Phenolic constituents of Pulicaria undulata (L.) C.A. Mey. sub sp. undulata (Asteraceae): Antioxidant protective effects and chemosystematic significances

One new naturally isoflavone compound, 5,7,2′,3′,4′ penta hydroxyl isoflavone-4′-O-β-glucopyranoside (1) was isolated from the aqueous methanol extract (AME) of Pulicaria undulata subsp. undulata, together with seven known compounds: kaempferol (2), kaempferol 3-O-β-glucoside (3), quercetin (4), quercetin 3-O-β-glucoside (5), quercetin 3-O-β-galactoside (6), quercetin 3,7-di OCH₃ (7), and caffeic acid (8). Their structures were established through chemical (acid hydrolysis) and spectral analysis (UV, NMR, and ESIM). The AME and some isolated compounds were evaluated as protective agents. Free radical scavenging using a microscaled 2,2-diphenyl-1-picrylhydrazyl assay was used to assess the direct antioxidant properties that were evaluated by the ability to protect murine Hepa1c1c7 liver cells against damage induced by the organic peroxide tert-butyl hydroperoxide. The neutral red uptake assay (NRU) was used to record the activity. Results of the 2,2-diphenyl-1-picrylhydrazyl assay recorded differential scavenging properties in ascending order: 5,7,2′,3′,4′ penta hydroxyl isoflavone-4′-O-β-glucopyranoside > quercetin > quercetin 3-O-galactoside > caffeic acid > quercetin 3,7-di-OCH₃ > kaempferol with 50% inhibitory concentrations of 3.9 μM, 7.5 μM, 11.4 μM, 12.2 μM, 78.1 μM, and 252.3 μM, respectively. The antioxidative potential reveals the potency of AME, quercetin, and quercetin 3,7-di-OCH₃. The latter compound showed full protection at 100 μM (33 μg/mL) against the induced toxicant effect where the 50% effective concentration was calculated as 33.6 ± 1.7 μM (11.1 μg/mL). In addition to quercetin, which was extensively shown previously as a cytoprotective agent, AME was less potent; it was capable of protecting 75% at 100 μg/mL with 50% effective concentration of 92.3 ± 4 μg/mL. Moreover, the isolated flavonoids were found to be significantly chemosystematic markers.     

Phenolic compounds isolated from Pilea microphylla prevent radiation-induced cellular DNA damage

Six phenolic compounds namely, quercetin-3-O-rutinoside (1), 3-O-caffeoylquinic acid (2), luteolin-7-O-glucoside (3), apigenin-7-O-rutinoside (4), apigenin-7-O-β-d-glucopyranoside (5) and quercetin (6) were isolated from the whole plant of Pilea microphylla using conventional open-silica gel column chromatography and preparative HPLC. Further, these compounds were characterized by 1D, 2D NMR techniques and high-resolution LC–MS. Compounds 1–3 and 6 exhibited significant antioxidant potential in scavenging free radicals such as DPPH, ABTS and SOD with IC₅₀ of 3.3–20.4 μmol/L. The same compounds also prevented lipid peroxidation with IC₅₀ of 10.4–32.2 μmol/L. The compounds also significantly prevented the Fenton reagent-induced calf thymus DNA damage. Pre-treatment with compounds 1–3 and 6 in V79 cells attenuated radiation-induced formation of reactive oxygen species, lipid peroxidation, cytotoxicity and DNA damage, correlating the antioxidant activity of polyphenols with their radioprotective effects. Compounds 1, 3 and 6 significantly inhibited lipid peroxidation, presumably due to 3′,4′-catechol ortho-dihydroxy moiety in the B-ring, which has a strong affinity for phospholipid membranes. Oxidation of flavonoids, with catechol structure on B-ring, yields a fairly stable ortho-semiquinone radical by facilitating electron delocalization, which is involved in antioxidant mechanism. Hence, the flavonoid structure, number and location of hydroxyl groups together determine the antioxidant and radioprotection mechanism.     

