Background
Methods
Collection and identification of plant
Preparation of plant extracts
Isolation of O. ochengi adult worms
Isolation of O. ochengi microfilariae
Preparation of mammalian cells
Preparation of stock solutions of plant extracts
Anti-filarial screening of plant extracts
Primary screens on adult worms
Primary screen on microfilariae
Secondary screens on microfilariae and adult worms
Toxicity studies
Cytotoxicity studies
Acute toxicity test
Gas chromatography–mass spectrometry (GC/MS) analysis
Results
Preparation of plant extracts
Name of plant | Plant part used | Mass of dry powder or residue (approx.)/g | Solvent | Mass of extract/g | % Recovery of extract | Extract code |
---|---|---|---|---|---|---|
Cyperus articulatus
| Root/rhizome | 700 | Hexane | 26.2 | 3.74 | *CARhex
|
673.8 | Methylene chloride | 5.8 | 0.86 | CARmc
| ||
668 | Methanol | 72.2 | 10.8 | CARmet
|
Activity of extracts of roots/rhizomes C. articulatus in primary screens
Test substance (concentration tested) | % Microfilarial motility reduction | % Adult male worm motility reduction | % Adult female worm death | Comment |
---|---|---|---|---|
CARhex (500 μg/ml) | 100 | 100 | 100 | Macro- and microfilaricidal |
CARmc (500 μg/ml) | 25 | 50 | 25 | Inactive |
CARmet (500 μg/ml) | 25 | 75 | 25 | Inactive on Mfs and adult females; moderately active on adult males |
Ivermectin (10 μg/ml) | 100 | NA | NA | Microfilaricidal |
NYBC01 (10 μM) | 100 | 100 | 100 | Macro- and microfilaricidal |
DMSO (2%) | 0 | 0 | 0 | Inactive |
Activity of the essential oil in secondary screens and cytotoxicity test
Parameter | Microfilariae | Adult male worm | Adult female worm | Monkey kidney cells (LLC-MK2) |
---|---|---|---|---|
IC50 (μg/ml) | 23.4 | 23.4 | 31.25 | 93.7 |
IC100 (μg/ml) | 62.5 | 62.5 | 125 | 250 |
SI = IC50 MKC/IC50 worm | 4.0 | 4.0 | 2.99 | - |
Acute oral toxicity test of the essential oil in mice
GC/MS analysis of the essential oil
Monoterpenes | ||
---|---|---|
Compound (Chemical name) | Retention time (RT) min | Nature of compound |
Camphenol, 6- | 4.4913 | Monoterpene alcohol |
Bicyclo[3.1.1 ]heptan-3-ol, 6,6-dimethyl-2-methylene-, [1S-(1 à,3à,5à)]- | 4.7638 | -do- |
Bicyclo[3.1.1 ]hept-3-en-2-ol, 4,6,6-trimethyl-, [1S-(1 à,2a,5à)]- | 4.8523 | -do- |
Bicyclo[3.1.0]hexan-3-ol, 4-methylene-1-(1-methylethyl)-, [1.S-(1 à,3a,5à)]- | 4.9535 | -do- |
(−)-Myrtenol | 5.8193 | -do- |
Bicyclo[3.1.0]hex-3-en-2-one, 4-methyl-1-(1-methylethyl)- | 6.0775 | Monoterpene ketone |
Bicyclo[3.1.1 ]hept-3-en-2-one, 4,6,6-trimethyl-,(1S)- | 6.0815 | -do- |
3,5-Heptadienal, 2-ethylidene-6-methyl- | 6.2340 | Monoterpene aldehyde |
Bicyclo[4.4.0]dec-2-ene-4-01, 2-methyl-9-(prop-1-en-3-01-2-yl)- | 15.8243 | |
Sesquiterpenes
| ||
Isolongifolene, 9,10-dehydro- | 9.0658 | Hydroxy compound |
Copaene | 9.2450 | |
α-Cubebene | 9.3067 | |
Cadina-1 (10),6,8-triene | 9.3247 | |
7-Tetracyclo[6.2.1.0(3.8)O(3.9)]undecanol, 4,4,11,11-tetramethyl- | 11.0275 | Sesquiterpene alcohol |
Naphthalene, 1,2,3,4,4a,5,6,8a-octahydro-7 -methyl-4-methylene-1-(1-methylethyl)-, (1à,4aà,8aà)- | 11.1640 | |
Naphthalene, 1,2,3,4-tetrahydro-1 ,6-dimethyl-4-(1-methylethyl)-, (1S-cis)- | 11.2919 | |
(+)-Epi-bicyclosesquipheliandrene | 11.5152 | |
2,3,4-Trifluorobenzoic acid, 4-nitrophenyl ester | 11.6408 | |
7-Tetracyclo[6.2.1.0(3.8)0(3.9)]undecanol, 4,4,11,11-tetramethyl- | 11.7243 | Sesquiterpene alcohol |
2-Naphthalenemethanol, 1,2,3,4,4a ,8a-hexahydro-à, à,4a, 8-tetramethyl-, [2R-(2à,4aà,8aà)]- | 11.7325 | -do- |
