No abstract

Natural products have important pharmacological activities. This study sought to investigate the activity of the compound betulinic acid (BA) against different strains of bacteria and fungi. The minimum inhibitory concentration (MIC) was determined and then the minimum bactericidal concentration (MBC) and minimum fungicidal concentration (MFC). After performing the in vitro tests, molecular modeling studies were carried out to investigate the mechanism of action of BA against the selected microorganisms. The results showed that BA inhibited the growth of microbial species. Among the 12 species (Staphylococcus aureus, S. epidermidis, Pseudomonas aeruginosa, Escherichia coli, Mycobacterium tuberculosis, Candida albicans, C. tropicalis, C. glabrata, Aspergillus flavus, Penicillium citrinum, Trichophyton rubrum, and Microsporum canis) investigated, 9 (75%) inhibited growth at a concentration of 561 µM and 1 at a concentration of 100 µM. In general, the MBC and MFC of the products were between 561 and 1122 μM. In silico studies showed that BA presented a mechanism of action against DNA gyrase and beta-lactamase targets for most of the bacteria investigated, while for fungi the mechanism of action was against sterol 14α-demethylase (CYP51) targets and dihydrofolate reductase (DHFR). We suggest that BA has antimicrobial activity against several species.

Quillaja saponins have an intrinsic capacity to interact with membrane lipids that self-assembles in nanoparticles (immunostimulating complexes or ISCOM-matrices) with outstanding immunoadjuvant activity and low toxicity profile. However, the expensive and laborious purification processes applied to purify Quillaja saponins used to assemble ISCOM-matrices show an important drawback in the large-scale use of this vaccine adjuvant. Thus, in this study, we describe a protocol to appropriately formulate ISCOM-matrices using the raw aqueous extract (AE) of Quillaja lancifolia leaves. In the presence of lipids, AE was able to self-assemble in nanostructures that resembles immunostimulating complexes (ISCOM). These negatively charged nanoparticles of approximately 40 nm were characterized by transmission electron microscopy and dynamic light scattering. In addition, well-known saponins with remarkable immunoadjuvant activity, as QS-21, were detected into nanoparticles. Thus, the easier, robust, cheaper, and environmentally friendly method developed here may be an alternative to the classical methods for ISCOM-matrices production that use high-purified saponins. Graphical abstract

Herein, the isolation of secondary metabolites from the aerial parts of Justicia aequilabris guided by HPLC-MS n and molecular networking analyses is reported. Twenty-two known compounds were dereplicated. Three new lignans (aequilabrines A− C (1−3)) and three known compounds (lariciresinol-4′-O-β-glucose (4), roseoside (5), and allantoin (6)) were obtained. The antiinflammatory activity of compounds 1−3 was evaluated in vitro by inhibiting the nitric oxide production (NO) and proinflammatory activity on the cytokine IL-1β. Compounds 2 and 3 showed significant inhibitory activity against NO production, with IC 50 values of 9.1 and 7.3 μM, respectively. The maximum inhibition of IL-1β production was 23.5% (1), 27.3% (2), and 32.5% (3).

No abstract

No abstract

Background: Natural products are useful agents for the discovery of new lead-compounds and effective drugs to combat coronaviruses (CoV). Objective: The present work provides an overview of natural substances, plant extracts, and essential oils as potential antiSARS-CoV agents. In addition, this work evaluates their drug-like properties which are essential in the selection of compounds in order to accelerate the drug development process. Methods: The search was carried out using PubMed, ScienceDirect and SciFinder. Articles addressing plant-based natural products as potential SARS-CoV or SARS-CoV-2 agents within the last seventeen years were analyzed and selected. The descriptors for Chemometrics analyzes were obtained in alvaDesc and the principal component analyzes (PCA) were carried out in SIMCA version 13.0. Results: Based on in vitro assays and computational analyzes, this review covers twenty nine medicinal plant species and more than 300 isolated substances as potential anti-coronavirus agents. Among them, flavonoids and terpenes were the most promising compound classes. In silico analyses of drug-like properties corroborate these findings and indicate promising candidates for in vitro and in vivo studies to validate their activity. Conclusion: This paper highlights the role of ethnopharmacology in drug discovery and simulates the use of integrative (in silico/ in vitro) and chemocentric approaches to strengthen current studies and guide future research in the field of antivirals agents.

No abstract