Corydecusines A-H, new phthalideisoquinoline hemicetal alkaloids from the bulbs of Corydalis decumbens inhibit Tau pathology by activating autophagy mediated by AMPK-ULK1 pathway.

Twelve phthalideisoquinoline hemiacetal alkaloids including eight new ones (1-8) and one natural alkaloid characterized by an aziridine moiety with unassigned NMR data (9), were isolated and identified from the bulbs of Corydalis decumbens. Their structures were established by comprehensive analyses of HRESIMS, NMR, X-ray crystallography, and ECD analyses. The unambiguously established structures of the phthalideisoquinoline hemiacetal alkaloids indicated that the absolute configurations of C-1, C-9, and C-7' were confusable only relied on coupling constants. A summary of their ECD spectra was concluded and provided an insight for C-1, C-9, and C-7' absolute configuration assignment. These new compounds were evaluated to induce autophagy flux through flow cytometry analysis. Moreover, compounds 2 and 6 could significantly induce autophagy and inhibit Tau pathology by AMPK-ULK1 pathway activation, which provided an avenue for anti-AD lead compounds discovery.

Cardiac glycosides from the roots of Streblus asper Lour. with activity against Epstein-Barr virus lytic replication.

Cardiac glycosides (CGs) show potential broad-spectrum antiviral activity by targeting cellular host proteins. Herein are reported the isolation of five new (1-5) and eight known (7-13) CGs from the roots of Streblus asper Lour. Of these compounds 1 and 7 exhibited inhibitory action against EBV early antigen (EA) expression, with half-maximal effective concentration values (EC50) being less than 60 nM, and they also showed selectivity, with selectivity index (SI) values being 56.80 and 103.17, respectively. Preliminary structure activity relationships indicated that the C-10 substituent, C-5 hydroxy groups, and C-3 sugar unit play essential roles in the mediation of the inhibitory activity of CGs against EBV. Further enzyme experiments demonstrated that these compounds might inhibit ion pump function and thereby change the intracellular signal transduction pathway by binding to Na+/K+-ATPase, as validated by simulated molecular docking. This study is the first report that CGs can effectively limit EBV lytic replication, and the observations made in this study may be of value for lead compound development.

Regulation of Immune Activation by Optical Control of TLR1/2 Heterodimerization.

The activation of toll-like receptors (TLRs) plays important roles in the immune response. The ability to control the activities of TLRs could be usable as a switch for immune response. Here we have rationally designed and synthesized a photoswitchable Pam3 CSK4 derivative-P10-to control the activation of TLR1/2. The ground-state trans-P10 was able to stimulate and activate antigen-presenting cells (APCs) by promoting TLR1/2 heterodimerization. However, cis-P10, derived from UV irradiation of trans-P10, reduced the activities of APCs by impeding the TLR1/2 heterodimerization. In the absence of UV radiation, the cis-P10 slowly returned to its ground trans state, restoring the activities of the APCs stimulation. Our results indicated that optical control of TLR1/2 heterodimerization mediated by the photoswitchable P10 offers the potential to regulate immune activation and inflammation.

Pam3CSK4-CDGSF Augments Antitumor Immunotherapy by Synergistically Activating TLR1/2 and STING.

Cyclic dinucleotides (CDNs), agonists of stimulator of interferon genes (STING), are promising agents for immunotherapy. However, the application of CDNs has been limited by their instability and low transmembrane efficiency. Here, we introduced a conjugated adjuvant of STING and TLR1/2, Pam3CSK4-CDGSF. Conjugating CDGSF with Pam3CSK4 increased the stability and intracellular delivery. In addition, by synergistically activating the STING and TLR pathways, Pam3CSK4-CDGSF was able to enhance immune activation. Both humoral and cellular immune responses were triggered by Pam3CSK4-CDGSF plus OVA (V4), and tumor growth was significantly inhibited after V4 administration. More importantly, V4 can also boost the antigen-specific CD8+ T cell response for cancer cell killing. Thus, the conjugated STING and TLR1/2 agonist Pam3CSK4-CDGSF can serve as a potent adjuvant for vaccine construction to augment antitumor immunotherapy.

Fully Synthetic Invariant NKT Cell-Dependent Self-Adjuvanting Antitumor Vaccines Eliciting Potent Immune Response in Mice.

