PURPOSE: In this study, we aimed to investigate dentatin isolated from C. excavata Burm.f., for anti-ulcer activity against ethanol ulcer model in rats.
METHODS: Gastric acid output, ulcer index, serum profile, histological evaluation using Hematoxylin and eosin (HE), periodic acid Schiff base stainings and immunohistochemical localization for heat shock proteins 70 (HSP70) were all investigated. Possible involvement of reduced glutathione (GSH), lipid peroxidation, prostaglandin E2 (PGE2), superoxide dismutase (SOD) enzymes, radical scavenging, and anti-Helicobacter pylori activity were investigated.
RESULTS: Dentatin showed anti-secretory activity against the pylorus ligature model and protected the gastric mucosa from ethanol ulceration, as revealed by the improved macroscopic and histological appearance. Dentatin significantly increased the gastric homogenate content of PGE2 GSH and SOD. Dentatin inhibited the lipid peroxidation as revealed by the reduced gastric content of malondialdehyde (MDA). Moreover, dentatin up-regulated HSP70 expression. However, dentatin showed insignificant anti-H. pylori activity.
CONCLUSION: Dentatin possesses gastro-protective activity, which could be attributed to the anti-secretory, mucus production, anti-oxidant, and HSP70 activities.
MATERIALS AND METHODS: Cytotoxicity was measured by the MTT assay and further confirmed via apoptosis, ROS, cell cycle, DNA fragmentation and cytokine assays.
RESULTS: ITHB4 demonstrated a lower IC50 compared to zerumbone in inhibiting the proliferation of MCF-7 cells. ITHB4 showed no toxicity against normal breast and human immune cells. Apoptosis assay revealed that ITHB4, at a concentration equal to the IC50, induces apoptosis of MCF-7 cells and cell cycle arrest at the sub-G1 and G2/M phases. ITHB4 triggered accumulation of intracellular ROS and nuclear DNA fragmentation. Secretion of pro-inflammatory cytokines induced inflammation and potentially immunogenic cell death.
CONCLUSION: ITHB4 has almost similar chemotherapeutic properties as zerumbone in inhibiting MCF-7 growth, and hence provide the basis for further experiments in animal models.
Method: This is a mixed-method study. The Motivated Strategies for Learning Questionnaire (MSLQ) was used to collect student SRL strategies while semi-structured interviews with faculty members and focus group discussions with students were used to gather data on the approaches that promote SRL. Student MSLQ was analysed using descriptive statistics while interviews were transcribed verbatim and thematically analysed.
Results: A pilot using MSLQ with 413 students recorded a Cronbach's alpha of 0.928 for the questionnaire. The actual study involved 457 Years 1 & 2 students. Students from both institutions are motivated by the Task Value, and they use Elaboration and Organisation strategies the most in their pre-clinical year. Three themes emerged from the qualitative analysis of this study: characteristics of strategies that promote SRL, hindrance in promoting SRL, and opportunities in promoting SRL.
Conclusions: Our findings indicate that students' intrinsic motivation is generally high in pre-clinical year. However, metacognition and critical thinking strategies will need to be enhanced among students. Despite knowing teaching and learning approaches could promote these strategies, many teachers are still not confident in doing so and hence training dang sharing best practices might be helpful in promoting SRL.