Effect of Indian honey on expression of p53 and cyclin B1 in HeLa cells

178-184Honey is a natural product collected from the nectar by honey bees and has a wide array of therapeutic important compounds called as phytochemicals. Cancer is one of the leading causes of death worldwide. Existing conventional cancer therapy which is mainly comprised of chemotherapeutic agents has side effects. Honey due to the presence of phytochemicals especially flavonoids and phenolic acids like apigenin, chrysin, quercetin and caffeic acid are found to inhibit the cancer growth. This effect varies among different honeys since they are dependent on the phytochemical composition and their concentrations in honey, which varies with respect to floral origin from which honey has been collected, geographical and climatic conditions. Thus, in the current study, phytochemical characterization of Jambhul, Rubber, Litchi and Drumstick honey samples along with their effect on the expression of proteins playing a vital role in the event of cell cycle and apoptosis i.e. Cyclin B1 and p53 proteins were determined by Flow cytometry. It was found that these honey samples contain apigenin, chrysin, quercetin and caffeic acid. These honeys exhibited an increase in expression of p53 whereas, expression of Cyclin B1 protein was reduced in HeLa cells treated with honey samples. The presence of phytochemical markers exhibiting promising anticancer potential along with the ability of alterations in the expression of these proteins proves that these honey samples have a potent anticancer activity which enhances the chances of these Indian honeys to be utilized in the treatment of cervical cancer

Evaluation of erythrocyte membrane lipids and proteins in renal disorders

Background: Membrane lipids and proteins play a significant part in imparting membrane its rheological properties. These parameters are altered in diseased states. Exploring the conformational changes in renal disorders can widen our understanding of its impact on the circulatory system. This could lead to a new diagnostic parameter to study the progress of a disease.Methods: 120 blood samples collected from 30 kidney donors, 30 stage 3-4 Chronic kidney disease (CKD) patients (group 1) and 30 stage 5 CKD patients on dialysis (pre and post dialysis) (group 2) were lysed and washed to obtain erythrocyte ghost membranes. The proteins extracted from these membranes were estimated colorimetrically using Micro BCA kit. Phospholipids were separated and quantified using HPTLC. Fatty acids and cholesterol were analysed using GCMS.Results: The erythrocyte membrane protein profile showed lower values in group 2 participants than group 1 participants, but this difference was not significant. Distinct decreases in percentages of palmitic acid, myristic acid, stearic acid, dodecanoic acid, cholesterol, phosphatidylserine, phosphatidylcholine and phosphatidylethanolamine were observed in both groups, with the lowest values in patients undergoing dialysis. Sphingomyelin and linoleic acid did not show any such trend across groups.Conclusions: The data is suggestive of an altered membrane structure in participants undergoing dialysis patients than the control group. This could be because of uremic toxins in the circulatory system affecting the membrane lipids. Decreased levels of essential phospholipids can impact the functions and lifespan of the erythrocytes. This could be a reason behind anaemia seen in most patients with CKD

Evaluation of surface properties of erythrocyte membranes in liver diseases

Background: The physicochemical properties of Red Blood Cell membranes (RBC) are altered in liver diseases. Langmuir monolayers offer an excellent model system to study biological membrane surface properties. The aim of this study was to evaluate surface properties of erythrocyte membranes in liver diseases.  Methods: Sixty-one patients with various liver diseases and fifteen controls were enrolled. Surface properties of RBC membrane were evaluated using Langmuir monolayers. Surface pressure area isotherms were recorded at body temperature using RBC membrane lipid extract. Student’s t-test and Analysis of variance tests were performed.Results: Mean maximum surface pressure and hysteresis area were significantly higher in cirrhotic and non-cirrhotic liver disease groups compared to controls. Within cirrhotics, mean maximum surface pressure and lift off area was significantly lower in the Child C group as compared to the Child A, B and A-B groups. The mean hysteresis area was significantly lower in the Child C group as compared to the Child B and A-B groups.Conclusion: The results of our study confirmed high rigidity of RBC membrane in mild and moderate liver cirrhosis and high fluidity in severe liver cirrhosis. This study may pave the way to the development of a surface activity based biophysical tool for therapeutic implication in liver diseases.

Occurrence of bio-immunactive inhibin in rat spermatids

Levels of inhibin in the spermatocyte and spermatid enriched fractions of rat testicular extract were estimated using a specific and sensitive radioimmunoassay. The fraction enriched in spermatids had the highest amounts of inhibin activity. The results of the study indicate that the spermatids may be likely source of inhibin

A folding transition underlies the emergence of membrane affinity in amyloid-β

Small amyloid-β (Aβ) oligomers have much higher membrane affinity compared to the monomers, but the structural origin of this functional change is not understood. We show that as monomers assemble into small n-mers (n < 10), Aβ acquires a tertiary fold that is consistent with the mature fibrils. This is an early and defining transition for the aggregating peptide, and possibly underpins its altered bioactivity

Steric crowding of the turn region alters the tertiary fold of amyloid-β18–35and makes it soluble

Aβ self-assembles into parallel cross-β fibrillar aggregates, which is associated with Alzheimer's disease pathology. A central hairpin turn around residues 23–29 is a defining characteristic of Aβ in its aggregated state. Major biophysical properties of Aβ, including this turn, remain unaltered in the central fragment Aβ18–35. Here, we synthesize a single deletion mutant, ΔG25, with the aim of sterically hindering the hairpin turn in Aβ18–35. We find that the solubility of the peptide goes up by more than 20-fold. Although some oligomeric structures do form, solution state NMR spectroscopy shows that they have mostly random coil conformations. Fibrils ultimately form at a much higher concentration but have widths approximately twice that of Aβ18–35, suggesting an opening of the hairpin bend. Surprisingly, two-dimensional solid state NMR shows that the contact between Phe19 and Leu34 residues, observed in full-length Aβ and Aβ18–35, is still intact in these fibrils. This is possible if the monomers in the fibril are arranged in an antiparallel β-sheet conformation. Indeed, IR measurements, supported by tyrosine cross-linking experiments, provide a characteristic signature of the antiparallel β-sheet. We conclude that the self-assembly of Aβ is critically dependent on the hairpin turn and on the contact between the Phe19 and Leu34 regions, making them potentially sensitive targets for Alzheimer's therapeutics. Our results show the importance of specific conformations in an aggregation process thought to be primarily driven by nonspecific hydrophobic interactions

The basic structural motif and major biophysical properties of Amyloid-β are encoded in the fragment 18–35

Aggregation and misfolding of the amyloid beta (Aβ) peptide is thought to initiate Alzheimer’s disease (AD). Here we study the role played by its central segment (Aβ18–35) in determining these properties. Aβ18–35 has a solubility of 18 μM. The soluble fraction consists mainly of small oligomers, which have mixed β-sheet and random coil structures. The monomer is mostly a random coil with some residual compactness. Aggregated Aβ18–35 forms fibrils of width 3.0 ± 0.7 nm, which is consistent with a hairpin shape. Each of these properties has a close similarity to Aβ40. Remarkably, solid state NMR indicates that the fibrils also retain the secondary structure and tertiary contacts of Aβ40. This is the shortest fragment of Aβ reported so far which preserves its fibrillar architecture, including the hairpin turn, as well as its solution phase conformational properties. Residues 18–35 should therefore be a key target of AD therapeutics