The role of ascorbic acid, selenium, and glutathione on benzo[a]pyrene-induced carcinogenesis in wistar rats.
OBJECTIVE
The carcinogenic action of polycyclic aromatic hydrocarbons (PAHs) can be inhibited by endogenous or exogenous compounds. This study was designed to elucidate the modifying action of 3 endogenous inhibitors- ascorbic acid (vit C) used alone, and selenium (Se) used in combination with glutathione (GSH).


METHODS
Chemical carcinogenesis was induced by benzo[a]pyrene(BaP). A hundred wistar rats were divided into 3 groups: the first group (G I) consisted of 42 animals, representing the control group. The two experimental groups (G II and G III) consisted of 38 and 20 rats, respectively. All groups were injected with BaP(10.08 mg subcutaneously-s.c). The first experimental G II was given only vit C (520 mg in 2% sugar solution per os - p.o.). The second experimental G III was given Se (0.1 mg p.o.) with GSH (200 mg p.o.). Tumor incidence and mean survival time were determined. Histological examination of the developed and excised tumors took place following death. The carcinogenic potency (CP) and anticarcinogenic potency (AP) of the substances used were calculated.


RESULTS
A statistically significant difference regarding the mean survival time in the two experimental groups (238.4-/+31 days and 344.9-/+48 days, respectively) compared to the control group (183.8-/+28 days) was found (p < 0.001). The CP of each of the 3 groups was 54.3, 41.2, and 28.9 units, respectively. The AP of vit C used alone was 13.1 units, representing a significant anticarcinogenic effect. The combination of Se + GSH showed an AP of 25.4 units, resulting in a significant prolongation of the mean survival time, which is considered a potent anticarcinogenic effect. Furthermore, a statistically significant difference was found also when the mean survival time of G III animals was compared with G II.


CONCLUSIONS
Vit C on its own and Se in combination with GSH represent strong endogenous inhibitors that can inhibit/reduce the carcinogenic action of BaP-induced carcinogenesis in wistar rats. The combination therapy used offered better in vivo results.
Charalabopoulos
K
K
Department of Physiology, Clinical Unit, Medical Faculty, University of Ioannina, Ioannina, Greece.
Karkabounas
S
S
Dimicco
P
P
Binolis
J
J
Charalabopoulos
A
A
Zelovitis
J
J
Avdikos
A
A
Metsios
A
A
Peschos
D
D
Agnantis
N J
NJ
Evangelou
A
A