Larvicidal Activity of Cinnamic Acid Derivatives: Investigating Alternative Products for Aedes aegypti L. Control

A Review of Botanical Extracts with Repellent and Insecticidal Activity and Their Suitability for Managing Mosquito-Borne Disease Risk in Mexico

Among the main arboviruses affecting public health in tropical regions are dengue, zika, and chikungunya, transmitted mainly by mosquitoes of the Aedes genus, especially Aedes aegypti. In recent years, outbreaks have posed major challenges to global health, highlighting the need for integrated and innovative strategies for their control and prevention. Prevention strategies include the elimination of vectors and avoiding mosquito bites; this can be achieved through the use of bioinsecticides and repellents based on plant phytochemicals, as they offer sustainable, ecological, and low-cost alternatives. Mexico has a variety of plants from which both extracts and essential oils have been obtained which have demonstrated significant efficacy in repelling and/or killing insect vectors. This review examines the current knowledge on plant species found in Mexico which are promising options concerning synthetic compounds in terms of their repellent and insecticidal properties against mosquitoes of the genus Aedes and that are friendly to the environment and health.

Chemical Compositions and Fumigation Effects of Essential Oils Derived from Cardamom, Elettaria cardamomum (L.) Maton, and Galangal, Alpinia galanga (L.) Willd, against Red Flour Beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)

This study explores the use of essential oils from cardamom (Elettaria cardamomum (L.) Maton) and galangal (Alpinia galanga (L.) Willd) as alternatives to synthetic insecticides for controlling the red flour beetle, Tribolium castaneum (Herbst). The chemical compositions of these oils were analyzed using GC-MS, and their fumigation effects were tested in a vapor-phase bioassay. The experiment followed a factorial design with four types of essential oils, namely, those manually extracted from cardamom leaves (MCL) and galangal leaves (MGL) and those commercially produced from cardamom seeds (CCS) and galangal rhizomes (CGR), at seven concentrations (0, 50, 100, 150, 200, 250, and 300 µL/L air). The manually extracted oils yielded 0.6% from cardamom leaves and 0.25% from galangal leaves. MCL contained 28 components, with eucalyptol (25.2%) being the most abundant, while CCS had 34 components, primarily α-terpinyl acetate (46.1%) and eucalyptol (31.2%). MGL included 25 components, mainly caryophyllene (28.7%) and aciphyllene (18.3%), whereas CGR comprised 27 components, with methyl cis-cinnamate (47.3%) and safrole (19.8%) as the major constituents. The fumigation bioassay results revealed that CGR was the most effective, demonstrating the highest mortality rates of T. castaneum across all the tested periods and concentrations, achieving up to 96% mortality at 168 h with a concentration of 300 µL/L air. Statistical analyses showed significant differences in mortality based on the type and concentration of essential oil, particularly after 96 h. These findings highlight the potential of CGR, with its advantages and differences in chemical composition, as an effective biopesticide against T. castaneum, with increasing efficacy over time and at higher concentrations.

Antifungal activity against Candida albicans of methyl 3,5-dinitrobenzoate loaded nanoemulsion

The objective of this study was to evaluate the antifungal activity of free methyl 3,5 dinitrobenzoate (MDNB) and its nanoemulsion (MDNB-NE) against strains of Candida albicans. Additionally, a molecular modeling study was also carried out to propose the mechanism of action and toxicity of MDNB. These results demonstrated the MDNB-NE presented a droplet size of 181.16 ± 3.20 nm and polydispersity index of 0.30 ± 0.03. MDNB and MDNB-NE inhibited the growth of all strains with minimum inhibitory concentrations of 0.27-1.10 mM. The biological results corroborated the molecular model, which pointed to a multi-target antifungal mechanism of action for MDNB in C. albicans. The study could serve as a basis for further research involving compounds with nitro groups with antifungal.

