Selective, broad-spectrum antiviral photodynamic disinfection with dicationic imidazolyl chlorin photosensitizers.

The COVID-19 pandemic exposes our vulnerability to viruses that acquire the ability to infect our cells. Classical disinfection methods are limited by toxicity. Existing medicines performed poorly against SARS-CoV-2 because of their specificity to targets in different organisms. We address the challenge of mitigating known and prospective viral infections with a new photosensitizer for antimicrobial photodynamic therapy (aPDT). Photodynamic inactivation is based on local oxidative stress, which is particularly damaging to enveloped viruses. We synthesized a cationic imidazolyl chlorin that reduced by > 99.999% of the percentage inhibition of amplification of SARS-CoV-2 collected from patients at 0.2 µM concentration and 4 J cm-2. Similar results were obtained in the prevention of infection of human ACE2-expressing HEK293T cells by a pseudotyped lentiviral vector exhibiting the S protein of SARS-CoV-2 at its surface. No toxicity to human epidermal keratinocytes (HaCaT) cells was found under similar conditions. aPDT with this chlorin offers fast and safe broad-spectrum photodisinfection and can be repeated with low risk of resistance.

Photodynamic disinfection of SARS-CoV-2 clinical samples using a methylene blue formulation.

The amplitude of the coronavirus disease 2019 (COVID-19) pandemic motivated global efforts to find therapeutics that avert severe forms of this illness. The urgency of the medical needs privileged repositioning of approved medicines. Methylene blue (MB) has been in clinical use for a century and proved especially useful as a photosensitizer for photodynamic disinfection (PDI). We describe the use of MB to photo-inactivate SARS-CoV-2 in samples collected from COVID-19 patients. One minute of treatment can reduce the percentage inhibition of amplification by 99.99% under conditions of low cytotoxicity. We employed a pseudotyped lentiviral vector (LVs) encoding the luciferase reporter gene and exhibiting the S protein of SARS-CoV-2 at its surface, to infect human ACE2-expressing HEK293T cells. Pre-treatment of LVs with MB-PDI prevented infection at low micromolar MB concentrations and 1 min of illumination. These results reveal the potential of MB-PDI to reduce viral loads in the nasal cavity and oropharynx in the early stages of COVID-19, which may be employed to curb the transmission and severity of the disease.

Antineoplastic potential and chemical evaluation of essential oils from leaves and flowers of Tagetes ostenii Hicken.

Breast and cervical cancer represent a major problem of women's global public health. Here, we investigated the chemical composition of essential oils from leaves and flowers of T. ostenii and the antineoplastic potential in a cervical cancer and breast cancer cell line, SiHa and MCF-7; and non-tumoral cells, HaCat. The chemical analysis revealed a predominance of oxygenated monoterpenes in both essential oils. The IC50 after 24 h of treatment was 72 ng/mL for EO 1 and 83 ng/mL for EO 2 in SiHa cells. For MCF-7 the IC50 was 174.3 ng/mL for EO 1. For HaCat cells it was 54.45 ng/mL for EO 1 and 20.83 ng/mL for EO 2. A synergistic effect with both essential oils and cisplatin was also verified. SiHa cells had their wound healing capacity reduced after 48 h of treatment with EO 2 and both essential oils were able to significantly inhibit the adhesion process and clonogenic ability after 24 h of treatment. Our results suggest a long-lasting inhibitory activity in SiHa cells because of the low recovery capacity of cells after treatment withdrawal. Flow cytometer with annexin V/propidium iodide demonstrated a majority cell death through late apoptosis after 24, 48 and 72 hours of treatment.

Antineoplastic potential of the aqueous crude extract of Eugenia uniflora L. in human cervical cancer

Abstract Considering the high prevalence of human cervical cancer and the adverse effects of the available treatments, it is important to develop studies involving plants. Eugenia uniflora L. is a Brazilian native plant widely used in folk medicine and some biological effects have already been described. In this study, we investigated the biologicals effects of the aqueous crude extract of E. uniflora leaves in relation to the viability of human cervical cancer cells (SiHa), non-tumorigenic cells HaCaT and human lymphocytes. Our results demonstrated that different concentrations of E. uniflora's extract significantly inhibited the viability of the Siha cell line at 24, 48 and 72 hours of treatment, but did not induce significant changes in the HaCat cell line and human lymphocytes. Tumor cells had adhesion capacity, migration processes, ability of colony forming and the potential to recover its viability after treatment. withdrawal, significantly reduced. The nuclear morphology revealed chromatin condensation, and the flow cytometry showed predominantly cell death by apoptosis in the treated tumor cells. Therefore, the E. uniflora's extract may contribute for future studies aiming at new therapeutic perspectives for human cervical cancer.