Vijaya Ramu Dirisala

Background/Objectives: The genus Shigella is one of the major pathological agents responsible for diarrhea and diarrhea-related mortality worldwide. It shows a decreasing sensitivity to most conventional antibiotics available today. Methods: Hence, an antimicrobial peptide, Octominin II, was conjugated to a cell-penetrating peptide (HIV-TAT) named TAT-Octominin II, and its antibacterial effect against Shigella flexneri was investigated. Results: TAT-Octominin II displayed minimum inhibitory and bactericidal concentrations of 10 and 25 µg/mL, respectively. It showed rapid membrane-permeabilizing activity, as observed in the ONPG assay. TAT-Octominin II treatment altered the cell membrane integrity and causing membrane damage in S. flexneri. Moreover, TAT-Octominin II increased oxidative stress, as evidenced by the upregulation of antioxidant genes, such as sodA, sodB, katG, oxyR, and soxR. Furthermore, TAT-Octominin II bound to genomic DNA and RNA, which likely inhibited the transcription and translation of bacterial proteins. In addition, TAT-Octominin II possessed lipopolysaccharide neutralization activity. In vitro toxicity analysis was performed using mammalian Raw 264.7 and HEK 293 cells, which showed no toxicity at lower concentrations (0–100 µg/mL). Conclusions: Overall, our results demonstrate that TAT-conjugated Octominin II exhibits enhanced antibacterial activity compared to Octominin II alone, suggesting that TAT-mediated delivery of AMPs could be a promising strategy to improve the therapeutic efficacy of AMPs.

The antioxidant properties of resveratrol (RES) against oxidative toxicity induced by testicular toxicants are well documented. The current study aimed to investigate the probable beneficial role of RES on male reproduction in adult rats following prepubertal exposure to perfluorooctanoic acid (PFOA). Healthy rats of the Wistar strain (23 days old) were allocated into four groups. Rats in group I did not receive any treatment, while rats in groups II, III, and IV received RES, PFOA, and RES + PFOA, respectively, between days 23 and 56 and were monitored for up to 90 days. Exposure to PFOA resulted in a significant reduction in spermiogram parameters, testicular 3β- and 17β-HSD activity levels, and circulatory levels of testosterone. A significant elevation in LPx, PCs, H₂O₂, and O₂⁻, associated with a concomitant reduction in SOD, CAT, GPx, GR, and GSH, was noticed in the testes, as well as region-specific changes in pro- and antioxidants in the epididymides of exposed rats compared to controls. A significant increase in serum FSH and LH, testicular cholesterol levels, and caspase-3 activity was observed in PFOA-exposed rats compared to controls. Histological analysis revealed that the integrity of the testes was deteriorated in PFOA-exposed rats. Transcriptomic profiling of the testes and epididymides revealed 98 and 611 altered genes, respectively. In the testes, apoptosis and glutathione pathways were disrupted, while in the epididymides, glutathione and bile secretion pathways were altered in PFOA-exposed rats. PFOA exposure resulted in the down-regulation in the testes of 17β-HSD, StAR, nfe2l2, ar, Lhcgr, and mRNA levels, associated with the up-regulation of casp3 mRNA, and down-regulation of alpha 1 adrenoceptor, muscarinic choline receptor 3, and androgen receptor in the epididymides of exposed rats compared to the controls. These events might lead to male infertility in PFOA-exposed rats. In contrast, restoration of selected reproductive variables was observed in RES plus PFOA-exposed rats compared to rats exposed to PFOA alone. Taken together, we postulate that prepubertal exposure to PFOA triggered oxidative damage and altered genes in the testes and epididymides, leading to suppressed male reproductive health in adult rats, while RES, with its steroidogenic, antiapoptotic, and antioxidant effects, restored PFOA-induced fertility potential in rats.

Previously, we showed that the crude methanol extracts of Leucas indica flowers exhibited antioxidant properties and in the current study, crude methanol flower extracts of L. indica showed anticancerous properties as evidenced cytotoxicity (MTT assay test) against the selected cancerous cell lines HeLa, HCT116, HL-60, and MCF-7. Therefore, further analysis was performed to isolate and purify the bioactive compound using activity-guided repeated fractionation of the methanol extract by silica gel column chromatography. After collection of different fractions, all the fractions were subjected to TLC analysis and the fractions which yielded the same compounds on TLC were further analyzed for physicochemical and spectroscopic analyses, e.g., UV, IR, ¹H NMR, ¹³C NMR, COSY, HSQC, and mass spectroscopy. The bioactive compound isolated was elucidated as 6-hydroxy-3-(4-hydroxyphenyl)-7-(3,4,5-trihydroxy-6-)(hydroxymethyl)tetrahydro-2H-pyran-2yl)-4H-chromen-4-one. Based on the antioxidant and anticancerous properties, L. indica might be a promising source of useful natural products and the newly bioactive compound might offer opportunities to develop new anticancerous drugs.

