What is Hibiscus?
Hibiscus (Hibiscus sabdariffa) is a flowering plant that can be either an annual or perennial herbaceous shrub, depending on the climate. It typically grows up to 2-3 meters in height and features large, showy flowers with five petals. The flowers can vary in color, including shades of red, pink, white, and yellow. The plant also produces red or maroon-colored calyces (sepals) that enclose the seeds.
The Roselle Hibiscus plant is native to temperate regions around the world. These include West Africa, Central America, Australia, Thailand, China, India and other warm climes.
Hibiscus is cultivated in many warm climates worldwide. It thrives in well-drained soil and requires ample sunlight to grow.
The red flower sepal and calyces of the Roselle plant are used to make Hibiscus tea. This tea is a mainstay beverage in many regions, especially in Central America and West Africa. Hibiscus tea is made by boiling the flowers until the water turns red.
Yet the flower is not the only medicinal part of this medicinal plant. Roselle’s bitter roots have been used in traditional medicine for digestive issues. The leaves of the plant are steamed or cooked with dal and rice dishes in Asia. And its stem fiber – bast fibre – is often used to make rope and burlap.
Hibiscus Compounds
Hibiscus contains various bioactive compounds, including:
Anthocyanins and proanthocyanidins: Responsible for the red color of the calyces and known for their antioxidant properties.
Flavonoids: Including quercetin and kaempferol, which contribute to the plant's antioxidant and anti-inflammatory effects.
Organic acids: Such as citric acid, malic acid, and hibiscus acid, which give the plant its tart flavor. They also include tartaric acid, oxalic acid and stearic acid.
Vitamins and minerals: Including vitamin C, beta-carotene, and minerals like calcium, magnesium, and potassium.
Traditional Herbalism
Hibiscus has a long history of use in traditional herbalism around the world. Here is what this herb has been used for:
Cardiovascular Health: Hibiscus tea is used in various cultures as a natural remedy to help lower blood pressure and cholesterol levels.
Digestive Health: The plant is used to relieve constipation, improve digestion, and soothe gastrointestinal issues.
Immune Support: Due to its vitamin C content, hibiscus is believed to boost immune function and promote overall health.
Culinary Uses:
Hibiscus is commonly brewed into herbal teas and beverages, either hot or cold, enjoyed for its refreshing taste and potential health benefits.
In some cuisines, hibiscus flowers or calyces are used in cooking to add flavor, color, and acidity to dishes.
The antioxidant properties of hibiscus help protect against oxidative stress and inflammation, potentially reducing the risk of chronic diseases. Let's discuss some of the research showing its medicinal effects.
Hibiscus lowers blood pressure
Research from the College of Medicine at Nigeria’s University of Enugu tested 80 adults recently diagnosed with hypertension. They had yet to receive any treatment. They were divided into three groups. One group was treated with Hibiscus. Another group was treated with the hypertension drug, hydrochlorothiazide – an ACE inhibitor. The third group was given a placebo.
After four weeks of treatment, the subjects were tested for blood pressure, urine electrolytes and given blood tests. The researchers found the Hibiscus treatment significantly reduced both systolic and diastolic blood pressure. It also reduced arterial pressure and reduced blood sodium levels.
This reduction in blood pressure from Hibiscus was similar in the drug group. However, the blood pressure reduction lasted longer when the patients were retested after halting their treatments.
Hibiscus beats ACE inhibitor drug
A 2015 study from the Medical Outpatients Clinic at Enugu State University tested 75 adults with high blood pressure. They were also divided into three groups. One group was treated with an extract of Hibiscus. Another group was given 10 milligrams of the ACE-inhibitor hypertension drug Lisinopril. The third group was given a placebo.
All the patients were treated for four weeks. After the four weeks, the researchers found the Hibiscus reduced blood pressure by an average of 76 percent. This beat the Lisinopril drug’s effects, which reduced blood pressure by 65 percent.
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| Courtesy of the Indian Journal of Pharmacology |
Furthermore, the Hibiscus began to significantly reduce systolic blood pressure during the second week of treatment, and continued to reduce it through the fourth week. The Lisinopril didn’t cause significant reduction of systolic blood pressure until the fourth week.
Hibiscus also beat the ACE inhibitor drug in reducing angiotensin-converting enzyme (ACE) and plasma aldosterone levels. The compared levels were 6.6 percent versus 5.6 percent and 32 percent versus 30 percent, respectively.
The Hibiscus treatments also didn’t come with the side effects seen in some in the Lisinopril treated group.
Not the only clinical study
This isn’t the only clinical study confirming Hibiscus’ ability to improve blood pressure. A study from Mexico’s Center of Biomedical Investigation tested 90 patients with hypertension. The patients were treated with 50 mg/day of the drug Captopril (another ACE inhibitor) or with 10 grams of Hibiscus flower mixed with water. Again, the treatment lasted four weeks.
The researchers found the Hibiscus reduced systolic blood pressure from an average of 139 to 124 mm Hg. And the average diastolic blood pressure was reduced from 91 to 79 mm Hg by the Hibiscus treatment over the four weeks. The researchers found the Captopril to also be effective in reducing blood pressure. But the difference in effectiveness was not significant. The researchers concluded:
“The obtained data confirm that the Hibiscus sabdariffa extract, standardized on 9.6mg of total anthocyanins, and captopril 50 mg/day, did not show significant differences relative to hypotensive effect, antihypertensive effectiveness, and tolerability.”
