Licochalcone a Exhibits Leishmanicidal Activity in vitro and in Experimental Model of Leishmania (Leishmania) Infantum

Network pharmacology and experimental verification of the mechanism of licochalcone A against Staphylococcus aureus pneumonia

Staphylococcus aureus strains cause the majority of pneumonia cases and are resistant to various antibiotics. Given this background, it is very important to discover novel host-targeted therapies. Licochalcone A (LAA), a natural plant product, has various biological activities, but its primary targets in S. aureus pneumonia remain unclear. Therefore, the purpose of this study was to identify its molecular target against S. aureus pneumonia. Network pharmacology analysis, histological assessment, enzyme-linked immunosorbent assays, and Western blotting were used to confirm the pharmacological effects. Network pharmacology revealed 33 potential targets of LAA and S. aureus pneumonia. Enrichment analysis revealed that these potential genes were enriched in the Toll-like receptor and NOD-like receptor signaling pathways. The results were further verified by experiments in which LAA alleviated histopathological changes, inflammatory infiltrating cells and inflammatory cytokines (TNF, IL-6, and IL-1β) in the serum and bronchoalveolar lavage fluid in vivo. Moreover, LAA treatment effectively reduced the expression levels of NF-κB, p-JNK, p-p38, NLRP3, ASC, caspase 1, IL-1β, and IL-18 in lung tissue. The in vitro experimental results were consistent with the in vivo results. Thus, our findings demonstrated that LAA exerts anti-infective effects on S. aureus-induced lung injury via suppression of the Toll-like receptor and NOD-like receptor signaling pathways, which provides a theoretical basis for understanding the function of LAA against S. aureus pneumonia and implies its potential clinical application.

Licochalcone A: A Potential Multitarget Drug for Alzheimer's Disease Treatment

Licochalcone A (Lico-A) is a flavonoid compound derived from the root of the Glycyrrhiza species, a plant commonly used in traditional Chinese medicine. While the Glycyrrhiza species has shown promise in treating various diseases such as cancer, obesity, and skin diseases due to its active compounds, the investigation of Licochalcone A's effects on the central nervous system and its potential application in Alzheimer's disease (AD) treatment have garnered significant interest. Studies have reported the neuroprotective effects of Lico-A, suggesting its potential as a multitarget compound. Lico-A acts as a PTP1B inhibitor, enhancing cognitive activity through the BDNF-TrkB pathway and exhibiting inhibitory effects on microglia activation, which enables mitigation of neuroinflammation. Moreover, Lico-A inhibits c-Jun N-terminal kinase 1, a key enzyme involved in tau phosphorylation, and modulates the brain insulin receptor, which plays a role in cognitive processes. Lico-A also acts as an acetylcholinesterase inhibitor, leading to increased levels of the neurotransmitter acetylcholine (Ach) in the brain. This mechanism enhances cognitive capacity in individuals with AD. Finally, Lico-A has shown the ability to reduce amyloid plaques, a hallmark of AD, and exhibits antioxidant properties by activating the nuclear factor erythroid 2-related factor 2 (Nrf2), a key regulator of antioxidant defense mechanisms. In the present review, we discuss the available findings analyzing the potential of Lico-A as a neuroprotective agent. Continued research on Lico-A holds promise for the development of novel treatments for cognitive disorders and neurodegenerative diseases, including AD. Further investigations into its multitarget action and elucidation of underlying mechanisms will contribute to our understanding of its therapeutic potential.

Models for cytotoxicity screening of antileishmanial drugs: what has been done so far?

A growing number of studies have demonstrated the in vitro potential of an impressive number of antileishmanial candidates in the past years. However, the lack of uniformity regarding the choice of cell types for cytotoxicity assays may lead to uncomparable and inconclusive data. In vitro assays relying solely on non-phagocytic cell models may not represent a realistic result as the effect of an antileishmanial agent should ideally be presented based on its cytotoxicity profile against reticuloendothelial system cells. In the present review, we have assembled studies published in the scientific literature from 2015 to 2021 that explored leishmanicidal candidates, emphasising the main host cell models used for cytotoxicity assays. The pros and cons of different host cell types as well as primary cells and cell lines are discussed in order to draw attention to the need to establish standardised protocols for preclinical testing when assessing new antileishmanial candidates.

