Journal of’ Etllnopircrn~lrrc~ol(ig~, 35
Elsevier Scientific
Publishers
( 1992)
Ireland
259
259-262
Ltd.
Study of Rwandese
medicinal plants used in the treatment scabies
G. Heyndrickx”, ‘Centre
de Recherehe sur la Pharmacopee
Technologique -
P. Brioenb and L. Van Puyvelde”
et la Mkdecinr
Traditionnelle
I.R.S. T., B. P. 227, Butare and hDtfpartement B.P.
-
CURPHAMETRA,
de Pharmacie.
Far&!
Institut de Recherche Scientifique
des Sciences, VniversitP Nationale
August
23, 1991)
A series of 15 medicinal plants used in the Rwandese traditional medicine to treat scabies has been screened against the mite Psoroptes cunicuh’. Four of the plants tested showed anti-scabies activity. activity;
Rwandese
traditional
and Methods
Plant materials
Plants were collected and identified by the authors. Voucher herbarium specimens are preserved in the herbarium of the Institut de Recherthe Scientifique et Technologique, Butare (Rwanda). Plant parts were dried in an oven at 40°C and powdered mechanically.
Correspondence
to: L. Van Belgium.
037%8741/92/.$05.00
Printed
activity
Preparation of extracts
In Rwanda, scabies is the most important problem in parasitic dermatology. In order to find new anti-scabies agents, a series of 15 medicinal plants used in the Rwandese traditional medicine to treat scabies (according to our personal enquiries directed towards traditional healers and farmers) (Van Puyvelde et al., 1975, 1977a,b, 1982; Desouter, 1982) was investigated for anti-scabies activity. The screening was performed in Petri dishes containing an agar layer with the plant extract on top. The mites were put in the centre and mortality was observed after 24 h of incubation.
Waasmunster,
for anti-scabies
medicine
IR~~UCtiOR
Materials
et
du Rwanda,
117, Butare (Rwanda)
(Accepted
Key words: anti-scabies
of
and Published
Puyvelde.
1992 Elsevier in Ireland
0
Maretak
Scientific
101, 9250
Publishers
Ireland
Approximately 30 g of the plant powder was extracted in a percolator with 95” ethanol until exhaustion. The ethanolic extract was evaporated under reduced pressure (40°C). The residue was taken up in 95” ethanol to obtain a con~ntration of 30 mglml. From the plant parts which had 100% lethal activity, four dilutions in 95” ethanol were prepared (IO-‘, lo-*, 10e3, 10e4). Four other extracts from each active plant were prepared by successive percolations with n-hexane, chloroform, water and 95” ethanol. After evaporation of the solvent under reduced pressure (40”(Z), the residues were taken up in their respective extraction solvent at a concentration of 30 mg/ml. Four dilutions were prepared (IO-‘, 10e2, 10m3, 10e4). Biological material All stages of Psoroptes cuniculi mites were used
in this test (larvae, nymphae, adults). As a reservoir we used naturally infected rabbits with ear mange. Anti-scabies activity
The screening of the plant extracts for antiscabies activity was performed by contact of the mites with the plant extract and monitoring the lethal activity. Ltd,
The extract (1.5 ml) was equally spread on the surface of a Petri dish (4 7.6 cm) containing an agar (1.5%) layer. The solvent was evaporated in a laminar air flow for 1 h. The concentration of the plant extract on the surface of the agar layer was TABLE
1 mgkm2 for the highest concentration. At least 30 mites of all stages were put in the centre of the plant extract and the closed Petri dishes were incubated for 24 h at 28°C and 80-90” humidity. All tests were made in triplicate. On each experimental
1
ANTI-SCABIES Botanical
ACTIVlTY
name (Family)
COIL No.
Aim2fhff.s pubim~n.s
(Thomson
ex Oliver)
Folk name
Plant parts”
Activityh
20
lgitovu
L
-
61
Umwisheke
22
Umugombe
L FL L
48
Umusununu
L
54
lgihondohondo
L
I4
timukararambwe
L
Umunindi
L
Umusororo
L
I17
lreke
L
223
lgitembatembe
R
Engl.