Evaluation of cytotoxic and apoptotic effects of the extracts and phenolic compounds of Astragalus globosus Vahl and Astragalus breviflorus DC

Astragalus L. is a genus member of the Fabaceae family, representing about 3,000 species all over the world and 380 species in Turkey. Astragalus species have been used in traditional medicine for many years. Astragalus globosus Vahl, known as “top geven”, is a dwarf, scapose, perennial herb, Astragalus breviflorus DC., known as “yünlü geven”, is an extremely spiny dwarf shrub. These endemic species grow in the Turkish cities of Erzurum, Kars, and Van. This is the first phytochemical and cytotoxic investigation of Astragalus globosus Vahl and Astragalus breviflorus DC. The main extracts and sub-fractions from the plants were evaluated for in vitro cytotoxic and apoptotic activities. The IC₅₀ values of dichloromethane, n-butanol, and water extracts of the aerial parts of A. globosus against the MCF-7 cell line were determined as 28.39, 868.60, and 1753.00 µg/mL. The values for the MDA-MB-231 cell line were 264.00, 620.30, and 1300.50 µg/mL, respectively. From A. globosus, the following were isolated: a flavone glycoside, diosmetin-7-O-rutinoside (1); and two flavonol glycosides, isorhamnetin-3-O-rutinoside (2) and quercetin-3-O-galactoside (3). From A. breviflorus, two phenolic acids, caffeic acid (4) and chlorogenic acid (5), and a flavan-3-ol, catechin (6), were isolated. Diosmetin-7-O-rutinoside was isolated from Astragalus species for the first time and showed the highest cytotoxic activities on the MCF-7 and MDA-MB-231 breast cancer cell lines with IC₅₀ values of 13.65 and 12.89 μg/mL, respectively. Moreover, we observed that diosmin exerts cytotoxic effects by causing cell necrosis.     

Flavonoid glycosides from leaves and straw of Oryza sativa and their effects of cytotoxicity on a macrophage cell line and allelopathic on weed germination

Five new flavonoids namely, 5-hydroxy-6-isoprenyl-7,4′-dimethoxyflavonol-3-O-β-d-arabinofuranoside (1), 5,7-dihydroxy-4′-methoxyflavone-7-O-β-d-arabinopyranosyl-2′′-n-decan-1′′′-oate (2), 3-butanoyl-5,6,8-trihydroxy-7,4′-dimethoxyflavonol--5-O-β-d-glucopyranoside (3), 7, 4′-dimethoxy-5-hydroxyflavone-5-O-α-d-arabinopyranosyl-(2′′?→?1′′′)-O-α-d-arabinopyranoside (4), and 5,6-dihydroxy-7, 4′-dimethoxyflavone-5-O-α-d-glucopyranoside (5), together with two known compounds, were isolated from the methanol extract of Oryza sativa leaves and straw. Their structures of new compounds were elucidated by 1D and 2D NMR spectral methods, viz: COSY, HMBC and HSQC aided by mass techniques and IR spectroscopy. The cytotoxicity of these compounds (1–7) were assessed by using (RAW 264.7) mouse macrophages cell line, and allelopathic effects of compounds (1–7) on the germination characteristics of barnyardgrass (Echinochloa oryzicola) and pigweed (Chenopodium album L.) were also evaluated. The compounds 1, 6 and 7 showed cytotoxicity and compounds 1–7 exhibited significant inhibitory activity on the seed germination of two weed species.     

