Current Chemical Biology - Volume 17, Issue 3, 2023

The genus Helianthemum from the Cistaceae family includes about 110 plants, which are well known for their wide therapeutic uses and interesting pharmacological activities. To the best of our knowledge, there are no previous comprehensive and critical reviews on the therapeutic applications, chemical composition, and biological properties of this genus. In this context, the present paper describes a systematic mini-review on the traditional use, phytochemical composition, and pharmacological properties of species belonging to the genus Helianthemum. For this, more than 75 papers covering the period from 1970 to 2022 were collected and analyzed to achieve this review. From 110 species of the genus Helianthemum, only 22 species were studied. Helianthemum species are widely used in folk medicine for the treatment of respiratory, hepatic, renal, psychiatric, and inflammatory diseases. According to the collected information, species from this genus have several pharmacological properties linked to their rich chemical composition, particularly in phenolic compounds and flavonoids. In fact, Helianthemum plants have antioxidant, antimicrobial, anti-inflammatory, analgesic, antidiabetic, insecticide, anticancer, antiulcer, larvicide, chemo, and hepatoprotective activities, justifying their various uses in traditional medicine. Despite the intense use of Helianthemum species in traditional human and veterinary medicine, few studies were conducted on the phytochemical composition and pharmacological activities of the plants constituting this genus. In fact, until now, the emphasis has only been on twenty-two species and the work carried out was not explanatory, especially for certain species. So it will be interesting to broaden the spectrum of the tested biological activities, especially for endemic species in order to understand the possible modes of action and to confirm the toxicity of certain species.

Background: The 4H-pyran compounds are an important class of heterocyclic compounds due to their diverse biological and pharmaceutical properties. Moreover, 4H-pyran is a crucial structural component commonly encountered in the pharmaceutical industry. Thus, it has recently gained significant attention from industry researchers and academic organizations. Herein, we report an efficient and eco-friendly one-pot strategy to synthesize bioactive compounds containing 4H-pyran motifs via a multicomponent reaction. This reaction occurs by reacting equimolar amounts of ethyl acetoacetate, malononitrile, and substituted aldehyde under mild conditions in the presence of a solid catalyst, MgO-MgAl2;O4;. This latter, was obtained by heat treatment, at 800°C, of a layered double hydroxide with the metal cation ratio of Mg²⁺/Al³⁺ = 3:1, and it was characterized by some techniques including XRD, TG-DTA, FT-IR and N2; adsorption-desorption. Therefore, bioactive compounds containing the pyran unit may possess intriguing biological properties. The synthetic protocol offers advantages such as a simple procedure, good to excellent yields, and easy catalyst separation from the reaction mixture. Methods: Substituted 4H-pyran derivatives were prepared by the condensation reaction of substituted aldehydes, ethyl acetoacetate and malononitrile using MgO-MgAl2;O4; catalyst under mild conditions. This study aims to develop an efficient methodology for synthesizing 4H-pyran heterocyclic compounds that have potential applications in biological sciences. The study utilizes MgO-MgAl2;O4; as a highly effective heterogeneous catalyst. Results: The present research details the synthesis of 4H-pyran bioactive compounds using sustainable reaction conditions, which resulted in high yields and facilitated the easy separation of the catalyst from the reaction mixture. Conclusion: In summary, the MgO-MgAl2;O4; spinel nanostructure has been successfully prepared and fully characterized by using different physicochemical techniques such as XRD, TG-DTA, FT-IR and N2; adsorption-desorption. Afterwards, its catalytic activity was investigated through the one-pot condensation of aryl aldehyde, malononitrile and ethyl acetoacetate. Moreover, it exhibits good catalytic activity for the synthesis of 4H-pyran derivatives under green conditions. These latter have many benefits, such as simple procedure, good to excellent yields and easy separation of the catalyst from the reaction mixture.

Aims: This work performed a preliminary characterization of two new peptidases from Ananas ananassoides. Background: Proteolytic enzymes, also known as peptidases, are found in all living things and play critical physiological roles in metabolism and cellular regulation. They account for roughly 60% of the enzymes used in industry and have high proteolytic activity, such as papain from Carica papaya latex and stem and fruit bromelains from the edible pineapple Ananas comosus. Objective: The wild pineapple Ananas ananassoides contains proteolytic enzymes, which motivated this study due to the potential applications of this type of enzyme. Methods: The fruit and stem of A. ananassoides were blended, clarified, and purified using chromatography (SP-Sepharose and Sephadex G-50). The molecular mass was determined using mass spectrometry (M.S.), and the N-terminal sequences were obtained and compared to other Bromeliaceae proteases. Fluorogenic substrates were used to determine the kinetic parameters. Results: As determined by M.S., the fruit and stem contain cysteine-peptidases with Mr of 27,329.6 and 23,912.5 Da, respectively, values that are very similar to those found in edible pineapple bromelains. Despite Mr and carbohydrate composition differences, both proteases have similar optimum pH values. They have similar temperature effects, though the stem protease is more thermally stable. Both proteases have a stronger preference for hydrophobic, polar, and basic residues. Both proteases hydrolyzed substrates containing polar and basic residues. Conclusion: A comparison of the N-terminal sequences (AVPQIIDW for fruit ananassains and AVPEIIDW for stem ananassains) reveals a high degree of homology when compared to other Bromeliaceae proteases such as papain.

