Background
Materials and methods
Plant materials
Preparation of the ethanolic extracts
Total phenolic content
Total flavonoid content
Analysis of phenolic contents by HPLC
Isolation of essential oils
GC-MS analysis
Antioxidant activities
Free radical-scavenging activity
ABTS assay
Reducing power assay
Phosphomolybdenum assay
Antimicrobial activity
Microorganisms
MIC determination
Anticancer activity
Cell lines and cell viability
MTT assay
Data analysis
Results and discussion
Total phenolic and flavonoid contents
Plant | phenolic content (mg/g extract) | flavonoid content (mg/g extract) |
---|---|---|
Ocimum basilicum
| 226 ± 2 | 213 ± 3 |
Thymus algeriensis
| 125 ± 1 | 118 ± 1 |
Identification of phenolic compounds by HPLC
Phenolic standard compounds | Standard retention time RT (min) |
Ocimum basilicum
(μg/g) |
Thymus
algeriensis
(μg/g) |
---|---|---|---|
Gallic acid | 6.8 | 17.61 | 10.49 |
3,4-dihydroxy benzoic acid | 10.7 | 21.56 | 1.42 |
4-hydroxy benzoic acid | 15.7 | 46.29 | 10.03 |
2,5 dihydroxybenzoic acid | 17.2 | 52.14 | 778.76 |
Chlorogenic acid | 18.2 | 25.11 | 22.68 |
Vanillic acid | 19.2 | 138.24 | 182.67 |
Epicatechin | 21.3 | 225.01 | 824.79 |
Caffeic acid | 22.7 | 6.48 | 33.30 |
p-coumaric acid | 26.1 | 12.83 | 83.80 |
Ferulic acid | 30.1 | 25.00 | 34.30 |
Rutin | 45.6 | 476.28 | 280.39 |
Ellagic | 47.7 | 27.64 | 374.58 |
Naringin | 49.7 | 21.02 | 120.67 |
Quercetin | 70.4 | 0.36 | 2.84 |
Cinnamic acid | 71.1 | 54.68 | 20.51 |
Essential oil yield and chemical composition
Constituents | LRI |
O. basilicum
(%)
|
T. algeriensis
(%)
| Method of identificationb |
---|---|---|---|---|
α-pinene | 941 | 0.3 | 6.8 | MS; LRI; RC |
camphene | 955 | - a | 0.8 | MS; LRI; RC |
sabinene | 977 | 0.4 | 0.7 | MS; LRI; RC |
β-pinene | 982 | 0.6 | 1.2 | MS; LRI; RC |
myrcene | 993 | 1.3 | 1.2 | MS; LRI; RC |
3-octanol | 994 | -a | - a | MS; LRI; RC |
α-terpinene | 1020 | - a | - a | MS; LRI; RC |
p-cymene | 1028 | - a | 0.3 | MS; LRI; RC |
limonene | 1032 | - a | 2.7 | MS; LRI; RC |
1,8-cineole | 1034 | 9.2 | 4.1 | MS; LRI; RC |
(Z)-β-ocimene | 1042 | 0.7 | - a | MS; LRI; RC |
(E)-β-ocimene | 1052 | 0.5 | 1.5 | MS; LRI; RC |
γ-terpinene | 1063 | - a | - a | MS; LRI; RC |
cis-sabinene hydrate | 1070 | - a | - a | MS; LRI; RC |
terpinolene | 1090 | 0.2 | 0.4 | MS; LRI; RC |
linalool | 1101 | 52.1 | 1.2 | MS; LRI; RC |
nonanal | 1104 | - a | - a | MS; LRI; RC |
pentylisovalerate | 1108 | 0.1 | - a | MS; LRI |
1-octen-3-yl acetate | 1111 | 0.1 | 0.4 | MS; LRI; RC |
cis-p-menth-2-en-1-ol | 1123 | - a | - a | MS; LRI |
3-octyl acetate | 1126 | 0.2 | - a | MS; LRI; RC |
α-campholenal | 1127 | - a | 0.5 | MS; LRI |
camphor | 1145 | - a | 1.1 | MS; LRI; RC |
trans-verbenol | 1147 | - a | 0.5 | MS; LRI; RC |
δ-terpineol | 1172 | 0.2 | - a | MS; LRI |
4-terpineol | 1179 | 0.1 | 0.5 | MS; LRI; RC |
α-terpineol | 1191 | 5.7 | 4.9 | MS; LRI; RC |
cis-dihydrocarvone | 1195 | - a | - a | MS; LRI; RC |
trans-carveol | 1219 | - a | 0.4 | MS; LRI; RC |
(Z)-3-hexenyl isovalerate | 1238 | - a | - a | MS; LRI; RC |
pulegone | 1239 | 0.2 | - a | MS; LRI; RC |
neral | 1242 | - a | 0.2 | MS; LRI; RC |
carvone | 1244 | - a | 0.3 | MS; LRI; RC |
linalyl acetate | 1259 | 19.1 | - a | MS; LRI; RC |
bornyl acetate | 1287 | - a | 3.1 | MS; LRI; RC |
