Isolation, structural and bioactivities of polysaccharides from Anoectochilus roxburghii (Wall.) Lindl.: A review.

Anoectochilus roxburghii (Wall.) Lindl. (A. roxburghii), a valuable herbal medicine in China, has great medicinal and edible value. Polysaccharides, as one of the main active components of A. roxburghii, comprise glucose, arabinose, xylose, galactose, rhamnose, and mannose in different molar ratios and glycosidic bond types. By varying the sources and extraction methods of A. roxburghii polysaccharides (ARPS), different structural characteristics and pharmacological activities can be elucidated. ARPS has been reported to exhibit antidiabetic, hepatoprotective, anti-inflammatory, antioxidant, antitumor, and immune regulation activities. This review summarizes the available literature on the extraction and purification methods, structural features, biological activities, and applications of ARPS. The shortcomings of the current research and potential focus in future studies are also highlighted. This review provides systematic and current information on ARPS to promote their further exploitation and application.

Sauropus androgynus L. Merr.-A phytochemical, pharmacological and toxicological review.

ETHNOPHARMACOLOGICAL RELEVANCE: Sauropus androgynus L. Merr is an underexploited perennial shrub traditionally used as a medicinal plant in South Asia and Southeast Asia. The plant is regarded as not just a green vegetable for diet, but as a traditional herb for certain aliments. For instance, it has traditionally been used to relieve fever, to treat ulcers and diabetes, to promote lactation and eyesight, and to reduce obesity. AIM OF THE STUDY: This paper aims to review the botany, phytochemistry, ethnopharmacology, and pharmacological activities of S. androgynus, and discuss the known chemical constituents at work in S. androgynus-induced bronchiolitis obliterans for providing new ideas to the mechanism of the disease and pharmacology research of the plant. MATERIALS AND METHODS: The data presented in this review were collected from published literatures as well as the electronic databases of PubMed, CNKI, Web of Science, SCI finder, ACS, Science Direct, Wiley, Springer, Taylor, Google Scholar, and a number of unpublished resources, (e.g. books, and Ph.D. and M.Sc. dissertations). RESULTS: The scientific literature indicates that S. androgynus is a valuable and popular herbal medicine whose nutritional value is also higher than that of other commonly used vegetables. Phytochemical analyses identified high content of fatty acids, flavonoids, and polyphenols as the major bioactive components in S. androgynus. Crude extracts and phytochemical compounds isolated from S. androgynus show a wide spectrum of in vitro and in vivo pharmacological activities such as antioxidant, anti-inflammatory, anti-ulcer, skin whitening, anti-diabetic, and immunoregulatory activities. The traditional use, such as increasing lactation, treating ulcers and diabetes, and reducing obesity, have been evaluated and studied with various methods. Numerous reports have revealed the unusual link between the consumption of S. androgynus and the induction of a chronic and irreversible obstructive disease (namely, bronchiolitis obliterans), indicating that the toxicity and side effects of this plant that is presently used in health care and medicine are a major area of concern. CONCLUSION: Though little importance was attached to this green plant, S. androgynus has notable phytochemical constituents and various pharmacological activities including antioxidant, anti-inflammatory, and anti-obesity activities. Studies have firmly established the association between excessive consumption of the uncooked S. androgynus juice over a period of time and the occurrence of bronchiolitis obliterans. It is inadvisable to ingest excessive amounts of S. androgynus before fully understanding the pathogenesis and induction mechanism of this fatal disease. The phytochemistry of S. androgynus, its pharmacology for traditional use, S. androgynus-induced bronchiolitis obliterans still need further investigation.

Mitochondrial membrane anchored photosensitive nano-device for lipid hydroperoxides burst and inducing ferroptosis to surmount therapy-resistant cancer.

Rationale: Ferroptosis is a regulated process of cell death caused by iron-dependent accumulation of lipid hydroperoxides (LPO). It is sensitive to epithelial-to-mesenchymal transition (EMT) cells, a well-known therapy-resistant state of cancer. Previous studies on nanomaterials did not investigate the immense value of ferroptosis therapy (FT) in epithelial cell carcinoma during EMT. Herein, we describe an EMT-specific nanodevice for a comprehensive FT strategy involving LPO burst. Methods: Mitochondrial membrane anchored oxidation/reduction response and Fenton-Reaction-Accelerable magnetic nanophotosensitizer complex self-assemblies loading sorafenib (CSO-SS-Cy7-Hex/SPION/Srfn) were constructed in this study for LPO produced to overcome the therapy-resistant state of cancer. Both in vitro and in vivo experiments were performed using breast cancer cells to investigate the anti-tumor efficacy of the complex self-assemblies. Results: The nano-device enriched the tumor sites by magnetic targeting of enhanced permeability and retention effects (EPR), which were disassembled by the redox response under high levels of ROS and GSH in FT cells. Superparamagnetic iron oxide nanoparticles (SPION) released Fe2+ and Fe3+ in the acidic environment of lysosomes, and the NIR photosensitizer Cy7-Hex anchored to the mitochondrial membrane, combined sorafenib (Srfn) leading to LPO burst, which was accumulated ~18-fold of treatment group in breast cancer cells. In vivo pharmacodynamic test results showed that this nanodevice with small particle size and high cytotoxicity increased Srfn circulation and shortened the period of epithelial cancer treatment. Conclusion: Ferroptosis therapy had a successful effect on EMT cells. These findings have great potential in the treatment of therapy-resistant epithelial cell carcinomas.