In our previous studies, we have demonstrated the association of certain variants of the thyroid-stimulating hormone receptor (TSHR), thyroid peroxidase (TPO), and thyroglobulin (TG) genes with congenital hypothyroidism. Herein, we explored the mechanistic basis for this association using different in silico tools. The mRNA 3'-untranslated region (3'-UTR) plays key roles in gene expression at the post-transcriptional level. In TSHR variants (rs2268477, rs7144481, and rs17630128), the binding affinity of microRNAs (miRs) (hsa-miR-154-5p, hsa-miR-376a-2-5p, hsa-miR-3935, hsa-miR-4280, and hsa-miR-6858-3p) to the 3'-UTR is disrupted, affecting post-transcriptional gene regulation. TPO and TG are the two key proteins necessary for the biosynthesis of thyroid hormones in the presence of iodide and H2O2. Reduced stability of these proteins leads to aberrant biosynthesis of thyroid hormones. Compared to the wild-type TPO protein, the p.S398T variant was found to exhibit less stability and significant rearrangements of intra-atomic bonds affecting the stoichiometry and substrate binding (binding energies, ΔG of wild-type vs. mutant: ‒15 vs. ‒13.8 kcal/mol; and dissociation constant, Kd of wild-type vs. mutant: 7.2E-12 vs. 7.0E-11 M). The missense mutations p.G653D and p.R1999W on the TG protein showed altered ΔG (0.24 kcal/mol and 0.79 kcal/mol, respectively). In conclusion, an in silico analysis of TSHR genetic variants in the 3'-UTR showed that they alter the binding affinities of different miRs. The TPO protein structure and mutant protein complex (p.S398T) are less stable, with potentially deleterious effects. A structural and energy analysis showed that TG mutations (p.G653D and p.R1999W) reduce the stability of the TG protein and affect its structure-functional relationship.

Background: Oral administration of biguanides (metformin) and sulfonylureas (gliclazide) are the most common approach of management of type 2 diabetes in humans. Among these diabetic patients, approximately 40–60% suffers from hypertension. Hence, the need of the day is application of polytherapy. A major challenge in polytherapy is the drug-drug interactions that may arise. Hence, this study is focused to develop a reverse phase high-performance liquid chromatography (RP-HPLC) method for concurrent estimation of diabetic drug metformin and hypertension drug valsartan using C18 column and find any possible pharmacokinetic interactions between the two drug combinations strategies, i.e., metformin-valsartan and gliclazide-valsartan in streptozotocin-induced diabetic rats. Result: The bioanalysis of drug-drug interaction pharmacokinetic result showed no significant difference in the t_max of single treatment of gliclazide and single treatment of metformin or upon co-administration with valsartan. Conclusion: Our study has shown that polytherapy of valsartan, a drug administered for hypertension along with hypoglycemic drugs metformin and gliclazide, can be advantageous and safe in patients suffering from both diabetes and hypertension.

High prevalence of congenital hypothyroidism (CH) among Indian newborns prompted us to establish population-specific reference ranges of TSH and to explore the contribution of the common genetic variants in TSHR, TPO, TG and DUOX2 genes towards CH. A total of 1144 newborns (593 males and 551 females) were screened for CH. SNV profiling (n = 22) spanning three candidate genes, i.e. TSHR, TPO and TG was carried out in confirmed CH cases (n = 45). In screen negative cases (n = 700), ten TSHR variants were explored to establish association with CH. No mutation found in DUOX2. The 2.5th to 97.5th percentiles of TSH in these newborns were 0.5 to 12.2 mU/L. In newborns with optimal birth weight, the cut-off was 10 mU/L. Lower or higher birth weight resulted in slightly higher TSH. Two TSHR variants, i.e. rs7144481 and rs17630128 were associated with agenesis, hypoplasia and goiter. The rs2268477 was associated with agenesis and hypoplasia. The rs1991517, rs2075176 and rs2241119 were associated with agenesis only. The rs7144481, rs17630128, rs1991517 and rs2268477 were associated with 2.17, 4.62, 2.91 and 2.29-fold increased risk for CH, respectively. Among the TPO variants, rs867983 and rs2175977 were associated with agenesis and goiter, respectively. Among the TG variants, rs2076740 showed association with agenesis and goiter. Two rare variants i.e. TPO g.IVS14-19 G>C and TG c.1262 C>T were observed in CH cases. No genetic variant identified in the two exons of DUOX2. To conclude, the current study established Indian population-specific normative values for TSH and demonstrates specific genotype–phenotype correlations among three candidate genes.

The objective of the current study is to explore the association of thyroid-stimulating hormone receptor (TSHR) rs1991517 polymorphism (c.2337 C > G, p.D727E) with congenital hypothyroidism (CH) through a case–control study followed by a meta-analysis. The case–control study was based on 45 CH subjects and 700 healthy controls. Meta-analysis comprised of seven published studies and our current findings (1044 CH cases and 1649 healthy controls). The allele contrast model showed that the presence of G- allele increased CH risk by 45% (OR: 1.45, 95% CI 1.20–1.76) and 41% (OR: 1.41, 95% CI 1.03–1.93) in fixed effect and random effect models, respectively. The GG- genotype is associated with 2.3-fold (95% CI 1.32–3.99) increased risk for CH in the fixed-effect model. I² (0.58) and Cochran’s Q test (Q: 16.72, p = 0.02) revealed evidence of heterogeneity in the association. No publication bias was observed by Egger’s test (p = 0.70). Sensitivity analysis revealed that even after excluding any study this polymorphism is associated with risk for CH. The rs1991517 mutation alters the binding affinity to cAMP (ΔG of 727D vs.727E: − 7.27 vs. − 7.34 kcal/mol). In conclusion, rs1991517 is a genetic risk factor for CH and exerts its impact by altering cAMP-mediated signal transduction.