For centuries, Moringa oleifera leaf has been used in traditional medicine for common ailments in many countries of the world. Traditionally, it is used in the treatment of hypertension.
Now, researchers have found that moringa oleifera leaf also suppresses pressure build-up in the eye, a precursor for glaucoma, a cause of reversible cause of blindness.
Glaucoma is a condition that causes damage to the eye’s optic nerve and gets worse over time. It’s often linked to a buildup of pressure inside the eye, what is medically termed intraocular pressure. Glaucoma tends to be inherited and may not show up until later in life.
In a study, researchers said moringa oleifera leaf water extract may be consumed as a form of adjunct therapy in controlling blood pressure and intraocular pressure.
This clinic-based observational study at the University of Benin Optometry Clinic in Benin City had investigated the effect of graded doses of Moringa oleifera leaf aqueous extract on intraocular and blood pressure.
It involved George, Gladys O; Ajayi, O.B and Oyemike, A.A and published in the 2018 edition of the Journal of the Nigerian Optometric Association.
They were divided into three groups of 10 participants in each group. Another group of 10 normotensive adults, aged-matched were used as a control group. Baseline intraocular pressure and blood pressure of each participant were measured.
Three different masked doses of Moringa oleifera water leaf extract labelled ‘E’, ‘F’, and ‘G’ were taken by groups 1, 2, and 3 respectively, while group 4 participants drank water only. Thereafter, intraocular pressure and blood pressure were measured at 30 minutes interval for the four groups until values returned to baseline.
These were people with no history of hypertension; they had no visual field defect, no remarkable eye or medical history. All were non-alcoholics and non-smokers.
Results showed that drinking water extract of Moringa oleifera leaf has significant hypotensive effect on intraocular pressure and blood pressure of the three experimental groups.
The effect was dose-dependent and the maximum reduction in blood pressure was at 60 minutes. This preceded the maximum reduction in intraocular pressure which occurred at 90 minutes, thereafter intraocular pressure and blood pressure rose toward baseline values.
They declared, “The lowering effect on intraocular pressure may have resulted from the fall in blood pressure which may have resulted from the high content of potassium and calcium in aqueous extract of Moringa oleifera leaf.
“The fall in blood pressure is believed to cause a resultant fall in intraocular pressure but further researches are needed in this area in order to determine the exact mechanism by which this occurs.
“Also, further investigations may be required to determine the therapeutic dose of Moringa oleifera leaf in the management of ocular and systemic hypertension.”
The researchers, however, suggested that the high potassium and calcium content of the water extract of Moringa oleifera leaf may have played a role in lowering blood pressure.
The main cause of hypertension is believed to be the increased level of sodium in the blood. When the level of potassium in the blood decreases, the absorption of sodium naturally increases leading to hypertension or high blood pressure. Blacks appear to be more sensitive to the blood pressure-suppressing effects of potassium.
Moringa oleifera leaf is one of the richest sources of potassium and potassium is known to prevent excessive absorption of sodium, thereby decreasing blood pressure.
Studies indicated that crude extract of Moringa oleifera leaves caused a fall in systolic, diastolic, and mean blood pressure in a dose-dependent manner.
Previously, corn silk had been documented to lower blood pressure and intraocular pressure (IOP) of humans and animals.
Corn silk is the shiny thread-like fibres that grow as part of ears of corn. When fresh, they are like silk threads of a light green or yellow colour.
In the 2013 study, researchers had studied the effects of masked doses of corn silk aqueous extract on the IOP and blood pressure of 20 adults with normal blood pressure and 20 others with raise eye pressures.
Also, they compared the effects of the varying doses of corn silk tea with masked doses of acetazolamide (a medication for treating glaucoma) on IOP of ocular hypertensive subjects only.
The results in the journal, Clinical and Experimental Optometry showed that corn silk tea may serve as an alternative therapy to acetazolamide since it has the same IOP-lowering effect.