Synthesis, toxicities and bio-activities of manganese complexes with CO and H2S dual donors

Intracellular Co-Delivery of Carbon Monoxide and Nitric Oxide Induces Mitochondrial Apoptosis for Cancer Therapy

Understanding the interplay between gasotransmitters is essential for unlocking their therapeutic potential. However, achieving spatiotemporally controlled co-delivery to target cells remains a significant challenge. Herein, we propose an innovative strategy for the intracellular co-delivery of carbon monoxide (CO) and nitric oxide (NO) gasotransmitters under clinically relevant wavelengths. This approach rationally couples aerobic photooxidative and anaerobic photocatalytic reactions within a polymeric micelle platform, using palladium(II) tetraphenyltetrabenzoporphyrin (PdTPTBP) as both photosensitizer and photocatalyst. Notably, the photooxidation-mediated release of CO generates a local hypoxic microenvironment, which facilitates the photoredox catalyzed release of NO. This self-adaptive micelle platform enables efficient uptake by tumor cells and intracellular co-delivery of CO and NO under 630 nm light irradiation, demonstrating potent anti-tumor activity in a 4T1 tumor-bearing mouse model via the synergistic induction of mitochondrial apoptosis.

Codelivery of Gaseous Signaling Molecules for Biomedical Applications

Gaseous signaling molecules (GSMs) including nitric oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H2S) have presented excellent therapeutic efficacy such as anti-inflammatory, anti-microbial and anti-cancer effects and multiple biomedical applications in recent years. As the three most vital signaling molecules in human physiology, these three GSMs show so intertwined and orchestrated interactions that the synergy of multiple gases may demonstrate a more complex therapeutic potential than single gas delivery. Consequently, researchers have been devoted to developing codelivery systems of GSMs by synthesizing a single molecule as a dual donor to maximize the gaseous therapeutic efficacy. In this minireview, we summarize the recent developments of molecules or materials enabling codelivery of GSMs for biomedical applications. It appears that compared with the abundant cases of codelivery of NO and H2S, research on codelivery of CO and the other two GSMs separately remains to be explored.

A Single-Component Dual Donor Enables Ultrasound-Triggered Co-release of Carbon Monoxide and Hydrogen Sulfide

The development of dual gasotransmitter donors can not only provide robust tools to investigate their subtle interplay under pathophysiological conditions but also optimize therapeutic efficacy. While conventional strategies are heavily dependent on multicomponent donors, we herein report an ultrasound-responsive water-soluble copolymer (PSHF) capable of releasing carbon monoxide (CO) and hydrogen sulfide (H2 S) based on single-component sulfur-substituted 3-hydroxyflavone (SHF) derivatives. Interestingly, sulfur substitution can not only greatly improve the ultrasound sensitivity but also enable the co-release of CO/H2 S under mild ultrasound irradiation. The co-release of CO/H2 S gasotransmitters exerts a bactericidal effect against Staphylococcus aureus and demonstrates anti-inflammatory activity in lipopolysaccharide-challenged macrophages. Moreover, the excellent tissue penetration of ultrasound irradiation enables the local release of CO/H2 S in the joints of septic arthritis rats, exhibiting superior therapeutic efficacy without the need for any antibiotics.

Hydrogen sulfide: Recent development of its dual donors and hybrid drugs

Hydrogen sulfide (H2 S) is an important gaseous signalling molecule known to be critically involved in regulating cellular redox homeostasis. As the beneficial and therapeutic effects of H2 S in pathophysiology, such as in cardiovascular and neurodegenerative diseases, have emerged, so too has the drive for the development of H2 S-releasing compounds (aka donors) and their therapeutic applications. Most reported donor compounds singularly release H2 S through biocompatible triggers. An emerging area in the field is the development of compounds that can co-deliver H2 S with other drugs or biologically relevant species, such as reactive oxygen and nitrogen species (ROS and RNS, respectively). These H2 S-based dual donors and hybrid drugs are expected to offset negative side effects from individual treatments or achieve synergistic effects rendering them more clinically effective. Additionally, considering that molecules exist and interact physiologically, dual donors may more accurately mimic biological systems as compared to single donors and allow for the elucidation of fundamental chemistry and biology. This review focuses on the recent advances in the development of H2 S-based dual donors and hybrid drugs along with their design principles and synergistic effects.

Hydrogen sulfide donating ent-kaurane and spirolactone-type 6,7-seco-ent-kaurane derivatives: Design, synthesis and antiproliferative properties

Motivated by our interest in hydrogen sulfide bio-chemistry and ent-kaurane diterpenoid chemistry, 14 hydrogen sulfide donating derivatives (9, 11a-c, 12a-c, 13, 14, 16a-c and 17a-b) of ent-kaurane and spirolactone-type 6,7-seco-ent-kaurane were designed and synthesized. Four human cancer cell lines (K562, Bel-7402, SGC-7901 and A549) and two normal cell lines (L-02 and PBMC) were selected for antiproliferative assay. Most derivatives showed more potent activities than the lead ent-kaurane oridonin. Among them, compound 12b exhibited the most potent antiproliferative activities, with IC₅₀ values of 1.01, 0.88, 4.36 and 5.21 μM against above human cancer cell lines, respectively. Further apoptosis-related mechanism study indicated that 12b could arrest Bel-7402 cell cycle at G1 phase and induce apoptosis through mitochondria related pathway. Through Western blot assay, 12b was shown to influence the intrinsic pathway by increasing the expression of Bax, cleaved caspase-3, cytochrome c and cleaved PARP, meanwhile suppressing procaspase-3, Bcl-2, Bcl-xL and PARP.

Toxicities and beneficial protection of H2S donors based on nonsteroidal anti-inflammatory drugs

On the basis of our previous study, the H₂S donors based on nonsteroidal anti-inflammatory drugs (NSAIDs) were further evaluated with regard to the following aspects: animal blood and urine analyses, liver and kidney toxicities, gastrointestinal protection, anti-hypertension, and myocardial protection. The test results showed that after the successive administration of the compound for 14 days, the number of white blood cells in the blood of rats reduced, and protein and leukocytes appeared in urine; further, α-lipoic-acid-acetaminophen ester (1) and ibuprofen-ADTOH ester (2) had a certain effect on the physiological tissue and function of rat liver, and their side-effects on the kidneys were obvious. However, when compared with NSAIDs as the precursors, the tested compounds displayed much fewer side-effects; particularly, for the gastrointestinal mucosa of rats, there were hardly any side-effects. Moreover, all the three compounds decreased blood pressures in spontaneously hypertensive rats in a concentration-dependent manner, even though this antihypertensive effect was weaker than those induced by nifedipine and captopril. In addition, three compounds protected H9c2 cells from injury via an antioxidation pathway; and they improved myocardial injury in spontaneously hypertensive rats. Compound 2 is the derivative of ibuprofen and has lower toxicity to rat cardiomyocytes than ibuprofen. Therefore, it may become a better substitute of ibuprofen in patients due to its lower cardiotoxicity.