Protective effect of Centaurea pallescens Del. against CCl4-induced injury on a human hepatoma cell line (Huh7)

Through a hepatoprotective bioassay-guided fractionation of the methanol extract from Centaurea pallescens Del. (Asteraceae), a new acylated flavonoid triglycoside, 4′-methoxy kaempferol 3-O-[α-l-rhamnopyranosyl-(1→3)-(2-O-E-p-coumaroyl)] β-d-glucopyranoside-7-O-(4-O-E-p-coumaroyl) α-l-rhamnopyranoside (1) was isolated from the highly active aqueous fraction. In addition, six known compounds were isolated from both aqueous (2–3) and ethyl acetate soluble fractions (4–7). The structure of (1) was determined by comprehensive analysis of 1D and 2D NMR and mass spectral data. The protective effects of the methanol extract of C. pallescens and its fractions on the human hepatoma cell line were evaluated using Silymarin as a positive control. Hepatoprotection was assessed through determination of aspartate aminotransferase (AST), alanine transaminase (ALT), and superoxide dismutase (SOD) activities in addition to glutathione (GSH) levels before and after incubating the cells with carbon tetrachloride. Compound 1, the major constituent of the aqueous fraction, showed a significant cytoprotection at 100 μg/mL as evidenced by decreasing ALT activity to 18.6 ± 0.12, and enhancing SOD activity to 264.6 ± 4.3 U/mL. Meanwhile, compound 2 at 10 μg/mL decreased AST activity to 5.8 ± 2.4 U/mL. Moreover, Compounds 2 and 3 at 1,000 μg/mL significantly enhanced GSH levels. In conclusion, the protective effects of C. pallescens extract, its fractions and compounds 1–3 are concluded to be partly mediated by its antioxidant activity.     

In vitro biological activity of Salvia fruticosa Mill. infusion against amyloid β-peptide-induced toxicity and inhibition of GSK-3β, CK-1δ, and BACE-1 enzymes relevant to Alzheimer's disease

Salvia species have been traditionally used to improve cognition and have been proved to be a potential natural treatment for Alzheimer’s disease. Salvia fruticosa Mill. (Turkish sage or Greek sage) demonstrated to have anticholinergic effects in vitro.The aim of this study was to understand the mechanism underlying the neuroprotective effects of S. fruticosa infusion and its representative compound rosmarinic acid, which was detected by LC-DAD-ESI-MS/MS. The protective effects of the S. fruticosa infusion (SFINF) and its major substance rosmarinic acid (RA) on amyloid beta 1–42 -induced cytotoxicity on SH-SY5Y cells together with p-GSK-3β activation were investigated. Their in vitro inhibitory effects against glycogen synthase kinase 3β, β-secretase, and casein kinase 1δ enzymes were also evaluated.The results showed that treatment with the all tested concentrations, SFINF significantly decreased Aβ 1–42-induced cytotoxicity and exhibited promising in vitro glycogen synthase kinase 3β inhibitory activity below 10 µg/mL (IC₅₀ 6.52 ± 1.14 µg/mL), in addition to β-secretase inhibition (IC₅₀ 86 ± 2.9 µg/mL) and casein kinase 1δ inhibition (IC₅₀ 121.57 ± 4.00). The SFINF (100 µg/mL and 250 µg/mL) also activated the expression of p-GSK-3β in amyloid beta 1–42 treated SH-SY5Y cells.The outcomes of this study demonstrated that the S. fruticosa infusion possessed activity to prevent amyloid beta 1–42 -induced neurotoxicity and provided proof that its mechanism may involve regulation of p-GSK-3β protein.     

The impact of different extracts of six Lamiaceae species on deleterious effects of oxidative stress assessed in acellular,prokaryotic and eukaryotic models in vitro