Discovery of Novel Cinnamic Acid Derivatives as Fungicide Candidates

Structural diversity derivatization from natural products is an important and effective method of discovering novel green pesticides. Cinnamic acids are abundant in plants, and their unparalleled structures endow them with various excellent biological activities. A series of novel cinnamic oxime esters were designed and synthesized to develop high antifungal agrochemicals. The antifungal activity, structure-activity relationship, and action mechanism were systematically studied. Compounds 7i, 7u, 7v, and 7x exhibited satisfactory activity against Gaeumannomyces graminis var. tritici, with inhibition rates of ≥90% at 50 μg/mL. Compounds 7z and 7n demonstrated excellent activities against Valsa mali and Botrytis cinerea, with median effective concentration (EC50) values of 0.71 and 1.41 μg/mL, respectively. Compound 7z exhibited 100% protective and curative activities against apple Valsa canker at 200 μg/mL. The control effects of 7n against gray mold on tomato fruits and leaves were all >96%, exhibiting superior or similar effects to those of the commercial fungicide boscalid. Furthermore, the quantitative structure-activity relationship was established to guide the further design of higher-activity compounds. The preliminary results on the action mechanism revealed that 7n treatment could disrupt the function of the nucleus and mitochondria, leading to reactive oxygen species accumulation and cell membrane damage. Its primary biochemical mechanism may be inhibiting fungal ergosterol biosynthesis. The novel structure, simple synthesis, and excellent activity of cinnamic oxime esters render them promising potential fungicides.

Assessment of antimalarial activity of crude extract of Chan-Ta-Lee-La and Pra-Sa-Chan-Dang formulations and their plant ingredients for new drug candidates of malaria treatment: In vitro and in vivo experiments

The emergence and spread of antimalarial drug resistance have become a significant problem worldwide. The search for natural products to develop novel antimalarial drugs is challenging. Therefore, this study aimed to assess the antimalarial and toxicological effects of Chan-Ta-Lee-La (CTLL) and Pra-Sa-Chan-Dang (PSCD) formulations and their plant ingredients. The crude extracts of CTLL and PSCD formulations and their plant ingredients were evaluated for in vitro antimalarial activity using Plasmodium lactate dehydrogenase enzyme and toxicity to Vero and HepG2 cells using the tetrazolium salt method. An extract from the CTLL and PSCD formulations exhibiting the highest selectivity index value was selected for further investigation using Peter's 4-day suppressive test, curative test, prophylactic test, and acute oral toxicity in mice. The phytochemical constituents were characterized using gas chromatography-mass spectrometry (GC-MS). Results showed that ethanolic extracts of CTLL and PSCD formulations possessed high antimalarial activity (half maximal inhibitory concentration = 4.88, and 4.19 g/mL, respectively) with low cytotoxicity. Ethanolic extracts of the CTLL and PSCD formulations demonstrated a significant dose-dependent decrease in parasitemia in mice. The ethanolic CTLL extract showed the greatest suppressive effect after 4 days of suppressive (89.80%) and curative (35.94%) testing at a dose of 600 mg/kg. Moreover, ethanolic PSCD extract showed the highest suppressive effect in the prophylactic test (65.82%) at a dose of 600 mg/kg. There was no acute toxicity in mice treated with ethanolic CTLL and PSCD extracts at 2,000 mg/kg bodyweight. GC-MS analysis revealed that the most abundant compounds in the ethanolic CTLL extract were linderol, isoborneol, eudesmol, linoleic acid, and oleic acid, whereas ethyl 4-methoxycinnamate was the most commonly found compound in the ethanolic PSCD extract, followed by 3-hydroxy-2-(4-hydroxy-3-methoxyphenyl)-4H-chromen-4-one, flamenol, oleic acid amide, linoleic acid, and oleic acid. In conclusions, ethanolic CTLL and PSCD extracts exhibited high antimalarial efficacy in vitro. The ethanolic CTLL extract at a dose of 600 mg/kg exhibited the highest antimalarial activity in the 4-day suppressive and curative tests, whereas the ethanolic PSCD extract at a dose of 600 mg/kg showed the highest antimalarial activity in the prophylactic test.

