Tropical jewel hisbiscus

Other Names

Agua de JamaicaBissapBunga rayaBunga sepatuChina roseChinese hibiscusFlor de JamaicaFlorida cranberryGonguraGudhalGuinea sorrelHawaiian hibiscusHibiscus rosa-sinensisHibiscus sabdariffaHibiscus sabdariffa L.Hibiscus sabdariffa var. altissimaHibiscus sabdariffa var. sabdariffaHibiscus tea plantIndian sorrelJamaicaJamaican sorrelKarkadéKarkadeKarkadiKembang sepatuLemon bushNatal roselleQueensland jelly plantRed sorrelRosa de JamaicaRose mallowRoselleRoselle hempSarilSembaruthiShoe flowerShoeblack plantSorrelSour-sourTropical hibiscusZobo

Synopsis

Tropical Jewel Hibiscus (Hibiscus sabdariffa L.): A Comprehensive Reference

1. Identity: Botanical Classification, Names, and Natural Source

Tropical Jewel Hibiscus is a marketing and trade designation applied to Hibiscus sabdariffa L., the species botanically recognized as roselle. Tropical jewel hibiscus (Hibiscus sabdariffa), often referred to as roselle or simply hibiscus, boasts a rich history in traditional medicine spanning continents and cultures. The term "Tropical Jewel Hibiscus" itself appears on supplement product labels and ingredient listings, but it maps directly to the same species covered by the peer-reviewed literature under the names H. sabdariffa and roselle.

H. rosa‐sinensis is an evergreen herbaceous medicinal plant belonging to the Malvaceae family and the Hibiscus genus, which has around 275 species in tropical and subtropical regions of the world. Hibiscus sabdariffa is a distinct species within this same genus and family. Roselle, also known as jamaica (in Spanish), red sorrel (in English), or karkadeh (in Arabic), is a plant named Hibiscus sabdariffa (HS), native to India and Malaysia, and is a tropical species extensively cultivated in tropical and subtropical regions worldwide, including Central and West Africa as well as South‐East Asia.

1.1 Common Names Across Cultures

It goes by various names, such as karkade, bissap, sour tea, and red tea. In North and East Africa it is called "karkade or carcade"; in Senegal it is known as bissap and in Nigeria as serrol; and in Iran it is known as "Chaye-Torosh." In Mexico and much of Latin America, the plant and its preparations are commonly called jamaica.

1.2 Botanical Description

Native to parts of North Africa and Southeast Asia, Hibiscus sabdariffa is a shrubby tropical plant that produces light yellow flowers with reddish-purple centers. After the petals drop from the flower, its remaining deep red calyces (the cup-like structures formed by the sepals) grow into seed-containing pods that look like flower buds. The plant has a distinct appearance, with large, deeply lobed leaves and striking flowers that eventually give way to the red calyces used in a variety of products.

1.3 Plant Parts Used

Most of the hibiscus plant's economic value, particularly as an ingredient in herbal teas, comes from the red calyx, although the leaves, seeds, and flowers are also used in local forms of traditional medicine. In commerce the calyces are known by the names hibiscus and roselle. There is evidence (in Sudan, Malaysia, China, and Africa) that its leaves are ingested raw or cooked, like a vegetable, while the seeds are eaten roasted or ground and used to prepare oils or as a substitute for coffee.

1.4 Common Preparations and Dosage Forms

Preparations obtained from HS calyxes (extracts, infusions, decoction, teas, beverages, capsules, and pills) are used as non-pharmacological therapies to prevent/control diverse chronic non-communicable diseases. Multiple different preparations have been tested in published clinical trials, which can be classified into raw herbs in the form of beverages, e.g. juice or tea (n = 25), standardised or unstandardised extracts (n = 18), and finished product formulations containing herbal raw material (n = 8). Dry hibiscus extracts used in clinical research are mainly prepared from the calyces and are often standardized according to anthocyanin content.

