Anti-hyperglycaemic Activity of Tribulus terrestris L Aerial Part Extract in Glucose-loaded Normal Rabbits

Purpose: To investigate the anti-hyperglycaemic activity of methanol extract of Tribulus terrestris L. Zygophyllaceae in glucose-loaded normal rabbits.Methods: The animals were randomly assigned to 4 groups (n = 5) and treated with a single oral dose. Group 1 served as normal control group and received distilled water; group 2 served as hyperglycaemic control; group 3 was treated with glibenclamide (5 mg/kg, aqueous suspension) and served as reference standard; group 4 received methanol extract of Tribulus terrestris L. (250 mg/kg). Groups 3 and 4 were orally treated with glucose (5 g/kg) after 1 h of drug and extract administration, respectively. Fasting blood glucose (FBG) was determined prior to (0 h) and at 30 min, 1, 2 and 3 h after dosing for acute toxicity study.Results: On comparing within groups, a single dose of the methanol extract of Tribulus terrestris L. lowered FBG to levels comparable to that of glibenclamide (36 vs. 55 %), and reaching the initial level (0 h) at 2 h. FBG were significantly (p < 0.05) lowered at 2 and 3 h in both glibenclamide (45.5 and 56.9 %) and extract (45.7 and 52.7 %) groups as compared with their respective glucose levels at 0.5 h. On the other hand, on comparing between groups, both glibenclamide and methanol extract significantly (p < 0.05, p < 0.001) lowered the rise in blood glucose at 1 h (33.9 and 22.5 %), 2 h (62.8 and 59.16 %), and 3 h (64.6 and 57.1 %) with respect to the hyperglycaemic control group.Conclusion: The methanol extract of the aerial parts of Tribulus terrestris L. possesses potential antihyperglycaemic activity in glucose loaded normal rabbits. Further studies on various organic solvents fractions and isolated compounds from this plant are required.Keywords: Tribulus terrestris L., Zygophyllaceae, Anti-hyperglycaemic activity, Fasting blood glucose, Acute toxicit

Hepatoprotective Effect of Pandanus odoratissimus L Inflorescence Extracts in Acetaminophen-treated Guinea Pigs

Purpose: To investigate the hepatoprotective activity of methanol extracts of peduncles, flowers and spathes of Pandanus odoratissimus L. inflorescence in acetaminophen-induced hepatotoxicity in guinea pigs.Methods: The animals were randomly assigned to 9 groups (3 animals per group) and treated orally for 10 consecutive days. Group 1 served as normal control and received distilled water (1 ml/kg); groups 2 - 4 received methanol extracts of peduncle, flower, and spathes of P. odoratissimus L. (500 mg/kg), respectively, in the absence of acetaminophen (APAP); group 5 served as hepatotoxic control and received APAP (3 g/kg) on days 1 and 2; group 6 served as standard treatment group and received silymarin (100 mg/kg) + 3 g/kg APAP on days 1 and 2; groups 7 - 9 received methanol extracts of peduncle, flower, and spathes of P. odoratissimus L. (500 mg/kg) respectively + 3 g/kg APAP on days 1 and 2. Serum enzyme activities (AST, ALT, ALP) and total bilirubin were determined. Histopathological examinations of the liver were also carried out.Results: The methanol extract of the peduncle alleviated the liver damage induced by APAP as evident by the improved histopathology picture similar to that of silymarin which presented with only mild hydropic and fatty changes. The extract also reduced the liver enzymes - AST, ALT and ALP - by 42, 50 and 59 %, respectively (p < 0.05), but the reduction (32 %) in total bilirubin was not significant 32 %. On the other hand, the flower extract only lowered AST and ALP by 31 and 48 % (p < 0.05), respectively, while the reduction in ALT and total bilirubin by 33 and 18 % respectively, was not significant.Conclusion: P. odoratissimus L. peduncle has potential hepatoprotective activity against APAPinduced hepatotoxicity in guinea pigs.Keywords: Pandanus odoratissimus L., Peduncle, Flowers, Hepatoprotection, Acetaminophen, Guinea pig

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

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

Insecticidal Activity and Free Radical Scavenging Properties of Isolated Phytoconstituents from the Saudi Plant Nuxia oppositifolia (Hochst.)

Chromatographic purification of the alcoholic extract from the aerial parts of the Saudi plant Nuxia oppositifolia (Hochst.), Benth., resulted in five isolated phenolic compounds. Two flavones, hispidulin (1) and jaceosidin (2), and the phenylethanoid glycosides, verbascoside (3), isoverbascoside (4), and conandroside (5), were identified and their chemical structures were determined by spectroscopic analyses. The insecticidal activity of compounds 1 and 2, in addition to 11 compounds isolated in a previous research (6–16), was evaluated against the Yellow Fever mosquito, Aedes aegypti. Four compounds displayed adulticidal activity with LD50 values of 2–2.3 μg/mosquito. Free radical scavenging properties of the plant extracts and compounds (1–5) were evaluated by measuring the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonate radical cation (ABTS•+) scavenging activity. All compounds exhibited notable activity, compared with the positive control, l-Ascorbic acid. This study suggests that N. oppositifolia could be a promising source of secondary metabolites, some with lethal adulticidal effect against Ae. aegypti

In Vitro Antiprotozoal Activity of Triterpenoid Constituents of Kleinia odora Growing in Saudi Arabia

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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

Acylated pregnane glycosides from Caralluma sinaica

Caralluma sinaica is sold on local markets of Saudi Arabia for various health benefits however no phytochemical study has specifically been performed on this species. NMR and UHPLC-ESI-TOF-MS profilings of the ethanolic extract of the whole plant reveal a very complex phytochemical composition dominated by pregnanes. Detailed information on its constituents was obtained after isolation. Six pregnane glycosides were obtained and characterized based on the extensive spectroscopic analysis (including IR, 1H NMR, 13C NMR and MS data), in addition to ten known compounds (seven pregnanes and three flavonoids). The compounds were identified as 12b-O-benzoyl-20-O-acetyl boucerin-3-O-6-deoxy-3-Omethyl-b-D-glucopyranosyl-(1?4)-b-D-cymaropyranosyl-(1?4)-b-D-cymaropyranoside, 12b-O-tigloyl-20-O-acetyl boucerin-3-O-b-D-glucopyranosyl-(1?4)-b-D-cymaropyranoside, 12b-O-benzoyl-20-O-acetyl boucerin-3-O-b-D-glucopyranosyl-(1?4)-b-D-digitalopyranosyl-(1?4)-b-D-cymaropyranosyl-(1?4)-b-Dcymaropyranoside,12b-O-benzoyl-20-O-acetyl boucerin-3-O-b-D-glucopyranosyl-(1?4)-thevetopyranosyl-(1?4)-b-D-cymaropyranosyl-(1?4)-b-D-cymaropyranoside, 12b-O-benzoyl-20-O-tigloyl boucerin-3-O-b-D-glucopyranosyl-(1?4)-b-D-cymaropyranoside, 12b-20-O-dibenzoyl boucerin-3-O-b-D-glucopyranosyl-(1?4)-b-D-cymaropyranosyl-(1?4)-b-D-cymaropyranoside. Finally, the isolated compounds were evaluated for their quinone reductase induction