Oral Administration of Tocotrienol Ameliorates Lead-Induced Toxicity in the Rat Brain

Tocotrienol on Lead-Induced Brain Toxicity
Vol. 11 No. 2 : 2016 (232-244)

Noor Azliza Wani AA Noor Azliza Wani AA
Zar Chi T Zar Chi T
Mohamad Fairuz Y Mohamad Fairuz Y
Teoh SL Teoh SL
Taty Anna K Taty Anna K
Azian AL Azian AL

Abstract
The occurrence of severe lead (Pb) poisoning has risen in certain countries. There is increasing evidence that chronic lead exposure disturbs the prooxidant: antioxidant balance in the brain tissue and alters brain histology. The present study observed the antioxidant effect of tocotrienol-rich fraction (TRF) on brain tissues of the experimental rats following lead poisoning. Eighteen (n=18) male Sprague-Dawley rats, 6-weeks old, were randomly divided into control (CTRL) group and experimental groups; fed with 0.2% w/v lead acetate, as PB2 group; and fed with 0.2% w/v lead acetate and daily TRF supplementation (200 mg/kg body weight) as PB2T group. The experiment was conducted for 30 days.  At the end of the study, the brain tissues were harvested and histopathological changes of the hippocampal region were observed. Biochemical findings such as brain lead, TRF and malondialdehyde (MDA) levels, and erythrocyte superoxide dismutase (SOD) activity were determined. It was observed that atypical apoptotic-like and disorganized neurons were present in the hippocampal region of the untreated PB2 group compared to PB2T group. Biochemical parameters showed a significant decrease (p < 0.05) in brain lead level in PB2T compared to PB. Even though no significant difference (p > 0.05) was obtained for MDA level, there was a significant increase (p < 0.05) in the erythrocyte SOD activity in PB2T compared to PB2 and CTRL. Supplementation with TRF improved histopathological changes in the brain tissues caused by lead exposure in drinking water by reducing lead accumulation in the brain of experimental rats. 
Keywords : lead, neurotoxicity, oxidative stress, rat, tocotrienol,
Abstrak
Kes keracunan plumbum (Pb) yang membimbangkan telah meningkat di beberapa negara tertentu. Semakin banyak bukti kajian menunjukkan pendedahan kronik terhadap plumbum memainkan peranan besar yang menyebabkan ketidakseimbangan prooksidan: antioksidan di dalam tisu otak dan perubahan histologi otak. Kajian ini dilakukan untuk mengenal pasti kesan agen antioksidan daripada kelapa sawit Malaysia, fraksi kaya tokotrienol (TRF) pada tisu otak tikus eksperimen berikutan keracunan plumbum. Lapan belas (n=18) tikus Sprague-Dawley jantan, berusia 6 minggu, dibahagikan secara rawak kepada kumpulan kawalan (CTRL) dan kumpulan eksperimen; didedahkan kepada 0.2% w / v plumbum asetat, sebagai kumpulan PB2; dan yang didedahkan kepada 0.2% w / v plumbum asetat bersama pengambilan suplemen TRF (200 mg / kg berat badan) sebagai kumpulan PB2T. Eksperimen ini dijalankan selama 30 hari. Pada akhir kajian, tisu otak telah diambil dan perubahan histopatologi di kawasan hippocampus diperhatikan. Keputusan biokimia seperti aras plumbum, TRF dan malondialdehid (MDA) dalam tisu otak serta aras aktiviti superoksida dismutase (SOD) dalam eritrosit telah ditentukan. Terdapat neuron atipikal berciri apoptosis dan tidak teratur diperhatikan di kawasan hippocampus bagi kumpulan Pb2 yang didedahkan kepada plumbum berbanding kumpulan Pb2T. Parameter- parameter biokimia tisu otak menunjukkan penurunan aras plumbum yang siginifikan (p<0.05) di dalam kumpulan Pb2T berbanding Pb2. Walaupun tiada perbezaan yang signifikan diperolehi (p>0.05) bagi aras MDA, terdapat peningkatan yang signifikan (p<0.05) bagi aktiviti SOD eritrosit dalam PB2T berbanding PB2 dan CTRL. Pengambilan suplemen TRF dilihat dapat membaiki perubahan histopatologi dalam tisu otak yang disebabkan oleh pendedahan plumbum melalui air minuman dengan mengurangkan pengumpulan plumbum dalam tisu otak tikus eksperimen.
Kata Kunci : neurotoksisiti, plumbum, tekanan oksidatif, tokotrienol,

Correspondance Address
Azian Abd Latiff. Anatomy Discipline, Faculty of Medicine, UniversitiTeknologi MARA, Sungai Buloh Campus, Jalan Hospital, 47000 Sungai Buloh, Selangor, Malaysia. Tel: 006-03-61267568 Fax: 006-03-61267483 E-mail: azianal@salam.uitm.edu.my