The effect of evening primrose oil on the radiation response and blood flow of mouse normal and tumour tissue.
OBJECTIVE
To investigate the effect of the oral administration of evening primrose oil on the radiation response and the blood flow of normal tissue and a tumour in BALB/c mice.


METHODS
Aliquots of evening primrose oil were fed to BALB/c mice daily and the radiation response of the skin was assessed by the determination of ED50 values for the incidence of moist desquamation, using probit analysis. Tumour radiosensitivity was investigated by determining the growth delay caused by irradiation of a transplantable rhabdomyosarcoma. The 86RbCl uptake technique was used to determine the blood flow in normal foot and tumour tissue. The fatty-acid content of red blood cells, plasma and tumour tissue was measured using gas chromatography.


RESULTS
Daily evening primrose oil dietary supplementation reduced the sensitivity of skin to radiation-induced moist desquamation and prevented the radiation-associated increase in blood flow that was observed in this tissue. No modification of tumour blood flow or of tumour sensitivity to radiation resulted from evening primrose oil supplementation of mice. Evening primrose oil supplementation resulted in changes in plasma levels of linoleic acid (LA), gamma-linolenic acid (GLA), dihomo-gamma-linolenic acid (DGLA) and arachidonic acid (AA). These changes were contingent on whether the mice had been irradiated or not. In red blood cells evening primrose oil supplementation increased the GLA level of unirradiated mice and the LA level at 20 days after irradiation. There were no changes in tumour fatty-acid levels as a result of evening primrose oil treatment.


CONCLUSIONS
Daily evening primrose oil supplementation reduced the sensitivity of skin to radiation-induced moist desquamation but did not alter tumour sensitivity to radiation.
Rahbeeni
F
F
Department of Radiation Oncology, University of Cape Town and Groote Schuur Hospital, Observatory, South Africa. fatima@ray.uct.ac.za
Hendrikse
A S
AS
Smuts
C M
CM
Gelderblom
W C
WC
Abel
S
S
Blekkenhorst
G H
GH
D000284:Administration, Oral; D000818:Animals; D001783:Blood Flow Velocity / Q000187:drug effects / Q000528:radiation effects; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism; D005227:Fatty Acids / Q000097:blood / Q000378:metabolism; D005228:Fatty Acids, Essential / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D008041:Linoleic Acids; D051379:Mice; D008807:Mice, Inbred BALB C; D031665:Oenothera biennis; D010938:Plant Oils; D011836:Radiation Tolerance / Q000187:drug effects*; D011838:Radiation-Sensitizing Agents / Q000008:administration & dosage / Q000494:pharmacology; D012513:Sarcoma, Experimental / Q000098:blood supply / Q000188:drug therapy* / Q000532:radiotherapy*; D014664:Vasodilation / Q000187:drug effects / Q000528:radiation effects; D017965:gamma-Linolenic Acid
D005227:Fatty Acids; D005228:Fatty Acids, Essential; D008041:Linoleic Acids; D010938:Plant Oils; D011838:Radiation-Sensitizing Agents; C028498:evening primrose oil; D017965:gamma-Linolenic Acid