Background: Argania spinosa L. seed oil is a Moroccan endemic product that is used traditionally as an alternative treatment for diabetes. Objective: The present work aims to evaluate the hemoglobin antiglycation and the antioxidant effect of roasted (Roil) and unroasted (UnRoil) Argan seed oil in vitro. Methods: The antioxidant activity was evaluated by different methods (total antioxidant capacity by the ammonium molybdate, metal chelating activity, ferric reducing antioxidant power, 1, 1-diphenyl- 2- picrylhydrazyl free radical scavenging, and β-carotene bleaching test), and the protein antiglycation effect was tested using hemoglobin, in vitro. Results: The results showed that both oils possess an important antioxidant effect and the roasting process did not influence the total antioxidant capacity, metal chelating activity, and β-carotene bleaching test. Although, it significantly influences the antiradical activity of Argania spinosa L. seed oil (p < 0.05) with IC50; values of 21.47 ± 0.076 μg/mL for Roil and 4.01 ± 1.13 μg/mL for UnRoil. Besides, Roil and UnRoil it significantly inhibit the hemoglobin glycation activity, with IC50; values of 1.09 ± 0.31 and 0.16 ± 0.031 mg/ml respectively. Moreover, it was noted that UnRoil has a lower IC50; value than Roil, which means that UnRoil has a more potent activity than Roil (p < 0.05). Conclusion: Argania spinosa L. seed oil is an essential source of natural antioxidants and hemoglobin antiglycation that plays a key role in scavenging of free radicals and might be used for reducing the development of diabetic complications.

Background: Stenotrophomonas maltophilia is a pathogenic bacteria that causes serious infectious complications in humans, especially in immune-compromised patients. Stenotrophomonas maltophilia is a gram-negative bacterium that is multidrug-resistant. Objective: The purpose of the study is to understand the diverse cellular and biological functions of cadmium-binding metalloproteins and to predict their role in pathogenicity, regulation, and growth. Methodology: Different in silico approaches were used to check the Functional Annotation, Subcellular Localization, Gene Ontology, and Bacterial toxin prediction have been used to identify the cellular and biological function of Cd-binding metalloproteins in Stenotrophomonas maltophilia. Results: Identified 116 Cd-binding proteins from the whole proteome sequence and functional domain, family, localization, and toxicity were also studied. Conclusion: The outcomes revealed that this study could be used in understanding the 116 cadmiumbinding proteins from the whole proteome sequence. This study shows the survival, growth, and pathogenicity of the bacteria.

Background: Various forms of epigenetic modification, including DNA methylation, contribute to hepatocellular carcinoma (HCC) dissemination, invasion, and metastasis. The Persian shallot (Allium hirtifolium Bioss.) is reported to have antibacterial, antifungal, antioxidant, and anticarcinogenic properties. Aims: In the present study, we examined the expression of DNA (cytosine-5)-methyltransferase 1 (DNMT1) and ten-eleven translocation methylcytosine dioxygenase 1 (TET1) at the mRNA level in HepG2 cells following treatment with Persian shallot extract. Method: Ethanolic extracts of Persian shallot were prepared and dried at 80°C and 50°C for 20 and 30 minutes, respectively. Different concentrations of dried shallot extract over the range of 0-250 µg/ml were prepared. HepG2 cells were cultured and the cytotoxicity of each extract concentration was measured using an MTT assay. The gene expression in treated and untreated cells was assessed by Real-time polymerase chain reaction (RT-PCR). Results: The half maximal inhibitory concentration (IC50) was determined to be 149 µg/ml using an MTT assay. A concentration of 175 µg/ml was found to reduce the expression of DNMT1 in the treated group compared to the control group (P<0.001). Furthermore, the TET1 mRNA of HepG2 cells was down-regulated significantly after treatment with 100 and 1000 µg/ml of Persian shallot extract (P<0.05). These doses reduced the viability of the samples by 60% or higher. Conclusion: This study provides evidence for the potential use of Persian shallot extract as a supplementary herbal agent for the treatment of HCC. The concentrations of extract used in this study are near or above the level required for toxicity, and as such, further study is warranted.