Biological evaluation of 1,3-benzodioxole acids points to 3,4-(methylenedioxy) cinnamic acid as a potential larvicide against Aedes aegypti (Diptera: Culicidae)

Aedes aegypti serves as the primary vector for viruses like dengue, Chikungunya, Zika, and yellow fever, posing a significant public health challenge in Brazil. Given the absence of approved vaccines for these diseases, effective mosquito control becomes paramount in preventing outbreaks. However, currently available chemical insecticides face issues related to toxicity and the emergence of resistance, necessitating the exploration of new active compounds. Drawing inspiration from natural products, we identified the 1,3-benzodioxole group as a key pharmacophore associated with insecticidal activity. Therefore, this study aimed to synthesize and assess the larvicidal activity of 1,3-benzodioxole acids against Ae. aegypti, as well as their toxicity in mammals. Among the compounds evaluated, 3,4-(methylenedioxy) cinnamic acid (compound 4) demonstrated larvicidal activity. It exhibited LC50 and LC90 values of 28.9 ± 5.6 and 162.7 ± 26.2 μM, respectively, after 24 h of exposure. For reference, the positive control, temephos, displayed both LC50 and LC90 values below 10.94 μM. These findings underline the significance of the 3,4-methylenedioxy substituent on the aromatic ring and the presence of a double bond in the aliphatic chain for biological activity. Furthermore, compound 4 exhibited no cytotoxicity towards human peripheral blood mononuclear cells, even at concentrations up to 5200 μM. Lastly, in mice treated with 2000 mg kg-1, compound 4 showed mild behavioral effects and displayed no structural signs of toxicity in vital organs such as the kidney, liver, spleen, and lungs.

Multitarget Compounds for Neglected Diseases: A Review

Neglected diseases are a group of infectious diseases, many of them parasitic, that mainly affect the poorest populations with limited access to health services, especially those living in remote rural areas and slums. According to the World Health Organization (WHO), neglected diseases put the lives of more than 200 million people at risk, and treatment is made difficult by the occurrence of resistance to existing medications, as well as the high level of toxicity. In this way, the potential of multitarget compounds is highlighted, defined as compounds designed to modulate multiple targets of relevance to disease, with the overall goal of enhancing efficacy and/or improving safety. Thus, the objective of our study is to evaluate existing multitarget compound approaches for neglected diseases, with an emphasis on Leishmaniasis, Chagas Disease, and Arboviruses. A literature review was performed by searching the database "Web of Sciences". In relation to the diseases covered in this work, Leishmaniasis, individually, was the one that presented the largest number of articles (11) that dealt with the topic, which can be justified by the high prevalence of this disease in the world, the second most common disease was Dengue, followed by Chagas disease, Chikungunya virus, and Zika virus. Furthermore, the multitarget potential of phenolic compounds was observed in all diseases under study, with the mechanisms related to the nucleus and transcription being the most reported mechanisms. From this perspective, it is worth highlighting the effectiveness of approaches related to multitarget drugs in discovering new therapeutic agents for neglected diseases.

Nanoemulsions and Solid Microparticles Containing Pentyl Cinnamate to Control Aedes aegypti

The Aedes aegypti mosquito is a vector of severe diseases with high morbidity and mortality rates. The most commonly used industrial larvicides have considerable toxicity for non-target organisms. This study aimed to develop and evaluate liquid and solid carrier systems to use pentyl cinnamate (PC), derived from natural sources, to control Ae. aegypti larvae. The liquid systems consisting of nanoemulsions with different lecithins systems were obtained and evaluated for stability over 30 days. Microparticles (MPs) were obtained by the spray drying of the nanoemulsions using maltodextrin as an adjuvant. Thermal, NMR and FTIR analysis indicated the presence of PC in microparticles. Indeed, the best nanoemulsion system was also the most stable and generated the highest MP yield. The PC larvicidal activity was increased in the PC nanoemulsion system. Therefore, it was possible to develop, characterize and obtain PC carrier systems active against Ae. aegypti larvae.