BHQ-Cyanine-Based "Off-On" Long-Circulating Assembly as a Ferroptosis Amplifier for Cancer Treatment: A Lipid-Peroxidation Burst Device.

Ferroptosis is an iron-dependent cell death caused by accumulation of lipid peroxidation (LPO), which is a new strategy for cancer treatment. Th current ferroptosis therapy nanodevices have low efficiency and side effects generally. Hence, we developed a Black Hole Quencher (BHQ)-based fluorescence "off-on" nanophotosensitizer complex assembly (CSO-BHQ-IR780-Hex/MIONPs/Sor). CSO-connected BHQ-IR780-Hex and -loaded magnetic iron oxide nanoparticles (MIONPs) and sorafenib (Sor) formed a very concise functionalized delivery system. CSO-BHQ-IR780-Hex disassembled by GSH attack and released IR780-Hex, MIONPs, and sorafenib. IR780-Hex anchored to the mitochondrial membrane, which would contribute to amplifying the efficiency of the photosensitizer. When NIR irradiation was given to CSO-BHQ-IR780-Hex/MIONPs/Sor-treated cells, iron supply increased, the xCT/GSH/GPX-4 system was triggered, and a lot of LPO burst. A malondialdehyde test showed that LPO in complex assembly-treated cells was explosive and increased about 18-fold compared to the control. The accumulation process of particles was monitored by an IR780-Hex photosensitizer, which showed an excellent tumor target ability by magnetic of nanodevice in vivo. Interestingly, the half-life of sorafenib in a nanodevice was increased about 26-fold compared to the control group. Importantly, the complex assembly effectively inhibits tumor growth in the breast tumor mouse model. This work would provide ideas in designing nanomedicines for the ferroptosis treatment of cancer.

Characterization, quantitation, similarity evaluation and combination with Na+,K+-ATPase of cardiac glycosides from Streblus asper.

Streblus asper Lour. (Moraceae) is a medicinal plant in Asian countries including India and Thailand, possessing activities of anti-tumor, anti-allergy, anti-parasitic and anti-bacterial. In this paper, characterization, quantitation and similarity evaluation of cardiac glycosides in different parts of S. asper were investigated by HPLC-Q-TOF-MS and chemometric methods. Then, the inhibition of Na+,K+-ATPase activity by the compounds isolated from S. asper was measured. Meanwhile, enzyme kinetics and molecular docking were determined to exhibit the combination modes between cardiac glycosides and Na+,K+-ATPase. As a result, twenty peaks of cardiac glycosides were assigned. Strophanthidin-3-O-α-l-rhamnopyranosyl-(1 → 4)-6-deoxy-ß-d-allopyranoside (1), glucostrebloside (2), strebloside (4) and mansonin (8) with a significant activity of inhibiting Na+,K+-ATPase (IC50 7.55-13.60 µM) were chosen for the determination of enzyme kinetics, exhibiting anticompetitive inhibitory characteristics towards Na+,K+-ATPase. Compound 4 could reasonably bind to the active sites of Na+,K+-ATPase, proved by molecular docking. Furthermore, the contents of the major compounds in four different parts of S. asper were extremely different, analyzed by chemometric methods, similarity analysis and principle compounds analysis. All these findings indicated that the contents of major compounds in different parts of S. asper were extremely different with a significant activity of inhibiting Na+,K+-ATPase, providing a reference for determination of effective part and administered dosage. The combination modes between cardiac glycosides and Na+,K+-ATPase were also revealed by enzyme kinetics and molecular docking, which provided a basis for further study of pharmacological activity.

C21 steroids from Streptocaulon juventas (Lour) Merr. induce apoptosis in HepG2.

Three new C21 steroids, i.e., (3ß,17α,20S)-pregn-5(6)-ene-3, 17, 20-triol-3-O-ß-d-digitalopyranosyl-(1 → 4)-ß-d-digitalopyranoside (4), (3ß,17α,20S)-pregn-5(6)-ene-3, 17, 20-triol-20-O-ß-d-glucopyranosyl-(1 → 6)-ß-d-glucopyranosyl-(1 → 2)-ß-d-digital-opyranoside (8), (3ß, 20R)-pregn-14(15)-ene-3, 20, 21-triol-3-O-ß-d-glucopy-ranoside (10), along with ten known C21 steroids were isolated from Streptocaulon juventas. Their structures were elucidated on the basis of 1D and 2D NMR spectroscopic techniques, mass spectrometry as well as comparison with the literature. All the isolated compounds were screened for their in vitro cytotoxicity against human liver cancer cells (HepG2) and the structure-activity relationships were also analyzed. Moreover, compounds 1-3, 5, 10-12, which displayed cytotoxic activities in HepG2 cells, were tested for the selective index (SI) by the ratio of cytotoxic effect on human hepatocytes (LO2) to that on HepG2. As a result, new compound 10 exhibited a good inhibitory activity against HepG2 with IC50 value 11.7 µM as well as high SI value 3.5. Furthermore, compound 10 could induce HepG2 cells apoptosis by flow cytometry.