(Acanthaceae) Chmrywdiunt
unihrosioider
L. (Chenopodiaceae) Ciwnopodiurn
ugonrlur
(Aellen) Aellen (Chenopodiaceae) Cru.s,~~~~t~~~~rrlu,,t ~~iri~l~ii~u~ (Benth.) S. Moore (Compositae) Drucurnu
.srrurlnwi
Engl. ( AgdVaCcde)
Gu~iu#7 spurilrnt L. subsp. ~f~i~;~nun~ Verde. (Rubiaceae) Hetcw~morphu rr(/idiuttr (Wendl.) Ecklon (Apiaceae) Inrtigofiw
Hochst.
282
et Zeyher
urrwiu
ex A. Rich.
(Leguminosae) Kufunchoe
in/qru
(Med.) 0. Kuntze (Crassulaceae) Nrwruuruncniu
miris
Verde
(A. Rich.) (Leguminosae) Pt*ntus l~~n~~~l~~r{i
374
L R
Oliv. (Rubiaceae) Ph~1olucc~u dud~wmdru
62
Umuhoko
I_ FR
Umukubagwa
L R
86
lgonde
L
31
Nkulimwonga
L
L’Herit (Phytolaccaceae) P.s~~r[~.sp~rn?u~? ,~~~r~~i~.?u~?f
237
Spach (Clusiaceae) Swmum
ungolcwe
Welw. (Pedaliaceae) Thdwrgiu
ululu
Boyer ex Sims (Acanthaceae) “L. leaf; R, root; FL, flower; FR, fruit, hlOO’X~mortality of the mites.
TABLE
2
ANTI-SCABIES TRATIONS
ACTIVITY
AT DIFFERENT
Plant
Heteromorpha
trifoliata
(leaf)
Neorautanenia
mitis (root)
Concentration mg/cm2
Anti-scabies activity
1 10-I 10-Z 10-J 10-4 1
+ -
10-l 10-Z 10-3 10-4 Pentas longiflora (root)
Psorospermum
febrifugum
1 10-l 10-Z 10-3 (root)
CONCEN-
10-4 1 10-l 10-2 10-3 10-4
+ + + +
Upon testing the ethanolic extract at different concentrations, the roots of N. mitis and P. longzjlora showed the greatest activity (Table 2). The results of the anti-scabies tests with the different fractions are summarized in Tables 3, 4, 5 and 6. The extract of N. mitis even showed activity at a concentration of 1 &cm2. This plant also has a good acaricidal activity (Van Puyvelde et al., 1985) and several iso-flavone type compounds were isolated from the roots, among them 120+ hydroxyrotenone (Van Puyvelde et al., 1987). It has to be noted that pure rotenone was used as an anti-scabies agent (Steeker, 1968). Actually, an anti-scabies solution and ointment, prepared with an ethanolic extract from the roots of N. mitis, are available commercially in Rwanda.
+ + + -
Acknowledgement
+ -
The authors are indebted to the Belgian Administration for Development Cooperation for financial support.
day, three control series with 30 mites of all stages were set up. In the first one 1.5 ml of a solution of 0.1% lindane* in acetone, a well-known scabicide, was used; in the second 1.5 ml of the respective extraction solvent was spread on the agar layer. Solvents were dried as described above. In the third control series, an untreated agar layer was used. After incubation, the Petri dishes were controlled with a binocular lens, magnification x 10. As a measure for antiscabies activity two factors were considered: (i) no mites on the cover of the dish, and (ii) no movement at all. Only 100% lethal activity was taken as a positive test (+).
TABLE
ANTI-SCABIES OF THE LEAF Extract
Hexane
Chloroform
mol.
Concentration
Anti-scabies activity
I 10-l
-
10-z 10-J 10-4 I
_
10-l 10-1 10-j 10-4 Water
lLindane: 1,2,3,4,5,6-hexachlorocyclohexane (C,H&l,; wt. 290.85), a well-known insecticide, scabicide.
