A local study has identified extracts of kola nut, bitter kola, alligator pepper, shea butter tree, bush cane/sugar cane, and African nutmeg as possible novel drugs for tuberculosis. CHUKWUMA MUANYA writes.

A STUDY of plants used traditionally for the management of tuberculosis in five local councils in Ogun State, has identified six plants with great potentials for developing novel drugs.

The six Nigerian plants, according to a study published recently in African Journal of Traditional Complementary and Alternative Medicines are: The fruit of Cola acumminata (kola nut), leaves of Garcinia kola (bitter kola), oil from Vitallaria parodoxa (sheabutter), stem of Costus afer (sugar cane), stem bark of Pycnanthus angolensis (African nutmeg), and fruits of Aframomum melegueta (alligator pepper).

The study tiled: “Traditional management of tuberculosis in Ogun State of Nigeria: The practice and ethnobotanical survey,” was conducted by researchers from the Department of Pharmacognosy, Faculty of Pharmacy, Olabisi Onabanjo University, Sagamu, Ogun State; and Department of Pharmacognosy, Faculty of Pharmacy, University of Ibadan, Oyo State.

According to the researchers, the aim of the study was to document herbs used in the management of tuberculosis and identify possible drug lead from the phytomedicine of these communities.

The researchers wrote: “A semi-structured questionnaire was used to obtain the required information on the use of herbal remedies for the management. A total of 50 respondents made up of herbalists (40.0 per cent), herb sellers (52.0 per cent) and traditional medicine practitioners (8.0 per cent) were interviewed in the study. The dominant age of respondents was in the range of 21 to 40 years (72.0 per cent). Duration of treatment of tuberculosis with herbs was between two to 12 weeks.

“A total of 36 plants belonging to 20 families were proffered for the management of tuberculosis. Eighty-four people (42 per cent) of the 50 respondents interviewed said that their clients observed no side effects and that the herbs were either available in the forest or bought from the markets.

“Cola acumminata (fruit), Garcinia kola (leaf), Vitallaria parodoxa (oil), Costus afer (stem), Pycnanthus angolensis (stem bark) and Aframomum melegueta (fruit) were the most frequently mentioned herbs. The ethnomedicines of the studied areas of Ogun State seem to have a high potential as a source of drug discovery of anti-tuberculosis. This is of utmost importance because people living with human immunodeficiency virus (HIV) are susceptible to tuberculosis.”

Formerly called Butryspermum paradoxum, Vitellaria paradoxa belongs to the plant family Sapotaceae. It is an immensely popular tree with many applications in folkloric medicine. It is commonly called shea butter in English, kareje in Fulfulde), kadanya in Hausa, koita in Gbagi, mmameng in Cham, okwuma in Ibo, and ori in Yoruba.

Previous studies have shown that different parts of the plant including leaves, roots, seeds, fruit and stem bark have been used in the treatment of enteric infections such as diarrhea, dysentery, helminthes and other gastrointestinal tract infections, skin diseases and wound infections. The bark is used to suppress cough and also to treat leprosy. It is rich in oil and together with the oil palm serve as sources of edible oil for many households in many parts of the Sahel Africa, particularly northern Nigeria. Fat extracts from the kernel of the plant is used extensively in cosmetics and chocolate industries.

Recent antimicrobial screening of stem bark extracts of Vitellaria paradoxa against some enteric pathogenic microorganisms found that there is scientific basis for the use of this plant as a traditional medicine and can therefore be used to source new antibiotic substances for the treatment of various enteric infections.

According to the study published in African Journal of Pharmacy and Pharmacology, preliminary phytochemical screening of the stem bark extracts of Vitellaria paradoxa revealed the presence of carbohydrates, alkaloids, saponins, tannins and cardiac glycosides. Ethanol, acetone and aqueous extracts of the plant inhibited the growth of pathogenic Escherichia coli, Klebsiella pneumonia, Proteus mirabilis, Shigella dysenterie and Salmonella typhi with varying degrees of activity with the ethanol extracts demonstrating the highest activity against all the test organisms.

The researchers concluded: “Results from this study showed the therapeutic activity of V. paradoxa against some selected members of the enterobacteriaceae. The plant can therefore be used to manage enteric infections like diarrheal diseases. Toxicological studies, purification and identification of the plant active principles should be embarked upon in addition to investigating its activity on a wider range of bacteria and fungi.”

Commonly called ginger lily, sugar cane or bush-cane, Costus afer belongs to the plant family Costaceae. In Nigeria, it is ukhueruoha in Edo; mbritem in Efik; kakii-zuwaa in Hausa; mbiritem in Ibibio; okpete, okpoto or okpete ohia in Ibo; andura in Jukun; achikku in Tiv; and atare tete-egun in Yoruba.

Previous studies have shown that the succulent stem is chewed as a remedy for cough. The root decoction is administered for the treatment of sleeping sickness and stomachache. It is also used in the treatment of diabetes mellitus in folklore medicine.

A study published in African Journal of Biotechnology found that methanol and aqueous extracts of Costus afer possess anti-oxidative properties as well as bioactive metabolites. “Thus, stem extracts of Costus afer could serve as sources of antioxidants and bioactive compounds for nutrition and therapeutic purposes.”

