Evaluation of radioprotective effect of vitamin E in salivary dysfunction in irradiated rats

Vitamin E ameliorates oral mucositis in gamma-irradiated rats (an in vivo study)

BACKGROUND

Radiation therapy is the primary treatment for neck and head cancer patients; however, it causes the development of oral mucositis accompanied by tissue structure destruction and functional alteration. This study was conducted to evaluate the effect of different doses of vitamin E as a treatment for radiationinduced oral mucositis in rat model.

METHODS

35 male albino rats were randomly divided into five groups: control, untreated radiation mucositis (single dose of 20 Gy), treated radiation mucositis; radiation (single dose of 20 Gy) then vitamin E at doses of 300, 360 and 500 mg/Kg for seven days started 24 h after irradiation. Body weight and food intake were evaluated for each rat. The mucositis score was assessed every day. Rats were sacrificed once at the end of the experiment, and tongue specimens were stained with hematoxylin and eosin, anti P53 and anti Ki67 antibodies.

RESULTS

Results indicated more food intake and less weight reduction in vitamin E treated groups and the contrary for gamma-irradiated group. Additionally, vitamin E delayed the onset and decreased the severity and duration of mucositis. It also restored the histological structure of lingual tongue papillae. Vitamin E treated groups showed a significant higher Ki67 and lower P53 expression as compared to untreated radiation group. The overall improvement increased as vitamin E dose increased. Finally, the amelioration can be attributed to the decreased apoptosis and increased proliferation of cells.

CONCLUSIONS

Vitamin E especially at dose of 500 mg/Kg could be an effective treatment for radiation-induced oral mucositis.

Vitamins and Radioprotective Effect: A Review

The radioprotective effect ex vivo, in vitro and in vivo of vitamins was reviewed using PubMed and Embase and conducted according to the PRISMA statement. A total of 38 articles were included in this review, which includes the radioprotective effect of vitamins from ex vivo, in vitro and in vivo studies. Vitamins A, C, D and E were used alone, in combination or with other nutritional and non-nutritional compounds. The use of vitamins in natural form or supplementation can be useful to reduce the radiation effect in the body, organs and/or cells. Only four (A, C, D and E) out of thirteen vitamins have been detected with radioprotective properties being mainly vitamin E followed by vitamin C, A and D.

In-vivo and in vitro assessments of the radioprotective potential natural and chemical compounds: a review

PURPOSE

The study of the radioactive role of natural and chemical substances on human and animal studies has been the subject of research by some researchers. Therefore, the review of some of the past and current studies conducted in this field, can provide helpful information to elucidate of the importance of radioprotective components in reducing radiation exposure side effects.

METHODS

The authors search for keywords including In vitro, In vivo, Radioprotective, Ionizing radiation, and Vitamin in ScienceDirect, Scopus, Pubmed, and Google Scholar databases to access previously published articles and search for more reference articles on the role of radioprotective materials from natural and chemical compounds.

RESULTS

Radiation exposure can produce reactive oxygen species (ROS) in the body, however most of which are eliminated by the body's natural mechanisms, but when the body's antioxidant systems do not have enough ability to neutralize free radicals, oxidative stress occurs, which causes damage to DNA and body tissues. Therefore, it is necessary use of alternative substances that reduce and inhibit free radicals.

CONCLUSION

In general, recommended that antioxidant component(s) can be protect tissue damages in humans or animals, due to the their ability to scavenge free radicals generated by ionizing radiation.

Effect of vitamin E and supragingival scaling on salivary gland function in patients with differentiated thyroid cancer treated with 131I

OBJECTIVE

The aim of this study was to evaluate the effect of vitamin E and supragingival scaling with vitamin C on the salivary glands of patients with differentiated thyroid carcinoma after 131I treatment.

METHODS

A total of 89 prospective patients with differentiated thyroid carcinoma were enrolled and randomly divided into the following groups: vitamin E group (n = 30, group A), vitamin C group (n = 30, group B) and supragingival scaling with vitamin C group (n = 29, group C). Using functional indices (e.g. maximum uptake fraction, uptake index, excretion fraction, secretion time and excretion rate), changes in the salivary gland functions before and a month after 131I treatment were assessed by dynamic imaging of salivary gland.

