Leishmaniasis is endemic in at least 98 countries. Due to the high toxicity and resistance associated with the drugs, we chose lignans as an alternative, due to their favorable properties of absorption, distribution, metabolism, excretion, and toxicity (ADMET). To investigate their leishmanicidal potential, the biological activities of a set of 160 lignans were predicted using predictive models that were built using data for Leishmania major and L. (Viannia) braziliensis. A combined analysis, based on ligand and structure, and several other computational approaches were used. The results showed that the combined analysis was able to select 11 lignans with potential activity against L. major and 21 lignans against L. braziliensis, with multitargeting effects and low or no toxicity. Of these compounds, four were isolated from the species Justicia aequilabris (Nees) Lindau. All of the identified compounds were able to inhibit the growth of L. braziliensis promastigotes, with the most active compound, (159) epipinoresinol-4-O-β-d-glucopyranoside, presenting an IC50 value of 5.39 µM and IC50 value of 36.51 µM for L. major. Our findings indicated the potential of computer-aided drug design and development and demonstrated that lignans represent promising prototype compounds for the development of multitarget drugs against leishmaniasis.

Objective To evaluate the anti‐fungal activity of Syzygium aromaticum essential oil and its inhibition of a multispecies biofilm in patients with oral candidiasis. Background Inhibiting biofilm formation on the denture surface is an important practice for preventing denture stomatitis. Materials and Methods The anti‐fungal activity against Candida albicans and non‐albicans Candida species was evaluated through the microdilution method to define Minimal Inhibitory (MIC) and Fungicidal (MFC) Concentrations. Time‐kill assay assessed growth kinetics of C. albicans based on pre‐determined time points (0, 1, 2, 4, 6 and 24 hours). A multi‐species biofilm was formed using human saliva from patients with oral candidiasis and anti‐biofilm activity determined by Colony Forming Units per milliliter (CFU/mL) count, fluorescence microscopy with calcofluor white to observe yeast presence and structure, and metabolic activity by XTT (2,3‐Bis‐(2Methoxy‐4‐Nitro‐5‐Sulfophenyl)‐2H‐Tetrazolium‐5‐carboxanilide) reduction assay. Results The essential oil showed an anti‐fungal activity against all Candida species (MIC 500‐1000 µg/mL, MFC 1000‐2000 µg/mL), and the time‐kill assay showed that 2000 µg/mL (from 2 hours onward) and 1000 µg/mL (from 4 hours onward) concentrations had substantially lower yeast growth than the negative control. In the biofilm analysis, the essential oil had a lower CFU/mL count and a biofilm metabolic activity (91.4%) than seen with its negative control, and in both analyses, the essential oil was not significantly different from the positive control (chlorhexidine). Morphological analysis showed amorphous and fragmented cellular structures after treatment with the essential oil. Conclusion Syzygium aromaticum essential oil had anti‐fungal activities, reduced the Candida growth kinetics substantially and inhibited the multi‐species biofilm formation.

Phytochemical analysis of Croton blanchetianus leaves was performed by. After that, a high performance liquid chromatography method was developed and validated for the determination of rutin in herbal drug and products of C. blanchetianus. The separation was achieved on a C18 column, and the mobile phase was composed of ultrapure water and methanol (acidified with trifluoroacetic acid) with a gradient of 0.8 ml/min. The method was validated following international guidelines. The chemical analysis revealed the presence of flavonoids. Among them rutin was used as the standard for validation. In the HPLC the presence of rutin was observed at 24.7 min. The method was robust, with no significant variations, and linear in the range evaluated with R2 > 0.99. Regarding the matrix effect, it was possible to prove the absence of interference of the constituents in the herbal drug. The precision was determined with a relative standard deviation of <1.34%. The recovery results were achieved between 89.29 and 101.21%. Furthermore, with partial validation, the method was proved to be suitable for the liquid extract, dry extract and effervescent granules. Therefore, this study demonstrated that the method is effective for the quality control analysis of C. blanchetianus leaves and products.

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.