Open Access Opinion Article

Disruption of Disulfide Bonds of Insulin Receptor as a Cause of Insulin Resistance in DM2

A. S. V. Prasad

International Journal of Biochemistry Research & Review, Page 1-4
DOI: 10.9734/IJBCRR/2016/24489

Many theories have been put forward to explain insulin resistance in DM2. The cause of insulin resistance still remained an enigma till date. Defect in insulin signaling pathway is one such possibility considered for insulin resistance in DM2. For insulin signal transduction to occur downstream, the insulin receptor should be in tetrameric, holo-enzyme form so that the conformational changes and auto-phosphorylation steps take place. A prerequisite to this is, linkage of the two α-sub-units and α,β -sub-units of the pair of the dimers by disulfide bonds. Without this, the receptor is in the α,β dimer half-enzyme form, devoid of any binding affinity to the ligand or auto- phosphorylating activity. The article intends to explore, disruption of the disulfide bond formation, as a possible cause of insulin resistance in DM2.

Open Access Original Research Article

The Effects of Aqueous and Ethanolic Extracts of Vitex doniana Leaf on Postprandial Blood Sugar Concentration in Wister Rats

O. E. Yakubu, O. F. C. Nwodo, S. M. C. Udeh, M. Abdulrahman

International Journal of Biochemistry Research & Review, Page 1-7
DOI: 10.9734/IJBCRR/2016/12893

In this study, the effects of the leaves of V. doniana aqueous and ethanolic extracts on postprandial blood glucose was analyzed. In the first experiment, 25 Wistar albino rats were divided into 5 groups of 5 rats each. Treatment was carried out orally for one day. Overnight fasted animals (group 2-4, 18 hrs) were orally administered different doses of the extract 10 minutes prior to the administration of sucrose at a dose of 2 g/kg. The postprandial blood sugar was measured before administration (at 0 minute), and after administration (30, and 60 minutes). In the second experiment, same procedure was repeated as in the first experiment but sucrose was substituted by glucose administration (2 g/kg). Results showed that both the 50 mg and 100 mg/kg ethanolic and aqueous extracts significantly decreased (p<0.05) the postprandial blood sugar concentration at 30 minutes compared to the control value. Conclusively, these results suggest that ethanolic and aqueous extracts of the leaves of Vitex doniana have remarkable inhibitory effects on α-glucosidase enzymes with promising clinical relevance of reducing hyperglycaemia via this mechanism.

Open Access Original Research Article

Phytochemical Analysis and In-vitro Antitrypanosomal Activity of Selected Medicinal Plants in Niger State, Nigeria

F. M. Madaki, A. Y. Kabiru, A. Mann, A. Abdulkadir, J. N. Agadi, A. O. Akinyode

International Journal of Biochemistry Research & Review, Page 1-7
DOI: 10.9734/IJBCRR/2016/24955

Trypanosomiasis is a disease caused by protozoan parasite belonging to the genus Trypanosoma. The disease affects both humans and animals. In this study, phytochemical analysis and in-vitro antitrypanosomal screening of crude methanol extracts of the leaves of Waltheria indica, Vernonia amygdalina, Albizia ferruginea, Camellia sinensis, Chamaecrista mimosoides and Hyptis suaveolens were carried out using standard methods. Highly parasitized blood from infected donor rats was diluted with glucose phosphate buffered saline solution and incubated with varying concentrations (1 mg/ml, 2 mg/ml and 4 mg/ml) of the extracts in Eppendorf tubes for 60 minutes. Aliquots from the mixtures were removed and observed under microscope for parasite motility at 5 minutes interval. Phytochemical screening revealed the presence of tannins, alkaloids, flavonoids, phenols and glycosides in all the plants’ extracts. Saponins were absent in H. suaveolens while steroids and phlobatannins were absence in C. mimosoides and H. suaveolens. All the plants’ extracts showed significant cessation of parasite motility with increase in incubation time and concentration of the extract. Complete cessation of the parasite motility was observed for all the extracts within 60 minutes of the study. The most active extract was W. indica at 4mg/ml which caused complete cessation of the parasite motility within 5 minutes whereas the least active plants C. mimosoides and H. suaveolens. Both caused complete cessation of the parasite motility within 25 minutes. Berenil, the standard drug, however, caused cessation of trypanosomal motility within 5 minutes even at 1 mg/ml. These results showed that methanol l extracts of the plants leaves screened especially Waltheria indica and Vernonia amygdalina have significant in vitro antitrypanosomal activity and may be potential source for the in vivo treatment of trypanosomiasis.