2. Traditional and Historical Use

2.1 Egypt and North Africa

In ancient Egypt, hibiscus tea was consumed as a refreshing beverage believed to lower body temperature, treat heart and nerve diseases, and serve as a mild diuretic. In Egypt and Sudan the deep red tea from the calyces, called karkade, is popular as a "refrigerant," i.e., a beverage that helps lower body temperature. A special drink known as Karkadeh, or "Tea of the Pharaohs," is believed to have been consumed by Egyptian royalty and was made from Hibiscus sabdariffa. Traditional practices like applying poultices recognized this plant's antibacterial and anti-inflammatory properties. Also valued for its deep red pigment, the calyces were used to dye fabrics used for ceremonies and for the socially elite.

2.2 Sub-Saharan and West Africa

In West African folk medicine, hibiscus has been historically employed to support cardiovascular health, aid digestion, and relieve symptoms associated with colds and respiratory ailments. In various African countries, H. sabdariffa is brewed into a popular drink called "Bissap." This soft drink is valued for its rich taste and health-promoting properties such as its potential to reduce body weight and improve liver health. The calyxes are regularly eaten dried or fresh and contribute a sour flavor to portions of mixed vegetables and sauces in meals. In West Africa, it remains central to traditional beverages such as bissap (Senegal) and zobo (Nigeria).

2.3 Asia

In regions such as China and Thailand, different parts of the roselle plant (including the flower, leaves, calyx, and corolla) are commonly consumed as a thirst‐quenching beverage. In Ayurvedic and traditional Chinese medicine, hibiscus has been combined with other botanicals to support liver function, manage high blood pressure, and promote skin health. Hibiscus sabdariffa L. is a local soft drink material and medicinal herb in Taiwan, used effectively in native medicines against hypertension, pyrexia, and liver disorders.

2.4 The Americas and Caribbean

In Latin America and the Caribbean it is the base of agua de Jamaica. During the 18th century, roselle became a plantation crop in the Caribbean as an alternative to imported cranberries. Roselle has been used in traditional medicine for centuries, particularly in African and Caribbean cultures, for its supposed health benefits and therapeutic properties.

2.5 Principal Traditional Indications

The greatest impact of roselle has been in Traditional Medicine/Complementary and Alternative Medicine (TCAM), where it has shown diuretic, choleretic, analgesic, antitussive, and hypotensive effects. Other effects observed are that it lessens blood viscosity, stimulates intestinal peristalsis, and reduces body temperature. Likewise, it has been used to treat nervous diseases, cardiovascular diseases and atherosclerosis, obesity, liver disorders, control arterial hypertension, and genital problems.

The traditional uses listed as belonging to Hibiscus sabdariffa in the ingredient category under the "Tropical jewel hibiscus" name include: anemia, poor digestion, fever, hypertension, kidney stones, menstrual irregularity, skin care, wounds and sores, and support for arteries and blood circulation.

3. Key Constituents and Active Compounds

3.1 Phytochemical Profile

The therapeutic properties of Hibiscus sabdariffa L. have been attributed to the bioactive compounds (phytochemicals) highlighting phenolic acids (especially protocatechuic acid), flavonoids, anthocyanins (delphinidin-3-sambubioside and cyanidin-3-sambubioside), organic acids, and some polysaccharides, on the whole.

The main phytochemicals found in H. sabdariffa flowers are anthocyanins, flavonoids, organic acids (mostly citric acid, hibiscus acid, and malic acid), glycosides, and fiber. While in calyxes, a similar proportion of these same organic acids and anthocyanins is observed but a low quantity of flavonoids and glycosides.

In general, the calyx of roselle is red, which gives the traditional color to drinks and infusions prepared with this plant. This characteristic color is attributed to the content of anthocyanins, while its acidic taste is due to the content of organic acids such as citric, malic, tartaric acid, and hibiscus acid.

