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In vitro antiaging activity of polyphenol rich Polyalthia longifolia (Annonaceae) leaf extract in Saccharomyces cerevisiae BY611 yeast cells

Hemagirri M, Sasidharan S

J Ethnopharmacol, 2022 Feb 15;290:115110.
PMID: 35181488 DOI: 10.1016/j.jep.2022.115110

ETHNOPHARMACOLOGICAL RELEVANCE: Polyalthia longifolia var. angustifolia Thw. (Annonaceae) is commonly used in traditional medicine as a tonic for rejuvenation and exhibiting good antioxidant activities.
AIM OF THE STUDY: To evaluate P. longifolia methanolic leaf extract (PLME) antiaging activity at 1 mg/mL in Saccharomyces cerevisiae BY611 yeast.
MATERIALS AND METHODS: The antiaging effect of PLME was studied via replicative lifespan assay, antioxidative stress assays, reactive oxygen species (ROS) determination, reduced glutathione (GSH) determination, superoxide dismutase (SOD) and Sirtuin 1 (SIRT1) genes regulation studies and SOD and SIRT1 proteins activities.
RESULTS: The PLME treatment increased the growth and prolonged the lifespan of the yeast significantly (p
Evaluation of In Situ Antiaging Activity in Saccharomyces cerevisiae BY611 Yeast Cells Treated with Polyalthia longifolia Leaf Methanolic Extract (PLME) Using Different Microscopic Approaches: A Morphology-Based Evaluation

Hemagirri M, Sasidharan S

Microsc Microanal, 2022 Mar 09.
PMID: 35260222 DOI: 10.1017/S1431927622000393

Polyalthia longifolia is known for its anti-oxidative properties, which might contribute to the antiaging action. Hence, the current research was conducted to evaluate the antiaging activity of P. longifolia leaf methanolic extract (PLME) in a yeast model based on morphology using microscopic approaches. Saccharomyces cerevisiae BY611 strain yeast cells were treated with 1.00 mg/mL of PLME. The antiaging activity was assessed by determining the replicative lifespan, total lifespan, vacuole morphology by light microscopy, extra-morphology by scanning (SEM), and intra-morphology by transmission (TEM) electron microscopy. The findings demonstrated that PLME treatment significantly accelerated the replicative and total lifespan of the yeast cells. PLME treatment also delays the formation of large apoptotic-like type 3 yeast cell vacuoles. The untreated yeast cells demonstrated aging morphology via SEM analysis, such as shrinking, regional invaginations, and wrinkled cell surface. The TEM analysis revealed the quintessential aging intracellular morphology such as swollen, wrinkled, or damaged vacuole formation of the circular endoplasmic reticulum, a rupture in the nuclear membrane, fragmentation of the nucleus, and complete damaged cytoplasm. Decisively, the present study revealed the vital role of PLME in the induction of antiaging activity in a yeast model using three microscopic approaches—SEM, TEM, and bright-field light microscope.
Crosstalk between protein misfolding and endoplasmic reticulum stress during ageing and their role in age-related disorders

Hemagirri M, Chen Y, Gopinath SCB, Sahreen S, Adnan M, Sasidharan S

Biochimie, 2023 Nov 02.
PMID: 37918463 DOI: 10.1016/j.biochi.2023.10.019

Maintaining the proteome is crucial to retaining cell functionality and response to multiple intrinsic and extrinsic stressors. Protein misfolding increased the endoplasmic reticulum (ER) stress and activated the adaptive unfolded protein response (UPR) to restore cell homeostasis. Apoptosis occurs when ER stress is prolonged or the adaptive response fails. In healthy young cells, the ratio of protein folding machinery to quantities of misfolded proteins is balanced under normal circumstances. However, the age-related deterioration of the complex systems for handling protein misfolding is accompanied by ageing-related disruption of protein homeostasis, which results in the build-up of misfolded and aggregated proteins. This ultimately results in decreased cell viability and forms the basis of common age-related diseases called protein misfolding diseases. Proteins or protein fragments convert from their ordinarily soluble forms to insoluble fibrils or plaques in many of these disorders, which build up in various organs such as the liver, brain, or spleen. Alzheimer's, Parkinson's, type II diabetes, and cancer are diseases in this group commonly manifest in later life. Thus, protein misfolding and its prevention by chaperones and different degradation paths are becoming understood from molecular perspectives. Proteodynamics information will likely affect future interventional techniques to combat cellular stress and support healthy ageing by avoiding and treating protein conformational disorders. This review provides an overview of the diverse proteostasis machinery, protein misfolding, and ER stress involvement, which activates the UPR sensors. Here, we will discuss the crosstalk between protein misfolding and ER stress and their role in developing age-related diseases.
RNA-sequencing exploration on SIR2 and SOD genes in Polyalthia longifolia leaf methanolic extracts (PLME) mediated anti-aging effects in Saccharomyces cerevisiae BY611 yeast cells

Hemagirri M, Chen Y, Gopinath SCB, Adnan M, Patel M, Sasidharan S

Biogerontology, 2024 Apr 15.
PMID: 38619670 DOI: 10.1007/s10522-024-10104-y

Polyalthia longifolia is well-known for its abundance of polyphenol content and traditional medicinal uses. Previous research has demonstrated that the methanolic extract of P. longifolia leaves (PLME, 1 mg/mL) possesses anti-aging properties in Saccharomyces cerevisiae BY611 yeast cells. Building on these findings, this study delves deeper into the potential antiaging mechanism of PLME, by analyzing the transcriptional responses of BY611 cells treated with PLME using RNA-sequencing (RNA-seq) technology. The RNA-seq analysis results identified 1691 significantly (padj