Constructing an effective therapeutic cancer vaccine is very attractive and promising for cancer immunotherapy. However, the poor immunogenicity of tumor antigens and suppression of the immune system in the tumor microenvironment are two major obstacles for developing effective cancer vaccines. Invariant NKT cells (iNKT cells), which are essential bridges between the innate and adaptive immune systems, can be rapidly activated by their agonists and, consequently, evoke whole immune systems. Herein, we conjugated a potent agonist of the iNKT cell, α-galactosylceramide (α-GalCer), with the tumor-associated MUC1 glycopeptide antigens as novel self-adjuvanting cancer vaccines through click chemistry. Immunological studies revealed that the mouse immune system was potently evoked and that high levels of tumor-specific IgG antibodies were elicited by vaccine conjugates without an external adjuvant. The produced antibodies could specifically recognize and bind to antigen-expressing cancer cells and, subsequently, induce cytotoxicity through complement-dependent cytotoxicity. Thus, the insertion of α-GalCer significantly improved the immunogenicity of the MUC1 glycopeptide and induced strong antigen-specific antitumor responses, indicating that α-GalCer is an effective built-in adjuvant for constructing potent chemical synthetic antitumor vaccines.

Self-Assembled Nano-Immunostimulant for Synergistic Immune Activation.

Immunotherapy has become one of the most promising therapies for the treatment of diseases. Synthetic immunostimulants and nanomaterial immunostimulant systems are indispensable for the activation of the immune system in cancer immunotherapy. Herein, a strategy for preparing self-assembled nano-immunostimulants (SANIs) for synergistic immune activation is reported. Three immunostimulants self-assemble into nanoparticles through electrostatic interactions. SANIs showed strong synergistic immunostimulation in macrophages. SANIs could also induce a strong antitumor immune response to inhibit tumor growth in mice and act as an efficient adjuvant of antitumor vaccines. Therefore, SANIs may be generally applied in cancer immunotherapy. This novel SANI strategy provides a new way for the development of both immunostimulants and -suppressants.

Myeloid Cell-Triggered In Situ Cell Engineering for Robust Vaccine-Based Cancer Treatment.

Following the success of the dendritic cell (DC) vaccine, the cell-based tumor vaccine shows its promise as a vaccination strategy. Except for DC cells, targeting other immune cells, especially myeloid cells, is expected to address currently unmet clinical needs (e.g., tumor types, safety issues such as cytokine storms, and therapeutic benefits). Here, it is shown that an in situ injected macroporous myeloid cell adoptive scaffold (MAS) not only actively delivers antigens (Ags) that are triggered by scaffold-infiltrating cell surface thiol groups but also releases granulocyte-macrophage colony-stimulating factor and other adjuvant combos. Consequently, this promotes cell differentiation, activation, and migration from the produced monocyte and DC vaccines (MASVax) to stimulate antitumor T-cell immunity. Neoantigen-based MASVax combined with immune checkpoint blockade induces rejection of established tumors and long-term immune protection. The combined depletion of immunosuppressive myeloid cells further enhances the efficacy of MASVax, indicating the potential of myeloid cell-based therapies for immune enhancement and normalization treatment of cancer.

STING and TLR7/8 agonists-based nanovaccines for synergistic antitumor immune activation.

Immunostimulatory therapies based on pattern recognition receptors (PRRs) have emerged as an effective approach in the fight against cancer, with the ability to recruit tumor-specific lymphocytes in a low-immunogenicity tumor environment. The agonist cyclic dinucleotides (CDNs) of the stimulator of interferon gene (STING) are a group of very promising anticancer molecules that increase tumor immunogenicity by activating innate immunity. However, the tumor immune efficacy of CDNs is limited by several factors, including relatively narrow cytokine production, inefficient delivery to STING, and rapid clearance. In addition, a single adjuvant molecule is unable to elicit a broad cytokine response and thus cannot further amplify the anticancer effect. To address this problem, two or more agonist molecules are often used together to synergistically enhance immune efficacy. In this work, we found that a combination of the STING agonist CDGSF and the Toll-like receptor 7/8 (TLR7/8) agonist 522 produced a broader cytokine response. Subsequently, we developed multicomponent nanovaccines (MCNVs) consisting of a PC7A polymer as a nanocarrier encapsulating the antigen OVA and adjuvant molecules. These MCNVs activate bone marrow-derived dendritic cells (BMDCs) to produce multiple proinflammatory factors that promote antigen cross-presentation to stimulate specific antitumor T-cell responses. In in vivo experiments, we observed that MCNVs triggered a strong T-cell response in tumor-infiltrating lymphocytes, resulting in significant tumor regression and, notably, a 100% survival rate in mice through 25 days without other partnering therapies. These data suggest that our nanovaccines have great potential to advance cancer immunotherapy with increased durability and potency. Electronic Supplementary Material: Supplementary material (synthesis of CDGSF, 522, PC7A and OVA; preparation of MCNVs; representative gating strategies for flow cytometry) is available in the online version of this article at 10.1007/s12274-022-4282-x.