3.2 Anthocyanins

The two dominant anthocyanins are delphinidin-3-sambubioside and cyanidin-3-sambubioside. Anthocyanins, particularly delphinidin-3-sambubioside (Dp-3-sam) and cyanidin-3-sambubioside (Cn-3-sam), are flavonoids with antioxidant and potential antitumor properties. Most of the studies coincide in mentioning that the beneficial effects of roselle are mainly attributed to anthocyanins, phenolic acids, and flavonoids.

3.3 Phenolic Acids and Flavonoids

H. sabdariffa aqueous extracts (HSE) are prepared from the dried flowers of H. sabdariffa L., which are rich in phenolic acids, flavonoids, and anthocyanins. Flavonoids and polyphenolic compounds present in H. sabdariffa are responsible for its anti‐inflammatory, antitumorigenic, antibacterial, antifungal, anti‐diabetic, antioxidant, and antipyretic properties. Bioactive compounds such as rutin, quercetin, and myricetin have been evaluated against different proteins such as α‐glucosidase and superoxide dismutase (SOD) to assess antidiabetic and hepatoprotective roles.

3.4 Organic Acids

Therapeutic properties of roselle have also been attributed to the bioactive compounds of the plant, including organic acids such as citric, hydroxycitric, hibiscus, tartaric, malic, and ascorbic acids. Its calyces are rich in organic acids such as hibiscus and citric acid, contributing to their tart, cranberry-like flavor.

3.5 Nutritional Composition

The nutritional composition of roselle has been studied on different occasions and various compounds with nutritional capacity have been found in the plant, including proteins, lipids, vitamins, fiber, and amino acids. The percentage and/or quantity of these compounds differ in each variety and the anatomical place of the plant that is studied.

4. Established and Proposed Mechanisms of Action

4.1 Angiotensin-Converting Enzyme (ACE) Inhibition

The hypotensive activity of H. sabdariffa has been partly attributed to inhibition of angiotensin-converting enzyme (ACE), the main catalyst for the conversion of angiotensin I to angiotensin II (a vasoconstrictor) leading to an increase in blood pressure. This mechanism of action is supported by human clinical trials that linked the hypotensive activity of H. sabdariffa extract to ACE inhibition and serum sodium lowering. In vitro studies have shown that cyanidin-3-sambubioside and delphinidin-3-sambubioside can competitively inhibit the active site of the angiotensin-converting enzyme (ACE).

4.2 Vasorelaxation

It has been proposed that hibiscus reduces blood pressure by increasing diuresis or vasodilation/vasorelaxation. The diuretic effects are thought to be through the increase in renal filtration rate or by increasing the renal excretion of sodium and chloride. The vasodilation or vasorelaxation effect is thought to involve the inhibition of calcium influx into vascular smooth muscle cells. Results from in vitro studies suggest that the strong vasorelaxant activity of butanolic extracts is essentially due to the presence of anthocyanins found in its fractions.

4.3 Antioxidant Activity

The plant's high content of vitamin C, anthocyanins, and polyphenols contributes to its powerful antioxidant effects, which have been harnessed in remedies aimed at promoting immune strength and reducing oxidative stress. It has been demonstrated that H. sabdariffa extracts, polyphenol-rich extracts, anthocyanins (HAs), and protocatechuic acid (PCA) exert many biologic effects. PCA and HAs protected against oxidative damage induced by tert-butyl hydroperoxide (t-BHP) in rat primary hepatocytes.

4.4 Anti-Atherosclerotic Mechanisms

In rabbits fed cholesterol and human experimental studies, hibiscus aqueous extract (HSE) has been evaluated as an atherosclerosis chemopreventive agent, as it inhibits LDL oxidation, foam cell formation, as well as smooth muscle cell migration and proliferation.

4.5 Xanthine Oxidase Inhibition (Uricosuric Effect)

Results showed that H. sabdariffa extract inhibited enzymes belonging to several classes, such as α-amylase, trypsin, chymotrypsin, xanthine oxidase, lipoxygenase, and angiotensin-converting enzyme. In particular, enzymatic kinetics of ACE indicated a competitive inhibition fashion of H. sabdariffa extract.