RESULTS

We compared the before and after 131I therapy results of the three groups. In group A (P  < 0.05), the excretion fraction and excretion rate of the left parotid gland were significantly higher, and the uptake index of the bilateral submandibular glands was significantly lower. No significant changes in salivary gland functional parameters were observed in group B (P > 0.05). The uptake index of the bilateral parotid glands and the excretion rate of the left parotid gland were significantly higher in group C (P < 0.05). The degree of serum amylase level reduction decreased significantly in group C (P < 0.05).

CONCLUSION

Vitamin E showed a protective effect on parotid excretion function in patients with differentiated thyroid carcinoma who underwent 131I treatment. Supragingival scaling may be a promising radiation protector because it is associated with a protective effect on the salivary gland functions.

Salivary parameters alterations after early exposure to environmental methylmercury: A preclinical study in offspring rats

BACKGROUND

Methylmercury (MeHg) is still considered a global pollutant of major concern; thus, it becomes relevant to investigate and validate alternative diagnostic methods to track early-life human exposure. This study aimed to evaluate the salivary parameters and to characterize potential mechanisms of oxidative damage on the salivary glands (SG) of offspring rats after pre- and postnatal environmental-experimental MeHg exposure.

METHODS

Pregnant Wistar rats were daily exposed to 40 μg/kg MeHg during both gestational and lactation periods. Then, the saliva of offspring rats was analyzed in terms of flow rate, amylase activity, and total protein concentration. The SG of the offspring rats were dissected to perform the oxidative biochemistry analyses of antioxidant capacity against peroxyl radicals (ACAP), lipid peroxidation (LPO), and nitrite levels.

RESULTS

Exposure to MeHg significantly decreased the ACAP, increased LPO and nitrite levels, decreased salivary flow rate, amylase activity, and total protein concentration.

CONCLUSION

Saliva analyses can predict damages induced by early-life MeHg exposure and may be used as an auxiliary diagnostic method.

Rational Design of Nanomaterials for Various Radiation-Induced Diseases Prevention and Treatment

Radiation treatments often unfavorably damage neighboring healthy organs and cause a series of radiation sequelae, such as radiation-induced hematopoietic system diseases, radiation-induced gastrointestinal diseases, radiation-induced lung diseases, and radiation-induced skin diseases. Recently, emerging nanomaterials have exhibited good superiority for these radiation-induced disease treatments. Given this background, the rational design principle of nanomaterials, which helps to optimize the therapeutic efficiency, has been an increasing need. Consequently, it is of great significance to perform a systematic summarization of the advances in this field, which can trigger the development of new high-performance nanoradioprotectors with drug efficiency maximization. Herein, this review highlights the advances and perspectives in the rational design of nanomaterials for preventing and treating various common radiation-induced diseases. Furthermore, the sources, clinical symptoms, and pathogenesis/injury mechanisms of these radiation-induced diseases will also be introduced. Furthermore, current challenges and directions for future efforts in this field are also discussed.

Radioprotective Effects of Amifostine, L-Carnitine and Vitamin E in Preventing Early Salivary Gland Injury due to Radioactive Iodine Treatment

OBJECTIVE

Standard treatment of differentiated thyroid cancer includes total thyroidectomy and high-dose Radioactive Iodine Therapy (RIT) for ablation of remnant thyroid tissue. When administered systemically, RIT can cause radiation-induced damage in non-targeted normal tissues. The aim of the present study was to compare the protective effects of amifostine (AMI), LCarnitine (LC), and Vitamin E (EVIT) against high dose radioactive iodine treatment induced Salivary Gland (SG) damage using SG scintigraphy and histopathological examination.

