Hypoglycaemic Activity of Acalypha fruticosa Forssk Extracts in Normal Rabbits

Purpose: To investigate the hypoglycaemic activity of various extracts of the aerial part of Acalypha fruticosa in normal rabbits.Methods: The rabbits were randomly assigned to 8 groups (n = 3) and treated with a single oral dose. Group 1 served as normal control and received 2 % dimethyl sulfoxide (DMSO, 3 ml/kg); group 2 served as standard  treatment and received metformin (300 mg/kg); groups 3 - 8 received different extracts of Acalypha fruticosa at a dose of (600 mg/kg) as follows: group 3, total methanol extract; group 4, Petroleum ether (PET) extract; group 5, chloroform extract; group 6, ethyl acetate extract; group 7, nbutanol extract; and group 8, aqueous extract. Serum glucose (fasting blood glucose, FBG) was determined using a diagnostic kit on a glucose analyzer.Results: A single dose of the aqueous extract of Acalypha fruticosa significantly lowered (p < 0.5) FBG at 1, 2, 4, and 6 h by 16, 29.5, 19.8, and 23.9 %, respectively, compared with normal control group, whereas standard treatment (metformin) did not affect FBG at all of these time-points measured. Furthermore, the aqueous extract (AEA) lowered FBG at 1, 2, 4, and 6 h by 24, 34.4, 25.9, and 17 %, respectively (p < 0.5), compared with  metformin treatment. Chloroform extract also significantly lowered FBG at 1, 2, and 4 h by 17.3, 24.8, and 14.7 %, respectively, compared to metformin treatment (p <0.5).Conclusion: The results of this study show that the aqueous extract of the aerial parts of Acalypha fruticosa possess potential hypoglycaemic activity but further studies are required to elucidate the exact mechanisms of action

Isolation, biological evaluation and validated HPTLC-quantification of the marker constituent of the edible Saudi plant Sisymbrium irio L.

AbstractPhytochemical investigation and chromatographic purification of the n-hexane fraction of the aerial parts of the edible Saudi plant Sisymbrium irio led to the isolation of β-sitosterol (1), stigmasterol (2) and β-sitosterol-β-d-glucoside (3). The cytotoxic effects of the n-hexane, dichloromethane, ethyl acetate and n-butanol fractions were tested against three cancer cell lines viz., MCF-7, HCT-116 and HepG2, using the crystal violet staining (CVS) method, while the antibacterial activity against a number of pathogenic bacterial strains, was also estimated using the broth microdilution assay. The n-hexane fraction showed potent cytotoxic activities against all tested human cancer cell lines (IC50: 11.7–13.4μg/mL), while the dichloromethane fraction was particularly potent against HCT-116 cells (IC50: 5.42μg/mL). On the other hand, the n-hexane and EtOAc fractions demonstrated significant inhibitory activities against the Gram positive bacteria S. pyogenes and C. perfringens; and the Gram negative bacterium S. enteritidis. Our results warrant the therapeutic potential of S. irio as nutritional supplement to reduce the risk of contemporary diseases. Additionally, a validated high performance thin-layer chromatography (HPTLC) method was developed for the quantitative analysis of biomarker β-sitosterol glucoside (isolated in high quantity) from the n-hexane fraction. The system was found to furnish a compact, sharp, symmetrical and high resolution band for β-sitosterol glucoside (Rf=0.43±0.002). The limit of detection (LOD) and limit of quantification (LOQ) for β-sitosterol glucoside was found to be 21.84 and 66.18ngband−1, respectively. β-sitosterol glucoside was found to be present only in n-hexane fraction (2.10μg/mg of dried fraction) while it was absent in the other fractions of S. irio which validated the high cytotoxic and antibacterial activity of n-hexane fraction of S. irio

Portulaca oleracea Linn seed extract ameliorates hydrogen peroxide-induced cell death in human liver cells by inhibiting reactive oxygen species generation and oxidative stress

Purpose: To investigate the protective effects of Portulaca oleracea seed extract (POA) against cytotoxicity, oxidative stress and reactive oxygen species (ROS) generation induced by hydrogen peroxide (H2O2) in human liver cells (HepG2).Methods: The extract (POA) was obtained by ethanol extraction of P. oleracea seeds. Cytotoxicity in HepG2 cells was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, neutral red uptake (NRU) assay and morphological changes. The cells were pre-exposed to noncytotoxic concentrations (5 - 25 μg/mL) of POA for 24 h, and then cytotoxic (0.25 mM) concentration of H2O2. After 24 h of exposure, MTT and NRU assays were used to evaluate cell viability, while morphological changes were assessed using phase contrast inverted microscopy. The effect of POA on reduced glutathione (GSH) level, lipid peroxidation (LPO), and ROS generation induced by H2O2 was also studied.Results: The results showed that pre-exposure to POA (25 μg/mL) significantly (p <0.01) attenuated the loss of cell viability by up to 38 % against H2O2-induced oxidative stress and ROS generation. In addition, POA (25 μg/mL) significantly (p <0.01) increased GSH level (31 %), but decreased the levels of LPO (37 %) and ROS generation (49 %).Conclusion: This study demonstrates that POA has the capacity to protect HepG2 cells against H2O2- induced cell death by inhibiting oxidative stress and ROS generation.Keywords: Portulaca oleracea, HepG2 cells, Cytotoxicity, Oxidative stress, Reactive oxygen specie