ACTIVITY OF DIFFERENT EXTRACTS OF HETEROMORPHA TRIFOLIATA
mglcm’
Results and Discussion
Out of 15 plants tested (19 plant samples), four showed an anti-scabies activity (100% mortality) in this test (Table 1). The control with lindane showed 100% morality. In the two other controls, no mortality was observed.
3
+
_
I 10-l 10-2 10-3
_ _ _
1o-J Ethanol
I
_
10-l 10-2 lo-3 10-4
_ _
262
TABLE
4
ANTI-SCABIES OF THE ROOT Extract
TABLE ACTIVITY OF DIFFERENT EXTRACTS OF NEORAUTANENIA MITIS Concentration m@icm 2
Hexane
Chloroform
Water
Ethanol
I 10-l 10-2 10-1 1O-4 I 10-I 10-z 10-3 10-4 I IO-’ 10-Z 10-j 10-h 1 10-l 10-Z
Anti-scabies activity
6
ANTI-SCABIES OF THE ROOT Extract
Concentration mgicm*
Anti-scabies Activity
Hexane
I 10-l 10-z 10-s lO-4 1 10-I 10-z 10-X 10-4 I 10-i 10-2 10-i
+ _
+ + + + Chloroform + + + + -
-
ACTIVITY OF DIFFERENT EXTRACTS OF PSOROSPERMUM FEBRIFUGUM
Water
Ethanol
+ + +
10-s 10-4
lO-4 1 lo- ’ 10-l 10-7 1o-4
_ _ _ _ _ _
-
References
TABLE
Desouter, S. (1982) Abr@ Agro-Pustoral Rwundu. Agence de Cooperation Culturelle et Technique, Paris, p. 144. Steeker, P.C. (1968) The Merck Index. Merck and Co., Inc., Rahway, N.Y., p. 923.
5
ANTI-SCABIES OF THE ROOT
ACTIVITY OF DlFFERENT OF PENTAS LONGIFLORA
EXTRACTS
Extract
Concentration rnp/o’
Anti-scabies activity
Hexane
1 10-l 10-Z 10-s 10-J 1 IO“ 10-2 10-I 10-e
f + +
Chloroform
Water
Ethanol
I 10-I 10-z 10-s 10-d I 10-l 10-z 10-I 10-h
+ + + -
_ _ + + _
Van Puyvelde, L., Pagezy, H. and Kayonga, A. (1975) Plantes medicinales et toxiques du Rwanda (I). AjiVque MPdit,ufe 14, 935-930. Van Puyvelde, L., Mukarugambwa, S., Rwangabo. P.C.. Nyaboyisonga. M. and Runyinya-Bwarabwiliza (1977a) Plantes Medicinales et Toxiques du Rwanda (It). Afrique Medicale, 16, 53 l-534. Van Puyvelde, L., Nyaboyisonga, M., Rwangabo, PC., Mukarugambwa, S., Kayonga, A. and RunyinyaBwarabwiliza (197lb) Enyuites Ethnoholuniques sur b ML’decine Truditionnelle Rwundrri.ve. Vol. I, Prefecture de Kibuye, UNR, Butare. Rwanda, p. 80. Van Puyvelde, L., Rwangabo, P.C., Runyinya-Bwarabwihza, Ayobangira, F.X. and Mungarulire. J. (1982) Piantes medicinales et toxiques du Rwanda (III). Afiique Medicufe 21, 401-404. Van Puyvelde, L., Geysen, D., Ayobangira, F.X., Hakizamungu, E., Nshimyimana, A. and Kalisa, A. (1985) Screening of medicinal plants of Rwanda for acaricidal activity. Journal of Ethnophnrmocology 13, 209-215. Van Puyvelde, L., De Kimpe, N., Mudaheranwa, J.P., Gasiga, A., Schamp, N., Declercq, J.P. and Van Meerssche, M. (1987) Isolation and structural elucidation of potentially insecticidal and acaricidal isoflavone-type compounds from Neorautunenia mitis. Journcrl qf Nuiurul Products 50, 349-356.