A novel STING agonist for cancer immunotherapy and a SARS-CoV-2 vaccine adjuvant.

A novel STING agonist, CDGSF, ipsilaterally modified with phosphorothioate and fluorine, was synthesized. The phosphorothioate in CDGSF might be a site for covalent conjugation. Injection of CDGSF generated an immunogenic ("hot") tumor microenvironment to suppress melanoma, more efficiently than dithio CDG. In particular, immunization with SARS-CoV-2 spike protein using CDGSF as an adjuvant elicited an exceptionally high antibody titer and a robust T cell response, overcoming the drawbacks of aluminum hydroxide. These results highlighted the therapeutic potential of CDGSF for cancer immunotherapy and the adjuvant potential of the STING agonist in the SARS-CoV-2 vaccine for the first time.

Black phosphorous nanosheet: A novel immune-potentiating nanoadjuvant for near-infrared-improved immunotherapy.

Intrinsic immune behaviors of nanomaterials and immune systems promote research on their adjuvanticity and the design of next generation nanovaccine-based immunotherapies. Herein, we report a promising multifunctional nanoadjuvant by exploring the immune-potentiating effects of black phosphorus nanosheets (BPs) in vitro and in vivo. The facile coating of BPs with phenylalanine-lysine-phenylalanine (FKF) tripeptide-modified antigen epitopes (FKF-OVAp@BP) enables the generation of a minimalized nanovaccine by integrating high loading capacity, efficient drug delivery, comprehensive dendritic cell (DC) activation, and biocompatibility for cancer immunotherapy. Systemic immunization elicits potent antitumor cellular immunity and significantly augments checkpoint blockade (CPB) against melanoma in a mouse model. Furthermore, near-infrared (NIR) photothermal effects of BPs create an immune-favorable microenvironment for improved local immunization. This study offers new insight into the integration of immunoactivity and photothermal effects for enhanced cancer immunotherapy by using a nanoadjuvant and thus potentially advances the design and application of multifunctional adjuvant materials for cancer nanotreatment.

Cardiac glycosides from the roots of Streblus asper Lour. and their apoptosis-inducing activities in A549 cells.

Phytochemical investigation of the roots of Streblus asper Lour. resulted in the isolation of six previously undescribed cardiac glycosides, designated 2'-de-O-methylstrebloside (1), cannogenol-3α-O-ß-D-gluopyranosyl-(1 â†’ 4)-6-deoxy -2,3-dimethoxyl-ß-D-fucopyranoside (2), periplogenin-3-O-α-L-rhamnopyranosyl -(1 â†’ 4)-6-deoxy-ß-D-allopyranoside (3), 5-de-O-hydroxylstrebloside (4), 5ßH-16ß-hydroxylkamaloside (5), and 17S, 21R-21-hydroxylstrebloside (6), and three known analogues (7-9). The structures were elucidated using NMR spectroscopic techniques, mass spectrometry, and comparison of the spectroscopic data with previously reported data. Compound 6 is a novel C-21 hydroxyl cardiac glycoside, its absolute configuration was established from the analysis of computational ECD calculations and NMR spectroscopic data. The effects of the cardiac glycosides on apoptosis and cytotoxicity were examined in human A549 lung cancer cells. All the compounds showed remarkable inhibitory activities, with IC50 values in the range of 0.01-6.08 µM. Furthermore, compound 3 was able to significantly inhibit A549 cell growth proliferation via the induction of apoptosis, due to the activation of caspases-3, -8 and -9 in A549 cells, as revealed by Western blot analysis.

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.

Traditional uses, phytochemistry, and pharmacology of Ficus hispida L.f.: A review.

