OBJECTIVE To assess the effects of polyprenols(isolated from Picea abies L.spruce needles)on muscle strength/tone and coordination,and to investigate whether polyprenols may protect atorvastatin-mediated muscle strength/tone weakness in female Wistar rats.METHODS Polyprenols at doses of 1,10 and 20mg·kg-1,atorvastatin 80mg·kg-1 or their combination were administered once daily per os for 16 consecutive days in Wistar female rats(n=9-10 per group).Assessment of muscle strength was performed by grip strength test(on day 15)and wire hang test(on day 16).Rotarod test was used to measured locomotor coordination and muscle tone(on day 16).General locomotor activity was evaluated in open field test(on day 15).Assessment of plasma cholesterol level and creatine kinase activity was done on day 17.RESULTS Atorvastatin-treated rats exhibited a marked decrease in grasping strength and hanging time.PP(20mg·kg-1)significantly protected against atorvastatin-induced muscle weakness in grip strength test,and restored it to control values.At all doses,polyprenols prolonged hanging time which was decreased by atorvastatin in wire hang test.Polyprenols per se at 1 and 10mg·kg-1 did not show difference compared to control group animals,while only at 20mg·kg-1 h anging time was prolonged vs.control in wire hang test.No changes between control and tested groups were observed in rotarod and open field tests.Blood cholesterol level was not changed in any of tested groups in female Wistar rats.Polyprenols(20mg·kg-1)significantly(by 25%)increased plasma creatine kinase activity but it was not affected by the combined treatment.CONCLUSION Since polyprenols acted as protectors of atorvastatin-induced muscle weakness,the combination of polyprenols with atorvastatin may be helpful for reducing muscle-related side effects in patients receiving a long-term atorvastatin therapy. OBJECTIVE To assess the effects of polyprenols (isolated from Picea abies L. spruce needles) on muscle strength / tone and coordination, and to investigate whether polyprenols may protect atorvastatin-mediated muscle strength / tone weakness in female Wistar rats. METHODS Polyprenols at doses of 1, 10 and 20 mg · kg-1, atorvastatin 80 mg · kg-1 or their combination were administered once daily per os for 16 consecutive days in Wistar female rats (n = 9-10 per group). Assessment of muscle strength was performed by The grip strength test (on day 15) and wire hang test (on day 16). Rotarod test was used to measure locomotor coordination and muscle tone (on day 16). Assessment of plasma cholesterol level and creatine kinase activity was done on day 17.RESULTS Atorvastatin-treated rats showed a marked decrease in grasping strength and hanging time. PP (20 mg · kg -1) significantly protected against atorvastatin-induced muscle weakness in grip strength test, and restored it to control values. All doses, polyprenols prolonged hanging time which was decreased by atorvastatin in wire hang test. Polyprenols per se at 1 and 10 mg · kg-1 did not show difference compared to control group animals, while only at 20 mg · kg-1 h anging time was prolonged vs. control in wire hang test. No changes between control and tested groups were observed in rotarod and open field tests. Blood cholesterol level was not changed in any of the tested groups in female Wistar rats Significantly increased plasma creatine kinase activity but it was not affected by the combined treatment. CONCLUSION Since polyprenols acted as protectors of atorvastatin-induced muscle weakness, the combination of polyprenols with atorvastatin may (20 mg · kg -1) be helpful for reducing muscle-related side effects in patients receiving a long-term atorvastatin therapy.