Open Access Original Research Article

Cystatin C- An Early Diagnostic Biomarker of Diabetic Kidney Disease

Sudarshan N. Shelke, Pramod W. Ingale, Pooja S. K. Rai, Shimi Sundharan

International Journal of Biochemistry Research & Review, Page 1-6
DOI: 10.9734/IJBCRR/2016/24760

Aim: This study aimed to evaluate serum cystatin C vs. Serum creatinine and BUN as a potential better marker for early diagnosis of diabetic kidney disease.

Study Design:  Cross-sectional study.

Place and Duration of Study: Department of Biochemistry, LTM Medical College, Sion, Mumbai, between January 2014 and November 2014.

Methodology: Diagnosed patients of type 2 diabetes mellitus were evaluated based on detailed history, clinical examination and laboratory investigations. Patients having frank proteinuria were excluded. Patients without proteinuria were tested for microalbuminuria. In study group, we included 50 patients having microalbuminuria and in control group, 50 patients without microalbuminuria. Blood urea nitrogen (BUN), serum creatinine and serum cystatin C were estimated. Results were analysed by unpaired t-test & P-value was determined.

Results: Serum cystatin C was found to be increased in the study group as compared with controls and the difference was statistically significant (P = .000). BUN (P = .26) and serum Creatinine         (P = .11) were found to be slightly higher in cases compared to control group but values were within reference range.

Conclusion: The results of this study suggest that serum cystatin C measurement is a useful, practical tool for the evaluation of renal involvement in the course of diabetes. BUN and serum creatinine values are affected by many factors like age, sex, muscle mass, diet. Serum cystatin C estimation offers a hope that diabetic kidney disease can be well prevented with appropriate interventions.

Open Access Original Research Article

In vitro Antisalmonellal and Antioxidant Activities of Extracts and Fractions of Curcuma longa L. Rhizomes (Zingiberaceae)

Norbert Kodjio, Serge S. Atsafack, Siméon P. C. Fodouop, Jules-Roger Kuiate, Donatien Gatsing

International Journal of Biochemistry Research & Review, Page 1-14
DOI: 10.9734/IJBCRR/2016/25106

Typhoid fever is still a major public health problem in developing countries, where it remains endemic. With a view to searching for new antityphoid substances, Curcuma longa rhizome extracts and fractions were assessed for their antisalmonellal and antioxidant activities. The antisalmonellal efficacy in terms of minimum inhibitory concentrations (MICs) of the different extracts and fractions was determined using serial microdilution method. The antioxidant activity was determined by measuring FRAP (ferric reducing-antioxidant power), DPPH radical scavenging, nitric oxide (NO) radical scavenging, ferrous ion-chelating and hydroxyl radical scavenging activities. Total flavonoids and total phenolic contents were also evaluated. The results showed that the extracts and fractions of Curcuma longa were effective against all the bacteria tested with MICs ranging from 32 to 1024 µg/mL. These results also showed that MeOH/CH2Cl2 (v/v, 1:1) extract, residual and ethyl acetate fractions possessed strong antioxidant activities (IC50< 20 µg/mL). Phytochemical screening showed the presence of alkaloids, flavonoids, saponins and phenols in all the extracts and fractions. In the light of the foregoing, it was obvious that Curcuma longa contains antisalmonellal and antioxidant principles which could be developed for the treatment of enteric fevers (typhoid and paratyphoid fevers) and the management of oxidative stress induced by the salmonellal infections. These findings support the claim of the local community about the use of this plant for the treatment of typhoid fever.

Open Access Review Article

Alternative Microbial Routes to Homoserine Activation and Sulfuration: Critical Steps in Methionine Biosynthesis

Bharani Thangavelu, Ronald E. Viola

International Journal of Biochemistry Research & Review, Page 1-22
DOI: 10.9734/IJBCRR/2016/25074

Background: Methionine is a sulfur-containing amino acid that is synthesized via a branch point in the aspartate metabolic pathway. S-adenosyl methionine is subsequently synthesized from methionine, and plays a critical role in the transfer of methyl groups to various biomolecules, including DNA, proteins and small-molecule secondary metabolites. The branch point that leads to the synthesis of methionine and S-adenosyl methionine starts with the activation of the hydroxyl group of homoserine.

Species Variation: The mode of activation of homoserine differs from plants to microorganisms, as well as within different microbial systems. At this point, depending on the species, at least three different activation routes have been identified. In addition, the route of sulfur assimilation in these systems can also vary from species to species.

Enzymology: Homoserine acyl transferases catalyze the primary routes to homoserine activation in microbes, and these enzymes are members of the α/β hydrolase superfamily. While the two different families of homoserine acyl transferases use the same kinetic and chemical mechanisms to catalyze this related reaction, they do so by using significantly different overall structures, as well as subtle differences in their closely related active site structures.

Conclusion: Since this pathway produces metabolites that play a number of critical biochemical roles in microorganisms, and because of the complete absence of related enzymes in mammals, the enzymes in this pathway represent novel targets for future antibiotic drug development.