Antibacterial and cytotoxicity evaluation of Arum hygrophilum Bioss.

OBJECTIVE: Arum hygrophilum Bioss is a plant native to Asia, Europe, and Northern Africa. It is consumed as beverages, spices, or cooked leaves to cure gastrointestinal infections and cancer. This study aims to determine the antibacterial and anticancer effectivenesss of A. hygrophilum Bioss. MATERIALS AND METHODS: Using the well-diffusion method, the antimicrobial activity of the plant's aqueous extract and five other organic extracts were evaluated against bacteria often associated with food poisoning. The assessment of the antiproliferative activity by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was done on five cancerous cell lines and on fibroblasts as a reference cell line. RESULTS: The growth of L. monocytogenes was significantly inhibited by the aqueous and ethanolic extracts. Both extracts had a minimum inhibitory concentration (MIC) of 62.5 mg/mL. The inhibition caused by the methanolic extract had a MIC of 500 mg/mL. The growth of S. aureus and MRSA were inhibited by the aqueous extract with a MIC of 500 mg/mL, while the inhibition caused by the ethanolic extract had a MIC of 250 mg/mL on MRSA and 500 mg/mL on S.aureus. Both strains of S.aureus were also inhibited by the 3-pentanon extract, while the butanol extract only exhibited a moderate growth inhibition against MRSA. The MTT assay showed that the aqueous extract had not affected the proliferation of cancer cell lines. The cytotoxicity of the ethanolic and methanolic extracts had no concentration-inhibition relationship and the IC50 values were above 800 µg/mL for all extracts. CONCLUSIONS: L. monocytogenes, S. aureus, and methicillin-resistant Staphylococcus aureus (MRSA) were inhibited by different Arum extracts. The antibacterial activity of Arum hygrophilum Bioss against foodborne pathogens makes it safe to use as a natural food preservative, and as a source for sanitizers and antimicrobials. Further investigation is recommended to determine the cytotoxicity of the plant against additional cancer cell lines.

Punicalagin and zinc (II) ions inhibit the activity of SARS-CoV-2 3CL-protease in vitro.

OBJECTIVE: Coronavirus 2019 (COVID-19) has now been declared as a worldwide pandemic. Currently, no drugs have been endorsed for its treatment; in this manner, a pressing need has been developed for any antiviral drugs that will treat COVID-19. Coronaviruses require the SARS-CoV-2 3CL-Protease (3CL-protease) for cleavage of its polyprotein to yield a single useful protein and assume a basic role in the disease progression. In this study, we demonstrated that punicalagin, the fundamental active element of pomegranate in addition to the combination of punicalagin with zinc (Zn) II, appear to show powerful inhibitory activity against SARS-CoV-2. MATERIALS AND METHODS: The 3CL protease assay kit was used to quantify 3CL protease action. The tetrazolium dye, MTS, was used to evaluate cytotoxicity. RESULTS: Punicalagin showed inhibitory action against the 3CL-protease in a dose-dependent manner, and IC50 was found to be 6.192 µg/ml for punicalagin. Punicalagin (10 µg/mL) demonstrated a significant inhibitory activity toward 3CL-protease activity (p < 0.001), yet when punicalagin is combined with zinc sulfate monohydrate (punicalagin/Zn-II) extremely strong 3CL-protease activity (p < 0.001) was obtained. The action of 3CL-protease with punicalagin/Zn-II was decreased by approximately 4.4-fold in contrast to only punicalagin (10 µg/mL). Likewise, we did not notice any significant cytotoxicity caused by punicalagin, Zn-II, or punicalagin/Zn-II. CONCLUSIONS: We suggest that these compounds could be used as potential antiviral drugs against COVID-19.