Potential SARS-CoV-2 Mpro steroid inhibitors from Aphanamixis polystachya (Wall.) R. N. Parker.

Herein, six previously undescribed steroids (1-6), were isolated from leaves and twigs of Aphanamixis polystachya (Wall.) R. N. Parker (Meliaceae). Their structures were elucidated by comprehensive spectroscopic analysis, including HRESIMS, 1D and 2D NMR, UV, and IR. Antiviral activity of these compounds were evaluated. Compounds 1-6 showed varying degrees of inhibitory activity against the severe acute respiratory syndrome coronavirus 2 main protease (SARS-CoV-2 Mpro) at 200 µM.

Four new tirucallane-type triterpenoids from Aphanamixis polystachya.

Four new tirucallane-type triterpenoids, polystanins H-K (1-4), were obtained from the stems and leaves of Aphanamixis polystachya. Their structures were elucidated by analysis of the spectroscopic data and comparison with literature data. Compounds 1 and 2 showed week inhibitory effects against NO production in LPS-stimulated RAW264.7 cells. All the isolates were investigated for their antifungal activities against drug-resistant Candida albicans.

Triterpenoids from the fruits of Aphanamixis polystachya and their inhibitory activities on nitric oxide production.

Nineteen triterpenoids, including five previously unknown (four triucallane-type derivatives and one highly oxidized A, B-seco limonoids), together with fourteen known triterpenoids, were isolated from the fruits of Aphanamixis polystachya. Their structures were elucidated by extensive spectroscopic analysis. All isolates were evaluated their anti-inflammatory activities. The result showed that all compounds inhibit LPS-induced nitric oxide production in RAW264.7 macrophages with their IC50 value ranging from 95 to 1332 uM, and compound 6 exhibited obvious anti-inflammatory activity comparable to that of the positive control, with IC50 values of 94.96 uM.

Two new triterpenoids from the fruits of Aphanamixis polystachya.

Two new triucallane triterpenoids, polystanin F (1) and polystanin G (2), along with eight known compounds (3-10) were isolated from the fruits of Aphanamixis polystachya. Their structures were established on the basis of extensive spectroscopic analysis. Moreover, eight compounds were evaluated for their in vitro cytotoxicity against three cancer cell lines (liver cancer RT112, colon cancer HCT-116 and breast cancer M231) using the MTT method. Compound 7 showed significant cytotoxic activity against HCT-116 with IC50 1.27 µM.

MicroRNA­138 promotes proliferation and suppresses mitochondrial depolarization in human pulmonary artery smooth muscle cells through targeting TASK­1.

MicroRNA (miR)­138 serves an important role in the proliferation, differentiation and apoptosis of human pulmonary artery smooth muscle cells (HPASMCs), indi-cating the involvement of miR­138 in the development and progression of pulmonary artery hypertension (PAH). Potassium channel subfamily K member 3 (TASK­1), a two­pore domain K+ channel, is expressed in HPASMCs and is associated with hypoxic PAH. However, whether miR­138 mediates PAH through targeting TASK­1 is not known. In the present study, HPASMCs were transfected with miR­138 mimic to establish a PAH model in vitro, and the effects of a miR­138 inhibitor and a TASK­1 inhibitor (A293) were examined. Cell proliferation and mitochondrial membrane potential (MMP) were measured by CCK­8 assay and flow cytometry, respectively. Reverse transcription-quantitative polymerase chain reaction and western blotting were performed to examine the expression of miR­138, TASK­1, Bcl­2, caspase­3 and activation of extracellular signal­regulated kinase 1/2 (ERK1/2). A dual­luciferase reporter assay was also used to analyse the expression level of TASK­1 in HPASMCs. The results of the present study demonstrated that the miR­138 mimic promoted proliferation and MMP level, which was similar to the effect of A293 treatment on HPASMCs. However, the miR­138 inhibitor inhibited the effects induced by miR­138 mimic or A293 treatment, as demonstrated by a decrease in proliferation and MMP level in HPASMCs, accompanied by a decrease of Bcl­2 and an increase of caspase­3 expression levels, as well as ERK1/2 activation. The dual­luciferase reporter assay indicated that TASK­1 expression was negatively regulated by miR­138. The results of the present study suggested that miR­138 promoted proliferation and suppressed mitochondrial depolarization of HPASMCs by targeting TASK­1.