Degradation of PET Bottles by an Engineered Ideonella sakaiensis PETase

Extensive plastic production has become a serious environmental and health problem due to the lack of efficient treatment of plastic waste. Polyethylene terephthalate (PET) is one of the most used polymers and is accumulating in landfills or elsewhere in nature at alarming rates. In recent years, enzymatic degradation of PET by Ideonella sakaiensis PETase (IsPETase), a cutinase-like enzyme, has emerged as a promising strategy to completely depolymerize this polymer into its building blocks. Here, inspired by the architecture of cutinases and lipases homologous to IsPETase and using 3D structure information of the enzyme, we rationally designed three mutations in IsPETase active site for enhancing its PET-degrading activity. In particular, the S238Y mutant, located nearby the catalytic triad, showed a degradation activity increased by 3.3-fold in comparison to the wild-type enzyme. Importantly, this structural modification favoured the function of the enzyme in breaking down highly crystallized (~31%) PET, which is found in commercial soft drink bottles. In addition, microscopical analysis of enzyme-treated PET samples showed that IsPETase acts better when the smooth surface of highly crystalline PET is altered by mechanical stress. These results represent important progress in the accomplishment of a sustainable and complete degradation of PET pollution.

Antileishmanial Activity of Cinnamic Acid Derivatives against Leishmania infantum

Leishmania infantum is the etiological agent of visceral leishmaniasis (VL) in South America, the Mediterranean basin, and West and Central Asia. The most affected country, Brazil, reported 4297 VL cases in 2017. L. infantum is transmitted by female phlebotomine sand flies during successive blood meals. There are no validated vaccines to prevent the infection and the treatment relies on drugs that often present severe side effects, which justify the efforts to find new antileishmanial drugs. Cinnamic acid derivatives have shown several pharmacological activities, including antiparasitic action. Therefore, in the present study, the biological evaluation of cinnamic acid and thirty-four derivatives against L. infantum is reported. The compounds were prepared by several synthesis methods and characterized by spectroscopic techniques and high-resolution mass spectrometry. The results revealed that compound 32 (N-(4-isopropylbenzyl)cinnamamide) was the most potent antileishmanial agent (IC₅₀ = 33.71 μM) with the highest selectivity index (SI > 42.46), followed by compound 15 (piperonyl cinnamate) with an IC₅₀ = 42.80 μM and SI > 32.86. Compound 32 was slightly less potent and nineteen times more selective for the parasite than amphotericin B (MIC = 3.14 uM; SI = 2.24). In the molecular docking study, the most likely target for the compound in L. infantum was aspartyl aminopeptidase, followed by aldehyde dehydrogenase, mitochondrial. The data obtained show the antileishmanial potential of this class of compounds and may be used in the search for new drug candidates against Leishmania species.

Synthetic Cinnamides and Cinnamates: Antimicrobial Activity, Mechanism of Action, and In Silico Study

The severity of infectious diseases associated with the resistance of microorganisms to drugs highlights the importance of investigating bioactive compounds with antimicrobial potential. Therefore, nineteen synthetic cinnamides and cinnamates having a cinnamoyl nucleus were prepared and submitted for the evaluation of antimicrobial activity against pathogenic fungi and bacteria in this study. To determine the minimum inhibitory concentration (MIC) of the compounds, possible mechanisms of antifungal action, and synergistic effects, microdilution testing in broth was used. The structures of the synthesized products were characterized with FTIR spectroscopy, ¹ H-NMR, ¹³ C-NMR, and HRMS. Derivative 6 presented the best antifungal profile, suggesting that the presence of the butyl substituent potentiates its biological response (MIC = 626.62 μM), followed by compound 4 (672.83 μM) and compound 3 (726.36 μM). All three compounds were fungicidal, with MFC/MIC ≤ 4. For mechanism of action, compounds 4 and 6 directly interacted with the ergosterol present in the fungal plasmatic membrane and with the cell wall. Compound 18 presented the best antibacterial profile (MIC = 458.15 μM), followed by compound 9 (550.96 μM) and compound 6 (626.62 μM), which suggested that the presence of an isopropyl group is important for antibacterial activity. The compounds were bactericidal, with MBC/MIC ≤ 4. Association tests were performed using the Checkerboard method to evaluate potential synergistic effects with nystatin (fungi) and amoxicillin (bacteria). Derivatives 6 and 18 presented additive effects. Molecular docking simulations suggested that the most likely targets of compound 6 in C. albicans were caHOS2 and caRPD3, while the most likely target of compound 18 in S. aureus was saFABH. Our results suggest that these compounds could be used as prototypes to obtain new antimicrobial drugs.

