Cleistanthin A induces apoptosis and suppresses motility of colorectal cancer cells

Natural products target programmed cell death signaling mechanisms to treat colorectal cancer

As a highly prevalent gastrointestinal malignant tumor, colorectal cancer poses a serious challenge in terms of increasing morbidity and mortality and late diagnosis due to the invisibility of the disease. Although existing therapies are diverse but limited in efficacy, the mechanism of programmed cell death (PCD) has become a focus of research due to its central role in maintaining body homeostasis and regulating tumor progression. Multimodal cell death pathways, such as apoptosis, autophagy, pyroptosis and ferroptosis, have shown unique advantages in inhibiting the proliferation and migration of colorectal cancer cells and enhancing the sensitivity to chemotherapy by responding to internal and external environmental stimuli. In recent years, natural products have risen to prominence by virtue of their multi-target synergistic effects and chemo-sensitizing properties, and have opened up a new direction for colorectal cancer treatment by precisely regulating the PCD pathway. In this paper, we searched PubMed, Web of Science and CNKI databases for relevant studies in the last 10 years using the keywords (Colorectal cancer) and (programmed cell death) and natural products. This work retrieved 59 studies (55 from the past 5 years and 4 from the past 10 years) to reveal the mechanism of action of natural products targeting PCD, aiming to provide theoretical support and practical guidance for the optimization of clinical therapeutic strategies and the development of innovative drugs.

Total Synthesis of the Furopyran Lignans Sumatranin A-D and the Proposed Structure of Sumatranin H

Sumatranins A-D are lignans isolated from the twigs of Cleistanthus sumatranus that contain a previously unseen furopyran in a tetrahydro-furo[2,3-b]chromene tricyclic system. In this work, sumatranins A-D were enantioselectively synthesized utilizing an Evans aldol reaction followed by acid-catalyzed cyclization as key steps. Additionally, the proposed structure of dibenzylbutyrolactone lignan sumatranin H, an apparent biosynthetic precursor to the furopyran lignans, was synthesized but determined to be inconsistent with the previously isolated data. The synthetic routes developed allows for the construction of a wide range of sumatranin-type lignans or unnatural analogues.

Cleistanthin A derivative disrupts autophagy and suppresses head and neck squamous cell carcinoma progression via targeted vacuolar ATPase

Head and neck squamous cell carcinoma (HNSCC) present a significant challenge due to its heterogeneity and limited treatment options, often resulting in severe side effects and poor survival rates with conventional chemoradiotherapy. Here, we investigated the anticancer activity of halogenated benzoate derivatives of cleistanthin A, ECDD-S16 and ECDD-S18, in HNSCC cells. Our findings revealed that ECDD-S18 exhibited remarkable cytotoxicity, surpassing that of cisplatin with minimal impact on normal and cisplatin-sensitive cells. Notably, ECDD-S18 induced apoptosis in a dose-dependent manner and effectively targeted vacuolar ATPase (V-ATPase), impairing lysosomal acidification. Intriguingly, ECDD-S18 inhibited autophagic flux, as evidenced by increased autophagosome but decreased autolysosome formation. Furthermore, proteomic analysis demonstrated downregulation of cathepsin D (CTSD), the lysosomal protease in ECDD-S18-treated HNSCC cells, concurrent with suppressed cell migration. ECDD-S18 also decreased expression of mesenchymal markers, suggesting inhibition of epithelial-mesenchymal transition (EMT). Importantly, cotreatment with ECDD-S18 and cisplatin enhanced the reduction in cell viability. Collectively, our results indicated that the anticancer activity of ECDD-S18 partly stems from its ability to disrupt lysosomal acidification and inhibit autophagy via targeted inhibition of V-ATPase. These findings underscore the therapeutic promise of ECDD-S18 in HNSCC treatment, either alone or in combination with existing drugs, while mitigating toxicity to normal cells.

Potential anti-Pythium insidiosum therapeutics identified through screening of agricultural fungicides

