alone, or in combination with antibiotics for the treatment of HP infection.

Role in hypertension
Drinking hibiscus tea may reduce blood pressure and offer cardiovascular benefits for people at risk of developing hypertension. Researchers recruited 65 adults with pre- and mild hypertension between the ages of 30 and 70 years to participate in their randomized, double-blind, placebo-controlled clinical trial. The participants were assigned to consume either three servings of brewed hibiscus tea per day or a placebo drink for six weeks. The results revealed that those in the hibiscus tea group displayed an average reduction of 7 mm Hg in their systolic blood pressure, compared to 1 mm Hg in the placebo group. There was also a small, but not significant decrease in diastolic blood pressure in the hibiscus tea group. These findings suggest that regularly incorporating 3 servings per day of hibiscus tea into the diet, effectively reduces blood pressure in pre- and mildly hypertensive adults. McKay DL, Chen CY, Saltzman E. Hibiscus sabdariffa tea (tisane) lowers blood pressure in prehypertensive and mildly hypertensive adults. J Nutr. 2010.

J Med Food. 2016. Hibiscus Sabdariffa L. Flowers and Olea Europea L. Leaves Extract-Based Formulation for Hypertension Care: In Vitro Efficacy and Toxicological Profile. Olea europaea L. leaves extract (Oe) and Hybiscus sabdariffa L. flowers extract (Hs) have calcium antagonistic properties. Aim of this work was to study the cardiovascular effects of Pres Phytum(), a nutraceutical formulation containing a mixture of the two extracts and the excipients, and investigate its possible off-target effects, using in vitro biological assays on guinea pig isolated organs. Cardiovascular effects were assessed using guinea pig atria and aorta. The effects of Pres Phytum on spontaneous gastrointestinal, urinary, and respiratory tracts smooth muscle contractility were evaluated. Pres Phytum exerted a vasorelaxant effect and a negative chronotropic effect at concentrations lower than those producing smooth muscle spontaneous contractility alterations in the other organs. Compared to Pres Phytum, the mixture did not exert negative inotropic activity, while it maintained a negative chronotropic efficacy. These experimental data suggest a possible nutraceutical use of this food supplement for the management of preclinical hypertension.

Fitoterapia. 2013. Hibiscus sabdariffa in the treatment of hypertension and hyperlipidemia: a comprehensive review of animal and human studies. The effectiveness of Hibiscus sabdariffa L. (HS) in the treatment of risk factors associated with cardiovascular disease is assessed in this review by taking a comprehensive approach to interpreting the randomized clinical trial (RCT) results in the context of the available ethnomedical, phytochemical, pharmacological, and safety and toxicity information. HS decoctions and infusions of calyxes, and on occasion leaves, are used in at least 10 countries worldwide in the treatment of hypertension and hyperlipidemia with no reported adverse events or side effects. HS extracts have a low degree of toxicity with a LD50 ranging from 2,000 to over 5,000mg/kg/day. There is no evidence of hepatic or renal toxicity as the result of HS extract consumption, except for possible adverse hepatic effects at high doses. There is evidence that HS acts as a diuretic, however in most cases the extract did not significantly influence electrolyte levels. Animal studies have consistently shown that consumption of HS extract reduces blood pressure in a dose dependent manner. In RCTs, the daily consumption of a tea or extract produced from HS calyxes significantly lowered systolic blood pressure (SBP) and diastolic blood pressure (DBP) in adults with pre to moderate essential hypertension and type 2 diabetes. In addition, HS tea was as effective at lowering blood pressure as the commonly used blood pressure medication Captropril, but less effective than Lisinopril. Total cholesterol, low-density lipoprotein cholesterol (LDL-C), and triglycerides were lowered in the majority of normolipidemic, hyperlipidemic, and diabetic animal models, whereas high-density lipoprotein cholesterol (HDL-C) was generally not affected by the consumption of HS extract. Over half of the RCTs showed that daily consumption of HS tea or extracts had favorable influence on lipid profiles including reduced total cholesterol, LDL-C, triglycerides, as well as increased HDL-C. Anthocyanins found in abundance in HS calyxes are generally considered the phytochemicals responsible for the antihypertensive and hypocholesterolemic effects, however evidence has also been provided for the role of polyphenols and hibiscus acid. A number of potential mechanisms have been proposed to explain the hypotensive and anticholesterol effects, but the most common explanation is the antioxidant effects of the anthocyanins inhibition of LDL-C oxidation, which impedes atherosclerosis, an important cardiovascular risk factor. This comprehensive body of evidence suggests that extracts of HS are promising as a treatment of hypertension and hyperlipidemia.

Indian J Pharmacol. 2015. Effects of aqueous extract of Hibiscus sabdariffa on the renin-angiotensin-aldosterone system of Nigerians with mild to moderate essential hypertension: A comparative study with lisinopril. The present study investigated the effects of aqueous extract of Hibiscus sabdariffa on the three basic components of renin-angiotensin-aldosterone system: Plasma renin, serum angiotensin-converting enzyme (ACE), and plasma aldosterone (PA) in mild to moderate essential hypertensive Nigerians and compared with that of lisinopril, an ACE inhibitor. HS reduced serum ACE and PA in mild to moderate hypertensive Nigerians with equal efficacy as lisinopril. These actions are possibly due to the presence of anthocyanins in the extract.

Metabolic syndrome X
J Complement Integr Med. 2016. Evaluation of the effects of roselle Hibiscus sabdariffa on oxidative stress and serum levels of lipids, insulin and hs-CRP in adult patients with metabolic syndrome: a double-blind placebo-controlled clinical trial. Roselle (Hibiscus sabdariffa) is a plant with antihyperlipidemic and antihypertensive effects. This study aimed to evaluate the effects of roselle calyces on the serum levels of lipids and insulin, inflammation, and oxidative stress in patients with metabolic syndrome (MetS). Forty adult patients with MetS were randomly assigned to receive either 500 mg of H. sabdariffa calyx powder or placebo once daily for 4 weeks. Systolic and diastolic blood pressures (SBP and DBP) and BMI (body mass index) as well as fasting serum levels of glucose (FPG; fasting plasma glucose), insulin, lipoproteins, triglycerides (TG), high-sensitivity C-reactive protein (hs-CRP), and malondialdehyde (MDA) were determined pre- and post-intervention and compared. Daily consumption of 500 mg of H. sabdariffa calyx powder can decrease SBP and serum TG in MetS patients.

Virus protection
Food Environ Virol. 2016. Aqueous Extracts of Hibiscus sabdariffa Calyces to Control Aichi Virus. Aqueous Hibiscus sabdariffa extracts possess antimicrobial properties with limited information available on their antiviral effects. Aichi virus (AiV) is an emerging foodborne pathogen that causes gastroenteritis.

Food Chem. 2014. Vitiquinolone--a quinolone alkaloid from Hibiscus vitifolius.