4.6 Anti-Inflammatory Mechanisms

The active ingredients in hibiscus are believed to disrupt microbial membranes, inhibit enzyme activity, and effectively scavenge free radicals, thereby exerting a broad spectrum of antimicrobial effects. H. sabdariffa has attracted widespread attention for its antioxidant, anti-inflammatory, and antimicrobial properties. The antimicrobial activity of Hibiscus species is largely due to their diverse phytochemical profiles, which include flavonoids, phenolic acids, anthocyanins, and organic acids.

5. Scientific Evidence by Area of Health Use

5.1 Cardiovascular Health: Blood Pressure (Hypertension)

This is the most extensively studied area for H. sabdariffa in humans. The evidence base includes multiple randomized controlled trials (RCTs) and several systematic reviews with meta-analyses.

Meta-Analytic Evidence: Four databases were searched for randomized clinical trials (RCTs) examining the efficacy of H. sabdariffa in patients with mild-to-moderate hypertension or hypertension associated with metabolic syndrome (MetS). A total of 13 RCTs (1,205 participants) were analyzed. Hibiscus sabdariffa significantly reduced both systolic blood pressure (SBP) and diastolic blood pressure (DBP) compared with placebo (mean difference –6.67 mm Hg for SBP, P = 0.004; and –4.35 mm Hg for DBP, P = 0.02). Subgroup analysis showed that the change in SBP and DBP was statistically significant in patients with hypertension only, whereas it was not significant in patients with hypertension associated with metabolic syndrome.

Individual RCTs — Comparison with Antihypertensives: Two studies compared Hibiscus sabdariffa to black tea; one study compared it to captopril and one to lisinopril. These studies found that hibiscus had greater blood pressure reduction than tea but less than the ACE-inhibitors. In one controlled and randomized clinical trial, patients from 30 to 80 years old with diagnosed hypertension and without antihypertensive treatment for at least 1 month before were included. The experimental procedure consisted of the administration of an infusion prepared with 10 g of dry calyx from H. sabdariffa in 0.5 L water (9.6 mg anthocyanin content), daily before breakfast, or captopril 25 mg twice a day, for 4 weeks.

Acute Effects: A polyphenol-rich HS drink (7.5 g of HS calyx powder in 250 mL, corresponding to 311 mg of gallic acid and 150 mg of anthocyanins) decreased postprandial systolic and diastolic blood pressure in subjects with a cardiovascular risk of 1 to 10% (aged 47 to 49 years) after 4 h of consumption relative to baseline, in a randomized, controlled, single-blinded, acute, and cross-over study. These effects were associated with the phenolic compounds (gallic, 4-O-methylgallic, and 3-O-methylgallic acids) of the HS infusion.

Vascular Function: Acute consumption of aqueous extract of hibiscus sabdariffa calyxes (HSC) caused a significant increase in % flow-mediated dilation (FMD) (p < 0.001), a non-significant decrease in systolic and diastolic BP, non-significant increase in urinary and plasma nitric oxide, and reduced response of serum glucose, plasma insulin, serum triacylglycerol and C-reactive protein (CRP) levels; and a significant improvement in the area under systemic antioxidant response curve (0 to 2 h). Gallic acid, 4-O-methylgallic acid, 3-O-methylgallic acid, and hippuric acid reached a maximum plasma concentration at 1 to 2 h post consumption. The extract of HSC improved postprandial vascular function and may be a useful dietary strategy to reduce endothelial dysfunction and CVD risk, although this requires confirmation.

Evidence Strength — Blood Pressure: Moderate to moderately strong. Multiple RCTs consistently demonstrate statistically significant reductions in both SBP and DBP. However, all studies, except one, were short-term and of poor quality with a Jadad scoring of less than 3, and did not meet international standards. The four randomized controlled studies in one earlier review do not provide reliable evidence to support recommending Hibiscus sabdariffa for the treatment of primary hypertension in adults. The larger, more recent meta-analyses provide somewhat stronger support, but call for high-quality, longer-term trials.

