title: Aloe emodin, an anthroquinone from Aloe vera acts as an anti aggregatory agent to the thermally aggregated hemoglobin.
abstract: Aggregation of proteins is a physiological process which contributes to the pathophysiology of several maladies including diabetes mellitus, Huntington's and Alzheimer's disease. In this study we have reported that aloe emodin (AE), an anthroquinone, which is one of the active components of the Aloe vera plant, acts as an inhibitor of hemoglobin (Hb) aggregation. Hb was thermally aggregated at 60°C for four days as evident by increased thioflavin T and ANS fluorescence, shifted congo red absorbance, appearance of β sheet structure, increase in turbidity and presence of oligomeric aggregates. Increasing concentration of AE partially reverses the aggregation of the model heme protein (hemoglobin). The maximum effect of AE was observed at 100μM followed by saturation at 125μM. The results were confirmed by UV-visible spectrometry, intrinsic fluorescence, ThT, ANS, congo red assay as well as transmission electron microscopy (TEM). These results were also supported by fourier transform infrared spectroscopy (FTIR) and circular dichroism (CD) which shows the disappearance of β sheet structure and appearance of α helices. This study will serve as baseline for translatory research and the development of AE based therapeutics for diseases attributed to protein aggregation.
authors.affiliation: Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, India.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Furkan
authors.affiliation: Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, India.
authors.forename: Md Tauqir
authors.initials: MT
authors.lastname: Alam
authors.affiliation: Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, India.
authors.forename: Asim
authors.initials: A
authors.lastname: Rizvi
authors.affiliation: Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, India.
authors.forename: Kashan
authors.initials: K
authors.lastname: Khan
authors.affiliation: Department of Chemistry, Faculty of Science, Aligarh Muslim University, Aligarh 202002, India.
authors.forename: Abad
authors.initials: A
authors.lastname: Ali
authors.affiliation: Department of Chemistry, Faculty of Science, Aligarh Muslim University, Aligarh 202002, India.
authors.lastname: Shamsuzzaman
authors.affiliation: Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, India. Electronic address: aabgeenanaim@gmail.com.
authors.forename: Aabgeena
authors.initials: A
authors.lastname: Naeem
mesh_terms: D000504:Aloe / Q000737:chemistry*; D000817:Anilino Naphthalenesulfonates / Q000737:chemistry; D000818:Animals; D000880:Anthraquinones / Q000737:chemistry / Q000494:pharmacology*; D052160:Benzothiazoles; D002417:Cattle; D002942:Circular Dichroism; D003224:Congo Red / Q000737:chemistry; D006454:Hemoglobins / Q000737:chemistry* / Q000648:ultrastructure; D009391:Nephelometry and Turbidimetry; D066329:Protein Aggregates / Q000187:drug effects*; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D013844:Thiazoles / Q000737:chemistry
chemical_list: D000817:Anilino Naphthalenesulfonates; D000880:Anthraquinones; D052160:Benzothiazoles; D006454:Hemoglobins; D066329:Protein Aggregates; D013844:Thiazoles; C009462:thioflavin T; D003224:Congo Red; C027132:1-anilino-8-naphthalenesulfonate; C518327:aloe emodin
keywords: Aggregation; Aloe emodin; Congo red; FTIR and TEM; Hemoglobin