METHODS

Forty adult guinea pigs were studied. Twenty guinea pigs receive 555-660 MBq 131Iodine intraperitoneally (IP) to ablate the thyroid and impair the parenchymal function of the SGs. The animals were divided into eight groups as follows: (1) Group 1 (control): 1 mL IP PS (physiological saline); (2) Group 2: single dose of 200 mg/kg IP AMI one hour prior to 1 mL IP PS; (3) Group 3: 200 mg/kg IP LC and 1 mL IP PS for 10 days; (4) Group 4: 40 mg/kg intramuscular (IM) EVITand 1 mL IP PS for 10 days; (5) Group 5: IP RIT after premedication; (6) Group 6: Single dose of 200 mg/kg IP AMI one hour prior to RIT and IP RIT after premedication; (7) Group 7: IP RIT after premedication and 200 mg/kg IP LC for 10 days starting one day before RIT; and (8) Group 8: IP RIT after premedication and 40 mg/kg IM EVIT for 10 days starting one day before RIT. Scintigraphy was performed 1 month after treatment. SGs were examined by light microscopy and a histopathological scoring system was used to assess the degree of SG damage.

RESULTS

There were significant differences in the body weight and thyroid hormone levels between the groups after treatment.

CONCLUSION

The individual use of AMI, LC and EVIT for radioprotection yield different levels of protection against radioactive iodine treatment injury in SGs; however, none of the agents could provide absolute protection at the doses administered in this experimental model.

Protective Effect of Alpha-Lipoic Acid on Salivary Dysfunction in a Mouse Model of Radioiodine Therapy-Induced Sialoadenitis

Radioiodine (RI) therapy is known to cause salivary gland (SG) dysfunction. The effects of antioxidants on RI-induced SG damage have not been well described. This study was performed to investigate the radioprotective effects of alpha lipoic acid (ALA) administered prior to RI therapy in a mouse model of RI-induced sialadenitis. Four-week-old female C57BL/6 mice were divided into four groups (n = 10 per group): group I, normal control; group II, ALA alone (100 mg/kg); group III, RI alone (0.01 mCi/g body weight, orally); and group IV, ALA + RI (ALA at 100 mg/kg, 24 h and 30 min before RI exposure at 0.01 mCi/g body weight). The animals in these groups were divided into two subgroups and euthanized at 30 or 90 days post-RI treatment. Changes in salivary ^99mTc pertechnetate uptake and excretion were tracked by single-photon emission computed tomography. Salivary histological examinations and TUNEL assays were performed. The ^99mTc pertechnetate excretion level recovered in the ALA treatment group. Salivary epithelial (aquaporin 5) cells of the ALA + RI group were protected from RI damage. The ALA + RI group exhibited more mucin-containing parenchyma and less fibrotic tissues than the RI only group. Fewer apoptotic cells were observed in the ALA + RI group compared to the RI only group. Pretreatment with ALA before RI therapy is potentially beneficial in protecting against RI-induced salivary dysfunction.

Radioprotective effect of vitamin E on salivary glands after radioiodine therapy for differentiated thyroid cancer: a randomized-controlled trial

OBJECTIVES

This study aimed to examine the radioprotective effect of vitamin E on salivary glands after radioactive iodine (I) therapy in patients with differentiated thyroid cancer.

PATIENTS AND METHODS

Eighty-two patients with differentiated thyroid cancer were enrolled in this study. They were divided randomly into four groups (control group: 22 cases, group A: 23 cases, group B: 22 cases, and group C: 15 cases) before postsurgical ablation therapy with 100 mCi I. The patients in groups A, B, and C received vitamin E 100, 200, and 300 mg/day orally, respectively, for a duration of 1 week before to 4 weeks after I therapy. Salivary gland function was assessed using salivary gland scintigraphy immediately before and 6 months after I therapy. Uptake fraction (UF), uptake index (UI), excretion fraction (EF), and excretion ratio (ER) of each salivary gland were measured and compared.

RESULTS

On comparison between before and after I therapy in the control group, there was a significant decrease in UF of both right and left parotid glands (all P<0.01). In group A, a significant increase in EF of the right parotid gland (P<0.01) and UI of the right submandibular gland (P<0.05) was found. In group B, there was a significant increase in UI of the right parotid gland and both submandibular glands (all P<0.01). In group C, there was a significant increase in UF of the left parotid gland (P<0.05) and the right submandibular gland (P<0.01). Also, there was a statistical increase in UI in both submandibular glands (all P<0.01). However, on comparing the changes in the post-I therapy salivary scintigraphy parameters among the four groups, there was a significant difference in ΔUI of the right parotid gland (P<0.05) and both submandibular glands (all P<0.01), as well as ΔER of the left parotid gland (P<0.05) and ΔUF of the left submandibular gland (P<0.05).

