MATERIALS AND METHODS: The inhibitory effects of hexane (LHXN), dichloromethane (LDCM), ethyl acetate (LEA) and methanol (LMEOH) extracts from leaves of PS on Aβ-induced production and mRNA expression of pro-inflammatory mediators in BV-2 microglial cells were assessed using colorimetric assay with Griess reagent, ELISA kit and real-time RT-PCR respectively. Subsequently, MTT reduction assay was used to evaluate the neuroprotective effects of PS leaf extracts against Aβ-induced microglia-mediated neurotoxicity in SH-SY5Y neuroblastoma cells. The levels of tau proteins phosphorylated at threonine 231 (pT231) and total tau proteins (T-tau) were determined using ELISA kits.
RESULTS: Polar extracts of PS leaves (LEA and LMEOH) reduced the Aβ-induced secretion of pro-inflammatory cytokines (IL-1β and TNF-α) in BV-2 cells by downregulating the mRNA expressions of pro-inflammatory cytokines. The inhibition of nitric oxide (NO) production could be due to the free radical scavenging activity of the extracts. In addition, conditioned media from Aβ-induced BV-2 cells pre-treated with LEA and LMEOH protected SH-SY5Y cells against microglia-mediated neurotoxicity. Further mechanistic study suggested that the neuroprotective effects were associated with the downregulation of phosphorylated tau proteins.
CONCLUSIONS: The present study suggests that polar extracts of PS leaves confer neuroprotection against Aβ-induced microglia-mediated neurotoxicity in SH-SY5Y cells by attenuating tau hyperphosphorylation through their anti-inflammatory actions and could be a potential therapeutic agent for Alzheimer's disease.
AIM: To evaluate the anti-tumour activity and toxicological effects of Orthosiphon stamineus extract formulation (ID: C5EOSEW5050ESA trademarked as Nuva-staticTM), and gemcitabine combination on pancreatic xenograft model.
METHODS: Mice were randomly divided into six groups of 6 mice each (n = 6) and given different treatments for 28 d. The study design consisted of a 2 x 3 factorial treatment structure, with gemcitabine (yes/no) by oral (at 1200 and 400 mg/kg per day). Human pancreatic cancer cells were injected subcutaneously into the flanks of athymic nude mice. C5EOSEW5050ESA (200 or 400 mg/kg per day) was administered orally, while gemcitabine (10 mg/kg per 3 d) was given intraperitoneally either alone or in combination treatment. Histopathological analyses of vital organs, tumour tissues, and incidence of lethality were analysed. Analyses of tumour necrosis and proliferation were determined by haematoxylin-eosin staining and immunohistochemistry for Ki-67, respectively.
RESULTS: No signs of toxicity or damage to vital organs were observed in all treatment groups compared to the untreated group. C5EOSEW5050ESA at 200 mg/kg and gemcitabine combination had no additive antitumor effects compared to a single treatment. Remarkably, a comparably greater response in a reduction in tumour growth, Ki-67 protein expression, and necrosis was demonstrated by 400 mg/kg of C5EOSEW5050ESA and gemcitabine combination than that of the individual agents.
CONCLUSION: These results highlighted the synergistic activity of C5EOSEW5050ESA with gemcitabine to reduce pancreatic tumour growth in mice compared to a single treatment. Thus, this study provides valuable insights into using C5EOSEW5050ESA as a complementary treatment with gemcitabine for pancreatic cancer.
RESULTS: In this study, several genetically modified sub-genotype B4 EV-A71 mutants were constructed by site-directed mutations at positions 158, 475, 486, 487 and 5262 or through partial deletion of the 5'-NTR region (∆ 11 bp from nt 475 to 486) to generate a deletion mutant (PD). EV-A71 mutants 475 and PD caused minimal cytopathic effects, produced lowest viral RNA copy number, viral particles as well as minimal amount of viral protein (VP1) in RD cells when compared to mutants 158, 486, 487 and 5262.
CONCLUSIONS: The molecular determinants of virulent phenotypes of EV-A71 sub-genotype B4 strain 41 (5865/Sin/000009) were found to differ from the C158 molecular determinant reported for the fatal EV-A71 sub-genotype B1 strain (clinical isolate 237). The site-directed mutations (SDM) introduced at various sites of the cDNA affected growth of the various mutants when compared to the wild type. Lowest viral RNA copy number, minimal number of plaques formed, higher infectious doses required for 50% lethality of RD cells and much reduced VP1 of the EV-A71 sub-genotype B4 strain 41 genome was attained in mutants carrying SDM at position 475 and through partial deletion of 11 bp at the 5'-NTR region.
METHODS: The effects of LPS-induced NLRP3 activation in the presence or absence of MCC950, NLRP3-specific inhibitor, was tested on a panel of three pancreatic cancer cell lines (SW1990, PANC1 and Panc10.05). Western blotting, cell viability kits and ELISA kits were used to examine the effects of LPS-induced NLRP3 activation and inhibition by MCC950 on NLRP3 expression, cell viability, caspase-1 activity and cytokine IL-1β, respectively.
RESULTS: LPS-induced inflammation in the presence of ATP activates NLRP3 that subsequently increases pancreatic cancer cell proliferation by increasing caspase-1 activity leading to overall production of IL-1β. The inhibition of the NLRP3 inflammasome activation via the specific NLRP3 antagonist MCC950 was able to reduce the cell viability of pancreatic cancer cells. However, the efficacy of MCC950 varies between cell types which is most probably due to the difference in ASC expressions which have a different role in inflammasome activation.
CONCLUSION: There is a dynamic interaction between inflammasome that regulates inflammasome-mediated inflammation in pancreatic adenocarcinoma cells.