Comparative Effect of Fresh, Thermoxidized and Irradiated Oil on Gastric Acid Secretion and Cytoprotection in Rats

The effect of chronic consumption of fresh, thermoxidized and irradiated palm oil on gastric acid secretion and cytoprotection in rats was studied. Gastric acid secretion was measured by the continuous perfusion method. Test diet made of rat chow mixed with fresh palm oil (FPO), thermoxidized palm oil (TPO) or irradiated palm oil (IPO) were used to feed rats. The control was fed on rat chow only. Feeding was for 8 weeks. They were all allowed water adlibitum. The results showed that there was no significant difference in weight gain among the groups. The basal acid secretion in control (6.00 ± 0.00mMol/L/hr) was significantly lower (P < 0.01) when compared with FPO (8.00 ± 0.00mMol/L/hr) or TPO (9.20 ± 0.00mMol/L/hr) respectively. The control value was not significantly different from that of IPO. Basal acid output in IPO group (6.20 ± 0.00mMol/Lhr) was significantly lower (P < 0.001) when compared with FPO or TPO group respectively. Administration of histamine followed a similar trend as found in basal secretion among groups. The degree of ulceration in IPO (16.80 ± 0.20) and FPO (17.80 ± 0.80) were each significantly lower (P < 0.001) than control value (29.20 ± 0.80). Among the test groups (FPO, TPO and IPO), the TPO group had significantly higher ulcer score (25.00 ± 1.21) than FPO and IPO groups. The results suggest that ingestion of themoxidized palm oil may be deleterious to health, fresh palm oil confers some protection against ulceration and that irradiation as a source of preservation may have no gastrointestinal hazard.KEY WORDS: Fresh, themoxidized and irradiated palm oil, acid secretion and ulceratio