CONCLUSION

Vitamin E exerts significant protective effects on the parotid and submandibular glands after I therapy.

Evaluation of radioprotective effect of aloe vera and zinc/copper compounds against salivary dysfunction in irradiated rats

The aim of this study was to evaluate the radioprotective and reparative effects of compounds based on aloe vera, zinc, and copper against salivary gland dysfunction in Wistar rats. A total of 150 Wistar rats were randomly divided into 12 groups, in which the animals received aloe vera and/or zinc and copper. In eight of these groups the animals were also subjected to irradiation before or after administration of the substances. After 27 days, sialometry tests were performed. Data were analyzed using ANOVA and the Tukey test (P < 0.05). Rats that had been administered aloe vera before or after irradiation showed a significantly higher salivary flow rate than rats that had been simply irradiated. When both substances were administered, a statistically significant difference in the salivary flow rate was observed in comparison with the irradiation alone group seven days after irradiation. The present results suggest that aloe vera exerts positive protective and reparative effects, and can be considered a potential radioprotective substance.

Simvastatin attenuates radiation-induced salivary gland dysfunction in mice

Objective

Statins are widely used lipid-lowering drugs, which have pleiotropic effects, such as anti-inflammation, and vascular protection. In our study, we investigated the radioprotective potential of simvastatin (SIM) in a murine model of radiation-induced salivary gland dysfunction.

Design

Ninety-six Institute of Cancer Research mice were randomly divided into four groups: solvent + sham irradiation (IR) (Group I), SIM + sham IR (Group II), IR + solvent (Group III), and IR + SIM (Group IV). SIM (10 mg/kg body weight, three times per week) was administered intraperitoneally 1 week prior to IR through to the end of the experiment. Saliva and submandibular gland tissues were obtained for biochemical, morphological (hematoxylin and eosin staining and Masson’s trichrome), and Western blot analysis at 8 hours, 24 hours, and 4 weeks after head and neck IR.

Results

IR caused a significant reduction of salivary secretion and amylase activity but elevation of malondialdehyde. SIM remitted the reduction of saliva secretion and restored salivary amylase activity. The protective benefits of SIM may be attributed to scavenging malondialdehyde, remitting collagen deposition, and reducing and delaying the elevation of transforming growth factor β1 expression induced by radiation.

Conclusion

SIM may be clinically useful to alleviate side effects of radiotherapy on salivary gland.

Radioprotective effects of lycopene and curcumin during local irradiation of parotid glands in Sprague Dawley rats

Radiotherapy effectively treats cancers of the head and neck. We investigated the possible protective effects of lycopene and curcumin on the parotid glands of 40 female Sprague Dawley rats during irradiation. The study followed European Union regulations 86/609/EEC, 2010/63/EU for animal experimentation. The animals were divided into 4 groups: those treated with curcumin and radiation, those treated with lycopene and radiation, those treated with dimethyl sulphoxide (DMSO) and radiation, and those treated with radiation alone. All compounds were given intraperitoneally the day before irradiation. The total dose of radiation was 20Gy. Morphological and histopathological analyses showed less cell necrosis in the group treated with curcumin than in the other groups, but the difference was not significant. Analysis of structural damage to the parotid ducts and vacuolisation showed significant differences among all groups (p=0.023, p<0.01). Lycopene and curcumin given 24 hours before irradiation reduced the structural damage to the salivary glands. Further studies are needed to confirm these findings.

Radioprotective effect of vitamin E in parotid glands: a morphometric analysis in rats