dihydroedulan IA | 1292 | - a | - a | MS; LRI |
isodihydrocarvyl acetate | 1329 | - a | - a | MS; LRI |
α-terpinyl acetate | 1352 | - a | 47.4 | MS; LRI; RC |
cis-carvyl acetate | 1364 | - a | - a | MS; LRI; RC |
neryl acetate | 1365 | 1.8 | 9.6 | MS; LRI; RC |
geranyl acetate | 1383 | 3.6 | 0.9 | MS; LRI; RC |
β-elemene | 1392 | - a | - a | MS; LRI |
(Z)-jasmone | 1395 | - a | - a | MS; LRI; RC |
β-caryophyllene | 1419 | 1.0 | 0.6 | MS; LRI; RC |
β-copaene | 1430 | - a | - a | MS; LRI |
aromadendrene | 1440 | - a | - a | MS; LRI; RC |
α-humulene | 1455 | 0.1 | - a | MS; LRI; RC |
(E)-β-farnesene | 1458 | 0.1 | - a | MS; LRI; RC |
cis-muurola-4(14), 5-diene | 1463 | 0.1 | - a | MS; LRI |
germacrene D | 1482 | - a | 0.6 | MS; LRI |
bicyclogermacrene | 1496 | - a | – | MS; LRI |
germacrene A | 1505 | - a | - a | MS; LRI |
δ-cadinene | 1524 | - a | - a | MS; LRI |
(E)-α-bisabolene | 1542 | - a | 0.2 | MS; LRI |
(E)-nerolidol | 1564 | - a | 3.5 | MS; LRI |
spathulenol | 1577 | - a | - a | MS; LRI |
caryophyllene oxide | 1582 | 0.1 | 0.9 | MS; LRI; RC |
viridiflorol | 1591 | 0.4 | - a | MS; LRI |
1, 10-di-epi-cubenol | 1615 | 0.1 | - a | MS; LRI |
T-cadinol | 1641 | - a | - a | MS; LRI |
T-muurolol | 1642 | - a | - a | MS; LRI |
Monoterpene hydrocarbons | 4.0 | 15.6 | ||
Oxygenated monoterpenes | 92.0 | 74.7 | ||
Sesquiterpene hydrocarbons | 1.3 | 1.4 | ||
Oxygenated sesquiterpenes | 0.6 | 4.4 | ||
Apocarotenes | 0.0 | 0.0 | ||
Non-terpene derivatives | 0.4 | 0.4 | ||
Total identified | 98.3 | 96.5 |
Antioxidant activities
DPPH assay
Plant/Control | Extract | IC50 (DPPH) (mg/mL) | IC50 (ABTS) (mg/mL) | AEAC-FRAP assay (μg/mL) | AEAC- Phosphomolybdenum assay (mg/mL) |
---|---|---|---|---|---|
Ocimum basilicum
| EE | 0.679 ± 0.0383a | 0.970 ± 0.022a | 3.657 ± 0.009 a | 0.005 ± 0.0003a |
EO | 16.296 ± 0.394c | 0.6870 ± 0.0203a | 0.003 ± 0.0007 c | 0.760 ± 0.001c | |
Thymus algeriensis
| EE | 1.560 ± 0.010 a | 1.743 ± 0.195a | 0.897 ± 0.064d | 0.007 ± 0.0006a |
EO | 1.437 ± 4.51 E-05d | 0.8960 ± 0.203a | 1.387 ± 0.265d | 0.432 ± 0.001c | |
Ascorbic acid | 0.002 ± 3.826 E-06b | 0.001 ± 5.13E-05b | ND | ND | |
Vitamin E | ND | ND | ND | 0.674 ± 0.057b | |
Trolox | ND | 0.003 ± 3.35E-05b | ND | ND | |
BHA | 1.685 ± 0.658b | ND | 1000 ± 0.047b | ND |
ABTS assay
Ferric-reducing antioxidant power test
Phosphomolybdenum assay
Antimicrobial activity
Extract |
S. epidermidis
|
S. aureus
|
B. subtilis
|
E. coli
|
K. pneumoniae
|
p. aeruginosa
|
C. albicans
|
C. glabrata
|
---|---|---|---|---|---|---|---|---|
O.basilicum
EE
| 128 | 128 | 64 | 128 | 256 | 256 | 64 | 128 |
T.algeriensis
EE
| 128 | 64 | 64 | 256 | 256 | 512 | 128 | 128 |
O.basilicum
EO
| 32 | 32 | 16 | 64 | 128 | 256 | 32 | 32 |
T.algeriensis
EO
| 32 | 32 | 32 | 64 | 256 | 512 | 64 | 32 |
Ampicillin
| 2 | 2 | 4 | 16 | 64 | 128 | – | – |
Amphotericin B
| – | – | – | – | – | – | 2 | 2 |
Anticancer activity
Extract |
MCF-7
|
MDA-MB-231
|
HeLa
|
PC3
|
K562
|
---|---|---|---|---|---|
O. basilicum
EE
| > 10,000 | > 10,000 | > 10,000 | > 10,000 | > 10,000 |
T. algeriensis
EE
| > 10,000 | > 10,000 | > 10,000 | > 10,000 | > 10,000 |
O. basilicum
EO
| 1090 ± 64 | 1012 ± 44 | 1052 ± 38 | 1028 ± 78 | 929 ± 18 |
T. algeriensis
EO
| 647 ± 16 | 715 ± 22 | 746 ± 19 | 1067 ± 96 | 300 ± 13 |