Tanshinone I: Pharmacological activities, molecular mechanisms against diseases and future perspectives

Dihydrotanshinone I inhibits gallbladder cancer growth by targeting the Keap1-Nrf2 signaling pathway and Nrf2 phosphorylation

BACKGROUND

Gallbladder cancer (GBC) poses a significant risk to human health. Its development is influenced by numerous factors, particularly the homeostasis of reactive oxygen species (ROS) within cells. This homeostasis is crucial for tumor cell survival, and abnormal regulation of ROS is associated with the occurrence and progression of many cancers. Dihydrotanshinone I (DHT I), a biologically effective ingredient isolated from Salvia miltiorrhiza, has exhibited cytotoxic properties against various tumor cells by inducing apoptosis. However, the precise molecular mechanisms by which dht I exerts its cytotoxic effects remain unclear.

PURPOSE

To explore the anti-tumor impact of dht I on GBC and elucidate the potential molecular mechanisms.

METHODS

The proliferation of GBC cells, NOZ and SGC-996, was assessed using various assays, including CCK-8 assay, colony formation assay and EdU staining. We also examined cell apoptosis, cell cycle progression, ROS levels, and alterations in mitochondrial membrane potential to delve into the intricate molecular mechanism. Quantitative PCR (qPCR), immunofluorescence staining, and Western blotting were performed to evaluate target gene expression at both the mRNA and protein levels. The correlation between nuclear factor erythroid 2-related factor 2 (Nrf2) and kelch-like ECH-associated protein 1 (Keap1) were examined using co-immunoprecipitation. Finally, the in vivo effect of dht I was investigated using a xenograft model of gallbladder cancer in mice.

RESULTS

Our research findings indicated that dht I exerted cytotoxic effects on GBC cells, including inhibiting proliferation, disrupting mitochondrial membrane potential, inducing oxidative stress and apoptosis. Our in vivo studies substantiated the inhibition of dht I on tumor growth in xenograft nude mice. Mechanistically, dht I primarily targeted Nrf2 by promoting Keap1 mediated Nrf2 degradation and inhibiting protein kinase C (PKC) induced Nrf2 phosphorylation. This leads to the suppression of Nrf2 nuclear translocation and reduction of its target gene expression. Moreover, Nrf2 overexpression effectively counteracted the anti-tumor effects of dht I, while Nrf2 knockdown significantly enhanced the inhibitory effect of dht I on GBC. Meanwhile, PKC inhibitors and nuclear import inhibitors increased the sensitivity of GBC cells to dht I treatment. Conversely, Nrf2 activators, proteasome inhibitors, antioxidants and PKC activators all antagonized dht I induced apoptosis and ROS generation in NOZ and SGC-996 cells.

CONCLUSION

Our findings indicated that dht I inhibited the growth of GBC cells by regulating the Keap1-Nrf2 signaling pathway and Nrf2 phosphorylation. These insights provide a strong rationale for further investigation of dht I as a potential therapeutic agent for GBC treatment.

Cryptotanshinone-Induced Permeabilization of Model Phospholipid Membranes: A Biophysical Study

The Danshen terpenoid cryptotanshinone (CPT) is gaining enormous interest in light of its various outstanding biological activities. Among those, CPT has been shown to interact with cell membranes and, for instance, to have antibacterial activity. Several works have shown that CPT alone, or in combination with other drugs, can effectively act as an antibiotic against various infectious bacteria. Some authors have related the mechanism underlying this action to CPT-membrane interaction. This work shows that CPT readily partitions into phosphatidylcholine membranes, but there is a limiting capacity of accommodation of ca. 1 mol CPT to 3 mol phospholipid. The addition of CPT to unilamellar liposomes composed of 1-palmitoyl-2-oleoylphosphatidylcholine (POPC) causes membrane permeabilization, as shown by fluorescent probe leakage. This process has been kinetically studied, as well as its modulation by incorporation of phosphatidylethanolamine or phosphatidylglycerol, as a model for pathogenic cell membranes. The thermotropic behavior of 1,2-dimyristoylphosphatidylcholine (DMPC) model membranes is weakly affected by CPT, but the terpenoid causes significant dehydration of the polar region of the bilayer and weak disordering of the acyl chain palisade, as observed in Fourier-transform infrared spectroscopy (FTIR) results. Small-angle X-ray scattering (SAXS) shows that CPT increases DMPC bilayer thickness, which could be due to localization near the phospholipid/water interface. Molecular dynamics (MD) simulations show that the lateral diffusion coefficient of the phospholipid increases with the presence of CPT. CPT extends from the polar head region to the center of the bilayer, being centered between the carbonyl groups and the unsaturated region of the POPC, where there is greater overlap. Interestingly, the free energy profiles of a water molecule crossing the lipid membrane show that the POPC membrane becomes more permeable in the presence of CPT. In summary, our results show that CPT perturbs the physicochemical properties of the phospholipid membrane and compromises its barrier function, which could be of relevance to explain part of its antimicrobial or anticancer activities.

