Plant polysaccharides can increase the number and variety of beneficial bacteria in the gut and produce a variety of active substances, including short-chain fatty acids (SCFAs). Gut microbes and their specific metabolites have the effects of promoting anti-inflammatory activity, enhancing the intestinal barrier, and activating and regulating immune cells, which are beneficial for improving immunity. A strong immune system reduces inflammation caused by external viruses and other pathogens. Coronavirus disease 2019 (COVID-19) is still spreading globally, and patients with COVID-19 often have intestinal disease and weakened immune systems. This article mainly evaluates how polysaccharides in plants can improve the immune system barrier by improving the intestinal microecological balance, which may have potential in the prevention and treatment of COVID-19.

Galangin (Gal) is a natural plant flavonoid. More and more evidence shows that Gal can achieve anti-tumor effects by regulating various mechanisms. However, its poor water solubility, low bioavailability, and insufficient lesion targeting limit its clinical application. To overcome these shortcomings, we designed and developed a mesoporous nanosystem (GE11-CuS) that actively located the target area and photo-controlled drug release, which promoted the rapid accumulation of drugs in tumor tissues under NIR irradiation, thus achieving positive effects against cancer. In this study, we explored the application of the Gal-loaded nanometer system (GE11-CuS@Gal) in the treatment of oral squamous cell carcinoma (OSCC) both in vitro and in vivo. The results exhibited that GE11-CuS@Gal had excellent targeting ability and could accumulate efficiently in tumor cells (HSC-3). Meanwhile, the temperature of GE11-CuS@Gal increasing rapidly under NIR illumination damaged the integrity of the carrier and allowed Gal molecules to escape from the pores of the nanoparticles. When the accumulation of Gal in the nidus reached a certain level, the intracellular ROS level could be significantly increased and the antioxidative stress pathway mediated by Nrf2/OH-1 was effectively blocked, to inhibit the growth and migration of tumors. In conclusion, the GE11-CuS improved the antitumor activity of Gal in the body, which laid a foundation for the treatment of OSCC with traditional Chinese medicine ingredients.

Gastric cancer is a major cause of cancer-related mortality on a global scale. Although 5-fluorouracil (5-FU) is a cornerstone chemotherapeutic for digestive tract malignancies, its efficacy is limited by dose-dependent toxicity and acquired resistance. Quercetin (QUC), a natural flavonoid, can sensitize tumor cells to 5-FU by modulating cell cycle-regulatory proteins. However, its limited water solubility and low bioavailability present significant limitations on its potential therapeutic application. In this study, we developed bioinspired pH-sensitive liposomes (NK-Lip@Q) functionalized for active targeting and acid-triggered drug release to enhance QUC delivery and synergistic anticancer activity with 5-FU. NK-Lip@Q exhibited a mean particle size of 206.36 ± 1.81 nm, an encapsulation efficiency of 60.69 ± 1.32 %, and a pH-dependent release profile with 72.75 ± 0.69 % cumulative release at pH 5.4. Cellular studies demonstrated efficient uptake by N87 cells, marked apoptosis induction (apoptosis ratio: 69.60 ± 8.71 %), and enhanced cytotoxicity in combination with 5-FU (Chou-Talalay combination index, CI = 0.68). In vivo, NK-Lip@Q could precisely accumulate in the target area, when co-administered with 5-FU, achieved significant tumor inhibition (tumor inhibition rate: 92.26 %) without obvious systemic toxicity. QUC complemented the anticancer action of 5-FU by regulating cell cycle-related genes, promoting apoptosis, and suppressing proliferation. In conclusion, this study demonstrates that NK-Lip@Q as a promising nanocarrier system that enhances the therapeutic performance of 5-FU by improving its synergistic antitumor efficacy in gastric cancer.

Introduction: Psoriasis is an autoimmune disease characterized primarily by chronic inflammation, with suboptimal clinical therapeutic outcomes. Quercetin, a bio-safe plant secondary metabolite, exerts anti‐inflammatory effects by modulating multiple signaling pathways and holds promise as a therapeutic candidate for psoriasis. Methods: Our preliminary studies demonstrated that silk protein (SF) derived from silkworm cocoons exhibits excellent biocompatibility and can form hydrogels, serving as an ideal drug carrier for skin applications. We loaded quercetin into the SF hydrogel system and systematically investigated the therapeutic efficacy of this composite formulation (QSF) against imiquimod-induced psoriasis models through in vitro and in vivo experiments. Results: The hydrogel exhibited desirable enzyme-responsive properties. When exposed to an in vitro microenvironment containing 10 nM MMP‐9, the hydrogel network rapidly disintegrated, achieving a cumulative quercetin release of 58.26% ± 7.64% within 24 h. The enriched quercetin in lesion tissues markedly reduced the positive expression levels of IL‐17, TNF‐α, and IL‐1β, with inhibition rates of 32.14%, 20.25%, and 33.71%, respectively, which effectively interrupted the inflammatory cascade and obviously alleviated skin desquamation and pruritus. Discussion: Collectively, the fabricated QSF hydrogel presents anti‐inflammatory and symptomatic relief effects, providing a feasible strategy and experimental basis for the development of novel topical preparations for psoriasis treatment.