Molecular Modeling and In Vitro Evaluation of Piplartine Analogs against Oral Squamous Cell Carcinoma

Cancer is a principal cause of death in the world, and providing a better quality of life and reducing mortality through effective pharmacological treatment remains a challenge. Among malignant tumor types, squamous cell carcinoma-esophageal cancer (EC) is usually located in the mouth, with approximately 90% located mainly on the tongue and floor of the mouth. Piplartine is an alkamide found in certain species of the genus Piper and presents many pharmacological properties including antitumor activity. In the present study, the cytotoxic potential of a collection of piplartine analogs against human oral SCC9 carcinoma cells was evaluated. The analogs were prepared via Fischer esterification reactions, alkyl and aryl halide esterification, and a coupling reaction with PyBOP using the natural compound 3,4,5-trimethoxybenzoic acid as a starting material. The products were structurally characterized using 1H and 13C nuclear magnetic resonance, infrared spectroscopy, and high-resolution mass spectrometry for the unpublished compounds. The compound 4-methoxy-benzyl 3,4,5-trimethoxybenzoate (9) presented an IC50 of 46.21 µM, high selectively (SI > 16), and caused apoptosis in SCC9 cancer cells. The molecular modeling study suggested a multi-target mechanism of action for the antitumor activity of compound 9 with CRM1 as the main target receptor.

Rotenoids from Clitoria fairchildiana R. Howard (Fabaceae) seeds affect the cellular metabolism of larvae of Aedes aegypti L. (Culicidae)

Non-domesticated species may represent a treasure chest of defensive molecules which must be investigated and rescued. Clitoria fairchildiana R. Howard is a non-domesticated Fabacea, native from the Amazonian Forest whose seeds are exquisitely refractory to insect predation. Secondary metabolites from these seeds were fractionated by different organic solvents and the CH₂Cl₂ fraction (CFD - Clitoria fairchildiana dichloromethane fraction), as the most toxic to 3rd instar Aedes aegypti larvae (LC₅₀ 180 PPM), was subjected to silica gel chromatography, eluted with a gradient of CH₂Cl₂: MeOH and sub fractioned in nine fractions (CFD1 - CFD9). All obtained fractions were tested in their toxicity to the insect larvae. Two rotenoids, a 11α-O-β-D-glucopyranosylrotenoid and a 6-deoxyclitoriacetal 11-O-n-glucopyranoside, were identified in the mixture of CFD 7.4 and CFD 7.5, and they were toxic (LC₅₀ 120 PPM) to 3rd instar Ae. aegypti larvae, leading to exoskeleton changes, cuticular detachment and perforations in larval thorax and abdomen. These C. fairchildiana rotenoids interfered with the acidification process of cell vesicles in larvae midgut and caused inhibition of 55% of V-ATPases activity of larvae treated with 80 PPM of the compounds, when compared to control larvae. The rotenoids also led to a significant increase in the production of reactive oxygen species (ROS) in treated larvae, especially in the hindgut region of larvae intestines, indicating a triggering of an oxidative stress process to these insects.

Synthesis of Coumarin and Homoisoflavonoid Derivatives and Analogs: The Search for New Antifungal Agents

A set of twenty-four synthetic derivatives, with coumarin and homoisoflavonoid cores and structural analogs, were submitted for evaluation of antifungal activity against various species of Candida. The broth microdilution test was used to determine the Minimum Inhibitory Concentration (MIC) of the compounds and to verify the possible antifungal action mechanisms. The synthetic derivatives were obtained using various reaction methods, and six new compounds were obtained. The structures of the synthesized products were characterized by FTIR spectroscopy: ¹H-NMR, ¹³C-NMR, and HRMS. The coumarin derivative 8 presented the best antifungal profile, suggesting that the pentyloxy substituent at the C-7 position of coumarin ring could potentiate the bioactivity. Compound 8 was then evaluated against the biofilm of C. tropicalis ATCC 13803, which showed a statistically significant reduction in biofilm at concentrations of 0.268 µmol/mL and 0.067 µmol/mL, when compared to the growth control group. For a better understanding of their antifungal activity, compounds 8 and 21 were submitted to a study of the mode of action on the fungal cell wall and plasma membrane. It was observed that neither compound interacted directly with ergosterol present in the fungal plasma membrane or with the fungal cell wall. This suggests that their bioactivity was due to interaction involving other pharmacological targets. Compound 8 was also subjected to a molecular modeling study, which showed that its antifungal action mechanism occurred mainly through interference in the redox balance of the fungal cell, and by compromising the plasma membrane; not by direct interaction, but by interference in ergosterol synthesis. Another important finding was the antifungal capacity of homoisoflavonoids 23 and 24. Derivative 23 presented slightly higher antifungal activity, possibly due to the presence of the methoxyl substituent in the meta position in ring B.