Role and molecular mechanism of Salvia miltiorrhiza associated with chemical compounds in the treatment of diabetes mellitus and its complications: A review

Diabetes mellitus (DM) is one of the most prevalent diseases worldwide, greatly impacting patients' quality of life. This article reviews the progress in Salvia miltiorrhiza, an ancient Chinese plant, for the treatment of DM and its associated complications. Extensive studies have been conducted on the chemical composition and pharmacological effects of S miltiorrhiza, including its anti-inflammatory and antioxidant activities. It has demonstrated potential in preventing and treating diabetes and its consequences by improving peripheral nerve function and increasing retinal thickness in diabetic individuals. Moreover, S miltiorrhiza has shown effectiveness when used in conjunction with angiotensin-converting enzyme inhibitors, angiotensin receptor blockers (ARBs), and statins. The safety and tolerability of S miltiorrhiza have also been thoroughly investigated. Despite the established benefits of managing DM and its complications, further research is needed to determine appropriate usage, dosage, long-term health benefits, and safety.

Dihydrotanshinone I-Induced CYP1 Enzyme Inhibition and Alteration of Estradiol Metabolism

Dihydrotanshinone I (DHTI) is a pharmacologically active component occurring in the roots of the herbal medicine Salvia miltiorrhiza Bunge. This study investigated DHTI-induced inhibition of CYP1A1, CYP1A2, and CYP1B1 with the aim to determine the potential effects of DHTI on the bioactivation of estradiol (E2), possibly related to preventive/therapeutic strategy for E2-associated breast cancer. Ethoxyresorufin as a specific substrate for CYP1s was incubated with human recombinant CYP1A1, CYP1A2, or CYP1B1 in the presence of DHTI at various concentrations. Enzymatic inhibition and kinetic behaviors were examined by monitoring the formation of the corresponding product. Molecular docking was further conducted to define the interactions between DHTI and the three CYP1s. The same method and procedure were employed to examine the DHTI-induced alteration of E2 metabolism. DHTI showed significant inhibition of ethoxyresorufin O-deethylation activity catalyzed by CYP1A1, CYP1A2 and CYP1B1 in a concentration-dependent manner (IC50 = 0.56, 0.44, and 0.11 μM, respectively). Kinetic analysis showed that DHTI acted as a competitive type of inhibitor of CYP1A1 and CYP1B1, whereas it noncompetitively inhibited CYP1A2. The observed enzyme inhibition was independent of NADPH and time. Molecular docking analysis revealed hydrogen bonding interactions between DHTI and Asp-326 of CYP1B1. Moreover, DHTI displayed preferential activity to inhibit 4-hydroxylation of E2 (a genotoxic pathway) mediated by CYP1B1. Exposure to DHTI could reduce the risk of genotoxicity induced by E2. SIGNIFICANCE STATEMENT: CYP1A1, CYP1A2, and CYP1B1 enzymes are involved in the conversion of estradiol (E2) into 2-hydroxyestradiol (2-OHE2) and 4-hydroxyestradiol (4-OHE2) through oxidation. 2-OHE2 is negatively correlated with breast cancer risk, and 4-OHE2 may be a significant initiator and promoter of breast cancer. The present study revealed that dihydrotanshinone I (DHTI) competitively inhibits CYP1A1/CYP1B1 and noncompetitively inhibits CYP1A2. DHTI exhibits a preference for inhibiting the genotoxicity associated with E2 4-hydroxylation pathway mediated by CYP1B1, potentially reducing the risk of 4-OHE2-induced genotoxicity.

Tanshinone-IIA mediated neuroprotection by modulating neuronal pathways

The progression of neurological diseases is mainly attributed to oxidative stress, apoptosis, inflammation, and trauma, making them a primary public concern. Since no drugs can stop these neurological disorders from happening, active phytochemical intervention has been suggested as a possible treatment. Among the several phytochemicals being studied for their potential health advantages, tanshinone-IIA (Tan-IIA ) stands out due to its wide range of therapeutic effects. Tan-IIA, derived from the Salvia miltiorrhiza plant, is a phenanthrenequinone. The pharmacological characteristics of Tan-IIAagainst various neurodegenerative and neuropsychiatric illnesses have led researchers to believe that the compound possesses neuroprotective potential. Tan-IIA has therapeutic potential in treating neurological diseases due to its capacity to cross the blood-brain barrier and its broad range of activities. In treating neurological disorders, Tan-IIA has been shown to have neuroprotective effects such as anti-apoptotic, anti-inflammatory, BBB protectant, and antioxidant properties. This article concisely summarises the latest scientific findings about the cellular and molecular aspects of Tan-IIA neuroprotection in relation to various neurological diseases. The results of preclinical studies on Tan-IIA provide insight into its potential application in future therapeutic development. This molecule rapidly establishes as a prominent bioactive compound for clinical research.

Rosmarinus officinalis and Skin: Antioxidant Activity and Possible Therapeutical Role in Cutaneous Diseases

The rosemary plant, Rosmarinus officinalis L., one of the main members of the Lamiaceae family, is currently one of the most promising herbal medicines due to its pharmaceutical properties. This research aimed to evaluate the antioxidant role of Rosmarinus officinalis and its bioactive compounds on the skin, with a focus on the newly emerging molecular mechanisms involved, providing extensive scientific evidence of its anti-inflammatory, antimicrobial, wound-healing and anticancer activity in dermatological practice. The search was conducted on articles concerning in vitro and in vivo studies in both animals and humans. The results obtained confirm the antioxidant role of R. officinalis. This assumption derives the possibility of using R. officinalis or its bioactive elements for the treatment of inflammatory and infectious skin pathologies. However, although the use of rosemary in the treatment of skin diseases represents a fascinating line of research, future perspectives still require large and controlled clinical trials in order to definitively elucidate the real impact of this plant and its components in clinical practice.