Quantum mechanical, molecular docking, molecular dynamics, ADMET and antiproliferative activity on Trypanosoma cruzi (Y strain) of chalcone (E)-1-(2-hydroxy-3,4,6-trimethoxyphenyl)-3-(3-nitrophenyl)prop-2-en-1-one derived from a natural product

Chagas disease is a leading public health problem. More than 8 million people are affected by the disease, which is endemic in 21 countries in Latin America, generating an average annual cost of 7.2 billion dollars per year. The conventional treatment of Chagas disease is carried out by administering the drug benznidazole (BZN), which has caused numerous adverse reactions. Hence, the search for new, more efficient, and less toxic anti-chagasic agents is essential. Recently, chalcones have been researched to propose new therapies against neglected diseases, mainly Trypanosoma cruzi. The objective of this work was to evaluate for the first time the antiproliferative potential of chalcone derived from the natural product on T. cruzi strain Y. The molecular structure of the chalcone was confirmed by spectrometric data. The toxicity of chalcone in LLC-MK2 cells indicated that a concentration of 514.10 ± 62.40 μM was able to reduce cell viability by 50%. Regarding the effect of chalcone on epimastigote forms, an IC₅₀ value of 46.57 ± 9.81 μM was observed; 45.92 ± 8.42 and 16.32 ± 3.41 μM at times of 24, 48 and 72 hours, respectively. The chalcone was able to eliminate trypomastigote forms at all concentrations tested, except for 31.25 μM, with LC₅₀ values of 117.90 ± 12.60 μM, lower than the reference drug BZN (161.40 ± 31. 80 μM). The mechanism of action may be related to the membrane damage provoked by reduction of the mitochondrial potential. The anti-T. cruzi effect can be assigned through some structural aspects of the chalcone as the nitro group (NO₂) is present, which can be enzymatically reduced forming a nitro radical, and the presence of methoxyl groups in the A ring of the chalcone. In silico studies showed that the chalcone had a higher affinity for cruzain when compared to BZN and the co-crystallized inhibitor KB2, as it presented a more thermodynamically stable complex in the order of -6.9 kcal mol^-1. The pharmacokinetic prediction showed a significant probability of antiprotozoal activity, a good volume of distribution after being absorbed in the intestine, and a low chance of activity in the central nervous system. Therefore, these results suggest that the chalcone can become a potential cruzain enzyme inhibitor with trypanocidal activity.

Total Synthesis of the Natural Chalcone Lophirone E, Synthetic Studies toward Benzofuran and Indole-Based Analogues, and Investigation of Anti-Leishmanial Activity

The potential of natural and synthetic chalcones as therapeutic leads against different pathological conditions has been investigated for several years, and this class of compounds emerged as a privileged chemotype due to its interesting anti-inflammatory, antimicrobial, antiviral, and anticancer properties. The objective of our study was to contribute to the investigation of this class of natural products as anti-leishmanial agents. We aimed at investigating the structure–activity relationships of the natural chalcone lophirone E, characterized by the presence of benzofuran B-ring, and analogues on anti-leishmania activity. Here we describe an effective synthetic strategy for the preparation of the natural chalcone lophirone E and its application to the synthesis of a small set of chalcones bearing different substitution patterns at both the A and heterocyclic B rings. The resulting compounds were investigated for their activity against Leishmania infantum promastigotes disclosing derivatives 1 and 28a,b as those endowed with the most interesting activities (IC₅₀ = 15.3, 27.2, 15.9 μM, respectively). The synthetic approaches here described and the early SAR investigations highlighted the potential of this class of compounds as antiparasitic hits, making this study worthy of further investigation.

Challenges and Tools for In Vitro Leishmania Exploratory Screening in the Drug Development Process: An Updated Review

Leishmaniases are a group of vector-borne diseases caused by infection with the protozoan parasites Leishmania spp. Some of them, such as Mediterranean visceral leishmaniasis, are zoonotic diseases transmitted from vertebrate to vertebrate by a hematophagous insect, the sand fly. As there is an endemic in more than 90 countries worldwide, this complex and major health problem has different clinical forms depending on the parasite species involved, with the visceral form being the most worrying since it is fatal when left untreated. Nevertheless, currently available antileishmanial therapies are significantly limited (low efficacy, toxicity, adverse side effects, drug-resistance, length of treatment, and cost), so there is an urgent need to discover new compounds with antileishmanial activity, which are ideally inexpensive and orally administrable with few side effects and a novel mechanism of action. Therefore, various powerful approaches were recently applied in many interesting antileishmanial drug development programs. The objective of this review is to focus on the very first step in developing a potential drug and to identify the exploratory methods currently used to screen in vitro hit compounds and the challenges involved, particularly in terms of harmonizing the results of work carried out by different research teams. This review also aims to identify innovative screening tools and methods for more extensive use in the drug development process.