MyMedR

Displaying publications 21 - 25 of 25 in total

Abstract:

Sort:

Novel targets of pentacyclic triterpenoids in Staphylococcus aureus: A systematic review

Chung PY

Phytomedicine, 2020 Jul 15;73:152933.
PMID: 31103429 DOI: 10.1016/j.phymed.2019.152933

BACKGROUND: Staphylococcus aureus is an important pathogen both in community-acquired and healthcare-associated infections, and has successfully evolved numerous strategies for resisting the action to practically all antibiotics. Resistance to methicillin is now widely described in the community setting (CMRSA), thus the development of new drugs or alternative therapies is urgently necessary. Plants and their secondary metabolites have been a major alternative source in providing structurally diverse bioactive compounds as potential therapeutic agents for the treatment of bacterial infections. One of the classes of natural secondary metabolites from plants with the most bioactive compounds are the triterpenoids, which comprises structurally diverse organic compounds. In nature, triterpenoids are often found as tetra- or penta-cyclic structures.
AIM: This review highlights the anti-staphylococcal activities of pentacyclic triterpenoids, particularly α-amyrin (AM), betulinic acid (BA) and betulinaldehyde (BE). These compounds are based on a 30-carbon skeleton comprising five six-membered rings (ursanes and lanostanes) or four six-membered rings and one five-membered ring (lupanes and hopanes).
METHODS: Electronic databases such as ScienceDirect, PubMed and Scopus were used to search scientific contributions until March 2018, using relevant keywords. Literature focusing on the antimicrobial and antibiofilms of effects of pentacyclic triterpenoids on S. aureus were identified and summarized.
RESULTS: Pentacyclic triterpenoids can be divided into three representative classes, namely ursane, lupane and oleananes. This class of compounds have been shown to exhibit analgesic, immunomodulatory, anti-inflammatory, anticancer, antioxidant, antifungal and antibacterial activities. In studies of the antimicrobial activities and targets of AM, BA and BE in sensitive and multidrug-resistant S. aureus, these compounds acted synergistically and have different targets from the conventional antibiotics.
CONCLUSION: The inhibitory mechanisms of S. aureus in novel targets and pathways should stimulate further researches to develop AM, BA and BE as therapeutic agents for infections caused by S. aureus. Continued efforts to identify and exploit synergistic combinations by the three compounds and peptidoglycan inhibitors, are also necessary as alternative treatment options for S. aureus infections.

Matched MeSH terms: Pentacyclic Triterpenes/pharmacology
Fulltext Betulinic acid was more cytotoxic towards the human breast cancer cell line MDA-MB-231 than the human promyelocytic leukaemia cell line HL-60

Latifah Saiful Yazan, Faujan Ahmad, Ooi, Choong Li, Raha Abdul Rahim, Hisyam Abdul Hamid, Lee, Pei Sze

Malaysian Journal of Pharmaceutical Science, 2009;7(1):23-37.
MyJurnal

Betulinic acid (BA) is a pentacyclic triterpene found in several botanical sources that has been shown to cause apoptosis in a number of cell lines. This study was undertaken to determine the in vitro cytotoxic properties of BA towards the human mammary carcinoma cell line MDA-MB-231 and the human promyelocytic leukaemia cell line HL-60 and the mode of the induced cell death. The cytotoxicity and mode of cell death of BA were determined using the MTT assay and DNA fragmentation analysis, respectively. In our study, the compound was found to be cytotoxic to MDA-MB-231 and HL-60 cells with IC50 values of 58 μg/mL and 134 μg/mL, respectively. Cells treated with high concentrations of BA exhibited features characteristic of apoptosis such as blebbing, shrinking and a number of small cytoplasm body masses when viewed under an inverted light microscope after 24h. The incidence of apoptosis in MDA-MB-231 was further confirmed by the DNA fragmentation analysis, with the formation of DNA fragments of oligonucleosomal size (180-200 base pairs), giving a ladder-like pattern on agarose gel electrophoresis. BA was more cytotoxic towards MDA-MB-231 than HL-60 cells, and induced apoptosis in MDA-MB-231 cells.

Matched MeSH terms: Pentacyclic Triterpenes
Transcriptome analysis of methicillin-resistant Staphylococcus aureus in response to stigmasterol and lupeol

Adnan SN, Ibrahim N, Yaacob WA

J Glob Antimicrob Resist, 2017 03;8:48-54.
PMID: 27992774 DOI: 10.1016/j.jgar.2016.10.006

