Ethnobotanical, pharmacological and chemical studies of plants used in the treatment of ‘Mwandza’ dermatites

Ethnobotanical, pharmacological and chemical studies of plants used in the treatment of ‘Mwandza’ dermatites

Fitoterapia 70 Ž1999. 579]585 Ethnobotanical, pharmacological and chemical studies of plants used in the treatment of ‘Mwandza’ dermatites M. Onanga,...

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Fitoterapia 70 Ž1999. 579]585

Ethnobotanical, pharmacological and chemical studies of plants used in the treatment of ‘Mwandza’ dermatites M. Onanga, A. EkouyaU , A. Ouabonzi, G.B. Itoua Laboratoire de Chimie des Plantes Medicinales, Faculte´ des Sciences, Uni¨ ersite´ Marien, Ngouabi, ´ BP 69 Brazza¨ ille, Congo Received 8 January 1999; accepted in revised form 19 May 1999

Abstract An ethnobotanical investigation in the Bokouele ´ ´ country, in the Cuvette region of Congo, was undertaken in order to record some of the plants used by local traditional therapists for the treatment of a disease locally known as ‘Mwandza’. Out of 60 plants recorded, a statistical study of those used in the presumably most efficient protocols, narrowed down the number to 20. Subsequent pharmacological tests have shown that some of these plants exhibit antibacterial andror antitumoral activities. Q 1999 Elsevier Science B.V. All rights reserved. Keywords: Ethnobotany; Congo; Mwandza; Antibacterial activity; Antitumor activity

1. Introduction In the Congo, there is an endemic fatal disease, known by the folk name of ‘Mwandza’ Žthunderbolt in mbochi language.. Actually, Mwandza seems to be a disease not clearly defined from a biomedical point of view and includes several pathologies: eczema, zona, psoriasis, itch, malignant prurigo, pyodermatites, depigmentation, herpes, allergic erythema, etc. Žinterviews of Pr. Itoua Ngaporo A. and Yala F., physicians at the ‘Centre Hospitalier et Universitaire de Brazzaville’.. Since these dermatites are evocative U

Corresponding author.

0367-326Xr99r$ - see front matter Q 1999 Elsevier Science B.V. All rights reserved. PII: S 0 3 6 7 - 3 2 6 X Ž 9 9 . 0 0 1 0 3 - 3

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of the clinical symptoms shown by some AIDS patients and Mwandza was known for some decades before the AIDS onset, it is important to know if a relation exists between Mwandza and AIDS. In 1990 and 1991, an anthropological investigation was undertaken in the Kouilou region, in south Congo, in the sect of healers of Mvulusi and at the A. Cisse ´ Hospital of Pointe-Noire, by a team of ORSTOM ethnologists directed by Franck Hagenbucher w1x. Among the main observations realized by this team, it is possible to mention the following ones: 1. Malignant prurigo which is a symptom highly evocative of the infection by HIV, appears to be the main syndrome of a disease called Mwandza Žthis disease, originating from north Congo, actually advances in the seaside front keeping the same name.; 2. The other symptoms mentioned by the folk doctors of Mvulusi are thinning down, fever, asthenia, herpes and zona; 3. Does the Mwandza representation grow gradually, incidentally and differently from other clinical signs of AIDS? The team of anthropologists could not answer clearly this question, because they could not study Mwandza in its original environment. However, this anthropological investigation corroborates the fact that the various pathologies connected to Mwandza are usually encountered as opportunist diseases of AIDS. The greater effectiveness of folk medicine with respect to modern medicine in the management of Mwandza is certified by the fact that certain traditional therapeutists often succeeded either to cure definitively or to significantly improve the health of patients who could not be cured by modern medicine. The social importance of Mwandza and the great efficiency of folk medicine in its treatment, justify all studies that aim to give a better knowledge of Mwandza and to the valorization of its traditional therapy. With the therapeutic evaluation in mind, our research team undertook ethnobotanical, pharmacological and chemical studies with the following specific targets: 1. To identify the plants which are really useful, in order to simplify the care protocol and to fight against mystifications; 2. To obtain and use only active extracts andror isolated constituents for better recipes; 3. To eliminate extracts andror compounds which are toxic or possess important secondary effects.

