Protective impact of melatonin on paclitaxel induced damage on skeletal muscle fibers in albino rats

Background

Paclitaxel is a chemotherapy used for the treatment of solid cancers. Patients receiving paclitaxel report fatigue. Melatonin is anti-inflammatory, antioxidant, and antiapoptotic. It is safe for human.

Aim

To evaluate the histological impact of paclitaxel on the skeletal muscle of rats and the potential protective effects of melatonin.

Materials and methods

Thirty-five albino rats were categorized into four groups. Group I contained 10 rats that were used as the control group. Group II comprised 5 rats that were administered a daily oral suspension of melatonin at a dosage of 5 mg/kg for 2 months. Group III included 10 rats given paclitaxel through intraperitoneal injection at a dosage of 16 mg/kg, diluted in 1 ml of normal saline, once weekly for 5 consecutive weeks. Group IV contained 10 rats that received melatonin and paclitaxel concomitantly at the same doses and duration as mentioned in group II and group III. Skeletal muscle specimens were processed to be examined by the light microscope.

Results

The paclitaxel injected group showed alteration in the histological structure of skeletal muscle. There were wide spaces between muscle bundles and between individual muscle fibers with an apparent increase in the connective tissue component of endomysium and perimysium. Congestion of the blood vessels and hemorrhage were observed. There was a discontinuation of muscle fibers and internalization of myonuclei. Most of the alternations were less pronounced in paclitaxel injected rats that received melatonin.

Conclusion

Melatonin could protect the skeletal muscle against changes induced by paclitaxel through its anti-inflammatory, antioxidant, and antiapoptotic effects.