Pycnanthus angolensis belongs to the Myristicaceae family. It is also called Pycnanthus kombo. The plant common names include African Nutmeg and Wild Nutmeg. In Nigerian languages, it is referred to as akomu in Yoruba, akujaadi in Hausa, and egwunoma in Ibo.

Ethnopharmacological survey of Pycnanthus angolensis, according to a study published in the Journal of Ethnopharmacology, confirms the potency of water extracts of the plant for wound healing and establishes antioxidant activities of the ethanolic extracts of the plant. The plant was reported to be good for stomach ulcer treatment due to its anti-adhesive activity against helicobacter pylori on human stomach cells.

Commonly called grains of paradise or alligator pepper, Aframomum melegueta is a tropical herbaceous perennial plant of the genus Aframomum belonging to the family zingiberaceae (ginger family). The phytochemicals obtained from the seed of Aframomum melegueta has been used for years in the treatment of infectious diseases. The grains of Aframomum melegueta possess active ingredients that may be exploited for local development of antimicrobials.

A study published in International Journal of Biology by researchers from Yaba College of Technology, Lagos concluded: “The plant Aframomum melegueta can be of immense use in phytomedicine and can be included in health care delivery system particularly in the developing economies. Further studies on more effective method of extracting only the necessary constituents and standard reconstitution means as well as other processing, refining and purification measures would be necessary. It can be concluded from this study that the extracts from the seed of Aframomum melegueta showed antimicrobial activity against the tested isolates at high concentration of 50mg/ml. This probably justifies its use as an antimicrobial agent.”

The presence of phenolic compounds in the seed of Aframomum melegueta indicates that this plant is an antimicrobial agents and this is because phenols and phenolic compounds have been extensively used in disinfections and remain the standard with which other bactericides are compared.

Extracts from the seed of Aframomum melegueta with have potent antiseptic or bactericidal properties, have therefore been used in treating wounds and preventions of infections.

Aframomum melegueta was tested for antimicrobial effects on five pathogenic bacteria, which include Bacillus cereus, Staphylococcus aureus, Escherictaia coli, Salmonella typhi and Klebsiella pneumonia. The plant extract of Aframomum melegueta was found inhibitory to the growth of Klebsiella pneumonia and Salmonella typhi.

The findings revealed that extract from Aframomum melegueta contain phytochemicals, which offer an enormous potential as bio control of these pathogens and source of antimicrobial agents of therapeutic importance.

Cola acuminata, a member of the Sterculiaceae family, is called obi-gbanja in Yoruba; goro in Hausa; and Oji in Ibo. It is is a tree and its fruit commonly called Kola nut is chewed widely among the populace for its stimulant effect.

The kola nut has a bitter flavor and contains caffeine. It is chewed in many West African cultures, individually or in a group setting. It is often used ceremonially, presented to tribal chiefs or presented to guests. It is preferred among African Muslims, who are forbidden to drink alcohol.

Chewing kola nut can ease hunger pangs. Kola nuts are often used to treat whooping cough and asthma. The caffeine present acts as a bronchodilator, expanding the bronchial air passages. Frequent chewing of the kola nut can also lead to stained teeth. Among the urban youth of West Africa, kola nut is becoming less popular.

Garcinia kola of the family Guttiferaceae is an indigenous herb in Nigeria colloquially referred to as “bitter kola”, “false kola” or “male kola.” Garcinia kola has been shown to have anti-inflammatory, anti-parasitic, antimicrobial and antiviral properties.

According to a team of researchers led by Maurice Iwu, Garcinia kola, is cultivated and distributed throughout West and Central Africa. Medicinal uses include, purgative, anti-parasitic, and antimicrobial. The seeds are used in the treatment of bronchitis and throat infections. They are also used to prevent and relieve colic, cure head or chest colds and relieve cough. Also the plant is used for the treatment of liver disorders and as a chewing stick.

Iwu in a study titled “New antimicrobials of plant origin” published in the Perspectives on new crops and new uses examined local Nigerian plants for antibiotic (antimicrobial) activities.

Meanwhile, the result of the Ogun State study showed that majority (greater 80 per cent) of the herbalists/Traditional Medicine Practitioner (TMP)/herb sellers claimed no occurrence of side effects following their use of the herbal remedies. The implies that the herbs are devoid of any undesirable effects when used or that the herbalists/TMP/herb sellers never took notice of such effects.

Another issue worthy of note is the average duration of treatment of tuberculosis using herbal remedy, which may be novel when compared to duration of treatment with chemotherapeutic agent. Treatment of tuberculosis by using anti TB requires six to 12 months while from the results obtained, no single duration of treatment of different respondents exceeds 12 weeks.

Some of the challenges encountered in the course of carrying out this survey include: Respondents were unwilling to give relevant information due to the fear of losing their major source of income, some could not distinguish between normal cough, asthma and tuberculosis.

Non experimental validation of anti-tuberculosis activity of these medicinal plants was done by the way of literature survey and it was found out that a number of this plant were been used for the treatment of tuberculosis in West Africa region and other part of the African continent generally (Burkill, 1985; Storey and Salem, 1997).