Rosiglitazone, a Peroxisome Proliferator-Activated Receptor-γ Agonist, Prevents Microparticle-Induced Vascular Hyporeactivity through the Regulation of Proinflammatory Proteins

Microparticles are plasma membrane vesicles with procoagulant and proinflammatory properties. We recently demonstrated that microparticles induce vascular hyporeactivity and evoke up-regulation of proinflammatory protein expression. This study dissected the effect of either in vitro treatment or short-term oral administration of the peroxisome proliferator-activated receptor-γ (PPARγ) agonist, rosiglitazone, on microparticle-induced vascular hyporeactivity of mouse vessels. Microparticles were produced from T cells by actinomycin D treatment. The effects of rosiglitazone on mouse aortic rings incubated with microparticles were investigated. Aortae treated in vitro with rosiglitazone or aortae taken from mice treated by oral administration of the same agonist completely prevented microparticle-induced vascular hyporeactivity in response to U46619 [9,11-dideoxy-11α, 9α-epoxymethanoprostaglandin F2α). These effects of rosiglitazone occurred independently of the presence of endothelium without modifications in blood parameters. The mechanisms involved abrogation of nitric oxide (NO) and prostacyclin overproduction linked to up-regulation of inducible NO-synthase and cyclooxygenase 2 elicited by microparticles. In addition, rosiglitazone treatment reduced the ability of microparticles to evoke increases in interleukin (IL)-6, IL-8, and nuclear factor (NF)-κB transcription, and NF-κB expression and activation. These results suggest that rosiglitazone, via PPARγ activation, counteracts vascular dysfunction associated with increased release of proinflammatory proteins elicited by microparticles. They underscore therapeutic perspective for rosiglitazone in vascular diseases involving enhanced participation of microparticles

Alpha-amylase and alpha-glucosidase enzyme inhibition and antioxidant potential of 3-oxolupenal and katononic acid isolated from Nuxia oppositifolia

Nuxia oppositifolia is traditionally used in diabetes treatment in many Arabian countries; however, scientific evidence is lacking. Hence, the present study explored the antidiabetic and antioxidant activities of the plant extracts and their purified compounds. The methanolic crude extract of N. oppositifolia was partitioned using a two-solvent system. The n-hexane fraction was purified by silica gel column chromatography to yield several compounds including katononic acid and 3-oxolupenal. Antidiabetic activities were assessed by α-amylase and α-glucosidase enzyme inhibition. Antioxidant capacities were examined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) scavenging assays. Further, the interaction between enzymes (α-amylase and α-glucosidase) and ligands (3-oxolupenal and katononic acid) was followed by fluorescence quenching and molecular docking studies. 3-oxolupenal and katononic acid showed IC50 values of 46.2 µg/mL (101.6 µM) and 52.4 µg/mL (119.3 µM), respectively against the amylase inhibition. 3-oxolupenal (62.3 µg/mL or 141.9 µM) exhibited more potent inhibition against α-glucosidases compared to katononic acid (88.6 µg/mL or 194.8 µM). In terms of antioxidant activity, the relatively polar crude extract and n-butanol fraction showed the greatest DPPH and ABTS scavenging activity. However, the antioxidant activities of the purified compounds were in the low to moderate range. Molecular docking studies confirmed that 3-oxolupenal and katononic acid interacted strongly with the active site residues of both α-amylase and α-glucosidase. Fluorescence quenching results also suggest that 3-oxolupenal and katononic acid have a good affinity towards both α-amylase and α-glucosidase enzymes. This study provides preliminary data for the plant’s use in the treatment of type 2 diabetes mellitus

Assessment of selected Saudi and Yemeni plants for mosquitocidal activities against the yellow fever mosquito Aedes aegypti