The main objective of this research was to evaluate the impact of methanolic, ethanolic and aqueous extracts of Origanum majorana L., Origanum vulgare L., Teucrium chamaedrys L., Teucrium montanum L., Thymus serpyllum L. and Thymus vulgaris L. (Lamiaceae) on the effects of free radicals using different model systems. The extracts were characterized on the basis of the contents of total phenolics, phenolic acids, flavonoids and flavonols, and also using high-performance liquid chromatography with diode-array detection. Antioxidant activity in vitro was assessed using DPPH assay. The genoprotective properties were tested using plasmid relaxation assay on pUC19 E. coli XL1-Blue, while SOS/umuC assay on Salmonella typhimurium TA1535/pSK1002 and Comet assay on human lung fibroblasts were used to assess the antigenotoxicity of the extracts. Ethanolic extracts had the most phenolics (up to 236.20 mg GAE/g at 0.5 mg/mL), flavonoids (up to 42.47 mg QE/g at 0.5 mg/mL) and flavonols (up to 16.56 mg QE/g at 0.5 mg/mL), and they exhibited the highest DPPH activity (up to 92.16% at 0.25 mg/mL). Interestingly enough, aqueous extracts provided the best protection of plasmid DNA (the lowest IC₅₀ value was 0.17 mg/mL). Methanolic extracts, on the other hand, most efficiently protected the prokaryotic DNA, while all the extracts had a significant impact against genomic damages inflicted on human fibroblasts. O. vulgare extracts are considered to be the most promising in preserving the overall DNA integrity against oxidative genomic damages. Moreover, HPLC-DAD analysis highlighted rosmarinic acid as the most abundant in the investigated samples (551.45 mg/mL in total in all the extracts), followed by luteolin-7-O-glucoside (150.19 mg/mL in total), while their presence correlates with most of the displayed activities. The novelty of this study is reflected in the application of a prokaryotic model for testing the antigenotoxic effects of Lamiaceae species, as no previous reports have yet been published on the genoprotective potential of these species.     

Dermatophagoides pteronyssinus-induced pro-inflammatory responses mediated via STAT3 and NF-kappaB signaling pathways in human bronchial epithelial cells – Inhibitory effects of Lafoensia pacari and ellagic acid

The house dust mite allergen Dermatophagoides pteronyssinus (Der p) is a major driver of allergic asthma. Studies from our group demonstrated anti-eosinophilic effects of ethanolic extract of Lafoensia pacari stem bark (and ellagic acid, isolated from L. pacari extract), used as traditional medicine in Brazil to naturally treat inflammatory conditions. Here, we extended these results through performing phytochemical analysis of the constituents of L. pacari using liquid chromatography-mass spectrometry and evaluating the anti-inflammatory effects of both L. pacari and ellagic acid in the human BEAS-2B bronchial epithelial cell line stimulated with Der p. Ellagic acid (major constituent), gallic acid, ferulic acid, chlorogenic acid and rosmarinic acid, but not flavonoids (rutin, kaempferol, luteolin and quercetin), were found in the L. pacari. Pro-inflammatory mediators, IL-6, IL-8 and CCL-2 production were increased in BEAS-2B stimulated with Der p (10 μg/mL, 24 h) compared to control. L. pacari (250 μg/mL) and ellagic acid (100 μM) significantly reduced the concentration of these mediators. L. pacari increased the production of the anti-inflammatory cytokine, IL-10. These results were associated with the downregulation of NF-κB and STAT3 pathways. These findings indicate a novel anti-inflammatory action for L. pacari and ellagic acid in the airways allergic inflammatory response.     

Phytochemical profile,antioxidant and cytotoxic potential of Parkinsonia aculeata L. growing in Saudi Arabia

Parkinsonia aculeata L. growing in Saudi Arabia was investigated for its phytochemical profile, antioxidant, and cytotoxic properties. UPLC-ESI-MS/MS was employed as a powerful technique for the characterization of secondary metabolites from a hydroalcoholic extract, dichloromethane, and ethyl acetate fractions of P. aculeata L. aerial parts. Sixty-nine compounds (flavonoids, anthocyanins, phenolics and fatty acids) were detected and characterized; flavonoids were the abundant components in the analyzed samples. The dichloromethane fraction was rich in phenolics as vanillic acid hexoside, flavonols as 3,7-dimthylquercetin, and flavones as 3′-hydroxymelanettin. However, the ethyl acetate fraction was rich in flavonoid-C-glycosides as luteolin-8-C-β-D-glucoside (orientin) and apigenin-8-C-glucoside (vitexin), flavonoid- O, C-diglycosides such as luteolin 7-O-[6′'-dihydrogalloyl]-glucosyl-8-C-pentosyl-(1 → 2)-glucoside and 2′'-O-rhamnosyl isoorientin. These compounds were identified for the first time in dichloromethane and ethyl acetate fractions of Saudi P. aculeata L.Additionally, all the samples were assessed for antioxidant activity using DPPH radical scavenging method and for cytotoxic activity through MTT assay. Accordingly, the most active fraction was the ethyl acetate which showed the highest antioxidant activity (SC₅₀ = 57.4 ± 1.2 μg/mL) compared with the positive control, ascorbic acid (SC₅₀ = 12.4 ± 0.5 μg/mL) and moderate cytotoxicity against HepG-2 (hepatocellular carcinoma) and MCF-7 (breast carcinoma) cell lines with IC₅₀ = 56.9 ± 3.1 and 95.8 ± 3.8 μg/mL, respectively compared with cisplatin (IC₅₀ = 3.67 ± 0.22 and 5.71 ± 0.57 μg/mL, respectively for both cell lines). The antioxidant and cytotoxic activities may be attributed to the presence of high percentage of phenolic compounds and hydroxylated flavonoids detected in ethyl acetate fraction using UPLS-ESI-MS/MS.     

