METHODS: The effect of geraniin on DENV-2 RNA synthesis in infected Vero cells was tested using quantitative RT-PCR. The in vivo efficacy of geraniin in inhibiting DENV-2 infection was then tested using BALB/c mice with geraniin administered at three different times. The differences in spleen to body weight ratio, DENV-2 RNA load and liver damage between the three treatment groups as compared to DENV-2 infected mice without geraniin administration were determined on day eight post-infection.
RESULTS: Quantitative RT-PCR confirmed the decrease in viral RNA synthesis of infected Vero cells when treated with geraniin. Geraniin seemed to provide a protective effect on infected BALB/c mice liver when given at 24 h pre- and 24 h post-infection as liver damage was observed to be very mild even though a significant reduction of DENV-2 RNA load in serum was not observed in these two treatment groups. However, when administered at 72 h post-infection, severe liver damage in the form of necrosis and haemorrhage had prevailed despite a substantial reduction of DENV-2 RNA load in serum.
CONCLUSIONS: Geraniin was found to be effective in reducing DENV-2 RNA load when administered at 72 h post-infection while earlier administration could prevent severe liver damage caused by DENV-2 infection. These results provide evidence that geraniin is a potential candidate for the development of anti-dengue drug.
METHODS: Geraniin was prepared from Nephelium lappaceum rind by reverse phase C-18 column chromatography. Cytotoxicity of geraniin towards Vero cells was evaluated using MTT assay while IC50 value was determined by plaque reduction assay. The mode-of-action of geraniin was characterized using the virucidal, attachment, penetration and the time-of-addition assays'. Docking experiments with geraniin molecule and the DENV envelope (E) protein was also performed. Finally, recombinant E Domain III (rE-DIII) protein was produced to physiologically test the binding of geraniin to DENV-2 E-DIII protein, through ELISA competitive binding assay.
RESULTS: Cytotoxicity assay confirmed that geraniin was not toxic to Vero cells, even at the highest concentration tested. The compound exhibited DENV-2 plaque formation inhibition, with an IC50 of 1.75 μM. We further revealed that geraniin reduced viral infectivity and inhibited DENV-2 from attaching to the cells but had little effect on its penetration. Geraniin was observed to be most effective when added at the early stage of DENV-2 infection. Docking experiments showed that geraniin binds to DENV E protein, specifically at the DIII region, while the ELISA competitive binding assay confirmed geraniin's interaction with rE-DIII with high affinity.
CONCLUSIONS: Geraniin from the rind of Nephelium lappaceum has antiviral activity against DENV-2. It is postulated that the compound inhibits viral attachment by binding to the E-DIII protein and interferes with the initial cell-virus interaction. Our results demonstrate that geraniin has the potential to be developed into an effective antiviral treatment, particularly for early phase dengue viral infection.
MATERIALS AND METHODS: This cross-sectional observational study comprised 523 health science students. A well-structured online questionnaire consisting of closed-ended questions based on student's general information, Patient Heath Questionnaire (PHQ)-9 and Generalized Anxiety Disorder (GAD)-7 scales were used to assess the psychological impact of COVID-19.
STATISTICAL ANALYSIS: SPSS-25 was used to analyze the outcome of this study. Multiple linear regression analysis test was used to assess variables which had impact on PHQ-9 and GAD-7 scores among the participants. A p-value of ≤ 0.05 was considered as statistically significant.
RESULTS: Among the 523 participants, 365 (69.55%) students were from developing countries and 158 (30.21%) from developed countries; 424 (81.1%) students were tested negative for COVID-19 and 99 (18.9%) had suffered from severe acute respiratory syndrome coronavirus 2 infection during pandemic. The mean GAD-7 and PHQ-9 scores were 7.16 ± 5.755 and 7.30 ± 6.166, respectively. Significant impact on anxiety levels was associated with age, gender, education status, and COVID-19 positive patient, while depression was not significantly associated with gender, COVID-19, and its reported symptoms in participants.
CONCLUSION: As the world is trying to contain the health effects of COVID-19, the psychological effects might take a longer time to be addressed. Our study highlights the dire need to identify mental well-being of health science students as this may have a direct impact on their professional commitments and future responsibilities.
METHOD: A total of 1441 adolescents were initially recruited via multistage cluster sampling. Subsequently, 294 at-risk adolescents were selected for further analyses through a specified cut-off score.
RESULTS: The results showed significant positive relationships among the study variables. Specifically, negative automatic thoughts emerged as a significant mediator in the relation between depression and suicidal behaviour (z = 7.15, p