Selenium-loaded cellulose film derived from Styela clava tunic accelerates the healing process of cutaneous wounds in streptozotocin-induced diabetic Sprague-Dawley rats

PURPOSE

Aims of this study is to evaluate the therapeutic effects and toxicity of Se-loaded cellulose film originated from Styela clava tunic (SeSCTF) on cutaneous wounds during diabetic conditions.

MATERIALS AND METHODS

Alterations in skin regeneration, angiogenesis and toxicity were examined using streptozotocine (STZ)-induced diabetic Sprague Dawley^® (SD) rats with surgical skin wounds after application of SeSCTF for 12 days.

RESULTS

SCTF showed high tensile strength (1.64 MPa), low elongation (28.59%), low water vapor transmission rate (WVTR) and outstanding porous structure. Although SeSCTF application did not induce any significant alterations in glucose concentration or toxicity, wound morphology was rapidly recovered in the SeSCTF treated group relative to the gauze (GZ) and SCTF treated group. Moreover, recovery of re-epithelization, wound contraction and number of blood vessel was observed in SeSCTF treated groups when compared with all other groups. Furthermore, the SeSCTF treated group showed complete recovery of key protein expressions of the downstream signaling pathway of vascular endothelial growth factor (VEGF), angiopoietin-2/1 (Ang-2/1), the signaling pathway of insulin receptors and anti-oxidative status.

CONCLUSIONS

Overall, the results of this study suggest that SeSCTF accelerates the healing process of cutaneous wounds in STZ-induced diabetic SD rats through stimulation of angiogenesis and the glucose receptor signaling pathway.

Ethanol extracts collected from the Styela clava tunic alleviate hepatic injury induced by carbon tetrachloride (CCl4) through inhibition of hepatic apoptosis, inflammation, and fibrosis

The Styela clava tunic (SCT) is known as a good raw material for preparing anti-inflammatory compounds, wound healing films, guided bone regeneration, and food additives. To investigate whether ethanol extracts of the SCT (EtSCT) could protect against hepatic injury induced by carbon tetrachloride (CCl₄) in ICR mice, alterations in serum biochemical indicators, histopathology, hepatic apoptosis, inflammation, and fibrosis were observed in ICR mice pretreated with EtSCT for 5 days before CCl₄ injection. EtSCT contained 15.6 mg/g of flavonoid and 37.5 mg/g phenolic contents with high 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (93.3%) and metal chelation activity (46.5%). The EtSCT+CCl₄-treated groups showed decreased levels of ALT, LDH, and AST, indicating toxicity and a necrotic area in the liver, while the level of ALP remained constant. The formation of active caspase-3 and enhancement of Bax/Bcl-2 expression was effectively inhibited in the EtSCT+CCl₄-treated groups. Furthermore, the levels of pro- and anti-inflammatory cytokines and the phosphorylation of p38 in the TNF-α downstream signaling pathway rapidly recovered in the EtSCT+CCl₄-treated groups. The EtSCT+CCl₄-treated groups showed a significant decrease in hepatic fibrosis markers including collagen accumulation, MMP-2 expression, TGF-β1 concentration, and phosphorylation of Smad2/3. Moreover, a significant decline in malondialdehyde (MDA) concentration and enhancement of superoxide dismutase (SOD) expression were observed in the EtSCT+CCl₄-treated groups. Taken together, these results indicate that EtSCT can protect against hepatic injury induced by CCl₄-derived reactive intermediates through the suppression of hepatic apoptosis, inflammation, and fibrosis.

Toxicity of antioxidative extract collected from Styela clava tunics in ICR mice

Some polymers and bioactive compounds derived from Styela clava tunic (SCT) have been reported as traditional medicine for the treatment of inflammation, oxidative stress and surgical wounds although there is little scientific evidence of their liver and kidney toxicity. To investigate the toxicity of ethanol extracts of SCT (EtSCT) in the liver and kidney of ICR mice, alterations in related markers including body weight, organ weight, urine composition, liver pathology and kidney pathology were analyzed following oral administration of 50 and 100 mg/kg body weight/day of EtSCT for 14 days. EtSCT showed a high level of free radical scavenging activity for DPPH (93.1%) and NO (16.2%) as well as the presence of 14.8 mg/mL of flavonoids and 36.2 mg/mL of phenolics, while EtSCT treated groups did not show any significant alterations in the body and organ weight, clinical phenotypes, urine parameters or mice mortality when compared with the vehicle treated group. In addition, constant levels of serum biochemical markers including alanine phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN) and serum creatinine (CRE) were maintained. Moreover, no specific histopathological features induced by most toxic compounds were observed in liver and kidney sections stained with hematoxilin and eosin. Therefore, the present results indicate that EtSCT with strong antioxidant activity cannot induce any specific toxicity in liver and kidney organs of ICR at doses of 100 mg/kg body weight/day.