Immunoregulatory Activity of Herbal Tea-Derived Carbon Dots

Abstract

The activation of immune cells by immunoregulatory active substances can improve the body immunity. Carbon dots (CDs) with immunoregulatory activity are rarely reported. In this study, transmission electron microscopy results demonstrate the existence of CDs in herbal tea, while Fourier transform infrared and X-ray photoelectron spectroscopy results suggest the participation of polyphenol in herbal tea CD (H-CD) formation. The photoluminescence spectrum has shown that H-CDs have fluorescence emission at 565 nm and exhibit an excitation-dependent property. The toxicity and immunostimulatory activity of H-CDs on mouse macrophage RAW264.7 suggested that H-CDs had no toxicity to RAW264.7 cells. Meanwhile, compared with herbal tea, H-CDs have more obvious effect of promoting the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase. In addition, the secretion of nitric oxide (NO) was promoted by H-CDs. This work suggests that H-CDs have stronger immunoregulatory function than that of original herbal tea, which provides a direction for the application of phenolic hydroxyl-modified CDs in the biomedical field.

Multifunctional Carbon Dots for Biomedical Applications: Diagnosis, Therapy, and Theranostic

“…Similarly, aspirin-based CDs retained the antiinflammatory effect of aspirin and even played a better performance than aspirin alone, CDs synthesized from exhibited remarkable antiviral activity, and Fu et al derived CDs with immunoregulatory activity from herbal tea. [176][177][178] These provide a new perspective: drugs can be used as synthetic precursors when designing CDs, allowing the synthetic nanoparticles to inherit the therapeutic functions of the precursors after the harsh synthesis process of high-temperature or high-pressure treatment. This will significantly broaden the use of CDs in disease treatment.…”

Dual-Responsive Cu(I) and Cu(II) Co-Doped Carbon Dots for Synergistic Chemodynamic-Photothermal Antitumor Therapy

“…As a kind of zero-dimensional nanomaterials, carbon dots (CDs) have recently made significant progress in cancer treatment due to high stability (the graphitized conjugated sp2 covalent carbon core) and good modifiability (rich functional groups on the surface). , Moreover, almost all carbon-containing substances can be used as precursors to prepare CDs, and some inherent characteristics of precursors could be retained. − …”

Resveratrol Carbon Dots Disrupt Mitochondrial Function in Cancer Cells

“…It was reported, for example, that C-dots derived from herbal tea polyphenols were more immunogenic relative to the individual molecules employed in the synthesis. 33 Similarly, C-dots synthesized from aspirin as the carbon source exhibited greater anti-inflammatory properties compared to aspirin alone. 34 Here, we show that C-dots synthesized from resveratrol as the sole carbon source target cancer cells, significantly reducing their viability and, importantly, disrupting their mitochondrial functionalities.…”

“…Furthermore, a notable feature ascribed to the display of bioactive residues on C-dots’ surfaces is the observation that C-dots exhibits greater biological activity compared to the molecular precursors. It was reported, for example, that C-dots derived from herbal tea polyphenols were more immunogenic relative to the individual molecules employed in the synthesis . Similarly, C-dots synthesized from aspirin as the carbon source exhibited greater anti-inflammatory properties compared to aspirin alone …”