Cycloisolongifolene, 8,9-dehydro- | 12.2912 | |
Caryophyllene oxide | 13.2509 | Sesquiterpene oxide |
Longipinocarvone | 13.7303 | |
3-lsopropyl-6, 7-dimethyltricycio[4.4.0.0(2,8)]decane-9, 1O-diol | 13.7752 | Sesquiterpene alcohol |
Compound (Chemical name)
|
Retention time (RT) min
|
Nature of compound
|
Sesquiterpenes (cont’d)
| ||
cis-Z-α-Bisabolene epoxide | 14.0907 | Sesquiterpene epoxide |
Longiverbenone | 14.9277 | |
2,2,7,7 -Tetramethyltricyclo[6.2.1.0(1 ,6)]undec-4-en-3-one | 15.6833 | Sesquiterpene ketone |
Acetic acid, 3-hyd roxy-6-isopropenyl-4, 8a-dimethyl-1 ,2,3,5,6,7,8, 8aoctahydronaphthalen-2-yl ester | 15.7474 | Sesquiterpene ester |
5( 1H)-Azulenone, 2,4,6,7,8, 8a-hexahydro-3, 8-dimethyl-4-( 1-methylethylidene)-, (8S-cis)- | 15.7488 | |
Perhydrocyclopropa[e]azulene-4,5,6-triol, 1,1 ,4,6-tetramethyl | 15.8186 | |
1 H-Cycloprop[e]azulen-7 -01, decahydro-1 ,1,7 -trimethyl-4-methylene-, [1ar-(1 aà,4aà,7a,7aa,7bà)]- | 15.8686 | |
(−)-Spathulenol | 15.8706 | Sesquiterpene alcohol |
Corymbolone | 15.9639 | Sesquiterpene ketoalcohol |
Spiro[4.5]decan-7 -one, 1,8-dimethyl-8,9-epoxy-4-isopropyl- | 16.1027 | Sesquiterpene ketone |
9H-Cycioisolongifolene, 8-oxo- | 16.2514 | |
2( 1H) Naphthalenone, 3,5,6,7,8, 8a-hexahyd ro-4, 8adimethyl-6-( 1-methylethenyl)- | 16.2630 | Sesquiterpene ketone |
E-15-Heptadecenal | 16.4377 | Sesquiterpene aldehyde |
6-lsopropenyl-4,8a-dimethyl-1 ,2,3,5,6,7,8,8aoctahydronaphthalene-2,3-diol | 16.4982 | Sesquiterpene alcohol |
2( 1H)-Naphthalenone, 4a,5,6, 7, 8,8a-hexahydro-6-[1-(hydroxymethyl)ethenyl]-4,8adimethyl-, [4ar-(4aà,6à,8aà)]- | 18.5973 | Sesquiterpene ketone |
1-Naphthalenol, decahydro-1 ,4a-dimethyl-7 -( 1-methylethylidene )-, [1 R-( 1à,4aa,8aà)]- | 27.1088 | Sesquiterpene alcohol |
Triterpenes
| ||
Cyclodecasiloxane, eicosamethyl- | 22.6754 | |
Polyterpenes
| ||
Tetracosamethyl-cyclododecasiloxane | 28.8145 | |
Compound (Chemical name)
|
Retention time (RT) min
|
Nature of compound
|
Hydrocarbons
| ||
2,6-Dimethyl-1 ,3,5,7-octatetraene, E, E- | 3.0988 | Unsaturated hydrocarbon |
Benzene, 1-methyl-3-(1-methylethyl)- | 3.1698 | Aromatic hydrocarbon |
1 H-Cycloprop[e]azulene, 1a,2,3,4,4a,5,6, 7boctahydro-1 ,1,4,7 -tetramethyl-, [1aR-(1aà,4à,4aa, 7bà)]- | 9.7772 | -do- |
3H-3a, 7-Methanoazulene, 2,4,5,6,7 ,8-hexahydro-1,4,9,9-tetramethyl-, [3aR-(3aà,4a,7à)]- | 9.8550 | -do- |
Benzene, 1-(1 ,5-dimethyl-4-hexenyl)-4-methyl- | 10.1253 | -do- |
Benzene, 1-methyl-4-(1 ,2,2-trimethylcyclopentyl)-,(R)- | 10.3648 | -do- |
Azulene, 1,2,3,5,6,7 ,8,8a-octahydro-1 ,4-dimethyl-7-(1-methylethenyl)-, [1 S-(1 à,7à,8aa)]- | 10.8948 | -do- |
α-Calacorene | 12.4888 | |
Octacosane | 29.3625 | |
Fatty acids
| ||
Oodecanoic acid | 14.0232 | |
n-Hexadecanoic acid | 19.4351 | Palmitic acid |
9, 12-0ctadecadienoic acid (Z, Z)- | 21.5769 | Linoleic acid |
cis-13-0ctadecenoic acid | 21.6267 | |
9,12, 15-0ctadecatrienoic acid, (Z, Z, Z)- | 21.6321 | |
cis-13-0ctadecenoic acid | 21.6355 | |
Octadecanoic acid | 21.7428 | |
Eicosanoic acid | 23.8517 | |
Esters
| ||
Isophthalic acid, di(2-methylprop-2-en-1-yl) ester | 11.5878 | |
Myrtenyl acetate | 23.3973 | |
Trichloroacetic acid, hexadecyl ester | 24.0485 | |
Bis(2-ethylhexyl)phthalate | 25.8520 | |
Oodecanoic acid, dodecyl ester | 26.0201 | |
(−)-trans-Pinocarvyl acetate | 27.9163 | |
Oodecanoic acid, tetradecyl ester | 28.0778 | |
Oodecanoic acid, hexadecyl ester | 30.1824 |