No abstract

The main challenge of plant chemical diversity exploration is how to develop tools to study exhaustively plant tissues. Their sustainable sourcing is a limitation as bioguided strategies and dereplication need quite large amounts of plant material. We examine if alternative solutions could overcome these difficulties by obtaining a secure, sustainable, and scalable source of tissues able to biosynthesize an array of metabolites. As this approach would be as independent of the botanical origin as possible, we chose eight plant species from different families. We applied a four steps culture establishment procedure, monitoring targeted compounds through mass spectrometry-based analytical methods. We also characterized the capacities of leaf explants in culture to produce diverse secondary metabolites. In vitro cultures were successfully established for six species with leaf explants still producing a diversity of compounds after the culture establishment procedure. Furthermore, explants from leaves of axenic plantlets were also analyzed. The detection of marker compounds was confirmed after six days in culture for all tested species. Our results show that the first stage of this approach aiming at easing exploration of plant chemodiversity was completed, and leaf tissues could offer an interesting alternative providing a constant source of natural compounds.

Based on ethnopharmacological studies, a lot of plants, as well as its compounds, have been investigated for the potential use as wound healing agents. In Brazil, Curatella americana is traditionally used by local people to treat wounds, ulcers and inflammations. However, to the best of our knowledge, its traditional use in the treatment of wounds has not been validated by a scientific study. Here, some compounds, many of them flavonoids, were identified in the hydroethanolic extract from the leaves of C. americana (HECA) by LC-HRMS and LC-MS/MS. Besides that, solutions containing different concentrations of HECA and a gel produced with this extract were evaluated for its antimicrobial, coagulant and wound healing activities on an excision mouse wound model as well as its acute dermal safety. A total of thirteen compounds were identified in HECA, mainly quercetin, kaempferol and glucoside derivatives of both, besides catechin and epicatechin known as wound healing agents. The group treated with 1% of HECA exhibited highest wound healing activity and best rate of wound contraction confirmed by histopathology results. The present study provides scientific evidence of, this extract (HECA) possess remarkable wound healing activity, thereby, supporting the traditional use.

The neural retina is a highly complex tissue composed of excitatory and inhibitory neurons and glial cells. Glutamate, the main excitatory neurotransmitter, mediates information transfer from photoreceptors, bipolar cells, and ganglion cells, whereas interneurons, mainly amacrine and horizontal cells, use γ-aminobutyric acid (GABA), the main inhibitory neurotransmitter. In this review we place an emphasis on glutamate and GABA transporters as highly regulated molecules that play fundamental roles in neurotransmitter clearance, neurotransmitter release, and oxidative stress. We pharmacologically characterized glutamate transporters in chicken retina cells and identified two glutamate transporters: one Na + -dependent transporter and one Na + -independent transporter. The Na + -dependent uptake system presented characteristics related to the high-affinity x AG -system (EAAT1), and the Na + -independent uptake system presented characteristics related to the x CG -system, which highly contributes to glutamate transport in the retina. Glutamate shares the x CG -system with another amino acid, L-cysteine, suggesting the possible involvement of glutathione. Both transporter proteins are present mainly in Müller glial cells. GABA transporters (GATs) mediate high-affinity GABA uptake from the extracellular space and terminate the synaptic action of GABA in the central nervous system. GABA transporters can be modulated by molecules that act on specific sites to promote transporter phosphorylation and dephosphorylation. In addition to a role in the clearance of GABA, GATs may also release GABA through a reverse transport mechanism. In the chicken retina, a GAT-1 blocker, but not GAT2/3 blocker, was shown to inhibit GABA uptake, suggesting that GABA release from retina cells is mainly mediated by a GAT-1-like transporter.

Introduction: Plants of the genus Phyllanthus (Euphorbiaceae), the “stone breaker” has long been used in folk medicine to treat hepatitis B, an important viral disease. In this regard some species of this genus were tested against viruses as Herpes simplex virus type 1 (HSV-1), COVID and Hepatitis C virus (HCV), showing expressive inhibition in some of them, attracting attention to the genus and to its chemical constituents. Although P. brasiliensis has no traditional use as an antiviral plant, these findings urge us to consider whether P. brasiliensis, plant widely distributed in the Brazilian Amazon and its compounds have antiviral activity against Vero cell lines infected with Mayaro, Oropouche, Chikungunya, and Zika viruses. Objectives: Thus, herein we describe a study of extracts' chemical diversity, antiviral activity, and specialized metabolites detected in different parts of the Phyllanthus brasiliensis (Aubl.) Poir., Methods: In this context, liquid chromatography-mass spectrometry is a crucial analytical method to reveal the identity of many drug candidates from extracts from medicinal plants used to treat diseases, including for instance infections by viruses. Results: As result, 44 compounds were annotated by mass spectrometry-based molecular networking approach. Along, the extracts were tested against Vero cell lines infected with Mayaro, Oropouche, Chikungunya, and Zika viruses. Overall, the results revealed that this species is high in fatty acids, flavones, flavan-3-ols, and lignans. Among them, especially lignans are known to have promising antiviral properties. In this context, in vitro assays revealed potent antiviral activity against different viruses, especially lignan-rich extracts MEB (EC50 = 0.80 µg.mL− 1, SI = 377.59), MEL (EC50 = 0.84 µg.mL− 1, SI = 297.62), and HEL (EC50 = 1.36 µg.mL− 1, SI = 735.29) against Zika virus (ZIKV). Conclusions: The potential of lignans was also supported by in silico antiviral prediction, and Tuberculatin (a lignan) stood out with high activity score and as a strong candidate from MEL extract. Therefore, authors believe that P. brasiliensis extracts contain metabolites that could be a new kick-off point with candidates for antiviral drug development, with lignans becoming a promising trend for further virology research.