Pythiosis is a life-threatening infectious disease caused by the oomycete Pythium insidiosum. Clinical manifestations of pythiosis include an eye, blood vessel, skin, or gastrointestinal tract infection. Pythiosis has been increasingly reported worldwide, with an overall mortality rate of 28%. Radical surgery is required to save patients' lives due to the limited efficacy of antimicrobial drugs. Effective medical treatments are urgently needed for pythiosis. This study aims to find anti-P. insidiosum agents by screening 17 agricultural fungicides that inhibit plant-pathogenic oomycetes and validating their efficacy and safety. Cyazofamid outperformed other fungicides as it can potently inhibit genetically diverse P. insidiosum isolates while exhibiting minimal cellular toxicities. The calculated therapeutic scores determined that the concentration of cyazofamid causing significant cellular toxicities was eight times greater than the concentration of the drug effectively inhibiting P. insidiosum. Furthermore, other studies showed that cyazofamid exhibits low-to-moderate toxicities in animals. The mechanism of cyazofamid action is likely the inhibition of cytochrome b, an essential component in ATP synthesis. Molecular docking and dynamic analyses depicted a stable binding of cyazofamid to the Qi site of the P. insidiosum's cytochrome b orthologous protein. In conclusion, our search for an effective anti-P. insidiosum drug indicated that cyazofamid is a promising candidate for treating pythiosis. With its high efficacy and low toxicity, cyazofamid is a potential chemical for treating pythiosis, reducing the need for radical surgeries, and improving recovery rates. Our findings could pave the way for the development of new and effective treatments for pythiosis.IMPORTANCEPythiosis is a severe infection caused by Pythium insidiosum. The disease is prevalent in tropical/subtropical regions. This infectious condition is challenging to treat with antifungal drugs and often requires surgical removal of the infected tissue. Pythiosis can be fatal if not treated promptly. There is a need for a new treatment that effectively inhibits P. insidiosum. This study screened 17 agricultural fungicides that target plant-pathogenic oomycetes and found that cyazofamid was the most potent in inhibiting P. insidiosum. Cyazofamid showed low toxicity to mammalian cells and high affinity to the P. insidiosum's cytochrome b, which is involved in energy production. Cyazofamid could be a promising candidate for the treatment of pythiosis, as it could reduce the need for surgery and improve the survival rate of patients. This study provides valuable insights into the biology and drug susceptibility of P. insidiosum and opens new avenues for developing effective therapies for pythiosis.

Isoliquiritigenin Inhibits Oral Squamous Cell Carcinoma and Overcomes Chemoresistance by Destruction of Survivin

The oncoprotein survivin plays a pivotal role in controlling cell division and preventing apoptosis by inhibiting caspase activation. Its significant contribution to tumorigenesis and therapeutic resistance has been well established. Isoliquiritigenin (ISL), a natural compound, has been recognized for its powerful inhibitory effects against various tumors. However, whether ISL exerts regulatory effects on survivin and its underlying mechanism in oral squamous cell carcinoma (OSCC) remains unclear. Here, we found that ISL inhibited the viability and colony formation of OSCC, and promoted their apoptosis. The immunoblotting data showed that ISL treatment significantly decreased survivin expression. Mechanistically, ISL suppressed survivin phosphorylation on Thr34 by deregulating Akt-Wee1-CDK1 signaling, which facilitated survivin for ubiquitination degradation. ISL inhibited CAL27 tumor growth and decreased p-Akt and survivin expression in vivo. Meanwhile, survivin overexpression caused cisplatin resistance of OSCC cells. ISL alone or combined with cisplatin overcame chemoresistance in OSCC cells. Overall, our results revealed that ISL exerted potent inhibitory effects via inducing Akt-dependent survivin ubiquitination in OSCC cells.

Antiradical Activity of Lignans from Cleistanthus sumatranus: Theoretical Insights into the Mechanism, Kinetics, and Solvent Effects

Sumatranus lignans (SL) isolated from Cleistanthus sumatranus have demonstrated bioactivities, e.g., they were shown to exhibit immunosuppressive properties in previous research. Their structure suggests potential antioxidant activity that has not attracted any attention thus far. Consistently, a comprehensive analysis of the antioxidant activity of these compounds is highly desirable with the view of prospective medical applications. In this work, the mechanism and kinetics of the antiradical properties of SL against hydroperoxyl radicals were studied by using calculations based on density functional theory (DFT). In the lipid medium, it was discovered that SL reacted with HOO• through the formal hydrogen transfer mechanism with a rate constant of 101-105 M-1 s-1, whereas in aqueous media, the activity primarily occurred through the sequential proton loss electron transfer mechanism with rate constants of 102-108 M-1 s-1. In both lipidic and aqueous environments, the antiradical activity of compounds 6 and 7 exceeds that of resveratrol, ascorbic acid, and Trolox. These substances are therefore predicted to be good radical scavengers in physiological environments.

Naringin Inhibits Colorectal Carcinogenesis by Inhibiting Viability of Colorectal Cancer Cells

OBJECTIVE

To explore the therapeutic effect of naringin on colorectal cancer (CRC) and the related mechanism.

METHODS

Cell counting kit-8 (CCK-8) assay and annexin V-FITC/PI assay were used to detect the effect of naringin (50-400 µg/mL) on cell proliferation and apoptosis of CRC cells, respectively. The scratch wound assay and transwell migration assay were used to assess the effect of naringin on CRC cell migration. Four-week-old male nude mice were injected with HCT116 cells subcutaneously to establish the tumor xenograft model. Naringin was injected intraperitoneally at 50 mg/(kg·d), with solvent and 5-fluorouracil treatment as control. The width and length of the tumors were measured and recorded every 6 days, and tumor tissues were photographed and weighed on the last day of the 24-d observation period. Immunohistochemical staining for caspase-3, proliferating cell nuclear antigen and TUNEL assay were used to evaluate the effect of naringin on cell proliferation and apoptosis in tumor tissues. The body weight, food and water intake of mice were recorded, and the major organs in different treatment groups were weighed on the last day and stained with hematoxylin and eosin for histological analysis. Meanwhile, the routine blood indicators were recorded.