Optimization of fermentation process of Cordyceps militaris and antitumor activities of polysaccharides in vitro

The influence of medium composition and cultural conditions on simultaneous yield of mycelia, intracellular polysaccharide, adenosine, and mannitol by Cordyceps militaris CGMCC 2909 was investigated with desirability functions in this study. An optimization strategy based on the desirability function approach, together with response surface methodology (RSM) has been used to optimize medium composition, and the optimal medium was obtained via the desirability as follows: yeast extract 10.33 g/L, sucrose 27.24 g/L, KH₂PO₄ 5.60 g/L and the optimal culture conditions are initial pH 6, 25°C, rotation speed 150 r/minute, inoculum size 4%(v/v), and medium capacity 40 mL/250 mL. Under these conditions, the yield of mycelia, intracellular polysaccharide, adenosine and mannitol reached 12.19 g/L, 0.6 g/L, 61.84 mg/L, and 1.38 g/L, respectively, and the D value was 0.77. Furthermore, the polysaccharides showed significant antitumor activities against HeLa and HepG2 in vitro in a dose-dependent manner in 72 hours. At a concentration of 1000 mg/mL, the inhibition rate of polysaccharides was 92.38% and 98.79%. The IC50 for HeLa and HepG2 were 70.91 μg/mL and 97.63 μg/mL, respectively.     

Extraction of bioactive compounds from buriti (Mauritia flexuosa L.) fruit by eco-friendly solvents: Chemical and functional characterization

Buriti (Mauritia flexuosa L.) is a palm tree found in several regions of Latin America. Buriti fruit is a rich source of bioactive compounds such as carotenoids and phenolic compounds. Thus, the aim of this study was to extract bioactive compounds from buriti fruit by ethanol and a supramolecular solvent system (SUPRAS) formed by octanoic acid aggregates. The extracts were evaluated for total carotenoids, β-carotene, phenolic compounds and antioxidant capacity. Additionally, SUPRAS extracts were characterized for antibacterial activity and modulating effect. The extraction of β-carotene with SUPRAS showed a yield of 5.82 ± 0.05 mg/g for the peel and 26.7 ± 0.02 mg/g for the pulp. In relation to total phenolic compounds, the yields were 32.1 ± 1.2 μg GAE/g for the peel and 24.53 ± 4.9 μg GAE/g for the pulp. The presence of gallic acid, quercetin and catechin stand out regarding the phenolics identified. The extracts showed antioxidant activity, with an emphasis on the extracts obtained by SUPRAS, which presented EC₅₀ (concentration required to obtain a 50% antioxidant effect) for the ABTS radical sequestration of 3.00 μg/mL for the peel and 0.84 μg/mL for the pulp. When combined with norfloxacin and gentamicin antibiotics, the extracts also showed a synergistic action against multi-resistant strains of Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. Thus, the extraction of bioactive compounds from buriti fruit using a safe, biocompatible, biodegradable and environmentally friendly solvent such as SUPRAS represents potential for developing new pharmaceuticals, cosmetics and functional foods.     