Sequence analysis and function of mosquito aeCCC2 and Drosophila Ncc83 orthologs

Dipteran insects have genes that code for two different Na⁺-dependent cation-chloride cotransporter (CCC) paralogs. Aedes aegypti aeNKCC1 is an ortholog of Drosophila melanogaster Ncc69, a bumetanide-sensitive Na⁺-K⁺-2Cl^- cotransporter (NKCC). Aedes aegypti aeCCC2 and aeCCC3 are orthologs of Drosophila Ncc83. Prior work suggests that the transport properties of aeCCC2 differ from canonical NKCCs. In particular, Xenopus oocytes expressing aeCCC2 have increased Na⁺-dependent membrane currents compared to controls, whereas NKCCs are electroneutral. Here, we further evaluated the function and localization of aeCCC2 and Ncc83. In oocytes expressing aeCCC2 or Ncc83, membrane potential (V_m) hyperpolarized upon Na⁺ removal; following hypotonic exposure the change in V_m was greater than it was in controls. In voltage-clamp experiments, membrane currents were concentration dependent on Na⁺ with an apparent affinity (K_m) of approximately 4.6 mM. In Malpighian tubules of larval and adult mosquitoes, aeCCC2 was localized along the basolateral aspect of principal cells. Sequence comparisons among transporters from Drosophila, Aedes, Anopheles, and Culex revealed 33 residues within the transmembrane domains (TMDs) that are fully conserved within paralogs but that differ between orthologs of NKCC1 and orthologs of aeCCC2/Ncc83. These residues are distributed across all 12 TMDs. Our results provide a foundation for further exploration of the structural basis for functional differences between insect Na⁺-dependent CCCs.

Antifungal Activity of N-(4-Halobenzyl)amides against Candida spp. and Molecular Modeling Studies

Fungal infections remain a high-incidence worldwide health problem that is aggravated by limited therapeutic options and the emergence of drug-resistant strains. Cinnamic and benzoic acid amides have previously shown bioactivity against different species belonging to the Candida genus. Here, 20 cinnamic and benzoic acid amides were synthesized and tested for inhibition of C. krusei ATCC 14243 and C. parapsilosis ATCC 22019. Five compounds inhibited the Candida strains tested, with compound 16 (MIC = 7.8 µg/mL) producing stronger antifungal activity than fluconazole (MIC = 16 µg/mL) against C. krusei ATCC 14243. It was also tested against eight Candida strains, including five clinical strains resistant to fluconazole, and showed an inhibitory effect against all strains tested (MIC = 85.3–341.3 µg/mL). The MIC value against C. krusei ATCC 6258 was 85.3 mcg/mL, while against C. krusei ATCC 14243, it was 10.9 times smaller. This strain had greater sensitivity to the antifungal action of compound 16. The inhibition of C. krusei ATCC 14243 and C. parapsilosis ATCC 22019 was also achieved by compounds 2, 9, 12, 14 and 15. Computational experiments combining target fishing, molecular docking and molecular dynamics simulations were performed to study the potential mechanism of action of compound 16 against C. krusei. From these, a multi-target mechanism of action is proposed for this compound that involves proteins related to critical cellular processes such as the redox balance, kinases-mediated signaling, protein folding and cell wall synthesis. The modeling results might guide future experiments focusing on the wet-lab investigation of the mechanism of action of this series of compounds, as well as on the optimization of their inhibitory potency.

