Kesavanarayanan Krishnan Selvarajan

Objectives: Research on endosymbionts is emerging globally and is considered as a potential source of bioactive phytochemicals. The present study examines the antioxidant and antidiabetic of the endophytic crude extract isolated from Leucaena leucocephala leaves. Methods: Endophytic bacteria were isolated from the leaves of L. leucocephala and 16S rRNA gene sequencing was used to establish their identity. The in vitro antioxidant effect of endophytic crude extract (LL) was evaluated using 2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) free radical scavenging methods. The in vitro antidiabetic properties of LL were evaluated using α-amylase and α-glucosidase enzyme inhibition assay. Results: The isolated endophytic bacteria were identified as Cronobacter sakazakii . LL displayed potent free radical scavenging effect against ABTS and DPPH radicals with an inhibitory concentration 50% (IC ₅₀ ) value of 17.49 ± 0.06 and 11.3 ± 0.1 μg/mL respectively. LL exhibited α-amylase and α-glucosidase inhibition with an IC ₅₀ value of 23.3 ± 0.08 and 23.4 ± 0.1 μg/mL respectively compared to the standard drug (acarbose). Both glucose loaded normoglycemic rats and STZ induced diabetic rats treated with LL (200 mg/kg) exhibited a considerable reduction in blood glucose levels p<0.01 after 8 h of treatment when compared to normal and diabetic control rats respectively. Conclusions: Thus, the study shows that LL has a wellspring of natural source of antioxidants, and antidiabetic agents and phytoconstituents present in endophytes could be the rich source for bioactive compounds.

Background:: Endophytic bacteria produce various bioactive secondary metabolites, which benefit human health. Tamarindus indica L. is well known for its medicinal value in human health care. Several studies have reported on its biological effects from various parts of T. indica, but only a few studies have been devoted to examining the biological activity of endophytes of T. indica. Objectives: In the present study, an endophyte was isolated from the leaves of T. indica and screened for its antimicrobial potential. Methods: The selected endophyte was identified by 16s rRNA partial genome sequencing and investigated for their antimicrobial potency. The preliminary phytochemical tests were conducted for the affirmation of phytoconstituents in the endophytic crude ethyl acetate extract of T. indica (TIM) and total phenolic content was performed. The antimicrobial potential of TIM was evaluated against human pathogenic ATCC gram-positive and gram-negative bacterial strains. Results: TIM exhibited an appreciable amount of gallic acid equivalent phenolic content (21.6 ± 0.04 mg GAE/g of crude extract). TIM showed the Minimum Inhibitory Concentration (MIC) at 250 μg/mL and Minimum Bactericidal Concentration (MBC) at 500 μg/mL among the selected human pathogenic ATCC strains. At MIC of 500 μg/mL, TIM displayed a significant zone of inhibition against P. aeruginosa and N. gonorrhoeae. Conclusion: The results from our study highlighted for the first time the antimicrobial potential of endophytic bacterial strain Bacillus velezensis in T. indica leaves and it could be further explored as a source of natural antimicrobial agents.

Objective: The aim of the research is to study the antimicrobial potential of Tamarindus indica leaves extract (Malaysian origin).Methods: T. indica leaves extraction was carried out by maceration (TIME) and Soxhlet extraction methods (TISE). The phytochemical test was conducted for the confirmation of various phytoconstituents present in the leaves extract. Antimicrobial assays were carried out by minimum bactericidal concentration (MBC), minimum inhibitory concentration (MIC), and agar well diffusion method against ATCC bacterial strains.Results: Ethanolic extraction of T. indica leaves by maceration method showed better yield (70.38%) compared to Soxhlet extraction method (60.55%). The qualitative phytochemical test on TISE and TIME were confirmed the presence of alkaloids, flavonoids, phenols, mucilage, tannins, steroids, proteins, and carbohydrates. TIME was selected for antimicrobial studies, and it was found to have MBC value of 500 μg/mL and MIC value of 250 μg/mL among various test bacteria, and it was also found to exhibit good zone of inhibition against Gram-negative bacteria such as Escherichia coli and Neisseria gonorrhoeae. Conclusion: These findings deduced that T. indica leaves have various phytochemical constituents which could be responsible for their natural antibacterial activity especially against Gram-negative bacteria.

Objectives: Current research is aimed to investigate the natural antimicrobial potential of Durio zibethinus murr. ethanol leaves extract (DZL).Methods: DZL was subjected to the preliminary phytochemical screening along with quantitative analysis of phenols and flavonoids. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were recorded. The agar well diffusion method was used to measure the antibacterial activity against gram positive and gram negative bacteria. The microorganisms used for the study were the ATCC strains of Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus, Streptococcus pyogenes, Neisseria gonorrhoeae, Pseudomonas aeruginosa and Escherichia coli.Results: DZL exhibited the highest MIC of 0.1mg/mL and MBC of 0.25 mg/mL against gram negative bacteria, Pseudomonas aeruginosa and Escherichia coli. At MIC of 0.1mg/mL, DZL displayed significant zone of inhibition against Pseudomonas aeruginosa and Escherichia coli compared to gentamycin.Conclusion: This research has shown that DZL has natural antibacterial properties against gram negative human pathogens.

Injury to podocytes is an early event in diabetic nephropathy leading to proteinuria with possible progression to end-stage renal failure. The podocytes are unique and highly specialized cells that cover the outer layer of kidney ultra-filtration barrier and play an important role in glomerular function. In the past few decades, adult stem cells, such as mesenchymal stem cells (MSCs) with a regenerative and differentiative capacity have been extensively used in cell-based therapies. In addition to their capability for regeneration and differentiation, MSCs contributes to their milieu by paracrine action of a series of growth factors via antiapoptotic, mitogenic and other cytokine actions that actively participate in treatment of podocyte damage through prevention of podocyte effacement, detachment and apoptosis. It is hoped that novel stem cell-based therapies will be developed in the future to prevent podocyte injury, thereby reducing the burden of kidney disease.

Background: Parkinson's disease (PD) is a neurodegenerative disease caused by the loss of dopaminergic (DA‐ergic) neurons in the substantia nigra (SN) and represented as a huge threat to the geriatric population. Cell replacement therapies (CRTs) have been proposed as a promising strategy to slow down or replace neuronal loss. Among the widely available cell sources, dental pulp stem cells (DPSCs) portray as an attractive source primarily due to their neural crest origin, ease of tissue procurement and less ethical hurdles.Materials and methods: We first demonstrated the in vitro differentiation ability of DPSCs towards DA‐ergic‐like cells before evaluating their neuro‐protection/neuro‐restoration capacities in MPTP‐induced mice. Transplantation via intrathecal was performed with behavioural assessments being evaluated every fortnight. Subsequent analysis investigating their immuno‐modulatory behaviour was conducted using neuronal and microglial cell lines.Results: It was apparent that the behavioural parameters began to improve corresponding to tyrosine hydroxylase (TH), dopamine transporter (DAT) and dopamine decarboxylase (AADC) immunostaining in SN and striatum as early as 8‐week post‐transplantation (P < 0·05). About 60% restoration of DA‐ergic neurons was observed at SN in MPTP‐treated mice after 12‐week post‐transplantation. Similarly, their ability to reduce toxic effects of MPTP (DNA damages, reactive oxygen species and nitric oxide release) and regulate cytokine levels was distinctly noted (P < 0·05) upon exposure in in vitro model.Conclusions: Our results suggest that DPSCs may provide a therapeutic benefit in the old‐aged PD mice model and may be explored in stem cell‐based CRTs especially in geriatric population as an attempt towards ‘personalized medicine’.