Regioselective Synthesis,Characterization, and Antimicrobial Activities of Some New Monosaccharide Derivatives

A regioselective acylation series of methyl α-D-glucopyranoside (1), methyl 3-O-benzoyl-4,6-O-benzylidene-α-D-mannopyranoside (1A), and methyl 4,6-O-benzylidene-2-O-(3,5-dinitrobenzoyl)-α-D-mannopyranoside (1B) has been carried out by the direct acylation method and afforded the 2,6-di-O-glucopyranoside and 2 or 3-O-mannopyranoside derivatives in an excellent yield. In order to obtain newer products, the 2,6-di-O-glucopyranoside derivative was further transformed to a series of 3,4-di-O-acyl derivatives containing a wide variety of functionalities in a single molecular framework. The structures of the newly synthesized compounds were elucidated on the basis of IR, ¹H-NMR, ¹³C-NMR, ¹³C-DEPT spectral data, and elemental analysis. These synthesized derivatives were screened for in vitro antimicrobial activities against ten human pathogenic and five phytopathogenic microorganisms. A number of test compounds showed remarkable antimicrobial activity comparable to, and in some cases even higher than, the standard antibiotics employed. It was observed that methyl 3,4-di-O-(3-chlorobenzoyl)-2,6-di-O-hexanoyl-α-D-glucopyranoside (8) exhibited a varied range of MIC from 12.5 μg/disc to 25 μg/disc by the disk diffusion method and 1000 μg/mL to 1250 μg/mL by the broth macrodilution method.     

A new flavonol glycoside from glandless cotton seeds

A new flavonol glycoside, namely quercetin 3-O-[α-d-apiofuranosyl(1–5)-β-d-apiofuranosyl(1–2)]-α-l-rhamnopyranosyl(1–6)-β-d-glucopyranoside (1), was isolated from glandless cotton seeds together with the known compounds quercetin 3-O-α-l-rhamnopyranosyl(1–2)-[α-l-rhamnopyranosyl(1–6)]-β-d-glucopyranoside (manghaslin, 2), kaempferol 3-O-β-d-apiofruranosyl(1–2)-β-d-glucopyranoside (3) and kaempferol 3-O-α-l-rhamnopyranosyl(1–6)-β-d-glucopyranoside (4). It is interesting that the tetrasaccharide fragment of 1 contained both a β-apiosyl and an unusual α-apiosyl group.     

Protective effect of polypeptides from larva of housefly (Musca domestica) on hydrogen peroxide-induced oxidative damage in HepG2 cells

Housefly (Musca domestica) is an important medical insect and its larva is an ideal high protein food source. We isolated from housefly larvae the polypeptides hydrolyzed by neutral protease (PHNP), and investigated the protective effect of PHNP on hydrogen peroxide (H₂O₂)-induced oxidative damage in HepG2 cells. Cells exposed to H₂O₂ showed a marked decrease in proliferation and intracellular superoxide dismutase (SOD) activity, and a significant increase in reactive oxygen species (ROS) level and malondialdehyde (MDA) content. H₂O₂ also caused apoptosis and mitochondrial dysfunction including mitochondrial fragmentation and the loss of mitochondrial membrane potential. Pretreatment with PHNP at concentrations of 2.5, 5, 10 μg/mL blocked these H₂O₂-induced cellular events in a dose-dependent manner. The effect of PHNP at 10 μg/mL is equal to that of ascorbic acid at 10 μM. In summary, PHNP has a protective effect against H₂O₂-induced oxidative injury in cells due to its ability to decrease intracellular ROS and elevate antioxidant enzyme activities.     