Toxicological assessment of Opuntia dillenii (Ker Gawl.) Haw. cladode methanol extract, fractions and its alpha pyrones: Opuntiol and opuntioside

ETHNOPHARMACOLOGICAL RELEVANCE

The edible plant Opuntia dillenii (Ker Gawl.) Haw. commonly known as Nagphana, belongs to the Cactaceae family. It is traditionally used to treat various ailments including inflammation, gastric ulcers, diabetes, hepatitis, asthma, whooping cough and intestinal spasm.

AIM OF THE STUDY

Despite its traditional use in various countries, detailed toxicological studies of O. dillenii cladode are few. Thus in the current study, toxicity of O. dillenii cladode derived methanol extract, fractions and its α-pyrones: opuntiol and opuntioside have been addressed.

METHODS

The test agents were assessed using both in vitro and in vivo toxicity assays. MTT on human embryonic kidney cell line (HEK-293), tryphan blue exclusion in rat neutrophils, Cytokinesis-B block micronucleus (CBMN) in human lymphocytes and genomic DNA fragmentation using agarose gel electrophoresis were performed. In acute toxicity test, mice orally received extract (5 g/kg) for 7 days followed by measurements of relative organ weight, biochemical (blood profile, liver and kidney function test) and histological studies (liver and kidney) were carried out. Rat bone marrow micronucleus genotoxicity assay was also conducted.

RESULTS

O. dillenii derived test agents were non-cytotoxic and had no effect on the integrity of DNA. Methanol extract (5 g/kg) orally administered in mice did not cause any significant change in relative organ weights, biochemical parameters and liver and kidney histology as compared to vehicle control. In parallel, extract did not stimulate micronuclei formation in rat bone marrow polychromatic erythrocytes.

CONCLUSION

These results led to conclude that edible O. dillenii extract is non-toxic via the oral route and appears to be non-cyto-, hepato-, nephro- or genotoxic, thereby supporting its safe traditional use against various ailments. Therefore, opuntiol and opuntioside may serve as lead compounds in designing new drug(s) derived from edible plants.

Cytotoxic and Antifungal Amides Derived from Ferulic Acid: Molecular Docking and Mechanism of Action

Amides derived from ferulic acid have a wide spectrum of pharmacological activities, including antitumor and antifungal activity. In the present study, a series of ten amides were obtained by coupling reactions using the reagents (benzotriazol-1-yloxy) tripyrrolidinophosphonium hexafluorophosphate (PyBOP) and N,N′-dicyclohexylcarbodiimide (DCC). All the compounds were identified on the basis of their IR, ¹H- and ¹³C-NMR, HRMS data, and with yields ranging from 43.17% to 91.37%. The compounds were subjected to cytotoxic tests by the alamar blue technique and antifungal screening by the broth microdilution method to determine the minimum inhibitory concentration (MIC). The amides 10 and 11 displayed the best result in both biological evaluations, and compound 10 was the most potent and selective in HL-60 cancer cells, with no cytotoxicity on healthy cells. This amide had antifungal activity in all strains and had the lowest MIC against Candida albicans and Candida tropicalis. The possible mechanism of antifungal action occurs via the fungal cell wall. Molecular modeling suggested that compounds 10 and 11 interact with the enzymes GWT1 and GSC1, which are essential for the development of C. albicans. The findings of the present study demonstrated that compounds 10 and 11 may be used as a platform in drug development in the future.

Indole glucosinolates exhibit anti-inflammatory effects on Ehrlich ascites carcinoma cells through modulation of inflammatory markers and miRNAs

BACKGROUND

Nuclear factor-κB (NF-κB) has been identified as the major link between inflammation and cancer. Natural agents that inhibit this pathway are essential in attenuating inflammation induced by cancer or chemotherapeutic drugs. High intake of Brassicaceae vegetables has been determined to modulate essential pathways related to chronic diseases. In this study, we investigated the anti-proliferative and anti-inflammatory effects of the indole glucosinolates; indole-3-carbinol (I3C) and its metabolite 3,3-diindolylmethane (DIM) on the inflammatory biomarkers and miRNAs controlling the NF-κB pathway.