5.2 Lipid Profile (Dyslipidemia)

The evidence for H. sabdariffa and lipid lowering is mixed and inconsistent across human studies.

Positive findings in adolescents: In a triple-blind randomized placebo-controlled clinical trial, 90 obese adolescents aged 12–18 years with documented dyslipidemia were randomly assigned in two groups; cases received 2 grams of fine powdered calyces of Hibiscus sabdariffa per day for one month, and controls received placebo powder with the same dietary and physical activity recommendations. Full lipid profile and fasting blood sugar were measured before and after the trial. Serum total cholesterol, low-density lipoprotein cholesterol, and serum triglyceride showed a significant decrease in the cases group.

Positive early human finding at higher dose: The only study in humans by Lin et al. (2007) demonstrated that 2 capsules of hibiscus sabdariffa extract (1 g), given 3 times a day (for a total of 3 g/day), significantly lowered serum cholesterol in hypercholesterolemic patients. However, this study was done for a short duration (4 weeks), and importantly, it was not clear whether body weight or dietary habits changed during the course of the treatment.

Null findings in adults: Sixty subjects with serum LDL values in the range of 130–190 mg/dl and with no history of coronary heart disease were randomized into experimental and placebo groups. The experimental group received 1 g of the extract for 90 days, while the placebo received a similar amount of maltodextrin, in addition to dietary and physical activity advice for the control of their blood lipids. While body weight, serum LDL cholesterol, and triglyceride levels decreased in both groups, there were no significant differences between the experimental and placebo group. It is likely that the observed effects were as a result of the patients following the standard dietary and physical activity advice.

In a randomized clinical trial, ninety hypertensive patients were assigned to receive Hibiscus Sabdariffa (HS) tea or black tea for 15 days, drinking the tea two times daily. There were no significant differences between pre- and post-experiment values within the two groups. An upward trend in total cholesterol, HDL, and LDL cholesterol was evident in both groups.

Evidence Strength — Lipids: Weak and mixed. Human studies show conflicting results across different doses, formulations, and populations. The effect appears more consistent in preclinical (animal) models than in human trials. Well-designed, adequately powered RCTs are lacking.

5.3 Antioxidant and Anti-Inflammatory Activity

In addition to cardiovascular effects, hibiscus extracts have shown antioxidant and anti-inflammatory activity in laboratory and animal studies. These findings support its traditional use as a general health tonic. However, while preliminary results are promising, more large-scale human clinical trials are needed to confirm these effects and to better understand optimal dosages and long-term safety.

Scientific evidence has demonstrated the pharmacological potential of roselle, including its antihypertensive, anti-hyperlipidaemic, anti‐inflammatory, antimicrobial, diuretic, uricosuric, and anaemia-treating effects.

Evidence Strength — Antioxidant/Anti-Inflammatory: Primarily in vitro and animal studies. Human clinical data remain very limited and insufficient for firm conclusions.

5.4 Diabetes and Blood Glucose

Roselle has been used in folk medicine for thousands of years. Thanks to the numerous active compounds, including polyphenols, polysaccharides, organic acids, or pectins, it is reported to exhibit hypoglycemic, antioxidant, hypotensive, and anti-lipidemic activities and numerous indirect effects that are related to them.

Acute consumption of aqueous extract of HSC led to a reduced response of serum glucose and plasma insulin levels, suggesting some effect on postprandial glycemic response in a controlled cross-over human study, though the change was non-significant in isolation. H. sabdariffa extract has also been shown to inhibit α-amylase, an enzyme involved in starch digestion, which may contribute to blunting post-meal glucose excursions. Animal research indicates that Hibiscus sabdariffa may reduce adipogenesis and fat accumulation, as well as inhibit the breakdown and absorption of starch.

Evidence Strength — Diabetes/Glucose: Preliminary. Mechanistic data (enzyme inhibition) and animal evidence exist; controlled human trials specifically targeting glycemic control are limited. The evidence is insufficient to support clinical claims in this area.