An international review of research that included Australia’s University of Western Australia, Perth analyzed the clinical research through 2014 on Hibiscus and hypertension. The researcher’s meta-analysis of five clinical studies found that Hibiscus reduced systolic blood pressure by an average of 7.58 mmHg and reduced diastolic blood pressure by an average of 3.53 mmHg. The researchers concluded:
“This meta-analysis of RCTs showed a significant effect of Hibiscus sabdariffa in lowering both systolic blood pressure and diastolic blood pressure.”
Hibiscus treats urinary tract infections
One of the mechanisms that provides Hibiscus with its benefit to blood pressure is its improved urinary clearance. For this reason, traditional use of Hibiscus has included urinary tract infections in some regions.
Researchers from Taiwan’s China Medical University put this traditional use to the test in a long-term care facility. Long-term residents at these facilities tend to experience a greater incidence of urinary tract infections. As a result, many residents are connected with urinary catheters. The doctors had the health care center serve residents who were on urinary catheters Hibiscus teas regularly. The researchers found the Hibiscus resulted in significantly fewer urinary tract infections.
The researchers also tested the mechanisms of Hibiscus with regard to the urinary tract. They found that Hibiscus significantly reduced renal inflammation by virtue of reducing LPS-induced inflammatory factors. This helped urinary clearance and reduced infections among the residents. The researchers concluded:
“This is the first report applying clinical observation-guided transcriptomic study to explore the application and mechanism of roselle [Hibiscus] on urinary tract infections. Our findings suggested that roselle drink ameliorated LPS-induced renal inflammation via downregulation of cytokine network, pro-inflammatory product production, and NF-κB pathway. Moreover, this report suggested the potential benefit of roselle drink on urinary tract infections.”
Hibiscus improves cholesterol levels
Multiple clinical studies have also found that Hibiscus reduces low-density lipoprotein cholesterol (LDL-c) and triglyceride levels. It also increases levels of the “good” high-density cholesterol (HDL-c).
These results taken from clinical research around the world can only mean one thing: Hibiscus increases cardiovascular health. It reduces blood pressure, improves cholesterol levels and improves the health of the kidneys and urinary tract.
Hibiscus fights triple-negative cancer
Breast cancer is the deadliest cancer in women. A quarter of all cancers are breast cancer, and 15 percent of all cancer deaths come from breast cancer. , and billions of woman contract breast cancer every year. One of the more dangerous forms of breast cancer is triple-negative breast cancer. This occurs when the cancer cells do not express hormone receptors such as estrogen or progesterone. This makes the cancer much harder to treat.
About 15 to 20 percent of breast cancer cases are considered triple-negative. With modern treatments, survival rates for triple-negative can be close to non-triple-negative forms of breast cancer.
But now we can introduce research showing that a natural treatment may be able to be added to triple-negative breast cancer.
Researchers from Canada’s University of Windsor produced a hot water extract from hibiscus flowers (Hibiscus rosa-sinesis). They fed three types of cancer cells the extract:
– Triple negative breast cancer line MCF-7
– Triple negative breast cancer line MDA-MB-231
– Normal healthy cells
The researchers gave these cells the hibiscus extract alone, and then compared the results with chemotherapy agents taxol, cisplatin, and tamoxifen.
The researchers tested the cancer cells at 48 hours and 96 hours following application. They found the hibiscus extract alone significantly killed the two cancer cells, but did not harm the healthy cells. The killing of the cancer cells occurred on a dose-dependent basis. This is the gold standard for determining an anticancer drug.
As mentioned, the researchers compared the results with the chemotherapy drugs. They did not find the chemotherapy drugs significantly killed (apoptosis) the MCF cancer cells, and only the taxol significantly killed MDA cancer cells.
In other words, the hibiscus extract beat the chemotherapy drugs:
“Hibiscus extract was able to selectively induce apoptosis in both triple-negative and estrogen-receptor positive breast cancer cells in a dosage-dependent manner.”
As mentioned, only the taxol was able to kill cancer cells significantly, and that was on only one of the cells lines. Meanwhile the hibiscus significantly killed both cancer cell lines. This means that the hibiscus was superior to all three major chemotherapy drugs.
Hibiscus improves chemotherapy
The researchers also tested the hibiscus extract against the cancer cell lines together with a combination of the chemotherapy drugs.
The study found that the hibiscus improved – enhanced – the ability of the chemotherapy drugs in fighting the cancer cells:
“Most importantly, addition of hibiscus extract was found to enhance the induction of apoptosis of chemotherapy treatments (taxol and cisplatin) in triple-negative breast cancer cells when compared to treatment alone.”
Other studies have confirmed findings
This is not the first study to show that hibiscus can treat cancer. A 2015 study from Taiwan’s National Defense Medical Center studied Hibiscus syriacus extracts on human triple-negative breast cancer cells.
The researchers found that not only did the hibiscus induce the killing of the breast cancer cells. It also inhibited the migration of the cancer cells, and their viability. The hibiscus was able to activate the p53 pathway and induce the p21 pathway, which causes the cell cycle to arrest.
Wow – nature can be seriously medicinal and taste great at the same time.
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