OBJECTIVES: Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen with multiple antibiotic resistance that causes morbidity and mortality worldwide. Multidrug-resistant (MDR) MRSA with increased resistance to currently available antibiotics has challenged the world to develop new therapeutic agents. Stigmasterol and lupeol, from the plant Phyllanthus columnaris, exhibit antibacterial activities against MRSA. The aim of this study was to utilise next-generation sequencing (NGS) to provide further insight into the novel transcriptional response of MRSA exposed to stigmasterol and lupeol.
METHODS: Time-kill analysis of one MRSA reference strain (ATCC 43300) and three clinical isolates (WM3, BM1 and KJ7) for both compounds was first performed to provide the bacteriostatic/bactericidal profile. Then, MRSA ATCC 43300 strain treated with both compounds was interrogated by NGS.
RESULTS: Both stigmasterol and lupeol possessed bacteriostatic properties against all MRSA tested; however, lupeol exhibited both bacteriostatic and bactericidal properties within the same minimum inhibitory concentration and minimum bactericidal concentration values against BM1 (12.5mg/mL). Transcriptome profiling of MRSA ATCC 43300 revealed significant modulation of gene expression with multiple desirable targets by both compounds, which caused a reduction in the translation processes leading to inhibition of protein synthesis and prevention of bacterial growth.
CONCLUSIONS: This study highlights the potential of both stigmasterol and lupeol as new promising anti-MRSA agents.

Matched MeSH terms: Pentacyclic Triterpenes/pharmacology*
Gene expression changes in the human fibroblast induced by Centella asiatica triterpenoids

Coldren CD, Hashim P, Ali JM, Oh SK, Sinskey AJ, Rha C

Planta Med, 2003 Aug;69(8):725-32.
PMID: 14531023

The molecular pathways underlying the diverse biological activity of the triterpeniod compounds isolated from the tropical medicinal plant Centella asiatica were studied with gene microarrays and real-time reverse transcription polymerase chain reaction (real-time RT-PCR) to quantify the expression of 1053 human genes in human fibroblasts. Fibroblast cells grown in culture were used as a model system to evaluate the stimulation of wound healing by titrated extract from Centella asiatica (TECA) as well as by the four principal triterpenoid components of Centella. TECA treatment effects the expression of genes involved in angiogenesis and the remodeling of extracellular matrix, as well as diverse growth factor genes. The extent of expression change of TNFAIP6, an extracellular hyaluronan binding protein, was found to be largely dose-dependent, to respond most strongly to the free acids asiatic acid and madecassic acid, and to increase in expression over 48 hours of treatment. These results show that Centella triterpenes evoke a gene-expression response consistent with their prevailing medical uses in the treatment of connective tissue disorders such as wound healing and microangiopathy. The identification of genes modulated by these compounds provides the basis for a molecular understanding of Centella's bioactivity, and opportunities for the quantitative correlation of this activity with clinical effectiveness at a molecular level.

Matched MeSH terms: Pentacyclic Triterpenes
Celastrol attenuates inflammatory responses in adipose tissues and improves skeletal muscle mitochondrial functions in high fat diet-induced obese rats via upregulation of AMPK/SIRT1 signaling pathways

Abu Bakar MH, Shariff KA, Tan JS, Lee LK

Eur J Pharmacol, 2020 Sep 15;883:173371.
PMID: 32712089 DOI: 10.1016/j.ejphar.2020.173371

Accumulating evidence indicates that adipose tissue inflammation and mitochondrial dysfunction in skeletal muscle are inextricably linked to obesity and insulin resistance. Celastrol, a bioactive compound derived from the root of Tripterygium wilfordii exhibits a number of attributive properties to attenuate metabolic dysfunction in various cellular and animal disease models. However, the underlying therapeutic mechanisms of celastrol in the obesogenic environment in vivo remain elusive. Therefore, the current study investigated the metabolic effects of celastrol on insulin sensitivity, inflammatory response in adipose tissue and mitochondrial functions in skeletal muscle of the high fat diet (HFD)-induced obese rats. Our study revealed that celastrol supplementation at 3 mg/kg/day for 8 weeks significantly reduced the final body weight and enhanced insulin sensitivity of the HFD-fed rats. Celastrol noticeably improved insulin-stimulated glucose uptake activity and increased expression of plasma membrane GLUT4 protein in skeletal muscle. Moreover, celastrol-treated HFD-fed rats showed attenuated inflammatory responses via decreased NF-κB activity and diminished mRNA expression responsible for classically activated macrophage (M1) polarization in adipose tissues. Significant improvement of muscle mitochondrial functions and enhanced antioxidant defense machinery via restoration of mitochondrial complexes I + III linked activity were effectively exhibited by celastrol treatment. Mechanistically, celastrol stimulated mitochondrial biogenesis attributed by upregulation of the adenosine monophosphate-activated protein kinase (AMPK) and sirtuin 1 (SIRT1) signaling pathways. Together, these results further demonstrate heretofore the conceivable therapeutic mechanisms of celastrol in vivo against HFD-induced obesity mediated through attenuation of inflammatory response in adipose tissue and enhanced mitochondrial functions in skeletal muscle.

Matched MeSH terms: Pentacyclic Triterpenes/pharmacology*