Evaluation of prophylactic and therapeutic effects of ruscogenin on acute radiation proctitis: an experimental rat model

Efficacy and mechanism of action of ginsenoside Rg3 on radiation proctitis in rats

OBJECTIVE

Radiation proctitis (RP) refers to rectal injury caused by radiation treatment of pelvic and retroperitoneal malignancies, which has a major impact on the treatment prognosis and quality of life of patients with cancer. The tetracyclic triterpene saponin monomer ginsenoside Rg3 (GRg3), the primary bioactive ingredient in ginseng extracts, has therapeutic effects against RP in rats. Here, we validated its efficacy and elucidated its mechanism of action.

METHODS

A rat RP model was established in 48 Wistar rats. Rats were randomly divided into control (untreated), irradiation, irradiation + dexamethasone, and irradiation + GRg3 (low-, medium-, and high-dose) groups. After 2 weeks' treatment, serum IL-4, IL-10, and TNF-α levels were tested by enzyme-linked immunosorbent assays. In rectal tissue, Ikbkb, Ikka, and Casp8 mRNA expression was detected by a reverse transcription-quantitative polymerase chain reaction. IKK-β, IκB-α, p-IκB-α, p50, and caspase-8 protein levels were determined by western blot analysis.

RESULTS

GRg3 significantly improved the general condition and histopathological damage in rats with RP. Moreover, GRg3 decreased the levels of factors that promote inflammation (TNF-α) and increased the levels of factors that reduce inflammation (IL-4 and IL-10). GRg3 markedly reduced the activation of NF-κB and caspase-8 signaling pathways.

CONCLUSIONS

Thus, GRg3 may reduce the inflammatory response by blocking the NF-κB signaling pathway and improving the balance of inflammation-related factors. GRg3 may also inhibit intestinal cell apoptosis by suppressing the TNF-α/caspase-8 signaling cascade, thereby reducing radiological rectal injury. Our results verify that GRg3 is a promising therapeutic agent for RP treatment and shed light on its mechanism.

Ruscogenin ameliorates dasatinib-induced intestinal barrier dysfunction via ErbB4/YAP and ROCK/MLC pathways

Dasatinib is effective in the treatment of chronic and acute myeloid leukemia, which could cause the side effect of gastrointestinal bleeding by overdose or longtime use. Ruscogenin (RUS) from the traditional Chinese medicine Ophiopogon japonicas could protect endothelial microvascular barrier function. In this study, the therapeutic effect and underlying mechanisms of RUS were investigated on intestinal barrier dysfunction induced by dasatinib. Male C57BL/6 J mice were given three doses of dasatinib (70, 140, 210 mg/kg, ig) and RUS (3, 10, 30 μg/kg, ip) to explore the effect of dasatinib on intestinal barrier and the intervention of RUS. It was proved that dasatinib could reduce intestinal blood flow, inhibit phosphorylation of EGFR family member v-erb-b2 avian erythroblastic leukemia viral oncogene homolog 4 (ErbB4)/YES-associated protein (YAP) and activation of Rho-associated coiled coil-containing protein kinase (ROCK)/phosphorylation of (myosin light chain) MLC. RUS could significantly increase intestinal blood flow, improve intestinal injury, reduce Evans blue leakage and serum content of FITC-dextran 4 kDa, and increase the expression of connexin (ZO-1, Occludin and VE-cadherin). Meanwhile, the in vitro effect of RUS (0.01, 0.1, 1 μM) on the dysfunction of the endothelial barrier was observed in dasatinib (150 nM)-pretreated HUVECs. The results showed that RUS suppressed dasatinib-induced the leakage of Evans blue, and degradation of F-actin and connexin. Furthermore, RUS could significantly increase the phosphorylation of ErbB4 at Tyr1284 site and YAP at Ser397 site, and inhibit ROCK expression and phosphorylation of MLC at Ser19 site in vivo and in vitro. In conclusion, the present research proved that RUS could suppress the side effects of dasatinib-induced intestinal barrier dysfunction by regulating ErbB4/YAP and ROCK/MLC pathways.

Ruscogenin Prevents Folic Acid-Induced Acute Kidney Damage by Inhibiting Rev-erbα/β-Mediated Ferroptosis

To investigate the pharmacodynamic effects of ruscogenin on acute kidney injury and the Rev-erbα/β regulation of ferroptosis intervention mechanism. The C57BL-6 mice were induced acute kidney injury with folic acid. Plasma, urine, and kidney samples were collected after intraperitoneal injection of ruscogenin (0.01, 0.1, and 1 mg/kg). We measured mouse kidney function indicators, including creatinine (CRE), blood urea nitrogen (BUN), N-acetyl-β-D-glucosidase (NAG), albumin, albumin and creatinine rate (ACR), renal index, and renal injury molecule-1 expression. Meanwhile, we detected the levels of ferroptosis indicators malondialdehyde (MDA), carbonylated proteins, iron ions, glutathione peroxidase 4 (GPX-4), and glutathione (GSH). The expression of solute carrier family 7 member 11 (Slc7a11), heme oxygenase-1 (HO-1), and Rev-erbα/β were detected by the Western blot and quantitative reverse transcription polymerase chain reaction (qRT-PCR), respectively. Ruscogenin (1 mg/kg) significantly reduced the index of folic acid-induced acute kidney injury and alleviated acute kidney injury. In kidney tissues, ruscogenin inhibited folic acid-induced Rev-erbα/β expression, restored HO-1 and SLC7A11 expression to normal levels, and alleviated ferroptosis. Ruscogenin ameliorates acute kidney injury via suppressing ferroptosis in kidney tissues through modulation of the Rev-erbα/β-SLC7A11/HO-1 pathway.

Activity of Experimental Mouthwashes and Gels Containing DNA-RNA and Bioactive Molecules against the Oxidative Stress of Oral Soft Tissues: The Importance of Formulations. A Bioreactor-Based Reconstituted Human Oral Epithelium Model

BACKGROUND

DNA-RNA compounds have shown promising protection against cell oxidative stress. This study aimed to assess the cytotoxicity, protective, or preventive effect of different experimental formulations on oral epithelia's oxidative stress in vitro.

METHODS

Reconstituted human oral epithelia (RHOE) were grown air-lifted in a continuous-flow bioreactor. Mouthwashes and gels containing DNA-RNA compounds and other bioactive molecules were tested on a model of oxidative stress generated by hydrogen peroxide treatment. Epithelia viability was evaluated using a biochemical MTT-based assay and confocal microscopy; structural and ultrastructural morphology was evaluated by light microscopy and TEM.

RESULTS

DNA-RNA showed non-cytotoxic activity and effectively protected against oxidative stress, but did not help in its prevention. Gel formulations did not express adequate activity compared to the mouthwashes. Excipients played a fundamental role in enhancing or even decreasing the bioactive molecules' effect.

CONCLUSION

A mouthwash formulation with hydrolyzed DNA-RNA effectively protected against oxidative stress without additional enhancement by other bioactive molecules. Active compounds, such as hyaluronic acid, β-Glucan, allantoin, bisabolol, ruscogenin, and essential oils, showed a protective effect against oxidative stress, which was not synergistic with the one of DNA-RNA. Incorporation of surfactant agents showed a reduced, yet significant, cytotoxic effect.