Development,pharmacological and toxicological evaluation of a new tablet formulation based on Cassia grandis fruit extract

The treatment of Diabetes mellitus (DM) involves drugs for controlling the blood glucose level, and for treating concomitant disorders such as obesity. Based on the potent antioxidant activity, the α-glycosidase and lipase inhibitory effect, and the potent hypoglycemic effect of the fruit extract of Cassia grandis Lf (CgE), in this work it was developed a novel tablet formulation (CgET) using CgE as the active ingredient. The excipients proportion was optimized by using a D-optimal mixture design. The effect of the compaction force (10, 13, 16, 19, and 22 kN) on the technological properties of tablets was evaluated. The optimized granules formulation was compressed at 16 kN, for producing tablets with excellent technological properties. Tablets showed a potent antioxidant effect (IC₅₀ = 1.45 μg/mL), and α-glycosidase inhibitory activity (IC₅₀ = 34.96 μg/mL) more potent than Acarbose (IC₅₀ = 63.25 μg/mL). Tablets exhibited a strong antiglycant effect by the oxidative (IC₅₀ = 22.45 ± 1.80 μg/mL) and non-oxidative (IC₅₀ = 25.49 ± 1.80 μg/mL) pathways, and produced (at 100 mg/kg) a hypoglycemic effect statistically equal to glibenclamide (25 mg/kg). CgET did not show oral acute toxicity (LC₅₀ > 2000 mg/kg), framed as a non-toxic products. Fruits of the Cassia grandis L f, an underutilized species from the Cuban’ eastern region; allow developing a novel tablet formulation that could be used for the treatment of diabetic patients.     

Tricin 4′-O-(erythro-β-guaiacylglyceryl) ether and tricin 4′-O-(threo-β-guaiacylglyceryl) ether isolated from Njavara (Oryza sativa L. var. Njavara), induce apoptosis in multiple tumor cells by mitochondrial pathway

Njavara is an important medicinal rice variety of Kerala, India widely used in Ayurveda for the treatment of rheumatoid arthritis, paralysis, neurodegenerative diseases and in rejuvenation therapy. The study evaluated, for the first time, antitumor effects of the two rare flavonolignans, tricin 4′-O-(erythro-β-guaiacylglyceryl) ether (compound 1) and tricin 4′-O-(threo-β-guaiacylglyceryl) ether (compound 2), isolated from ‘Njavara’ black. Both the compounds induced apoptosis in three cancer cell lines colon adenocarcinoma cell line HCT 116, ovarian cancer cell line SKOV3 and breast cancer cell line MCF-7. Chromatin condensation in the three cancer cell lines by Hoechst staining showed >50 % of apoptosis by compounds 1 and 2 at concentration 40 and 30 μg/ml, respectively after 48 h. Further studies substantiated that both the compounds targeted cancer cells through mitochondrial membrane potential loss and subsequent chromatin condensation. Both compounds significantly increased the Annexin V binding thus confirming compounds 1 and 2 to be potential apoptotic agents.     

Design and synthesis of 4′‐((5‐benzylidene‐2,4‐dioxothiazolidin‐3‐yl)methyl)biphenyl‐2‐carbonitrile analogs as bacterial peptide deformylase inhibitors

Herein, we report the synthesis and screening of 4′‐((5‐benzylidene‐2,4‐dioxothiazolidin‐3‐yl)methyl)biphenyl‐2‐carbonitrile analogs 11(a–j) as bacterial peptide deformylase (PDF) enzyme inhibitors. The compounds 11b (IC₅₀ value = 139.28 μm ), 11g (IC₅₀ value = 136.18 μm ), and 11h (IC₅₀ value = 131.65 μm ) had shown good PDF inhibition activity. The compounds 11b (MIC range = 103.36–167.26 μg/mL), 11g (MIC range = 93.75–145.67 μg/mL), and 11h (MIC range = 63.61–126.63 μg/mL) had also shown potent antibacterial activity when compared with standard ampicillin (MIC range = 100.00–250.00 μg/mL). Thus, the active derivatives were not only PDF inhibitors but also efficient antibacterial agents. To gain more insight on the binding mode of the compounds with PDF enzyme, the synthesized compounds 11(a–j) were docked against PDF enzyme of Escherichia coli and compounds exhibited good binding properties. The results suggest that this class of compounds has potential for development and use in future as antibacterial drugs.     