ETHNOPHARMACOLOGICAL RELEVANCE: Ficus hispida L.f. (Moraceae) has long been used as a traditional medicine in India, China, Sri Lanka, Australia, and Myanmar in the treatment of diarrhea, ulcer, anemia, diabetes, inflammation, and cancer. AIM OF THE REVIEW: This review provides a systematic comment on the botany, traditional uses, and phytochemical and pharmacological studies of F. hispida, with an aim to make critical update of the current knowledge and obtain opportunities for further therapeutic potential. MATERIALS AND METHODS: The information was derived from scientific literature databases including PubMed, Baidu Scholar, Google Scholar, Web of Science, and Science Direct. Additional information was gathered from books, Ph.D. and M.Sc. dissertations, and unpublished materials. RESULTS AND DISCUSSION: F. hispida is used especially in Chinese and Indian traditional medical systems as a remedy for skin disorders, respiratory diseases, and urinary diseases. Wound healing, anti-inflammatory, antinociceptive, sedative, antidiarrheal, antiulcer, antimicrobial, antioxidant, hepatoprotective, antineoplastic, and antidiabetic activities have been reported for crude extracts and isolated metabolites, but the methodologies in these studies often have inadequate design and low technical quality. More than 76 compounds have been isolated from F.hispida, including sesquiterpenoids and triterpenoids, flavonoids, coumarins, phenylpropionic acids, benzoic acid derivatives, alkaloids, steroids, other glycosides, and alkanes, but the method of bioassay-guided fractionation is seldom applied in the isolation from F. hispida. CONCLUSION: F. hispida is used widely in traditional medicines and has multiple pharmacological effects that could support traditional uses. However, pharmacological studies should be viewed with caution because of the inappropriate experimental design. More in vitro and in vivo research is urgently needed to study the molecular mechanisms and assess the effective and safe dose of F. hispida.

Novel Mannitol-Based Small Molecules for Inhibiting Aggregation of α-Synuclein Amyloids in Parkinson's Disease.

The aggregation of the amyloidogenic protein α-synuclein (α-Syn) into toxic oligomers and mature fibrils is the major pathological hallmark of Parkinson's disease (PD). Small molecules that inhibit α-Syn aggregation thus may be useful therapeutics for PD. Mannitol and naphthoquinone-tryptophan (NQTrp) have been shown in the past to inhibit α-Syn aggregation by different mechanisms. Herein, we tested whether the conjugation of Mannitol and NQTrp may result in enhance efficacy toward α-Syn. The molecules were conjugated either by a click linker or via a PEG linker. The effect of the conjugate molecules on α-Syn aggregation in vitro was monitored using Thioflavin T fluorescence assay, circular dichroism, transmission electron microscopy, and Congo red birefringence assay. One of the conjugate molecules was found to be more effective than the two parent molecules and as effective as a mixture of the two. The conjugate molecules attenuated the disruptive effect of α-Syn on artificial membrane of Large Unilamellar Vesicles as monitored by dye leakage assay. The conjugates were found to be have low cytotoxicity and reduced toxicity of α-Syn toward SH-SY5Y neuroblastoma cells. These novel designed entities can be attractive scaffold for the development of therapeutic agents for PD.

Designable Immune Therapeutical Vaccine System Based on DNA Supramolecular Hydrogels.

Immunotherapy is believed to be an ideal method to treat cancer because it can break the immunotolerance of tumor and induce robust immunoresponse. However, constructing a wide antigen-adaptive, easy-handling, and biodegradable system that can recruit and activate antigen-presenting cells (APCs) much effectively is still a challenge. Herein, we show an injectable DNA supramolecular hydrogel vaccine (DSHV) system which could efficiently recruit and activate APCs in vitro and in vivo. The in vitro processes have been visualized by fluorescence microscopy. Through intraperitoneal or subcutaneous injection, the DSHV system can mimic the function of a lymph node where the APCs are recruited and activated by the high local concentration of cytosine-phosphate-guanine. Subsequently, strong immune response and obvious antitumor effects have been obtained. Our findings demonstrated that the DSHV system could serve as a general platform for tumor vaccination and benefit the personalized cancer therapy in the near future.

Targeting STING with cyclic di-GMP greatly augmented immune responses of glycopeptide cancer vaccines.

Cyclic di-GMP (CDG) was applied to MUC1 glycopeptide-based cancer vaccines with physical mixing and built-in (at 2'-OH of CDG) strategies for activating the STING pathway. CDG in both strategies behaved as a potent immunostimulant and contributed to high titers of IgG antibodies and the expression of multiple cytokines.