Phytochemical investigation, molecular docking studies and DFT calculations on the antidiabetic and cytotoxic activities of Gmelina philippensis CHAM.

ETHNOPHARMACOLOGICAL RELEVANCE: Gmelina philippensis CHAM is an ornamental plant that is distributed in South Asia and warm regions of the Mediterranean area. The plant is traditionally applied in folk medicine for the treatment of diabetes. AIM OF THE STUDY: To evaluate the cytotoxic and the antidiabetic activities of the ethanolic extract of G. philippensis aerial parts. To isolate the metabolite(s) responsible for these activities and to elucidate the mechanism of action by molecular docking study. MATERIALS AND METHODS: Compounds (1-11) were isolated using various chromatographic techniques and their structures were determined by NMR spectroscopic and mass spectrometric analysis. The cytotoxic effect was tested using viability test and MTT assay. Antidiabetic activity was evaluated by measuring the inhibitory activity of the ethanolic extracts and compounds against α-glucosidase and α-amylase activities. Modeling and docking simulations were performed using Molecular Operating Environment software and the crystal structure of protein kinases CDK2, (1PYE) and AKT1 (4GV1), in addition to α-glucosidase (3TOP) and α-amylase (2QV4). RESULTS: Compounds 2, 3 and 8 were isolated for the first time from the plant and identified as: gmelinol (2), apigenin (3) and tyrosol (8). While ß-sitosterol-3-O- ß-D-glucopyranoside (4) vicenin-II (7), rhoifolin (9), isorhoifolin (11) were isolated for the first time from the genus, along with and the new iridoid 6-O-α-L-(2″-O-benzoyl-4″-O-trans-p-methoxycinnamoyl)rhamnopyranosyl-1α- ß-D-glucopyranoside catalpolgenin (6). In addition, to the previously reported compounds: mixture of ß -sitosterol and stigmasterol (1), and 6- O- α-L-(2″,3″,4″-tri-O -benzoyl)rhamnopyranosylcatalpol (5) and 6-O-α-L-(2″-O-trans-p-methoxycinnamoyl)rhamnopyranosylcatalpol (10). The cytotoxic activity against hepatocellular carcinoma (HepG-2) cell lines for compounds 2, 5, 7, 9 and 11 was conducted using cisplatin as a standard. Gmelinol (2) exhibited strong cytotoxic activity against HepG-2 cell lines with IC 50 value of 3.6 ± 0.1 µg/ml which is more potent than the standard cisplatin IC 50 = 8.7 ± 0.9 µg/ml. Molecular modeling of 2 against diverse targets of protein kinases suggested that CDK-2 and AKT-1 could be the dual probable kinase targets for its cytotoxic action. Compound 2 showed α-amylase inhibition activity with IC 50 value of 60.9 (µg/ml) while, compounds 5 showed strong α-glucosidase inhibition activity with IC 50 values of 41.7 (µg/ml) compared to acarbose with IC 50 value of 34.7, 30.6 (µg/ml). Molecular docking of compounds 2 and 5 on α-glucosidase (3TOP) and α-amylase (2QV4) enzymes revealed high binding affinity and active site interactions comparable to native ligand acarbose. CONCLUSION: The ethanolic extract of G. philippensis CHAM aerial parts is effective against HepG-2 cell lines, α-amylase and α-glucocidase activities. Biologically guided isolation indicated that compounds 2 and 5 are responsible for these activities. These results were supported by DMF calculations that detected the molecular areas responsible for protein interactions shown via docking studies.

Cytotoxic and anti-diabetic potential, metabolic profiling and insilico studies of Syzygium cumini (L.) Skeels belonging to family Myrtaceae.

LC-HR-MS-coupled metabolic profiling of the methanol extracts from different parts of Syzygium cumini (L.), which was extensively identified via DNA fingerprinting, led to dereplication of 24 compounds. Cytotoxic investigation highlighted both extracts as the most potent, against both MCF-7 and MDA-231 Cell lines, with IC50 value of 5.86 ± 0.63 µg/ml and against HCT -116 cell line, with IC50 value of 1.24 ± 0.09 µg/ml, respectively. A molecular docking study was performed on the dereplicated compounds, which highlighted myricetin-3-glucoside (7), myricitrin (12), reynoutrin (15) and quercitrin (16) as the top scoring ligands within the protein active site (FIH-1). Interestingly, the extracts were significant against streptozotocin-induced diabetes in the order of flowers > seeds > leaves with BGL level of 98.9 ± 4.3, 123.2 ± 4.9 and 132.8 ± 5.9 mg/dl, respectively. The study highlights the health benefits of Syzygium cumini (L.) as a promising cytotoxic source.

The inhibition of inducible nitric oxide production in lipopolysaccharide-stimulated rat macrophages and in silico studies by flavonoids from Iris spuria L. rhizomes.

ETHNOPHARMACOLOGICAL RELEVANCE: Iris is the largest genus in the family Iridaceae. Iris plants are distributed in tropical regions of the world. They are used as ornamentals and traditionally used to treat a variety of ailments. AIM: This study aimed to evaluate the anti-inflammatory effect of flavonoids isolated from Iris spuria L. MATERIALS AND METHODS: The isolated flavonoids (1-4) were identified on the basis of different spectroscopic methods (1D- and 2D-NMR) and co-TLC with authentic samples. The anti-inflammatory effect was tested on lipopolysaccharide (LPS)-induced nitric oxide (NO) production from rat-isolated peritoneal macrophages. Modeling and docking simulations of the compounds were performed using Molecular Operating Environment software and the crystal structure of the murine inducible nitric oxide synthase (iNOS). RESULTS: Four flavonoids (1-4) had been isolated from the rhizomes of Iris spuria L. (Hocka Hoona) for the first time. They were characterized as 5,7,2'-trihydroxy-6-methoxyflavanone (1), tectorigenin 7-O-ß-D-glucopyranoside (2), tectorigenin 4'-O-ß-D-glucopyranoside (3), and tectorigenin 4'-O-[ß-D-glucopyranosyl(1 â†’ 6)-ß-D-glucopyranoside] (4). The selective inducible NO synthase inhibitor; aminoguanidine was used as a positive control. The production of nitric oxide (NO) was inhibited in a dose-dependent manner of the isolated compounds along with isoflavonoids (5-9) previously isolated from Iris spuria L. (Calizona). A concentration of 60 µg/ml of all tested compounds showed a significant inhibitory effect compared to media with LPS. Molecular modeling experiments supported the obtained biological data. CONCLUSION: Our results reveal that flavonoids isolated from I. spuria L. (Hocka Hoona) and I. spuria L. (Calizona) appear to have a potential anti-inflammatory effect via inhibition of iNOS.