Tables 1,
2, and
3 show the genetic and biochemical data obtained with various concentrations of
Hypogymnia physodes, Ramalina polymorpha and
Usnea florida, on cultured blood cells, respectively. All the lichen extracts at tested concentrations did not induce significant (p < 0,05) number of CAs and MNs. However, the Mitomycin C applied culture (positive control) showed about three fold increases of both parameters as compared to control
- group.
In the present study, it was established that the extracts of
H. physodes, R. polymorpha and
U. florida lichen species were non-genotoxic. The results obtained through the preseht stugy did not indicate any significant increases in the ratios of the CAs and MNs in lymphocytes exposed to lichen extracts as compared to control values. In fact, CA test is regarded as a very important and useful indicator of exposure to biological and chemical agents (
29). MN assay provides a measure of both chromosome breakage and chromosome loss or non-disjunction in clastogenic and aneugenic events, respectively (
30). And damaged DNA can lead to aneuploidy and/or chromosomal instability, which is believed to be major contributor to tumor progression (
31). Our findings are in accordance with the previous reports. Koparal
et al. (
32) investigated cytotoxic and genotoxic activities of the lichen
Ramalina farinacea and the lichen
Cladonia foliacea and suggested that usnic acid (a main component of lichens) was non-genotoxic shown by the absence of MN induction in human lymphocytes. Again, Zeytinoglu
et al. (
33) investigated the genotoxic/antigenotoxic activities of the extract from lichen
Cetraria aculeata in TA98 and TA100 strains of Salmonella typhimurium in the presence or absence of metabolic activity and in human lymphocytes. They have reported that the lichen extract was not mutagenic in all systems. Again, the genotoxic effects of the water extracts of
Pseudevernia furfuracea, Dermotocarpon intestiniforme, Ramalina capitata, Parmelia pulla and
Rhizoplaca melanophthalma lichens were ascertained by sister-chromatid exchange (SCE) and MN tests in human whole blood cultures. According to results of this study, it was established that these lichen extracts had also no genotoxic effect (
34). The separated components of Chinese lichen extract such as AMH-C, AMH-D and AMH-E were determined as non genotoxic in Ames test (
35). Turkez
et al. (
10) studied the effects of methanol, acetone, n-hexane and ether extracts obtained from the lichen,
Pseudovernia furfuracea, on genotoxicity in cultured human blood cells by SCE and and MN tests. The researchers observed that
P. furfuracea extracts exhibited non-mutagenic properties in both test systems.
Different concentrations of
H. physodes and
R. polymorpha (50 mg/L) and
U. florida (100 mg/L) caused significant increases of TAC level when compared to control
- value. In contrast,
H. physodes (at concentrations of 1000 and 2000 mg/L),
R. polymorpha (at concentration of 2000 mg/L) and
U. florida (at concentrations of 1000 and 2000 mg/L) caused significant decreases of TAC level. As shown from the results presented in
Tables 1,
2 and
3, the TOS levels increased at higher concentrations of
H. physodes (250, 500, 1000 and 2000 mg/L) and
U. florida (2000 mg/L). However,
R. Polymorpha did not cause any significant increases of TOS levels. Besides, the cultures found to be sterile at concentartions of 1000, 2000 and 1000 mg/L for
H. Physodes, R. polymorpha and
U. florida, respectively.
The results of the present study reveal that treatment with aqueous extracts of
H. physodes, R. polymorpha and
U. florida lichen species provide antioxidant effects at different degree. Similarly to our findings, various reports, especially published in last ten years, indicated the antioxidant properties of several lichen species. According to the previous studies, the extracts of
Cladonia clathrata (
8),
Pseudovernia furfuracea (
10),
Xanthoparmelia spp. (
36),
Lethariella sernanderi, L. cashmeriana, and
L. sinensis (
37),
Lobaria pulmonaria (
38),
Usnea ghattensis (
39),
Usnea longissima (
40), Graphidaceae (
41),
Lethariella canariensis (
42),
Cetraria islandica (
19),
Parmelia caperata and
P. soredians (
43),
Dermatocarpon miniatum (
44),
Parmotrema stuppeum (45) were found to have antioxidant properties.