Evaluation of bronchodialatory and antimicrobial activities of Otostegia fruticosa: A multi-mechanistic approach

Otostegia fruticosa, a plant belonging to the family Lamiaceae, is endemic to Ethiopia. In Ethiopian traditional medicine, O. fruticosa has been used for the treatment of several respiratory-related disorders. The present study was designed to evaluate the bronchodilatory and antimicrobial activities of O. fruticosa leaves crude extract (Of.Cr). Ex-vivo experiments were conducted on guinea-pig trachea provided with physiological oxygenated buffer solution using emkaBath setup. The crude extract was analyzed by gas chromatography-mass spectrometry. Of.Cr, showed the presence of terpenes, fragrance components, saponins, and higher fatty acids. Of.Cr when tested on contracted tracheal chains with carbamylcholine (CCh, 1 µM) and high K⁺ (80 mM) produced relaxation by showing higher potency against CCh with incomplete inhibition of high K⁺. Dicyclomine, used as a positive control, also showed selectively higher potency to inhibit CCh when compared with its effect against K⁺. In the anticholinergic curves, Of.Cr at 1 mg/mL deflected CCh-induced concentration–response curves (CRCs) competitively to the right like dicyclomine (0.03 µM) and atropine whereas a higher dose of Of.Cr (3 mg/mL) produced a non-parallel shift in the CCh curves like a higher dose of dicyclomine (0.1 µM). In the calcium channel inhibitory assay, Of.Cr at 3 & 5 mg/mL, deflected CRCs of Ca⁺⁺ to the right like verapamil, used as positive control. Of.Cr, at concentrations (1–3 mg/mL) increases cAMP levels in isolated tracheal homogenates, similar to positive control phosphodiesterase inhibitor (papaverine). When tested for antibacterial activity against standard and clinical strains, Of.Cr was found more active (MIC 475 µg/ml) against S. aureus (NCTC 6571), while the maximum inhibition (MIC 625 µg/ml) was observed by the extract when tested against MRSA. These results determine the mechanistic pathways of the observed bronchodilatory effect of Otostegia fruticosa with a combination of anticholinergic and dual inhibition of phosphodiesterase and voltage-gated Ca⁺⁺ channels.     

In vitro genotoxic and antigenotoxic effects of an exopolysaccharide isolated from Lactobacillus salivarius KC27L

Exopolysaccharide isolated from Lactobacillus salivarius (new genus name Ligilactobacillus) KC27L strain (EPS_KC27L) exhibits antioxidant properties with 1,1-diphenyl-2-picrylhydrazase (DPPH) radical and superoxide anion radical (O₂^-.) scavenging effect and iron ion (Fe²⁺) chelating activity. This study aimed to investigate the in vitro genotoxic effects of EPS_KC27L alone (12.50, 25.00, 50.00, and 100.00 μg/mL) and its antigenotoxic activity against DNA damage induced by mitomycin-C (MMC; 0.20 μg/mL), methyl methanesulfonate (MMS; 5.00 μg/mL), and hydrogen peroxide (H₂O₂; 100 μM). For this purpose, chromosome aberration (CA), sister chromatid exchange (SCE), micronucleus (MN), and comet assays were performed in human peripheral lymphocytes. In addition, the structure of EPS_KC27L was investigated in the scanning electron microscope (SEM). EPS_KC27L alone did not cause a significant genotoxic effect in CA, SCE, MN, and comet tests. EPS_KC27L significantly decreased the frequency of CA, SCE, and MN induced by MMC and MMS. EPS_KC27L also significantly reduced DNA damage induced by H₂O₂. This study showed that the EPS_KC27L alone has no genotoxic risk at these concentrations and shows antigenotoxic activity against MMC, MMS, and H₂O₂. Consequently, EPS_KC27L was found to exhibit chemopreventive activity against genotoxic agents. This effect is believed to be due to the antioxidant properties of EPS_KC27L.