© 2019 by the authors. Marine organisms are recognized as a source of compounds with interesting biological activities. Vibrio neocaledonicus has been reported on for its high effectiveness against corrosion in metals but it has been little studied for its chemical and biological activities. In this study, four compounds were isolated from V. neocaledonicus: indole (1); 1H-indole-3-carboxaldehyde (2); 4-hydroxybenzaldehyde (3) and Cyclo (-Pro-Tyr) (4); using a bioassay-guided method, since in a previous study it was found that the ethyl acetate extract was active on the enzymes acetylcholinesterase (AChE), alpha-glucosidase (AG) and xanthine oxidase (XO). The inhibitory activities of the three compounds against AChE, AG and XO was also evaluated. In addition, the enzymatic inhibitory activity of indole to the toxins from the venom of Bothrops asper was tested. Results showed that indole exhibited strong inhibitory activity to AG (IC50 = 18.65 ± 1.1 µM), to AChE, and XO (51.3% and 44.3% at 50 µg/mL, respectively). 1H-indole-3-carboxaldehyde displayed strong activity to XO (IC50 = 13.36 ± 0.39 µM). 4-hydroxybenzaldehyde showed moderate activity to XO (50.75% at 50 µg/mL) and weak activity to AChE (25.7% at 50 µg/mL). Furthermore, indole showed a significant in vitro inhibition to the coagulant effect induced by 1.0 µg of venom. The findings were supported by molecular docking. This is the first comprehensive report on the chemistry of V. neocaledonicus and the bioactivity of its metabolites

New Cytotoxic Seco-Type Triterpene and Labdane-Type Diterpenes from Nuxia oppositifolia

Chromatographic purification of the n-hexane and dichloromethane extracts of Nuxia oppositifolia aerial parts, growing in Saudi Arabia, resulted in the isolation and characterization of three new labdane-type diterpene acids, 2β-acetoxy-labda-7-en-15-oic acid (1), 2β-acetoxy-7-oxolabda-8-en-15-oic acid (2), 2β-acetoxy-6-oxolabda-7-en-15-oic acid (3), and one new seco-triterpene, 3,4-seco olean-12-en-3,30 dioic acid (4), together with 10 known lupane, oleanane and ursane-type triterpenes, as well as the common phytosterols, β-sitosterol and stigmasterol (5–16). Their structures have been assigned on the basis of different spectroscopic techniques including 1D and 2D NMR. Moreover, 13 of the isolated compounds were tested on the human cancer cell lines HeLa (cervical), A549 (lung) and MDA (breast), and most of the compounds showed potent cytotoxic activities in vitro

Oxidative Stress Mediated Cytotoxicity, Cell Cycle Arrest, and Apoptosis Induced by Rosa damascena in Human Cervical Cancer HeLa Cells

Rosa damascena Mill (Damask rose), belonging to the Rosaceae family, is known for medicinal purposes in traditional medicine system. However, its anticancer activity has not been studied yet in detail. Herein, we aimed to investigate the cytotoxic effects of R. damascena hexane (RA-HE) and methanolic (RA-ME) extracts against human breast (MCF-7), lung epithelial (A-549), and cervical (HeLa) cancer cells. The RA-HE and RA-ME showed more potent cytotoxic effects against HeLa cells with an IC50 of 819.6 and 198.4 μg/ml, respectively. Further, cytotoxic concentrations of most effective extract (RA-ME) were used to evaluate the mechanism of cytotoxicity involved in HeLa cells. A concentration-dependent induction of lipid peroxidation (LPO) and reduction of glutathione (GSH) in HeLa cells treated with 250-1000 μg/ml of RA-ME confirms the association of oxidative stress. We also detected a noteworthy increase in reactive oxygen species (ROS) production and a decline in mitochondrial membrane potential (MMP) level in RA-ME-exposed HeLa cells. Flow cytometric data showed a strong dose-response relationship in cell cycle analysis between subG1 phase in HeLa cells and RA-ME treatment. Similarly, a concentration-dependent increase was recorded with Annexin V assay in HeLa cells going to late apoptosis. In conclusion, our findings suggest that RA-ME-induced cytotoxicity and apoptosis in HeLa cells are mediated by oxidative stress

Vacillantins A and B, New Anthrone C-glycosides, and a New Dihydroisocoumarin Glucoside from Aloe vacillans and Its Antioxidant Activities

A new dihydroisocoumarin glucoside, vacillanoside (3), and two new anthrone C-glycosides microdantin derivatives; vacillantin A (10) and B (11), together with nine known compounds belonging to the anthraquinone, anthrone and isocoumarin groups were isolated from the leaves of Aloe vacillans. The structures were determined based on spectroscopic evidence including 1D and 2D nuclear magnetic resonance (NMR) spectroscopy and high resolution mass spectrometry (HRESIMS) data, along with comparisons to reported data. The leaves were used to extract compounds with different solvents. The extracts were tested for antioxidant activity with a variety of in vitro tests including 2,2-diphenyl-1-picrylhydrazyl (DPPH•), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonate (ABTS•+), ferric reducing antioxidant power assay (FRAP), superoxide, and nitric oxide radical scavenging assays. The dichloromethane fraction was most active, displaying significant free radical scavenging activity. The n-butanol fraction also showed notable activity in all assays. Therefore, these findings support the potential use of A. vacillans leaves as an antioxidant medication due to the presence of polyphenolic compounds