No abstract

This study investigated the antiviral activity of aqueous leaf extract of Costus speciosus (TB100) against influenza A. Pretreatment of TB100 in RAW264.7 cells enhanced antiviral activity in an assay using the green fluorescence-expressing influenza A/Puerto Rico/8/1934 (H1N1) virus. The fifty percent effective concentration (EC50) and fifty percent cytotoxic concentration (CC50) were determined to be 15.19 ± 0.61 and 117.12 ± 18.31 µg/mL, respectively, for RAW264.7 cells. Based on fluorescent microscopy, green fluorescence protein (GFP) expression and viral copy number reduction confirmed that TB100 inhibited viral replication in murine RAW264.7 and human A549 and HEp2 cells. In vitro pretreatment with TB100 induced the phosphorylation of transcriptional activators TBK1, IRF3, STAT1, IKB-α, and p65 associated with interferon pathways, indicating the activation of antiviral defenses. The safety and protective efficacy of TB100 were assessed in BALB/c mice as an oral treatment and the results confirmed that it was safe and effective against influenza A/Puerto Rico/8/1934 (H1N1), A/Philippines/2/2008 (H3N2), and A/Chicken/Korea/116/2004 (H9N2). High-performance liquid chromatography of aqueous extracts led to the identification of cinnamic, caffeic, and chlorogenic acids as potential chemicals for antiviral responses. Further confirmatory studies using these acids revealed that each of them confers significant antiviral effects against influenza when used as pretreatment and enhances the antiviral response in a time-dependent manner. These findings suggest that TB100 has the potential to be developed into an antiviral agent that is effective against seasonal influenza.

No abstract

The post-harvest loss of rice during storage due to insect infestation, particularly by rice weevil (Sitophilus oryzae), and the utilization of synthetic insecticides for pest management are two major concerns in the current world. Therefore, this study aimed to evaluate the potential of clove (Syzygium aromaticum) part formulations as alternatives to S. oryzae management. The contact repellent activity of clove part essential oils was tested by the filter paper impregnated method. The fumigation mortality of essential oils was tested, and mortality percentage & LD50 values were computed. Further, the composition of essential oils was analyzed using Gas Chromatography–Mass Spectrometry. The yield of clove stem essential oil (5.52%) was significantly higher than leaf essential oil (3.92%). Among two essential oils, stem oil with a 100 µL dose showed the highest repellency (100.00±0.00%) and mortality (96.67±3.33%) while 50 and 75 µL doses caused similar mortality (83.30±3.33%) after 5 days. The lowest LD50 (28.06 µLL-1) was observed on day 5, indicating the higher toxicity of stem oil. Eugenol (73.73 & 82.56%), β-caryophyllene (24.84 & 16.67%), α.-humulene (0.82 & 0.33%) and 1S, CIS-calamenene (0.14 & 0.03%) were detected as the major components responsible for the repellent and insecticidal potential of stem and leaf essential oils. Hence, clove parts could be potential biopesticides, and clove stem essential oil could be the most effective alternative for rice weevil management.