Assessment of anti-amyloidogenic activity of marine red alga G. acerosa against Alzheimer's beta-amyloid peptide 25-35.

OBJECTIVE: The amyloid hypothesis stimulates the discovery of compounds, which promotes beta-amyloid peptide (Aß) clearance, thereby altering the underlying pathophysiology of Alzheimer's disease (AD). Hence, the present study aims at the evaluation of anti-amyloidogenic potential of Gelidiella acerosa. METHODS: Prevention of Aß 25-35 aggregate formation and disaggregation of pre-formed fibrils by G. acerosa was evaluated in three phases by thioflavin T spectrophotometric assay. The results were further validated by confocal microscopic analysis. The conformational changes in the aggregated and non-aggregated Aß in the presence of G. acerosa were analyzed by Fourier transform infrared (FTIR) spectroscopic analysis. RESULTS: Phase-I study shows that G. acerosa reverts (4.56 ± 0.35 AU at 96 hours) the increase in fluorescence intensity of aggregated Aß (18.76 ± 0.99 AU) significantly (P < 0.05) as that of non-aggregated peptides, which suggests that G. acerosa prevents the formation of oligomers from monomers. The seaweed also prevents the fibril formation even after the aggregation process was initiated at 20 hours, which was verified by the significant (P < 0.05) decrease in the fluorescence intensity (2.94 ± 0.0721 AU) at 36 hours (Phase II). In addition, G. acerosa promotes fibrillar destabilization (Phase III), which was further substantiated by confocal microscopic analysis. Fourier transform infrared spectroscopy reveals that alteration in amide I and amide II band spectrum, which occurs due to Aß 25-35 aggregation was restored upon co-treatment with G. acerosa benzene extract. CONCLUSION: Overall, the results suggest that G. acerosa might have direct interaction with the aggregated peptide, thereby preventing oligomerization and fibrillation of Aß 25-35.

Assessment of the protective potential of Premna tomentosa (L. Verbenaceae) extract on lipid profile and lipid-metabolizing enzymes in acetaminophen-intoxicated rats.

OBJECTIVES: The liver is often damaged by environmental toxins, poor eating habits, alcohol and over-the-counter drug use that damage and weaken the liver, leading to important public health problems such as hepatitis, cirrhosis, and alcoholic liver diseases. It is cardinal to treat liver disorders, because it affects the biochemistry of the cell directly. Damage to the liver can be prevented by including a balanced diet that includes nutrients and herbs that support a healthy liver. Premna tomentosa (PT) is one such herbal drug used widely in India for the treatment of liver disorders, and we have already reported the hepatoprotective potential and antioxidant property of methanolic extract of PT leaves. Because injury to the liver can promote a variety of reactions with consequent effect on lipids, the present study was designed to elucidate the hypolipidemic effect of PT extract in acetaminophen (AA)-induced hepatotoxicity in rats. DESIGN AND SUBJECTS: Animals were pretreated with PT extract (750 mg/kg, orally) for 15 days and then induced with hepatotoxicity by AA (640 mg/kg, intraperitoneally). RESULTS: PT extract pretreatment significantly inhibited induced alterations in the levels of cholesterol, triglycerides, free fatty acids, phospholipids, serum lipoproteins, and lipid-metabolizing enzymes. CONCLUSIONS: The results indicate that PT extract improves lipid metabolism and has the potential for use in hepatic disorders.