scholarly journals Comparison of the Antibacterial Activity of Australian Terminalia Spp. Extracts Against Klebsiella Pneumoniae: Novel Treatment for Ankylosing Spondylitis

Author(s):  
Ian Cock ◽  
Reece Courtney

Abstract Traditional medicines prepared using Terminalia species have been used globally to treat inflammation and pathogenic infections. Recent studies have demonstrated that multiple Asian and African Terminalia spp. inhibit bacterial triggers of some autoimmune inflammatory disease, including ankylosing spondylitis. Despite this, the effects of Australian Terminalia spp. on a bacterial trigger of ankylosing spondylitis (K. pneumoniae) remain unexplored. Fifty-five extracts from five Australian Terminalia spp. were investigated for K. pneumoniae growth inhibitory activity. Methanolic, aqueous and ethyl acetate extracts of most species and plant parts inhibited K. pneumoniae growth, with varying potencies. Methanolic leaf extracts were generally the most potent bacterial growth inhibitors, with MIC values of 66 µg/mL (T. ferdinandiana), 128 µg/mL (T. carpenteriae) and 83 µg/mL (T. petiolares). However, the aqueous leaf extract was the most potent T. grandiflora extract (MIC = 87 µg/mL). All T. catappa extracts displayed low growth inhibitory activity. The Terminalia spp. methanolic leaf extracts were examined by LC-MS and GC-MS. All contained a relative abundance of simple gallotannins (particularly gallic and chebulic acids), the flavonoid luteolin, as well as the monoterpenoids cineole and terpineol. Notably, all Terminalia spp. were non-toxic or of low toxicity in ALA and HDF toxicity assays, highlighting their potential for preventing the onset of ankylosing spondylitis and treating its symptoms once the disease is established.

Biomolecules ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 56
Author(s):  
Ivan Bassanini ◽  
Silvia Parapini ◽  
Erica E. Ferrandi ◽  
Elena Gabriele ◽  
Nicoletta Basilico ◽  
...  

The natural triterpene celastrol (CE) is here used as lead compound for the design and synthesis of a panel of eleven CE carboxamides that were tested in vitro for their growth inhibitory activity against Leishmania infantum and L.tropica parasites. Among them, in vitro screening identified four basic CE carboxamides endowed with nanomolar leishmanicidal activity, against both the promastigotes and the intramacrophage Leishmania amastigotes forms. These compounds also showed low toxicity toward two human (HMEC-1 and THP-1) and one murine (BMDM) cell lines. Interestingly, the most selective CE analogue (compound 3) was also endowed with the ability to inhibit the ATPase activity of the Leishmania protein chaperone Hsp90 as demonstrated by the in vitro assay conducted on a purified, full-length recombinant protein. Preliminary investigations by comparing it with the naturally occurring Hsp90 active site inhibitor Geldanamycin (GA) in two different in vitro experiments were performed. These promising results set the basis for a future biochemical investigation of the mode of interaction of celastrol and CE-inspired compounds with Leishmania Hsp90.


2021 ◽  
Vol 14 (1) ◽  
pp. 49
Author(s):  
David Méndez-Luna ◽  
Loreley Araceli Morelos-Garnica ◽  
Juan Benjamín García-Vázquez ◽  
Martiniano Bello ◽  
Itzia Irene Padilla-Martínez ◽  
...  

The implementation of chemo- and bioinformatics tools is a crucial step in the design of structure-based drugs, enabling the identification of more specific and effective molecules against cancer without side effects. In this study, three new compounds were designed and synthesized with suitable absorption, distribution, metabolism, excretion and toxicity (ADME-tox) properties and high affinity for the G protein-coupled estrogen receptor (GPER) binding site by in silico methods, which correlated with the growth inhibitory activity tested in a cluster of cancer cell lines. Docking and molecular dynamics (MD) simulations accompanied by a molecular mechanics/generalized Born surface area (MMGBSA) approach yielded the binding modes and energetic features of the proposed compounds on GPER. These in silico studies showed that the compounds reached the GPER binding site, establishing interactions with a phenylalanine cluster (F206, F208 and F278) required for GPER molecular recognition of its agonist and antagonist ligands. Finally, a 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide (MTT) assay showed growth inhibitory activity of compounds 4, 5 and 7 in three different cancer cell lines—MIA Paca-2, RCC4-VA and Hep G2—at micromolar concentrations. These new molecules with specific chemical modifications of the GPER pharmacophore open up the possibility of generating new compounds capable of reaching the GPER binding site with potential growth inhibitory activities against nonconventional GPER cell models.