Elsevier Scientific
Publishers
( 1992)
Ireland
259
259-262
Ltd.
Study of Rwandese
medicinal plants used in the treatment scabies
G. Heyndrickx”, ‘Centre
de Recherehe sur la Pharmacopee
Technologique -
P. Brioenb and L. Van Puyvelde”
et la Mkdecinr
Traditionnelle
I.R.S. T., B. P. 227, Butare and hDtfpartement B.P.
-
CURPHAMETRA,
de Pharmacie.
Far&!
Institut de Recherche Scientifique
des Sciences, VniversitP Nationale
August
23, 1991)
A series of 15 medicinal plants used in the Rwandese traditional medicine to treat scabies has been screened against the mite Psoroptes cunicuh’. Four of the plants tested showed anti-scabies activity. activity;
Rwandese
traditional
and Methods
Plant materials
Plants were collected and identified by the authors. Voucher herbarium specimens are preserved in the herbarium of the Institut de Recherthe Scientifique et Technologique, Butare (Rwanda). Plant parts were dried in an oven at 40°C and powdered mechanically.
Correspondence
to: L. Van Belgium.
037%8741/92/.$05.00
Printed
activity
Preparation of extracts
In Rwanda, scabies is the most important problem in parasitic dermatology. In order to find new anti-scabies agents, a series of 15 medicinal plants used in the Rwandese traditional medicine to treat scabies (according to our personal enquiries directed towards traditional healers and farmers) (Van Puyvelde et al., 1975, 1977a,b, 1982; Desouter, 1982) was investigated for anti-scabies activity. The screening was performed in Petri dishes containing an agar layer with the plant extract on top. The mites were put in the centre and mortality was observed after 24 h of incubation.
Waasmunster,
for anti-scabies
medicine
IR~~UCtiOR
Materials
et
du Rwanda,
117, Butare (Rwanda)
(Accepted
Key words: anti-scabies
of
and Published
Puyvelde.
1992 Elsevier in Ireland
0
Maretak
Scientific
101, 9250
Publishers
Ireland
Approximately 30 g of the plant powder was extracted in a percolator with 95” ethanol until exhaustion. The ethanolic extract was evaporated under reduced pressure (40°C). The residue was taken up in 95” ethanol to obtain a con~ntration of 30 mglml. From the plant parts which had 100% lethal activity, four dilutions in 95” ethanol were prepared (IO-‘, lo-*, 10e3, 10e4). Four other extracts from each active plant were prepared by successive percolations with n-hexane, chloroform, water and 95” ethanol. After evaporation of the solvent under reduced pressure (40”(Z), the residues were taken up in their respective extraction solvent at a concentration of 30 mg/ml. Four dilutions were prepared (IO-‘, 10e2, 10m3, 10e4). Biological material All stages of Psoroptes cuniculi mites were used
in this test (larvae, nymphae, adults). As a reservoir we used naturally infected rabbits with ear mange. Anti-scabies activity
The screening of the plant extracts for antiscabies activity was performed by contact of the mites with the plant extract and monitoring the lethal activity. Ltd,
The extract (1.5 ml) was equally spread on the surface of a Petri dish (4 7.6 cm) containing an agar (1.5%) layer. The solvent was evaporated in a laminar air flow for 1 h. The concentration of the plant extract on the surface of the agar layer was TABLE
1 mgkm2 for the highest concentration. At least 30 mites of all stages were put in the centre of the plant extract and the closed Petri dishes were incubated for 24 h at 28°C and 80-90” humidity. All tests were made in triplicate. On each experimental
1
ANTI-SCABIES Botanical
ACTIVlTY
name (Family)
COIL No.
Aim2fhff.s pubim~n.s
(Thomson
ex Oliver)
Folk name
Plant parts”
Activityh
20
lgitovu
L
-
61
Umwisheke
22
Umugombe
L FL L
48
Umusununu
L
54
lgihondohondo
L
I4
timukararambwe
L
Umunindi
L
Umusororo
L
I17
lreke
L
223
lgitembatembe
R
Engl.
