The contribution of indigenous knowledge using plants to provide native remedies for varieties of ailment has been a fulcrum many African scientists rely on to validate traditional medicine for the cure of chronic cardiovascular diseases(CVD) such as hypertension.
Many people have hypertension without knowing it. Hypertension remains the most threatening risk factor for developing cardiovascular diseases such as stroke and heart failure.
For instance, studies from South Africa found that 32.1 per cent of men and18.9 per cent of women over 30 years had a 20 per cent or higher risk of developing CVD in the next 10 years.
From one part of the continent to another, contributions of indigenous knowledge to native remedies of hypertension vary. This is obvious from information on the therapies for high blood pressure in the Yoruba speaking communities of Ilugun area of Ogun State.
Ilugun people of Ogun State are distinct Yoruba indigenes found in Odeda Local Government and Abeokuta South Local Government of Ogun State. Like other Yoruba groups, they appreciate and adore their culture. Part of this appreciation of culture and plant conservation is the use of plant species for the maintenance of their health.
Interestingly, a survey of the plants used by the people of Ilugun area as remedy for high blood pressure, which is prevailing in the area, among the older ones, undertaken between January 2007 and April 2008 using personal communication and questionnaires found out that nine different plants were being used for treating high blood pressure.
These plants are Ficus exasperata. Heliotropium indicum; Afromomum melegueta (guinea pepper or alligator pepper); Justicia schimperi; Persea Americana (avocado) and Talinium triangulare (water leaf). Others are Acreage paniculatum (called Nigerian powder-flask fruit), Newboldia laevis (referred to as akoko tree in Yoruba) and Chenopodium ambrosioides (referred to as climbing black pepper or Benin pepper in English and ewe im?? or Arunpale in Yoruba).
The plant, Ficus exasperata is a small tree or shrub that bears figs, which usually appear in pairs in the leaf axils. It is popularly referred to as sand paper tree in Nigeria. It is also known by local names such as; Kawusa (Nupe), Ameme (Edo), Eepin (Yoruba), Anwerenwa (Igbo).
Different parts of this plant are traditionally used for treatment of various ailments or disorders in Nigeria and across the African continent. Traditional healers used its leaves and barks as a worm expeller and the root bark is used for treatment of asthma. It has also been reported that the leaves are used for treating ulcer. The decoction of the stem bark and the leaves are also used in parts of Southern Nigeria for painful menses.
Heliotropium indicum is found in tropical and non-tropical countries bearing various names, such as Cock???s comb (Gambia), Indian heliotrope, and Agogo Igun or Ogbe Akuko (Yoruba – Nigeria). Its chemical constituent made it useful for treatment of wound, ulcer, fever abscesses, rashes and warts.
According to Burkill H. M in his book entitled, The useful plants of west tropical Africa, Justicia schimperi is referred to as budidiyo in Hausa; shigel kirgegu in Kanuri and obe dudu in Yoruba. In Togoland and Northern part of Ghana, an extract of the boiled leaves is given to babies to loosen their bowels, and the leaves are applied to wounds to promote healing. In Congo the leaves mixed with oil and salt are eaten for heart troubles and in Gabon the boiled up leaves serve as a soap-substitute.
The 2009 survey documented in the African Journal of Pharmacy and Pharmacology was entitled ???Ethno-phyto therapeutic information for the treatment of high blood pressure among the people of Ilugun, Ilugun area of Ogun State, south-west Nigeria??? It was carried out by Laval I. O; Uzokwe N. E; Asinwa I. O. and Igboanugo A. B. from the Forestry Research Institute of Nigeria, Ibadan in collaboration with Ladipo D. O from the Centre for Renewable Natural Resources, Research and Development (CENRAD), Ibadan.
The plants with the highest potency according to the respondents are Ficus exasperate root bark, Heliotropium indicum and Afromomum melegueta, Justicia schimperi, Newboldia laevis and Chenopodium ambrosioides.
In preparing these herbal treatment for usage, the root back of Ficus exasperate is to be chewed daily after each meal for four days. Also, alligator pepper is added to a whole plant of H. indicum, charred and the powder used with hot pap intermittently twice daily for seven days.
In addition, the infusion made from boiling J. schimperi and avocado leaves is taken every night before sleep for six days. The whole roots of water leaf plant can be boiled in water and its decoction taken three times daily for seven days.
Also, a decoction for treating hypertension can also be made from the root of Nigerian powder-flask fruit plant (referred to as sanga in Yoruba) and leaves of A. paniculatum (ewe akoko). The decoction is to be taken in the morning before eating for eight days. Similarly, a decoction of the leaves of C. ambrosioides is usually adviced to be taken once at night for 10 days to treat hypertension.
The researchers found out that some plants were used in combination, although they could not explain why they were mixed. However, they suggested that there may be the possibility of synergy between some of the constituents in the plant species to make them more potent.
They concluded that such documentation of African medicinal plants is becoming increasingly necessary because of the rapid loss of the species and their natural habitats due to anthropogenic activities.
A previous study in 2007 indicated in the journal, Act. Pol. Pharm, the efficacy of water extract of Ficus exasperata leaves also used by some communities in Edo and delta States. The study carried out by Ayinde B.A; Omogbai E.K and Amaechina F. C from the Faculty of Pharmacy, University of Benin, Benin City, Nigeria.
They wrote: ???The water extract showed a dose related reduction in mean arterial blood pressure. At 10 mg/kg, a reduction of 16.6 mmHg was observed, whereas at 30 mg/kg, a fall in mean arterial pressure of 38.3 mmHg was obtained.???
Written by Sade Oguntola