Plasma fatty acid abnormality in Sudanese drug-resistant epileptic patients

Abstract

Intervention studies have demonstrated that the n-3 fatty acids, docosahexaenoic and eicosapentaenoic acids, ameliorate seizure frequency in patients with drug-resistant epilepsy (DRE). There is a scarcity of fatty acid status of patients with epilepsy. We have investigated blood fatty acids of patients with DRE and assessed the indices of elongase and desaturase activities. DRE patients (n = 83) and healthy controls (n = 31) were recruited form Soba University Hospital Neurology Referral Clinic and Ibn-Auf paediatric Teaching Hospital Neurology Referral Clinic, Khartoum, Sudan. Fatty acid composition of plasma total lipids, phosphatidylcholine and neutral lipids were analysed. The patients compared with their healthy counterparts had higher levels of C14:0, C16:0, C18:0, C20:0, C22:0 (p<0.05) and C24:0, and total saturates (p<0.05). Similarly, the proportions of C16:1n-7, 18:1n-7, C18:1n-9, C20:1n-9, C24:1n-9 and total monounsaturated fatty acids; p<0.005) were higher in the drug-resistant patients. Conversely, the patients had lower levels of n-6 (C18:2n-6, C18:3n-6, C20:4n-6, n-6 metabolites and total n-6; p<0.005 and C20:2n-6 and C20:3n-6; p<0.05) and n-3 (C20:5n-3, C22:5n-3, C22:6n-3, ∑EPA and DHA, n-3 metabolites and total n-3; p<0.05) fatty acids. Indices of elongase and desaturase activities - The plasma total lipid ratios of C16:0/C14:0 (p = 0.001), C18:0/C16:0 (p = 0.001), C16:1n-7/C16:0 (p = 0.027), C18:1n-9/C18:0 (p = 0.022) and C22:4n-6/C20:4n-6 (p = 0.008) were higher and C18:3n-6/C18:2n-6 (p = 0.05), C20:4n-6/C20:3n-6 (p = 0.032) and C20:4n-6/C18:2n-6 (p>0.05) lower in the patients with drug-resistant epilepsy than in the healthy control subjects. DRE is associated with blood fatty acid perturbation and abnormal activities of long-chain fatty acid elongase (ELOVL-6), stearoyl-coenzyme A desaturase-1 (SCD-1), delta 6-fatty acid desaturase (D6D) and delta 5 fatty acid desaturase (D5D). N-3 fatty acids are known to ameliorate seizures frequency and dampen neuronal hyperexcitability. Therefore, patients with DRE should be regularly monitored and, if necessary, supplemented with n-3 fatty acids.

Keywords: Drug resistance; Epilepsy; Plasma fatty acids.