MATERIALS AND METHODS: The effect of TH on both bacteria was investigated using MIC, MBC, growth curve, time-kill curve, scanning electron microscopy (SEM) and RT-qPCR.
RESULTS: The MIC of TH against P. aeruginosa and S. pyogenes was 18.5% (w/v) and 13% (w/v) respectively and MBC was 25% (w/v) for both bacteria. Spectrophotometric readings of at least 90% inhibition yielded MIC90 values of TH, 18.5% (w/v) and 15% (w/v) for P. aeruginosa and S. pyogenes respectively. A time-kill curve demonstrated a bactericidal with a 4-log reduction estimated within 8 hours. Using SEM, loss of structural integrity and marked changes in cell shape were observed. RT-qPCR analysis showed that TH reduced the pattern of gene expression in both bacteria, with a trend toward reduced expression of the virulence genes of interest.
CONCLUSION: This study suggests that TH could potentially be used as an alternative therapeutic agent for microbial infection particularly against these two organisms.
OBJECTIVE: The objective of this study is to search for more potent benzimidazole-based cholinesterase inhibitors, through the modification of the 1- and 2-positions of the benzimidazole core.
METHODS: Synthesis of compounds were carried out via a 4-step reaction scheme following a previously reported protocol. Structure-activity relationship of the compounds are established through in vitro cholinesterase assays and in silico docking studies. Furthermore, cytotoxicity and blood brain barrier (BBB) permeability of the compounds were also investigated.
RESULTS: Among the synthesised compounds, three of them (5IIa, 5IIb, and 5IIc) exhibited potent selective butyrylcholinesterase inhibition at low micromolar level. The compounds did not show any significant cytotoxicity when tested against a panel of human cell lines. Moreover, the most active compound, 5IIc, was highly permeable across the blood brain barrier.
CONCLUSION: In total 10 benzimidazole derivatives were synthesized and screened for their AChE and BuChE inhibitory activities. Lead compound 5Iic, represents a valuable compound for further development as potential AD therapeutics.
Materials and Methods: The whole plant of C. roseus was extracted using methanol extraction method. Phytochemical qualitative screening was carried out for C. roseus extract according to standard procedures used to test for the presence of alkaloid, saponin, terpenoid and steroid. Cytotoxicity was assessed using 3-(4,5-dimethylthiazol-2,5-diphenyltetrazolium bromide (MTT) assay. Plaque reduction assays were carried out to evaluate the antiviral activity of C. roseus extract against herpes simplex virus type 1 (HSV-1). These include post-treatment, pre-treatment and virucidal assays.
Results: C. roseus extract contain secondary metabolites such as alkaloid, saponin and terpenoid but does not contain steroid. Cytotoxicity screening against Vero cells using MTT assay showed that the CC50 values for crude extract of C. roseus was 0.5 mg/mL. The extract prepared from C. roseus possesses phytochemical compound that was non-cytotoxic to the cell with potential antiviral activity. Plaque reduction assays against herpes simplex virus type 1 (HSV-1) showed that the selective indices (SI = CC50 / EC50) of C. roseus extract in post-treatment, pre-treatment and virucidal assays were 36, 20 and 4.7 respectively. The results revealed that the extract prepared from C. roseus possesses phytochemical compound that was non-cytotoxic to the cell with potential antiviral activity.
Conclusion: This study showed that C. roseus extract has promising potential to be explored as anti-HSV-1 agent regardless of the mode of treatment.