(Acanthaceae) Chmrywdiunt
unihrosioider
L. (Chenopodiaceae) Ciwnopodiurn
ugonrlur
(Aellen) Aellen (Chenopodiaceae) Cru.s,~~~~t~~~~rrlu,,t ~~iri~l~ii~u~ (Benth.) S. Moore (Compositae) Drucurnu
.srrurlnwi
Engl. ( AgdVaCcde)
Gu~iu#7 spurilrnt L. subsp. ~f~i~;~nun~ Verde. (Rubiaceae) Hetcw~morphu rr(/idiuttr (Wendl.) Ecklon (Apiaceae) Inrtigofiw
Hochst.
282
et Zeyher
urrwiu
ex A. Rich.
(Leguminosae) Kufunchoe
in/qru
(Med.) 0. Kuntze (Crassulaceae) Nrwruuruncniu
miris
Verde
(A. Rich.) (Leguminosae) Pt*ntus l~~n~~~l~~r{i
374
L R
Oliv. (Rubiaceae) Ph~1olucc~u dud~wmdru
62
Umuhoko
I_ FR
Umukubagwa
L R
86
lgonde
L
31
Nkulimwonga
L
L’Herit (Phytolaccaceae) P.s~~r[~.sp~rn?u~? ,~~~r~~i~.?u~?f
237
Spach (Clusiaceae) Swmum
ungolcwe
Welw. (Pedaliaceae) Thdwrgiu
ululu
Boyer ex Sims (Acanthaceae) “L. leaf; R, root; FL, flower; FR, fruit, hlOO’X~mortality of the mites.
TABLE
2
ANTI-SCABIES TRATIONS
ACTIVITY
AT DIFFERENT
Plant
Heteromorpha
trifoliata
(leaf)
Neorautanenia
mitis (root)
Concentration mg/cm2
Anti-scabies activity
1 10-I 10-Z 10-J 10-4 1
+ -
10-l 10-Z 10-3 10-4 Pentas longiflora (root)
Psorospermum
febrifugum
1 10-l 10-Z 10-3 (root)
CONCEN-
10-4 1 10-l 10-2 10-3 10-4
+ + + +
Upon testing the ethanolic extract at different concentrations, the roots of N. mitis and P. longzjlora showed the greatest activity (Table 2). The results of the anti-scabies tests with the different fractions are summarized in Tables 3, 4, 5 and 6. The extract of N. mitis even showed activity at a concentration of 1 &cm2. This plant also has a good acaricidal activity (Van Puyvelde et al., 1985) and several iso-flavone type compounds were isolated from the roots, among them 120+ hydroxyrotenone (Van Puyvelde et al., 1987). It has to be noted that pure rotenone was used as an anti-scabies agent (Steeker, 1968). Actually, an anti-scabies solution and ointment, prepared with an ethanolic extract from the roots of N. mitis, are available commercially in Rwanda.
+ + + -
Acknowledgement
+ -
The authors are indebted to the Belgian Administration for Development Cooperation for financial support.
day, three control series with 30 mites of all stages were set up. In the first one 1.5 ml of a solution of 0.1% lindane* in acetone, a well-known scabicide, was used; in the second 1.5 ml of the respective extraction solvent was spread on the agar layer. Solvents were dried as described above. In the third control series, an untreated agar layer was used. After incubation, the Petri dishes were controlled with a binocular lens, magnification x 10. As a measure for antiscabies activity two factors were considered: (i) no mites on the cover of the dish, and (ii) no movement at all. Only 100% lethal activity was taken as a positive test (+).
TABLE
ANTI-SCABIES OF THE LEAF Extract
Hexane
Chloroform
mol.
Concentration
Anti-scabies activity
I 10-l
-
10-z 10-J 10-4 I
_
10-l 10-1 10-j 10-4 Water
lLindane: 1,2,3,4,5,6-hexachlorocyclohexane (C,H&l,; wt. 290.85), a well-known insecticide, scabicide.