5.5 Diuretic Activity

Decoctions of Hibiscus sabdariffa L. are very popular for the preparation of homemade refreshing drinks and are also used medicinally for a variety of ailments. Particularly remarkable are the various scientific reports supporting diuretic and antihypertensive potentials. Extracts showed remarkable diuretic and natriuretic effects in animal models at doses of 50, 100, and 200 mg/kg body weight.

Evidence Strength — Diuretic: Well-supported in animal studies and has a plausible mechanism (renal sodium and chloride excretion). Limited controlled human data, but consistent with traditional use and pharmacological models.

5.6 Uric Acid and Gout (Uricosuric Effect)

The uricosuric effect of roselle (Hibiscus sabdariffa), a genus of the Malvaceae family rich in flavonoids and phenolic acid, was investigated in subjects with and without a history of renal stones. Researchers investigated the effects of H. sabdariffa extract (HSE) on oxonic acid (OA)-induced hyperuricemia in rats. The HSE affected serum uric acid levels and urate enzymes such as uricase and xanthine oxidase (XO).

Evidence Strength — Uric Acid: Primarily animal and in vitro data. Human evidence is very limited. This area requires further clinical investigation.

5.7 Antimicrobial Properties

Historically, cultures throughout Africa, Asia, and the Caribbean have utilized hibiscus for its health benefits, including its role in treating high blood pressure, digestive problems, and skin conditions. The rich phytochemical profile of hibiscus, particularly its high content of anthocyanins and flavonoids, has attracted increasing scientific interest, particularly with regard to its antimicrobial properties.

Evidence Strength — Antimicrobial: In vitro evidence only at this time. No well-designed human clinical trials specifically assess antimicrobial outcomes.

5.8 Oncology (Anticancer Research)

Anthocyanins, particularly delphinidin-3-sambubioside and cyanidin-3-sambubioside, are flavonoids with antioxidant and potential antitumor properties. This has been investigated in the context of H. sabdariffa-derived anthocyanins administered intratumorally. Findings highlight the potential of H. sabdariffa-derived anthocyanins as adjuvants in cancer therapy, as when administered intratumorally they enhance chemotherapy efficacy and immunogenicity. However, further studies are needed to optimize dosing strategies, evaluate long-term safety, and assess clinical applicability.

Evidence Strength — Anticancer: Entirely preclinical (in vitro and animal studies). No human clinical evidence currently supports anticancer claims. This research is at an early exploratory stage.

6. Body Systems and Health Areas Associated with H. sabdariffa

Cardiovascular system: Blood pressure reduction (most clinically supported), vascular function, endothelial health, anti-atherosclerotic activity
Metabolic system: Lipid profile modulation (mixed evidence), blood glucose/insulin response (preliminary), uric acid regulation (animal/in vitro)
Renal system: Diuretic activity, natriuresis, uricosuric effects
Hepatic system: Hepatoprotective activity (predominantly animal studies)
Immune system: Immunomodulatory and anti-inflammatory effects (primarily in vitro and animal data)
Gastrointestinal system: Traditional use for digestion; starch digestion inhibition (in vitro)
Skin: Traditional use for wound healing and skin conditions

7. Dosage Forms and Dosages Reported in Clinical Studies

The dosages of studied extracts varied, ranging from 250 mg to 10 g per day, with a mean anthocyanin content of 80.2 mg/day.

Trials investigating the hypotensive effect of hibiscus have evaluated oral daily dosages of an infusion prepared with 10 g of dry H. sabdariffa calyx in water (standardized to 9.6 mg of anthocyanin content per dose), or an herbal medicinal product prepared from H. sabdariffa dried calyx extract (standardized to 250 mg of total anthocyanins per dose); treatment duration in these studies was 4 weeks.

In a 2014 systematic review and meta-analysis investigating blood pressure effects, H. sabdariffa aqueous extract dosages used included 2 "spoonfuls" daily, 100 mg daily, and 3.75 g daily for a duration of 15 days to 6 weeks.

