Effect of passive cigarette smoke on mouse placenta and the role of antioxidants

To study the effects of passive cigarette smoke on the architecture of mouse placenta and to observe the preventive role of antioxidants if any.

It was a randomized control trial. Female mice of Balb C strain (51) were mated and grouped as follows: Groups, C: control, S: exposed to smoke and SV: exposed to smoke and given antioxidants (vitamin C, E) and sacrificed at 19 dpc (days post coitus). 14 animals from C, 12 from S and 14 from SV had healthy pregnancies. Their placentae were studied microscopically. The relative thickness of the labyrinthine, spongiotrophoblast-I, spongiotrophoblast-II, and decidual layers were measured. The area of spongiotrophoblast-I was calculated using a computerized software programme.

The mean relative thickness and area of the spongiotrophoblast-I in S (14.46 +/- 1.88%, 5.89 +/- 0.87%) was significantly more (p = 0.03, p = 0.035 respectively) as compared to the controls (9.47 +/- 1.31%, 3.95 +/- 0.24%). In SV these values (13.96 +/- 1.2% and 5.74 +/- 0.82%) did not show any significant improvement as compared to S (p = 0.035). The mean relative thickness of the labyrinthine, spongiotrophoblast II, and decidual layer in the control group was 44.49 +/- 2.51%, 19.06 +/- 2.48, 19.44 +/- 0.68 respectively. None of these showed any significant difference from each other in the three groups.

Cigarette smoke causes a significant disturbance in the architecture of mouse placenta which could not be prevented by antioxidants. Therefore, these effects may be due to other toxic substances present in the smoke rather than free radicals.