Pteridophytes, represented by ferns and allies, are an important phytogenetic bridge between lower and higher plants (gymnosperms and angiosperms). Ferns have evolved independently of any other species in the plant kingdom being its secondary metabolism a reservoir of phytoconstituents characteristic of this taxon. The study of the possible medicinal uses of Polypodium vulgare L. (Polypodiaceae), PV, has increased particularly when in 2008 the European Medicines Agency published a monograph about the rhizome of this species. Thus, our objective is to provide scientific knowledge on the methanolic extract from the fronds of P. vulgare L., one of the main ferns described in the Prades Mountains, to contribute to the validation of certain traditional uses. Specifically, we have characterized the methanolic extract of PV fronds (PVM) by HPLC-DAD and investigated its potential cytotoxicity, phototoxicity, ROS production and protective effects against oxidative stress by using in vitro methods. Our results show that PVM is not cytotoxic against the different cell lines assessed, but we found potential cytoprotective and cellular repair activity in 3T3 fibroblast cells. This biological activity could be attributed to the high content of polyphenolic compounds; thus, this extract is positioned as a potential candidate for pharmaceutical uses.

Industrial hemp (Cannabis sativa L.), due to its bioactive compounds (terpenes and cannabinoids), has gained an increasing interest in different fields, including medical purposes. The evaluation of the safety profile of hemp essential oil (EO) and its encapsulated form (nanoemulsion, NE) is a relevant aspect for potential therapeutic applications. This study aimed to evaluate the toxicolog-ical effect of hemp EOs and NEs from cultivars Carmagnola CS and Uso 31, on three cell lines se-lected as models for topical and inhalant administration, by evaluating the cytotoxicity and the cytokine expression profiles. Results show that EOs and their NEs have comparable cytotoxicity, if considering the quantity of EO present in the NE. Moreover, cells treated with EOs and NEs showed, in most of the cases, lower levels of pro-inflammatory cytokines compared to Etoposide used as positive control, and the basal level of inflammatory cytokines was not altered, suggest-ing a safety profile of hemp EOs and their NEs to support their use for medical applications.

Although the COVID-19 pandemic appears to be diminishing, the emergence of SARS-CoV-2 variants represents a threat to humans due to its inherent transmissibility, immunological evasion, virulence, and invulnerability to existing therapies. The previous COVID-19 pandemic affected more than 500 million people and caused over 6 million deaths. Vaccines are essential, but in circumstances when vaccination is not accessible or in individuals with compromised immune systems, drugs can give additional protection. Targeting host signaling pathways is recommended due to their genomic stability and resistance barriers. Plant-derived products, which have been used in traditional medicine for treating pathological conditions, offer structurally novel therapeutic compounds including anti-viral. In addition, plant-derived bioactive substances might serve as the ideal basis for developing sustainable/efficient/cost-effective anti-viral alternatives. Epigenetic modifications in the genome can affect gene expression without altering DNA sequence. Host cells can use epigenetic gene regulation as a mechanism to silence incoming viral DNA molecules, while viruses have recruited cellular epi transcriptomic (covalent modifications of RNAs) modifiers to increase the translational efficiency and transcript stability of viral transcripts to enhance viral gene expression and replication. Moreover, viruses manipulate host cells' epigenetic machinery to ensure productive viral infections. Environmental factors, such as natural products, may influence epigenetic modifications. In this review, we are exploring the potential of plant-derived substances as epigenetic modifiers for broad-spectrum anti-viral activity, reviewing modulation processes and anti-viral effects on DNA and RNA viruses, and addressing future research objectives in this rapidly emerging field.

Erigeron floribundus (Asteraceae) is an herbaceous plant widely used in the Cameroonian traditional medicine to treat various diseases of microbial and non-microbial origin. In the present study we evaluated the in vitro biological activities displayed by the essential oil obtained from the aerial parts of E. floribundus, namely the antioxidant, antimicrobial and antiproliferative activities. Moreover, we investigated the inhibitory effects of E. floribundus essential oil on nicotinate mononucleotide adenylyltransferase (NadD), a promising new target for developing novel antibiotics, and Trypanosoma brucei, the protozoan parasite responsible for Human African trypanosomiasis. The essential oil composition was dominated by spathulenol (12.2%), caryophyllene oxide (12.4%) and limonene (8.8%). The E. floribundus oil showed a good activity against Staphylococcus aureus (IZD of 14 mm, MIC of 512 µg/mL). Interestingly, it inhibited the NadD enzyme from S. aureus (IC50 of 98 µg/mL), with no effects on mammalian orthologue enzymes. In addition, T. brucei proliferation was inhibited with IC50 values of 33.5 µg/mL with the essential oil and 5.6 µg/mL with the active component limonene. The essential oil exhibited strong cytotoxicity on HCT 116 colon carcinoma cells with an IC50 value of 14.89 µg/mL, and remarkable ferric reducing antioxidant power (TEAC= 411.9 μmol TE/g).