Local plant provides novel painkilling, wound healing compounds - The Guardian

Thursday, 17 October 2013 00:00 CHUKWUMA MUANYA Features - Natural Health

Synthetic painkillers have been associated with unpleasant side effects such as organ failure. But the discovery in large quantities of molecules identical to popular synthetic painkiller, Tramadol, may provide the elusive ‘safe’ treatment for headaches, joints and waist pains and heal ‘stubborn’ ulcers and wounds. CHUKWUMA MUANYA writes.
SCIENTISTS have recorded giant strides in ongoing efforts to identify pharmaceutically active substances in traditional medicinal plants.
French researchers from the Grenoble Institute of Neurosciences reported recently in the journal Angewandte Chemie that the African plant Nauclea latifolia produces large quantities of molecules that are identical to Tramadol, a wholly synthetic medication that is used worldwide as a painkiller.
Commonly called African peach or African pincushion tree, Nauclea latifolia belongs to the Rubiaceae family. In Nigeria, it is called Ebeyesi in Yoruba, Ubuluinu in Igbo and Tafashiya or Marga in Hausa.
Nauclea latifolia is a small straggling shrub that is abundant throughout sub-Saharan Africa especially in the tropical rain forest in Nigeria.
In traditional medicine, the plant is used to treat different pathologies including epilepsy, fevers, malaria, and pain.
Earlier studies found that the stem bark of Nauclea latifolia is bitter in taste. It yields tannins used in dyeing fabrics. It is an antipyretic and a febrifuge. It has a beneficial effect on anorexia, atonal dyspepsia and anemia. It is diuretic with effect in blennorhagia and kidney troubles.
Blennorrhagia is an excess of such discharge, often specifically referring to that seen in gonorrhoea.
Nauclea latifolia has also been reported to have analgesic property giving relieve for rheumatism, cough toothaches and pain in fever.
Previous study reported that the ethanol extract of the bark of Nauclea latifolia reduced systolic, diastolic and mean arterial pressure in normotensive (normal blood pressure) rats in a dose dependent manner.
In another study the bark of Nauclea latifolia produced anticonvulsant, sedative and anxiolytic (inhibits anxiety) activity in mice. The decoction from the bark strongly increased the total sleep time induced by diazepam. Ethanol extract of Nauclea latifolia decreased the level of parasitaemia in a dose-dependent manner in mice experimentally infected with Trypanosome brucei.
The stem is taken as chewing stick to treat tooth decay. It is applied topically to wounds. A decoction is used to wash sores and is gargled for oral troubles. The bark is chewed as a mouth antiseptic, to relief bad taste resulting from indigestion and as a vermifuge (worm expeller). When taken in excess, it is emetic, purgative, emmenagogic (induces menstrual flow) and even abortifacient (induces abortion).
Tramadol is a centrally acting synthetic opioid analgesic used to treat moderate to moderately severe pain. The drug has a wide range of applications, including treatment of rheumatoid arthritis, restless legs syndrome, motor neurone disease and fibromyalgia.
The French researchers discovered that Tramadol is also produced naturally in relatively high concentrations in the roots of Nauclea latifolia. This is the first time ever a synthetic medication produced by the pharmaceutical industry has been discovered in strong concentrations in a natural source.
The team of European researchers led by Michel De Waard were able to isolate the components in the plant that were responsible for the presumed analgesic effects by analysing the root bark.
De Waard said: “The biggest surprise in this study was the fact that this molecule was a known one. It was identical to Tramadol, a synthetic medication developed in the seventies. This medication is used world-wide, because although it is a derivative of morphine, it has fewer side effects than morphine, in particular addiction problems.”
In order to confirm their results, the researchers tested different processes with the aim of proving that the substance discovered was of natural origin. The team’s analysis, were confirmed by three independent laboratories. “All results converge and confirm the presence of Tramadol in the root bark of Nauclea latifolia. On the other hand, no trace of this molecule was detected in the aerial part of the shrub (leaves, trunk or branches),” De Waard said.
The study reports that the concentration of Tramadol in the dried bark extracts was measured at 0.4 per cent and 3.9 per cent. “These are extremely high levels of active substance,” De Waard noted.