2021 ◽  
pp. 096032712110214
Author(s):  
JY Lee ◽  
HM Lim ◽  
CM Lee ◽  
S-H Park ◽  
MJ Nam

Indole-3-carbinol (I3C) is a phytochemical that exhibits growth-inhibitory activity against various cancer cells. However, there are limited studies on the effects of I3C on colon cancer cells. In this study, the growth-inhibitory activity of I3C against the human colorectal carcinoma cell line (LoVo) was examined. The results of the 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide, colony formation, and cell counting assays revealed that I3C suppressed the proliferation of LoVo cells. Microscopy and wound-healing analyses revealed that I3C affected the morphology and inhibited the migration of LoVo cells, respectively. I3C induced apoptosis and DNA fragmentation as evidenced by the results of fluorescein isothiocyanate-conjugated annexin V staining and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling assay, respectively. Additionally, I3C arrested the cell cycle at the G0/G1 phase and enhanced the reactive oxygen species levels. Western blotting analysis revealed that treatment with I3C resulted in the activation of apoptotic proteins, such as poly(ADP-ribose) polymerase, caspase-3, caspase-7, caspase-9, Bax, Bim, and p53 in LoVo cells. These results indicate that I3C induces apoptosis in LoVo cells by upregulating p53, leading to the activation of Bax and caspases. Taken together, I3C exerts cytotoxic effects on LoVo cells by activating apoptosis.


1989 ◽  
Vol 264 (3) ◽  
pp. 1534-1542
Author(s):  
T C Wright ◽  
J J Castellot ◽  
M Petitou ◽  
J C Lormeau ◽  
J Choay ◽  
...  

Development ◽  
1991 ◽  
Vol 112 (1) ◽  
pp. 33-42
Author(s):  
P.A. Eccleston ◽  
R. Mirsky ◽  
K.R. Jessen

In the developing peripheral nerve, Schwann cells proliferate rapidly and then become quiescent, an essential step in control of Schwann cell differentiation. Cell proliferation is controlled by growth factors that can exert positive or inhibitory influences on DNA synthesis. It has been well established that neonatal Schwann cells divide very slowly in culture when separated from neurons but here we show that when culture was continued for several months some cells began to proliferate rapidly and non-clonal lines of immortalised Schwann cells were established which could be passaged for over two years. These cells had a similar molecular phenotype to short-term cultured Schwann cells, except that they expressed intracellular and cell surface fibronectin. The difference in proliferation rates between short- and long-term cultured Schwann cells appeared to be due in part to the secretion by short-term cultured Schwann cells of growth inhibitory activity since DNA synthesis of long-term, immortalised Schwann cells was inhibited by conditioned medium from short-term cultures. This conditioned medium also inhibited DNA synthesis in short-term Schwann cells stimulated to divide by glial growth factor or elevation of intracellular cAMP. The growth inhibitory activity was not detected in the medium of long-term immortalised Schwann cells, epineurial fibroblasts, a Schwannoma (33B), astrocytes or a fibroblast-like cell-line (3T3) and it did not inhibit serum-induced DNA synthesis in epineurial fibroblasts, 33B cells or 3T3 cells. The activity was apparently distinct from transforming growth factor-beta, activin, IL6, epidermal growth factor, atrial natriuretic peptide and gamma-interferon and was heat and acid stable, resistant to collagenase and destroyed by trypsin treatment. We raise the possibility that loss of an inhibitory autocrine loop may contribute to the rapid proliferation of long-term cultured Schwann cells and that an autocrine growth inhibitor may have a role in the cessation of Schwann cell division that precedes differentiation in peripheral nerve development.


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