One human study demonstrated that 2 capsules of hibiscus sabdariffa extract (1 g), given 3 times a day (for a total of 3 g/day), was used for cholesterol lowering over 4 weeks.

In a dyslipidemia trial in obese adolescents, participants received 2 grams of fine powdered calyces of Hibiscus sabdariffa per day for one month.

A polyphenol-rich HS drink used in an acute cross-over study corresponded to 7.5 g of HS calyx powder in 250 mL, providing 311 mg of gallic acid and 150 mg of anthocyanins.

In one study, eighteen participants consumed 2 g of Hibiscus sabdariffa or oolong tea twice daily for six weeks.

No universally standardized therapeutic dose is established in the peer-reviewed literature, and the variety of preparations, extract concentrations, and anthocyanin contents across studies makes direct comparison difficult.

8. Safety Considerations and Drug Interactions

8.1 General Safety Profile

Available review evidence suggests H. sabdariffa extracts have a favourable safety profile in humans at doses below 32.3 mg/kg body weight per day, and 500 mL/day of tea with concentrations below 30 g/L for up to 6 months. Insufficient evidence on longer duration of consumption still raises concern, as indicated by preclinical toxicity studies assessing the liver, kidneys, and male reproductive organs. Evidence of interactions with modern drugs should be strongly considered.

8.2 Adverse Events Reported

The most frequent adverse events in pharmacovigilance reports involved renal and urinary disorders (n = 8), followed by liver toxicity (n = 3). Several studies have indicated that high doses of hibiscus tea for relatively long terms might have a diverse influence on reproductive systems, kidney, and liver functions.

8.3 Sub-Chronic Toxicity (Animal Data)

One study revealed that aqueous extract of H. sabdariffa calyces (AEHSC) has some toxic effects in rats on sub-chronic administration. In addition, the extracts produced significant diuretic activity. Hence, prolonged oral consumption of the extract may not be recommended based on these animal data. A study in workers from Nigeria that consumed an HSL infusion containing 2.3 and 4.6 g/kg/day for 12 weeks showed histological distortion of tubules, disruption of normal testicular epithelial organization, disintegration of sperm cells, and a decrease in epididymis sperm counts.

8.4 Drug Interactions

ACE Inhibitors / Antihypertensive Drugs: It is not unusual for patients who are on orthodox antihypertensive medications to use medicinal H. sabdariffa drinks concomitantly without regard to the possibility of herb-drug interactions. Previous studies showed that Hibiscus sabdariffa is co-administered with antihypertensives and antihyperlipidemics, thus predisposing to herb-drug interactions.

Captopril: Researchers investigated the pharmacokinetic interaction between H. sabdariffa L. aqueous extract and captopril, a frequently prescribed antihypertensive. Preclinical rat data indicate a pharmacokinetic interaction exists, though the clinical significance in humans requires further characterization.

Hydrochlorothiazide: This study examined the pharmacokinetic and pharmacodynamic interactions of H. sabdariffa extract (HSE) and hydrochlorothiazide (HCT), a commonly prescribed diuretic drug. Given that both hibiscus and hydrochlorothiazide exhibit diuretic and antihypertensive properties, concurrent use creates the potential for additive or synergistic effects that may require monitoring.

Chloroquine: Hibiscus-based beverages have been reported to significantly reduce the bioavailability of chloroquine.

8.5 Need for Further Research

Generally, there is a recognized need for more well-designed controlled clinical studies in humans on the kinetics of hibiscus extracts and their ingredients and related effects of their long-term consumption. Further validation in large, controlled clinical trials or safety cohort studies on standardised H. sabdariffa preparations, and rigorous post-marketing surveillance, are warranted.

References

Health Conditions

Health conditions that Tropical jewel hisbiscus may help support.

No conditions available.

Body Systems

Body systems that Tropical jewel hisbiscus may help support.

No body systems available.