METHODS AND RESULTS

In our study, we inoculated Ehrlich ascites carcinoma (EAC) cells in female albino mice, which increased their packed cell volume and induced a significant increase in the levels of several cytokines and inflammatory biomarkers (NF-κB IL-6, IL-1b, TNF-α, and NO). A significant elevation in inflammatory-medicated miRNAs (miR-31 and miR-21) was also noted. Treatment with 5-fluorouracil (5-FU) significantly reduced packed cell volume and viable cell count. However, it was accompanied by a significant increase in the levels of inflammatory markers and expression of miR-31 and miR-21. Nevertheless, although treatment with indoles (I3C and DIM) significantly reduced the packed cell volume and viable cell count, their prominent effect was the marked reduction of all inflammatory biomarkers compared to both the EAC untreated group and the EAC group treated with 5-FU. Moreover, the anti-inflammatory effect of I3C or DIM was accompanied by a significant decrease in the expression of miR-31 and miR-21.

CONCLUSION

Our findings have; therefore, revealed that I3C and DIM have strong anti-inflammatory effects, implying that their use as a co-treatment with chemotherapeutic drugs can effectively improve the anti-tumor effect of chemotherapeutic drugs.

Larvicidal activity and in silico studies of cinnamic acid derivatives against Aedes aegypti (Diptera: Culicidae)

Cinnamic acid derivatives (CAD's) represent a great alternative in the search for insecticides against Aedes aegypti mosquitoes since they have antimicrobial and insecticide properties. Ae. aegypti is responsible for transmitting Dengue, Chikungunya, and Zika viruses, among other arboviruses associated with morbimortality, especially in developing countries. In view of this, in vitro analyses of n-substituted cinnamic acids and esters were performed upon 4th instar larvae (L4) of Ae. aegypti, as well as, molecular docking studies to propose a potential biological target towards this mosquitoes species. The larvicide assays proved that n-substituted ethyl cinnamates showed a more pronounced activity than their corresponding acids, in which p-chlorocinnamate (3j) presented a LC₅₀ value of 8.3 µg/mL. Thusly, external morphologic alterations (rigid and elongated body, curved bowel, and translucent or darkened anal papillae) of mosquitoes' group exposed to compound 3j, were observed by microscopy. In addition, an analytical method was developed for the quantification of the most promising analog by using high-performance liquid chromatography with UV detection (HPLC-UV). Molecular docking studies suggested that the larvicide action is associated with inhibition of acetylcholinesterase (AChE) enzyme. Therefore, expanding the larvicidal study with the cinnamic acid derivatives against the vector Ae. aegypti is important for finding search for more effective larvicides and with lower toxicity, since they have already shown good larvicidal properties against Ae. aegypti.

Computational modeling predicts potential effects of the herbal infusion "horchata" against COVID-19

Bioactive plant-derived molecules have emerged as therapeutic alternatives in the fight against the COVID-19 pandemic. In this investigation, principal bioactive compounds of the herbal infusion “horchata” from Ecuador were studied as potential novel inhibitors of the SARS-CoV-2 virus. The chemical composition of horchata was determined through a HPLC-DAD/ESI-MSⁿ and GC–MS analysis while the inhibitory potential of the compounds on SARS-CoV-2 was determined by a computational prediction using various strategies, such as molecular docking and molecular dynamics simulations. Up to 51 different compounds were identified. The computational analysis of predicted targets reveals the compounds’ possible anti-inflammatory (no steroidal) and antioxidant effects. Three compounds were identified as candidates for M^pro inhibition: benzoic acid, 2-(ethylthio)-ethyl ester, l-Leucine-N-isobutoxycarbonyl-N-methyl-heptyl and isorhamnetin and for PL^pro: isorhamnetin-3-O-(6-Orhamnosyl-galactoside), dihydroxy-methoxyflavanone and dihydroxyphenyl)-5-hydroxy-4-oxochromen-7-yl]oxy-3,4,5-trihydroxyoxane-2-carboxylic acid. Our results suggest the potential of Ecuadorian horchata infusion as a starting scaffold for the development of new inhibitors of the SARS-CoV-2 M^pro and PL^pro enzymes.