Also, a recent study published in International Journal of Pharmaceutical Biomedical Science found that crude extracts of Nauclea latifolia showed significant wound healing activity when topically administered.
The researchers from the Faculties of Pharmacy, Universities of Uyo and Benin, concluded: “The methanol crude extract and the ethylacetate fraction demonstrated significant increase in wound closure. Any of the phytochemical constituents present in Nauclea latifolia may be responsible for the wound-healing activity.
“Studies with other plants have shown that phytochemical constituents like tannins and flavonoids are known to promote wound healing process mainly due to their astringent and antimicrobial properties, which appears to be responsible for wound contraction and increased rate of epithelisation.
“The methanol crude extract and the ethylacetate fraction showed significant wound healing activity when topically administered on rabbits.
“The results offer pharmacological reason for the traditional use of the powdered stem bark of Nauclea latifolia for healing wounds. Further studies are therefore needed to better assess the potential value of Nauclea latifolia extracts as wound healing agents.”
Nigerian researchers from Adekunle Ajasin University, Akungba-Akoko, Ondo State, in another study published in April 2013 edition of European Journal of Medicinal Plants concluded: “This study contributes to the determination of potent compounds like alkaloids, phylobatannins, cardiac glycosides, saponins and steroids in the locally available plant materials. Kigelia africana, Nauclea latifolia and Staudtia stipitata extracts showed different efficacy, and therefore could be employed in the management of ulcer disease caused by non-steroidal antiinflammatory drugs.”
Peptic ulcer is a sore (which may be an acute or chronic inflammation) of the stomach or duodenum caused by a number of factors including bacterial infection by Helicobacter pylori, Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) such as starvation followed by aspirin or ibuprofen treatment, excessive drinking of alcohol, and smoking.
Among the plants that have been reported to be useful in the treatment of ulcer include whole plant of Diodia sarmentosa, leaves of Cassia nigricans, Ficus exasperate, and Synclisia scabrida, roots of roots of Zapoteca portoricensis, Morinda citrifolia, Azadirachta indica, Asparagus racemosus, Aspilia africana, Kielmeyera coriacea and Carica papaya.
In Nigeria, Kigelia africana (Sausage tree, uyan tree in Yoruba), Nauclea latifolia (Pin cushion tree and egbesi in Yoruba), and Staudtia stipitata, commonly known as noive and oropa or Ewe Gbomorin in Yoruba are tropical trees in Africa used for treating various ailments and remedies. The multipurpose nature of these herbal trees makes them important for everyday use in the African set up. Bark extracts of K. africana is reported to have anti malarial, anti cancer, anti aging potentials with additional abilities to treat venereal diseases, wounds, renal ailments, eczema, depression, body weakness and impetigo.
Kigelia africana also called “sausage tree” because of the shape of its fruit is part of the family Bignoniaceae and Scrophulariaceae order. It is traditionally used for its effectiveness in aspirin-induced ulcerogenic animals compared to 3.0 for the reference drug (Cimetidine at 300mg/kg) and control with 1.67±0.27, while the leaf extracts of S. stipitata showed the least efficacy.
The researchers write: “This study contributes to the search for potent and locally available plant materials for managing ulcer disease caused by non-steroidal antiinflammatory drugs.  Other traditional uses include, use of the fruit for its antimicrobial properties in combating skin problems such as acne, eczema, wound dressing, and as water disinfectant. Kigelia africana had been reported to contain antibacterial and antifungal properties, analgesic and anti-inflammatory, antidiarrhoeal, antiprotozoal, antimalarial and antineoplastic potentials [18,19,].
“Nauclea latifolia bark is used in the management of pain, fever and malaria; wounds, coughs and gonorrhoea in eastern and southern Nigeria. The roots of this plant are used to induce abortion, as a purgative and for treating hypertension. N. latifolia has been found to be useful in treating malaria caused by Plasmodium falciparum and against enteric bacteria: Bacillus subtilis, Escherichia coli, Salmonella enteritidis, Pseudomonas aeruginosa and Klebsiella pneumonia.
“Nauclea latifolia is noted to be anti-nociceptive, anti- inflammatory and anti-pyretic activities that justifies its use in malaria ethnopharmacy and subsequent development for clinical application; leaves of N. latifolia possesses hypoglycaemic activity when used on alloxan-induced diabetic rats.”