Dibenzocyclooctadiene lignans from Kadsura coccinea alleviate APAP-induced hepatotoxicity via oxidative stress inhibition and activating the Nrf2 pathway in vitro.

Phytochemical investigation on the roots of Kadsura coccinea led to the isolation five previously unknown dibenzocyclooctadiene lignans, named heilaohusuins A-E (1-5). Their structures determined by NMR spectroscopy, HR-ESI-MS, and ECD spectra. Hepatoprotection effects of a series of dibenzocyclooctadiene derivatives (1-68) were investigated against acetaminophen (APAP) induced HepG2 cells. Compounds 2, 10, 13, 21, 32, 41, 46, and 49 showed remarkable protective effects, increasing the viabilities to > 52.2% (bicyclol, 52.1 ± 1.3%) at 10 µM. The structure-activity relationships (SAR) for hepatoprotective activity were summarized, according to the activity results of dibenzocyclooctadiene derivatives. Furthermore, we found that one new dibenzocyclooctadiene lignan heilaohusuin B attenuates hepatotoxicity, the mechanism might be closely correlated with oxidative stress inhibition via activating the Nrf2 pathway.

A review of lignans from genus Kadsura and their spectrum characteristics.

Kadsura belongs to the Schisandroideae subfamily of Magnoliaceae. Plants from genus Kadsura are widely distributed in the South and Southwest of China. The plants of the genus are widely used as folk medicine for a long time in history, with the functions of relieving pain, promoting 'qi' circulation, activating blood resolve stasis, and applications in the treatment of rheumatoid arthritis and gastroenteric disorders. Lignans are the primary characteristic constituents with various biological activities of plants from genus Kadsura. This paper summarized 81 lignans isolated from the plants of genus Kadsura over the past eight years (from 2014 to 2021), which belong to five types: dibenzocyclooctadienes, spirobenzofuranoid dibenzocyclooctadienes, aryltetralins, diarylbutanes and tetrahydrofurans. Each type of these lignans possess typical characteristics in proton magnetic resonance (1H NMR) and carbon-13 nuclear magnetic resonance (13C NMR) spectra, the NMR regularities of these types of lingans were summarized, which provided a useful reference for the structural analysis of lignans. The relationships between lignans and pharmacodynamics were also systematically analyzed, lignans were predicted to be the quality markers (Q-marker) of Kadsura genus.

Heilaohuguosus A-S from the fruits of Kadsura coccinea and their hepatoprotective activity.

Phytochemical investigations on the fresh fruits of Kadsura coccinea (Lem.) A. C. Sm. have led to the isolation of fourteen undescribed 2,2'-cyclolignans named heilaohuguosus A-N, four undescribed aryltetrahydronaphthalene lignans, heilaohuguosus O-R and one tetrahydrofuran lignan, heilaohuguosu S, with twenty-seven previously described lignan analogues. Their structures and absolute configurations of heilaohuguosus A-S were established by spectroscopic methods including 1D and 2D-NMR techniques and CD experiments. All isolated compounds were evaluated for their hepatoprotective activity against APAP-induced toxicity in HepG-2 cells, four 2,2'-cyclolignans, heilaohuguosus A and L, tiegusanin I and kadsuphilol I showed good hepatoprotective activities against APAP toxicity in HepG-2 cells with cell survival rates of 53.5 ± 1.7%, 55.2 ± 1.2%, 52.5 ± 2.4%, and 54.0 ± 2.2% (positive control bicyclol, 52.1 ± 1.3%) at 10 µM, respectively.

Kadsura coccinea: A rich source of structurally diverse and biologically important compounds.

Kadsura coccinea belongs to medicinally important genus Kadsura from the Schisandraceae family. It has been used in traditional Chinese medicine (TCM) for the treatment of rheumatoid arthritis and gastroenteric disorders. The initial phytochemical work focused on the identification of some structurally novel and diverse natural products, which turned the attention of many researchers towards this plant. Thus far, 202 compounds have been reported in this plant. Lignans and terpenoids were found as the main chemical constituents of this plant. Some of the triterpenoids and sesquiterpenoids with novel structures are of particular interest for natural product researchers. The isolated compounds of this plant have shown different bioactivities including anti-tumor, anti-HIV, anti-inflammatory, nitric oxide (NO) production inhibitory and other pharmacological effects. This review systematically summarizes all the phytochemical and pharmacological work done so far on K. coccinea, and can be used as a reference for future research on this plant.

Chemical characterization of constituents from Polygonatum cyrtonema Hua and their cytotoxic and antioxidant evaluation.

Twenty-four compounds were isolated from the roots of Polygonatum cyrtonema Hua, including a new octopamine dimer, named trans-bis(N-feruloyl)octopamine (1). The structure was established on the basis of spectroscopic and chemical methods. All the extracts and compounds were evaluated for cytotoxic and antioxidant activities by using MTT and chemiluminescence assay. The extracts showed activity against MCF-7 and HepG-2 cell lines from IC50 0.30 to 1.01 mg mL-1. Compound 3 exhibited activity against HepG-2 cell lines with IC50 8.99 µM. Compound 7 exhibited activity against Hela cell lines with IC50 2.53 µM and BGC-823 cell lines with IC50 7.77 µM. Moreover, compound 7 showed antioxidant with IC50 12 µM compared to the positive control with IC50 77 µM. Compound 16 exhibited activity against HepG-2 cell lines with IC50 1.05 µM and MCF-7 cell lines with IC50 1.89 µM. These results indicated that this plant might be potential in natural medicine and healthy food.