Summer Research Fellowship Programme of India's Science Academies 2017
Studies on anti-glycating effects of three varieties of
finger millet (Eleusine coracona)
G. Balaji
Anna University, Chennai, Tamil Nadu
Guided by
G. Bhanuprakash Reddy
ICMR-National Institute of Nutrition
Abstract
Diabetes and its associated pathologies has been a major speculation among growing
population in this world. Globally, an estimated 422 million adults were living with diabetes
in 2014, compared to 108 million in 1980. The global prevalence of diabetes has nearly
doubled since 1980, rising from 4.7 to 8.5% in the adult population. The prevalence of
diabetes is increasing as it would reach 300 million people worldwide in 2025 (WHO report
2016). Protein glycation due to Maillard reaction which sparks the formation of advanced
glycation end products is one of the major cause for the diabetic associated pathological
complications (Chi-Hao Wu et al., 2011). Inhibition of formation of AGE’s ameliorate
complications of diabetics such as neuropathy, nephropathy, retinopathy, cardio myopathy
etc (Singh et al.). Traditionally various whole cereal diet and also herbal supplements has
been long followed to prevent such diabetic complications. These Nutraceuticals and
functional foods have gained much importance in present world due to its potential
therapeutic values as it has propitious effect in alleviating diabetes. Finger millet one of the
minor cereal variety grown almost all parts of the country shows pacifying response in
allaying diabetic associated complications. This finger millet encompasses wide range
dietary fibres, carbohydrates with low glycaemic index and higher sustaining power, high
phytochemicals such as polyphenols, flavonoids, antioxidants etc. Recent studies of finger
millet on animal model manifests propitious effect of polyphenols in type 2 diabetes
(Shobana et al., 2010). In this study three different varieties of finger millet such as CO9,
CO14, GPU28 were chosen for investigation. Invitro AGE’s were synthesized with Bovine
serum albumin (BSA) and Methyl Glyoxal. In vitro analytical methods such as AGE and
tryptophan fluorescence, western blot, protein carbonyls, metal chelating activity, DPPH
assay, AR inhibitory assay (Saraswat et al., 2018) were employed. This study evidenced
salubrious effect of these three-millet’s polyphenolic extracts to be type 1 and type 2
inhibitors of AGE. We propose use of these nutraceuticals can benefit diabetics in
preventing associated health complications.
Abbreviations
AGE
Advanced Glycation Endproducts
APS
Ammonium Per Sulphate
BSA
Bovine Serum Albumin
CEL
Carboxy ethyl Lysine
CML
Carboxy Methyl Lysine
DG
Deoxyglucosones
DNPH
2,4-Dinitro,Phenyl Hydrazine
DPPH
2,2-Diphenyl-picryl-Hydrazyl
EDTA
Ethylene Diamine Tetra Acetic Acid
FFI
2-(2-furoyl)-4(5)-(2-furanyl)-1-himidozole
GAE
Gallic Acid Equivalent
GOLD
Glyoxal Lysine Dimer
HCl
Hydrochlorc Acid
HRE
Heat Reflux Extract
MOLD
Methyl Glyoxal Lysine Dimer
PBS
Phosphate Buffer Saline
PBST
Phosphate Buffer Saline with Tween-20
QE
Quercetin Equivalents
SDS- PAGE
Sodium Dodecyl Sulphate- Poly Acrylamide Gel
SMP
Skimmed Milk Powder
TCA
Trichloro Acetic Acid
TEMED
TetramethylethyleneDimer
UAE
Ultrasonic Assisted Extract
1. Introduction
Proteins are complex biomolecules in an organism which is a pivot of all physiochemical
processes. This word was first coined by Jons Jacob Berzelius from Greek word proteius
meaning holding first place. Proteins are the building blocks of our human system. Amino
acids are the fundamental backbone of proteins. There were about 20 amino acids which joins
in various configurations to form protein. Proteins are organ specific, therefore function of
protein is attributed to the structure and functions of amino acids in that protein chain. (Felix
Haurowitz, Daniel E. Koshland et al., Principles of Biochemistry, Leninger).
Protein functions as antibody that bind to specific foreign particles such as virus, bacteria and
provide us immunological barriers. Proteins act as enzymes which carries out thousands of
reactions that takes place in cells. They also assist in the formation of new molecules by
reading the genetic information stored in DNA for example phenyl alanine hydroxylase.
Proteins are sometimes messengers which aids in transmission of signals to co-ordinate
biological process between different cells, tissues and organs. These proteins also form the
structural basis of cells such as collagen.
Any alteration in structure of proteins will results in loss of function and formation of complex
products which leads to various forms of illness.
1.1. Basic structure of proteins
1.1.1. Primary Structure
The sequence of amino acids joined together by peptide bonds that make up a protein or
polypeptide chain is known as primary structure (Fig. 1). Peptide bonds are created by
enzyme catalysed condensation reactions and broken down by enzyme catalysed hydrolysis
reactions.
Fig. 1. Primary structure.
Fig. 2. (a) Beta pleated structure and (b) Alpha helix.