RESULTS

CCK-8 and annexin V-FITC/PI results confirmed that naringin (100, 200, and 400 µg/mL) could inhibit proliferation and promote apoptosis. The scratch wound assay and transwell migration assay results confirmed the inhibitory activity of naringin against CRC cells migration. In vivo results demonstrated the inhibitory effect of naringin on tumor growth with good bio-compatibility.

CONCLUSION

Naringin inhibited colorectal carcinogenesis by inhibiting viability of CRC cells.

Sumatranins A-J: Lignans with Immunosuppressive Activity from Cleistanthus sumatranus

Chemical investigation of the twigs of Cleistanthus sumatranus (Phyllanthaceae) led to the isolation of 10 undescribed lignans, sumatranins A-J (1-10). Compounds 1-4 are unprecedented furopyran lignans characterized by a unique 2,3,3a,9a-tetrahydro-4H-furo[2,3-b]chromene heterotricyclic framework. Compounds 9 and 10 are rare 9'-nor-dibenzylbutane lignans. Structures were established based on analyses of spectroscopic data, X-ray crystallographic data, and experimental ECD spectra. Immunosuppressive assays revealed compounds 3 and 9 displayed moderate inhibitory effects with good selectivity indexes against LPS-induced B lymphocyte proliferation.

Dimeric oxyberberine CT4-1 targets LINC02331 to induce cytotoxicity and inhibit chemoresistance via suppressing Wnt/β-catenin signaling in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a type of cancer characterized by high recurrence rates. Overcoming chemoresistance can reduce HCC recurrence and improve patients' prognosis. This work aimed to identify HCC chemoresistance-associated long non-coding RNA (lncRNA) and find an effective drug targeting the identified lncRNA for ameliorating the chemoresistance. In this investigation, bioinformatics analysis based on The Cancer Genome Atlas revealed a new chemoresistance index and suggested LINC02331 as an HCC chemoresistance and patients' prognosis-associated lncRNA that served as an independent prognostic indicator. Moreover, LINC02331 promoted DNA damage repair, DNA replication, and epithelial-mesenchymal transition as well as attenuated cell cycle arrest and apoptosis through regulating Wnt/β-catenin signaling, thus stimulating HCC resistance to cisplatin cytotoxicity, proliferation, and metastasis. Interestingly, we developed a novel oxidative coupling approach to synthesize a dimeric oxyberberine CT4-1, which exerted superior anti-HCC activities without obvious side effects measured by in vivo mice model and could downregulate LINC02331 mice model and could downregulate LINC02331 to mitigate LINC02331-induced HCC progression by suppressing Wnt/β-catenin signaling. RNA sequencing analyses verified the involvement of CT4-1-affected differential expression genes in dysregulated pathways and processes, including Wnt, DNA damage repair, cell cycle, DNA replication, apoptosis, and cell adhesion molecules. Furthermore, CT4-1 was demonstrated to be an effective cytotoxic drug in ameliorating HCC patients' prognosis with a prediction model constructed based on RNA-sequencing data from CT4-1-treated cancer cells and public cancer database. In summary, HCC chemoresistance-associated LINC02331 independently predicted poor patients' prognosis and enhanced HCC progression by promoting resistance to cisplatin cytotoxicity, proliferation, and metastasis. Targeting LINC02331 by the dimeric oxyberberine CT4-1 that exhibited synergistic cytotoxicity with cisplatin could alleviate HCC progression and improve patients' prognosis. Our study identified LINC02331 as an alternative target and suggested CT4-1 as an effective cytotoxic drug in HCC treatment.

The chemistry and efficacy benefits of polysaccharides from Atractylodes macrocephala Koidz

Atractylodes macrocephala Koidz (AM), traditional Chinese medicine (TCM) with many medicinal values, has a long usage history in China and other oriental countries. The phytochemical investigation revealed the presence of volatile oils, polysaccharides, lactones, flavonoids, and others. The polysaccharides from AM are important medicinal components, mainly composed of glucose (Glc), galactose (Gal), rhamnose (Rha), arabinose (Ara), mannose (Man), galacturonic acid (GalA) and xylose (Xyl). It also showed valuable bioactivities, such as immunomodulatory, antitumour, gastroprotective and intestinal health-promoting, hepatoprotective, hypoglycaemic as well as other activities. At the same time, based on its special structure and pharmacological activity, it can also be used as immune adjuvant, natural plant supplement and vaccine adjuvant. The aim of this review is to summarize and critically analyze up-to-data on the chemical compositions, biological activities and applications of polysaccharide from AM based on scientific literatures in recent years.