2. Methodology 2.1. Ethnobotany The ethnobotanical investigation was carried out at Bokouele and its surround-

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ings, in the Congo basin country, in north Congo, at nearly 450 km from Brazzaville. This site is known as an important center for Mwandza treatment. The following 10 healers were contacted: Etokabeka Georges, Ikolo Bernard, Kaki Albert, Kobo Nicodeme, Koya Albert, Mboumabeka Euphrene, Ololo Michel, ` ` Ombete Philippe, Omeni Blaise and Onanga Omer. In order to assure the protection of their secrets, each healer was individually consulted on the various clinical signs of the illness, on the protocols used for each form of the disease, the mode of preparation of the drugs and the plants used in each protocol. 2.2. Chemistry Using classical chemical tests w2,3x, plants were screened at the place of collection for the detection of main secondary metabolites. Freeze-dried aqueous extracts of the ground dried plant materials Žalways trunk barks in this phase of preliminary screening. were prepared for the bioassays. Table 1 Mwandza dermatites: treatments, clinical signs and protocols used by healers for their cure Nature of the treatment

Clinical signs of the different forms of the disease

Therapeutic protocols

Curative

Depigmentation of the skin

1. Incision on the depigmented zones followed by applications of a toasted bark powder of a selection of plants. 2. Local massage with a selection of plants

Itching Swelling Constellation of pimples

3. Coating the body with an ointment made from oil Žspecific palm tree oil depending on the case. and bark powder of specific plants. 4. Drinking of a beverage made from the juice of braised leaves of specific plants. 5. Eating of pieces of crude parts of plants purposely allotted to several heaps to be taken at different specific moments during the day. 6. Wearing a bracelet made with plant fibers and bird feathers Žat the end of the treatment ..

Leprosy-like sores with alternation of warmth and coldness sensations

7. Drinking of a decoction of a mixture of stem barks of several plants in palm wine Žthree glasses per day, in the morning, at noon and in the evening.. 8. Bathing with an aqueous maceration Žfor one night. of the barks of various plants.

None

9. Regular Žweekly or monthly. absorption of a potion obtained by maceration in palm wine of some 15 plants selected among the most used in curative treatments Žthe resulting solution is exposed to the sun light for several days before use..

Preventive

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2.3. Pharmacology The lyophilisates were then tested for eventual antibacterial and antitumoral activities by two specialized laboratories of the Institut de Chimie des Substances Naturelles of CNRS at Gif-sur-Yvette ŽFrance.. 1. Antibacterial activity determined by disk diffusion method w4x against Escherichia coli, Pseudomonas aeruginosa, Proteus ¨ ulgaris and Staphylococcus aureus. 2. Antitumoral activity determined by cytostase on human cancer cells ŽKB cells.. The test extracts were deposited when the culture started. After 3 days, inhibition percentages were estimated by a colorimetric method using neutral red, by comparison with reference cells w5x.

3. Results and discussion 3.1. Ethnobotanical in¨ estigation Following the indications of the healers, 60 plants were checked, collected and Table 2 Main plants used for the treatment of Mwandza dermatites a N8

1 2 3 4 5 6

Vernacular name

Scientific name

Family

Users Žfrequency.

Yandza Onkouele Onka Keba Mbouele Omamayi

Klainedoxa gabonensis Pierre ex Engl. Lophira alata Banks ex Gaertn. f. Daniellia pynaertii De Wild. Coelocaryon preussii Warb. Carapa procera DC. Tetrorchidium didymostemon ŽBaill.. Pax et K. Hoffm. Alstonia booeni De Wild. Carapa procera DC.var. palustre Ongokea gore ŽHua.Pierre Milicia excelsa ŽWelw.. C.C. Berg Syzygium sp. Macaranga sp. Costus afer Ker-Gawl. Olax wildemanii Engl. Berlinia congolensis ŽE.G. Backer. Keay Piptadeniastrum africanum ŽHook f.. Brenan Nauclea latifolia Sm. Kalanchoe crenata Britten Justicia insularis T. Anders. Polygonum sp.

Irvingiaceae Ochnaceae Caesalpiniaceae Myristicacea Meliaceae Euphorbiaceae

10r10 9r10 7r10 7r10 7r10 7r10

Apocynaceae Meliaceae Olacaceae Moraceae Myrtaceae Euphorbiaceae Zingiberaceae Olacaceae Caesalpiniaceae Mimosaceae Rubiaceae Crassulaceae Acanthaceae Polygonaceae

7r10 6r10 6r10 5r10 5r10 5r10 5r10 5r10 4r10 4r10 4r10 4r10 4r10 4r10

7 8 9 10 11 12 13 14 15 16

Onkoua Opessi Onguehe Onlondo Ekongo Oteli Mwamwande Ondzendzenli Boloho Onkoungou

17 18 19 20

Idoudouhou Djoa Indoho Itelama a

Use frequency: number of healers using the plantrtotal number Ž10. of contacted healers.

