Very rapid quantification of malondialdehyde (MDA) in rat brain exposed to lead, aluminium and phenolic antioxidants by high-performance liquid chromatography-fluorescence detection.

Toxic metals (lead, aluminium) are widely found in our environment. Humans are exposed to these metals from numerous sources, including contaminated air, water, soil and food. The current study was performed to assess the potential of tannic acid and curcumin against aluminum (Al)- and lead (Pb)-induced developmental neurotoxicity in Wistar rats. Malondialdehyde (MDA) is considered a presumptive biomarker for lipid peroxidation in living organisms. A simple, very fast and reliable high-performance liquid chromatographic (HPLC) method has been developed and validated for the analysis of MDA in rat brain tissues. After rat brain was homogenized, MDA was reacted with thiobarbituric acid (TBA) to form MDA-(TBA)2, a red-colored adduct with maximum absorbance at 532 nm. HPLC separation of adduct in rat brain was performed two columns: new generation Phenomenex Gemini C18 column and Hypersil ODS C18. A HPLC mobile phase consisted of 40:60 (vol/vol) methanol-KH2PO4 was found to be the most suitable composition for this separation. Under the chromatographic conditions described, the MDA-TBA adduct had a retention time of approximately 1.4 min, good separation and sensitivity. The detection limit (0.036 nmol/ml) is low, precision is good and the analysis time is very short (1.495 min). The response is linear in the concentration range of 2.5-20.0 nmol/ml (correlation coefficient r=0.99970). Treatment with tannic acid and curcumin reduced the accumulation of the Al and Pb in rat's brain. It may conclude that tannic acid and curcumin as a chelating agent were more effective to reduce LPO levels in Al treatments group than Pb groups.

Biochemical effects of chlorpyrifos and deltamethrin on altered antioxidative defense mechanisms and lipid peroxidation in rat liver.

Pesticides such as organophosphorus and organochlorine compounds commonly used in agriculture for achieving better quality products are toxic substances and lead to generation of reactive oxygen species (ROS) which have harmful effects on human health. While pyrethroid pesticides are used in preference to organophosphates and organochlorines due to their high effectiveness, low toxicity to non-target organisms and easy biodegradability, they may also produce oxidative stress. Thus, we investigated the effects of chlorpyrifos (CP, an organophosphate) and deltamethrin (DM, a pyrethroid pesticide) treatments at low and high doses on lipid peroxidation (LPO) and antioxidant enzyme activities such as SOD, GSH-Px and CAT in rat liver following 16 weeks exposure. Antioxidative defence mechanisms and lipid peroxidation in rat liver tissues display different responses depending on different pesticide treatments and doses. Biochemical analysis showed that administrations of the chlorpyrifos and deltamethrin cause liver damage. In the present study, we observed that lipid peroxidation levels are higher at high doses than at low doses, but DM caused more pronounced increase than CP. Experimentally, we have also observed that oxidant-antioxidant balance is more affected by deltamethrin treatment than by chlorpyrifos.