MATERIALS AND METHODS: Chondrocyte/agarose constructs were treated with varying concentrations of TNFα (0.1-100 ng/ml) and cultured at 5 and 21 % oxygen tension for 48 h. In separate experiments, constructs were subjected to dynamic compression (15 %) and treated with TNFα (10 ng/ml) and/or L-NIO (1 mM) at 5 and 21 % oxygen tension using an ex vivo bioreactor for 48 h. Markers for catabolic activity (NO, PGE2) and tissue remodelling (GAG, MMPs) were quantified by biochemical assay. ADAMTS-5 and MMP-13 expression were examined by real-time qPCR. 2-way ANOVA and a post hoc Bonferroni-corrected t test were used to analyse data.
RESULTS: TNFα dose-dependently increased NO, PGE2 and MMP activity (all p
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.
MATERIALS AND METHODS: Male Sprague-Dawley rats were divided into four groups (n=6 rats per group) as Control, KA, Propolis and KA+Propolis. The control group and KA group have received vehicle and saline. Propolis group and propolis + KA group were orally administered with propolis (150 mg/kg body weight), five times every 12 hours. KA group and propolis +KA group were injected subcutaneously with kainic acid (15 mg/kg body weight) and were sacrificed after 2 hrs. CC, CB and BS were separated, homogenized and used for estimation of NOS, caspase-3, NO and TNF-α by commercial kits. Results were analyzed by one way ANOVA, reported as mean + SD (n=6 rats), and p<0.05 was considered statistically significant.
RESULTS: The concentration of NO, TNF-α, NOS and caspase-3 activity were increased significantly (p<0.001) in all the three brain regions tested in KA group compared to the control. Propolis supplementation significantly (p<0.001) prevented the increase in NOS, NO, TNF-α and caspase-3 due to KA.
CONCLUSION: Results of this study clearly demonstrated that the propolis supplementation attenuated the NOS, caspase-3 activities, NO, and TNF-α concentration and in KA mediated excitotoxicity. Hence propolis can be a possible potential protective agent against excitotoxicity and neurodegenerative disorders.
MATERIALS AND METHODS: Male Sprague-Dawley rats were divided into four groups; Control group and KA group received vehicle and saline. Propolis group and propolis + KA group were orally administered with propolis (150mg/kg body weight), five times every 12 hours. KA group and propolis + KA group were injected subcutaneously with kainic acid (15mg/kg body weight) and were sacrificed after 2 hrs and CC, CB and BS were separated homogenized and used for estimation of GS activity, NO, TBARS, and TAS concentrations by colorimetric methods. Results were analyzed by one-way ANOVA, reported as mean + SD from 6 animals, and p<0.05 considered statistically significant.
RESULTS: NO was increased (p< 0.001) and GS activity was decreased (p< 0.001) in KA treated group compared to control group as well as propolis + KA treated group. TBARS was decreased and TAS was increased (p< 0.001) in propolis + KA treated group compared KA treated group.
CONCLUSION: This study clearly demonstrated the restoration of GS activity, NO levels and decreased oxidative stress by propolis in kainic acid mediated excitotoxicity. Hence the propolis can be a possible potential candidate (protective agent) against excitotoxicity and neurodegenerative disorders.