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Table 3 Phytochemical screening of plants used by healers in the treatment of Mwandza dermatites a Plants

Alkaloids

Flavonoids

Tannins

Saponins

Quinones

Steroids Terpenoids

Klainedoxa gabonensis Lophira alata Daniella pynaertii Coelocaryon preussii Carapa procera Tetrorchidium didymostemon Alstonia boonei Carapa procera var. palustre Ongokea gore Milicia excelsa Syzygium sp. Macaranga sp. Berlinia congolensis Piptadeniastrum africanum

q y y q q y

y y y y q y

q q q q y y

y y y q q q

q y y y y y

" y y q y y

q q

y q

y y

y q

y y

q y

q y y q y y

y q q q y y

q q q q q q

y q y y q q

y y y y y y

y y y y q

a

y

q , positive test; y, negative test.

identified at the Faculte ´ des Sciences de Brazzaville and at the National Herbar´ ŽCERVE. of Brazzaville. ium of the Centre d’Etudes sur les Ressources Vegetales ´´ Plants and treatment modalities are chosen by the healers according to the clinical signs presented by the patient as shown in Table 1. Treatments last on a variable time period, from 1 to 3 months, according to the stage and the form of the disease. The cures are given in a detached place, especially set up, in the open air under the shade of trees, in the backyard of the healer’s house.

Table 4 Antibacterial activity of the aqueous extracts of plants used by healers in the treatment of Mwandza dermatites a Extract

Klainedoxa gabonensis Carapa procera Syzygium sp. Piptadeniastrum africanum

Yield Ž%.

Tested concentration Žmgrml.

Inhibition zone Žmm. E.c.

P.a.

P.¨ .

S.a.

0.50

16

y

q

q

qqq

1.76 1.54 1.85

13 15.2 16.8

y y "

y y q

q q q

qq qq q

a Inhibition zone.y, no inhibition; ", - 10 mm; q, 10]11 mm; qq, 12]15 mm; qqq, ) 15 mm. E.c. s Escherichia coli; P.a. s Pseudomonas aeruginosa; P.v. s Proteus ¨ ulgaris; S.a. s Staphylococcus aureus.

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Successful treatments, apparently the majority, are characterized either by total cure Žhealth recovery and definitive disappearance of the symptoms. or remission Žhealth improvement and temporary disappearance of the symptoms.. However, the most severe forms, as purulent sores, are often fatal when treatment fails. The protocols ŽTable 1. n. 1 Žpowder., n. 3 Žointment., n. 7 Ždecoction. and n. 8 Žmaceration., claimed as the most efficient, and the frequency of plant utilization in these protocols led us to select a first group of 20 plants, belonging to 16 different families ŽTable 2., for preliminary phytochemical and biological study. Since the above protocols are all based on the use of barks of specific plants, the trunk barks of the selected plants have been used in these studies. 3.2. Phytochemical screening The results obtained on 14 of the most interesting plants are shown in Table 3. 3.3. Antibacterial acti¨ ity Four plants showed some activity, even if none against all tested strains ŽTable 4.. 3.4. Antitumoral acti¨ ity At 50 mgrml, all extracts were atoxic to KB human tumor cells with the exception of Klainedoxa gabonensis and Piptadeniastrum africanum Žinhibition 77 and 15%, respectively.. As K. gabonensis seemed to be the most active plant, a further preliminary study was made with different solvent successive extracts Ždichloromethane, ethyl ether, ethyl acetate, methanol, water.. Methanolic extract showed higher antibacterial activity when ethereal extract was the most cytotoxic indicating that different active constituents might be responsible for these two biological properties Ždata not shown.. In conclusion, among the 60 plants said to be used by the 10 healers from Bokouele for the treatment of this serious endemic disease called ‘Mwandza’, 20 plants were selected as they were claimed to be the most effective and because of the frequency of their use in these protocols. The studies performed on the aqueous extracts of the trunk barks of the selected plants led to the following results: 1. Four species possess antibacterial acticity, two of them with a wide spectrum; 2. Two species show antitumor activity, one with high level of growth inhibition of human tumor cells KB; 3. For the most potent plant, antibacterial and cytotoxic active constituents seem to be different from those present in different extracts Žmethanol and ethyl ether extracts, respectively..

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These results suggest that a more detailed chemical investigation of active plants, particularly of Klainedoxa gabonensis, is necessary. Moreover, further pharmacological studies, with the collaboration of clinicians, if possible, are deserved.

Acknowledgements Authors are thankful to Dr Franc¸oise Khuong-Huu, CNRS, Institut de Chimie des Substances Naturelles, Gif-sur-Yvette, France for her help in this study and to Mrs C. Servy and C. Tempete ˆ for the determination of antibacterial and antitumor activities.

References w1x w2x w3x w4x w5x

Hagenbucher F. Rapport d’enquete anthropologique, Congo. Paris: ORSTOM, 1991. Fansworth NA. J Pharm Sci 1966;55:225. Bouquet A. Med ´ Trop 1968;28:49. Bauer AW, Kirby WM, Sherris JC, Turck M. Am J Clin Pathol 1966;45:493. Finter NB. J Gentile Virol 1969;5:419.