Chemical constituents from the leaves of Sindora siamensis var. maritima and their antimicrobial and α-glucosidase inhibitory activities.

Two new glycosides, sindosides A-B (1-2), along with 11 previously identified metabolites (3-13), were isolated from an ethanolic extract of the leaves of Sindora siamensis var. maritima. The structures of the purified phytochemicals were elucidated by interpreting their spectroscopic data (IR, NMR, and HRMS). The absolute configuration of compound 1 was established by experimental and calculated ECD spectra. The antimicrobial results revealed that compound 8 selectively inhibited C. albicans fungal with a MIC value of 64 µg/mL, whereas 11 presented a weak inhibition toward E. faecalis, S. aureus, and B. cereus bacterial strains with the same MIC value of 128 µg/mL. Interestingly, compounds 1, 2, 8, 9, and 11 showed α-glucosidase inhibitory activity with IC50 values ranging from 14.42 ± 0.21 to 30.62 ± 0.18 µM, which were more active than the positive control (acarbose, with an IC50 value of 46.78 ± 1.37 µM). Enzyme kinetic analysis revealed that compounds 1, 2, and 11 behaved as uncompetitive inhibitors with Ki values of 8.60 ± 1.04, 5.16 ± 0.73, and 7.17 ± 0.98 µM, respectively.

Whole exome sequencing revealed novel pathogenic variants in Vietnamese patients with FEVR.

Background: Familial exudative vitreoretinopathy (FEVR) is a rare inherited disorder marked by incomplete retinal vascularization associated with exudation, neovascularization, and tractional retinal detachment. FEVR is genetically heterogeneous and is caused by variants in six genes: FZD4, LRP5, NDP, TSPAN12, ZNF408, and CTNNB1. In addition, the phenotypic overlap between FEVR and other disorders has been reported in patients harboring variants in other genes, such as KIF11, ATOH7, and RCBTB1. Purpose: To identify pathogenic variants in Vietnamese pediatric patients diagnosed with FEVR and to investigate the clinical findings in correlation with each causative gene. Methods: A total of 20 probands underwent ocular examinations with fundoscopy (ophthalmoscopy) or fluorescein angiography. Genomic DNA was extracted from the peripheral blood of the probands and their family members. Multiplex ligation-dependent probe amplification (MLPA) was employed to detect copy number variants of FEVR-causing genes. Short variants were screened by whole-exome sequencing (WES) and then validated by Sanger sequencing. Results: Fluorescein angiography showed retinal vascular anomalies in all patients. Other ocular abnormalities commonly found were strabismus, nystagmus, exudation, and retinal detachment. Genetic analysis identified 12 different variants in the FZD4, NDP, KIF11, and ATOH7 genes among 20 probands. Four variants were novel, including FZD4 c.169G>C, p.(G57R); NDP c.175-3A>G, splicing; KIF11 c.2146C>T, p.(Q716*) and c.2511_2515del, p.(N838Kfs*17). All patients with the KIF11 variant showed signs of microcephaly and intellectual disability. The patient with Norrie syndrome and their family members were found to have a deletion of exon 2 in the NDP gene. Conclusions: This study sheds light on the genetic causes of ocular disorders with the clinical expression of FEVR in Vietnamese patients. WES was applied as a comprehensive tool to identify pathogenic variants in complex diseases, such as FEVR, and the detection rate of pathogenic mutations was up to 60%.

Aplydactylonins A-C, three new sesquiterpenes from the Vietnamese sea hare Aplysia dactylomela and their cytotoxicity.

Aplydactylonins A-C (1-3), three new sesquiterpenes, were isolated from the Vietnamese sea hare Aplysia dactylomela. Their structures and absolute configurations were elucidated based on spectroscopic analysis, X-ray crystallography, and density functional theory (DFT) calculations of NMR and ECD data. Compound 2 exhibited cytotoxicity against HepG2, DU145 and A549 cells with respective IC50 values of 4.08 ± 0.63, 38.64 ± 1.04 and 12.33 ± 0.95 µM. In addition, HepG2 cells treated with 5 µM compound 2 for 48 h showed a significant increase in early apoptotic cells (P < 0.05) and increased caspase 3 activity (P < 0.01). Moreover, compound 2 induced sub-G1 phase arrest in HepG2 cells.

Essential Oils of Lemongrass (Cymbopogon citratus Stapf) Induces Apoptosis and Cell Cycle Arrest in A549 Lung Cancer Cells.

Essential oils were extracted from the culm and leaf of Cymbopogon citratus collected from different regions of Vietnam and analyzed using GC/MS. The results showed that citral is the major component accounting for 61.20%-76.46% of the essential oils. The citral content was higher in the essential oil obtained from the leaf than in that from the culm of lemongrass in all regions. In particular, camphene, valerianol, and epi-α-muurolol can be used to differentiate essential oils originating from leaves versus culms. The cytotoxic effects of the essential oils on various lung cancer cell lines were evaluated in the present study. All essential oils exhibited cytotoxicity in the tested cells. The Ha Loc leaf essential oil (HLL) exhibited the most potent effects on A549 and H1975 cells, with IC50 values of 1.73 ± 0.37 and 4.01 ± 0.30 µg/mL, respectively. The Hy Cuong leaf essential oil (HCL) showed the strongest effect on H1299 cells, with an IC50 value of 2.45 ± 0.21 µg/mL. The Kim Duc culm (KDC) essential oil exerted the strongest cytotoxic effects against H1650 cells, with an IC50 value of 4.86 ± 0.29 µg/mL. The HLL induced apoptosis and cycle arrest in A549 cells according to flow cytometric analysis and fluorescent nuclear staining assays. The western blot analysis indicated that HLL induced the apoptotic effect by altering the regulating proteins of the apoptosis process such as caspase-3, Bcl-2, and Bax. The data strongly suggested that the intrinsic pathway may play an important role in the apoptotic effects of HLL.

Degalactotigonin, a Steroidal Glycoside from Solanum nigrum, Induces Apoptosis and Cell Cycle Arrest via Inhibiting the EGFR Signaling Pathways in Pancreatic Cancer Cells.

Degalactotigonin (1) and three other steroidal compounds solasodine (2), O-acetyl solasodine (3), and soladulcoside A (4) were isolated from the methanolic extract of Solanum nigrum, and their chemical structures were elucidated by spectroscopic analyses. The isolated compounds were evaluated for cytotoxic activity against human pancreatic cancer cell lines (PANC1 and MIA-PaCa2) and lung cancer cell lines (A549, NCI-H1975, and NCI-H1299). Only degalactotigonin (1) showed potent cytotoxicity against these cancer cell lines. Compound 1 induced apoptosis in PANC1 and A549 cells. Further study on its mechanism of action in PANC1 cells demonstrated that 1 significantly inhibited EGF-induced proliferation and migration in a concentration-dependent manner. Treatment of PANC1 cells with degalactotigonin induced cell cycle arrest at G0/G1 phase. Compound 1 induced downregulation of cyclin D1 and upregulation of p21 in a time- and concentration-dependent manner and inhibited EGF-induced phosphorylation of EGFR, as well as activation of EGFR downstream signaling molecules such as Akt and ERK.