ACTIVITY OF DIFFERENT EXTRACTS OF HETEROMORPHA TRIFOLIATA
mglcm’
Results and Discussion
Out of 15 plants tested (19 plant samples), four showed an anti-scabies activity (100% mortality) in this test (Table 1). The control with lindane showed 100% morality. In the two other controls, no mortality was observed.
3
+
_
I 10-l 10-2 10-3
_ _ _
1o-J Ethanol
I
_
10-l 10-2 lo-3 10-4
_ _
262
TABLE
4
ANTI-SCABIES OF THE ROOT Extract
TABLE ACTIVITY OF DIFFERENT EXTRACTS OF NEORAUTANENIA MITIS Concentration m@icm 2
Hexane
Chloroform
Water
Ethanol
I 10-l 10-2 10-1 1O-4 I 10-I 10-z 10-3 10-4 I IO-’ 10-Z 10-j 10-h 1 10-l 10-Z
Anti-scabies activity
6
ANTI-SCABIES OF THE ROOT Extract
Concentration mgicm*
Anti-scabies Activity
Hexane
I 10-l 10-z 10-s lO-4 1 10-I 10-z 10-X 10-4 I 10-i 10-2 10-i
+ _
+ + + + Chloroform + + + + -
-
ACTIVITY OF DIFFERENT EXTRACTS OF PSOROSPERMUM FEBRIFUGUM
Water
Ethanol
+ + +
10-s 10-4
lO-4 1 lo- ’ 10-l 10-7 1o-4
_ _ _ _ _ _
-
References
TABLE
Desouter, S. (1982) Abr@ Agro-Pustoral Rwundu. Agence de Cooperation Culturelle et Technique, Paris, p. 144. Steeker, P.C. (1968) The Merck Index. Merck and Co., Inc., Rahway, N.Y., p. 923.
5
ANTI-SCABIES OF THE ROOT
ACTIVITY OF DlFFERENT OF PENTAS LONGIFLORA
EXTRACTS
Extract
Concentration rnp/o’
Anti-scabies activity
Hexane
1 10-l 10-Z 10-s 10-J 1 IO“ 10-2 10-I 10-e
f + +
Chloroform
Water
Ethanol
I 10-I 10-z 10-s 10-d I 10-l 10-z 10-I 10-h
+ + + -
_ _ + + _
Van Puyvelde, L., Pagezy, H. and Kayonga, A. (1975) Plantes medicinales et toxiques du Rwanda (I). AjiVque MPdit,ufe 14, 935-930. Van Puyvelde, L., Mukarugambwa, S., Rwangabo. P.C.. Nyaboyisonga. M. and Runyinya-Bwarabwiliza (1977a) Plantes Medicinales et Toxiques du Rwanda (It). Afrique Medicale, 16, 53 l-534. Van Puyvelde, L., Nyaboyisonga, M., Rwangabo, PC., Mukarugambwa, S., Kayonga, A. and RunyinyaBwarabwiliza (197lb) Enyuites Ethnoholuniques sur b ML’decine Truditionnelle Rwundrri.ve. Vol. I, Prefecture de Kibuye, UNR, Butare. Rwanda, p. 80. Van Puyvelde, L., Rwangabo, P.C., Runyinya-Bwarabwihza, Ayobangira, F.X. and Mungarulire. J. (1982) Piantes medicinales et toxiques du Rwanda (III). Afiique Medicufe 21, 401-404. Van Puyvelde, L., Geysen, D., Ayobangira, F.X., Hakizamungu, E., Nshimyimana, A. and Kalisa, A. (1985) Screening of medicinal plants of Rwanda for acaricidal activity. Journal of Ethnophnrmocology 13, 209-215. Van Puyvelde, L., De Kimpe, N., Mudaheranwa, J.P., Gasiga, A., Schamp, N., Declercq, J.P. and Van Meerssche, M. (1987) Isolation and structural elucidation of potentially insecticidal and acaricidal isoflavone-type compounds from Neorautunenia mitis. Journcrl qf Nuiurul Products 50, 349-356.
