The consumption of hibiscus tea or zobo is growing in
popularity owing to accumulating evidence that it has benefits against excess
weight, constipation, upset stomach, diabetes and can safely reduce blood
pressure and cholesterol, two major risk factors for cardiovascular disease.
Among the best-described health benefits of Hibiscus
sabdariffa, also commonly referred to as roselle, is blood pressure control for
hypertension and many patients on conventional antihypertensives may also
consume iced zobo drink to beat the increasing atmospheric temperature.
Studies have shown that a two-week period of zobo extract
administration could produce the antihypertensive activity. However, in a new
study, experts warn against long term consumption of zobo drink by individuals
on captopril, a conventional hypertension medication.
According to them, regular intake of zobo drink with
captopril, one of the angiotensin-converting enzyme inhibitor may be
potentially dangerous. This could lead to a lowering of the blood pressure than
initially planned.
Angiotensin converting enzyme (ACE) inhibitors such as
captopril dilate the blood vessels to lower hypertension or treat heart
failure.
Even though the intake of the antihypertensive with zobo
drink does not influence the antihypertensive potency of captopril or cause any
side effects, they said two weeks of regular intake of zobo drink with
captopril can reduce the efficacy of the drug. This was contained in the
2020 edition of Evidence-based Complementary and Alternative Medicine.
Ingestion of zobo drink with conventional medicines such as
paracetamol, chloroquine and antibiotics in many communities are very common,
without regard to the possibility of herb-drug interactions. Being natural
products, individuals wrongly believe they are always safe to be taken with
drugs.
When herbal therapies and drugs (prescription or
non-prescription medications) are used together, they can interact in the body,
causing changes in the way the herbs and/or the drugs work. Such changes are
called herb-drug interactions. They can be beneficial or harmful, depending on
the type of interaction.
More than 300 species of hibiscus can be found around the
world and most of its varieties are used as ornamentals. However, there are two
main types of Hibiscus sabdariffa cultivated for its jute-like fibre and its
edible calyces. Its infusion made from its bright red calyces, which is
commonly called zobo, is consumed hot or cold. This tea is often sweetened with
sugar.
For the study on the possible effect of prolonged administration
of zobo extract on captopril in the body, male rats were divided into two
groups of six. The first group received a single dose of captopril suspension
while the second group received zobo daily for two weeks prior to the same
captopril dose.
Multiple blood samples were collected at predetermined times
after the antihypertensive was administration and its concentration in these
blood samples were assessed using ultrahigh-pressure liquid
chromatography-tandem mass spectrometry.
Previously, experts at the Usman Danfodiyo University,
Sokoto, and Ahmadu Bello University, Zaria, said taking zobo along with the
prescription drug lisinopril, a blood pressure medication, ensures its better
effectiveness in blood pressure control.
The availability of lisinopril alone and in the presence of
Hibiscus tea was determined at the stomach, intestine and blood pH.
The 2019 study, which involved I. Nasir, M. Aminu, A.M.
Ismail, A Salisu and G Magaji, published in the Tropical Journal of
Pharmaceutical Research, found that taking lisinopril with zobo drink or
hibiscus tea could enhance its availability consequent to the increased
dissolution of lisinopril in simulated gastric, intestinal and blood pH.
Dr I. Nasir declared: “It is a common practice to see
individuals taking a prescription drug for antihypertensive medications outside
the hospital while also taking zobo drink and moringa. They believe that when
they take it together, they get better. And when you check their blood
pressure, it would have dropped miraculously.”
He added “the result of the study has proven that the zobo
drink helps in checking their high blood pressure.”
According to him, “its pharmacological effect will
definitely be seen. In fact, there is a banker; all that she takes in the
morning for her hypertension is the sour zobo drink which contains no additive
like sugar.
“Many studies have shown that zobo drink has some
antihypertensive effect. In fact, some prescribers recommend that instead of
using water to swallow the drug, they could use a zobo drink. But they advise
not to take zobo drink that contains sugar.”
The researchers, however, said further studies on the effect
of varying concentrations of zobo on the bioavailability of lisinopril would
still need to be evaluated.
However, people taking blood pressure medications like the
Angiotensin converting enzyme (ACE) inhibitors such as lisinopril should avoid
consuming large amounts of zobo as well as foods high in potassium including
avocados, oranges and orange juice, potatoes, spinach, tomatoes and tomato
source.