The aim of this study was to evaluate the radioprotective effect of vitamin E on rat parotid glands by morphometric analysis. Sixty male rats were divided into 5 groups (n=6): control, in which animals received olive oil solution; olive oil/irradiated, in which animals received olive oil and were irradiated with a dose of 15 Gy of gamma radiation; irradiated, in which animals were irradiated with a dose of 15 Gy gamma radiation; vitamin E, which received α-tocopherol acetate solution; vitamin E/irradiated, which received α-tocopherol acetate solution before irradiation with a dose of 15 Gy gamma rays. Half of the animals were euthanized at 8 h, and the remaining at 30 days after irradiation. Both parotid glands were surgically removed and morphometric analysis of acinar cells was performed. Data were subjected to two-way ANOVA and Tukey's test (α=0.05). Morphometric analysis showed a significant reduction in the number of parotid acinar cells at 30 days in olive oil/irradiated and irradiated groups. In groups evaluated over time a significant reduction was shown at 30 days in olive oil/irradiated and irradiated groups, indicating that ionizing radiation caused tissue damage. The vitamin E/irradiated group presented more acinar cells than the irradiated group, but no statistically significant difference was observed (p>0.05). In conclusion, vitamin E seems to have failed as a radioprotective agent on acinar cells in rat parotid glands.

Vitamin E Analogs as Radiation Response Modifiers

The potentially life-threatening effects of total body ionizing radiation exposure have been known for more than a century. Despite considerable advances in our understanding of the effects of radiation over the past six decades, efforts to identify effective radiation countermeasures for use in case of a radiological/nuclear emergency have been largely unsuccessful. Vitamin E is known to have antioxidant properties capable of scavenging free radicals, which have critical roles in radiation injuries. Tocopherols and tocotrienols, vitamin E analogs together known as tocols, have shown promise as radioprotectors. Although the pivotal mechanisms of action of tocols have long been thought to be their antioxidant properties and free radical scavenging activities, other alternative mechanisms have been proposed to drive their activity as radioprotectors. Here we provide a brief overview of the effects of ionizing radiation, the mechanistic mediators of radiation-induced damage, and the need for radiation countermeasures. We further outline the role for, efficacy of, and mechanisms of action of tocols as radioprotectors, and we compare and contrast their efficacy and mode of action with that of another well-studied chemical radioprotector, amifostine.

Does vitamin E protect salivary glands from I-131 radiation damage in patients with thyroid cancer?

OBJECTIVES

Salivary gland impairment after high-dose radioiodine (¹³¹I) treatment is well recognized. The aim of this study was to determine the protective effect of vitamin E on radiation-induced salivary gland dysfunction in patients undergoing ¹³¹I treatment for differentiated thyroid cancer.

METHODS

Thirty-six patients with differentiated thyroid carcinoma were enrolled in this study. They were randomly divided into two groups before postsurgical ablation therapy with 3700-5550 MBq ¹³¹I: the control group, comprising 17 patients, and the vitamin E group, comprising 19 patients. All 19 patients in the experimental group received vitamin E at a dose of 800 IU/day for a duration of 1 week before to 4 weeks after I therapy and the 17 patients in the control group received a placebo for the same duration. Salivary gland function was assessed using salivary gland scintigraphy with intravenous injection of 370 MBq Tc-pertechnetate in two phases, one immediately before and the other 6 months after ¹³¹I ablative therapy. First-minute uptake ratio, maximum uptake ratio, maximum secretion percentage, and excretion fraction (EF) of each salivary gland were measured and compared between the study phases for the two groups.

RESULTS

There was no significant difference between preablative and postablative salivary scintigraphic indices in the experimental vitamin E group, whereas maximum secretion percentage and EF of the right submandibular gland and EF of the left parotid gland were significantly decreased in the control group. There was also a higher significant decrease in the EF of the left parotid gland in the control group compared with the vitamin E group.

CONCLUSION

Vitamin E consumption may be associated with a significant protective effect against radiation-induced dysfunction in salivary glands following single-dose ¹³¹I therapy in patients with differentiated thyroid cancer.

Resveratrol attenuates radiation-induced salivary gland dysfunction in mice

OBJECTIVES/HYPOTHESIS

In our study we investigated the radioprotective effect of resveratrol (RES) in a murine model of radiation-induced salivary gland dysfunction.

STUDY DESIGN

Ninety-six Institute of Cancer Research mice were randomly divided into four groups: solvent (group I), RES treated (group II; 20 mg/kg/d), 15 Gy irradiation with solvent treatment (group III), and 15 Gy irradiation with RES treatment (group IV; 15 Gy and 20 mg/kg/d RES). RES (group II and IV) was administered intraperitoneally 3 days prior to irradiation through the conclusion of the experiment.

METHODS

Saliva and submandibular gland tissues were obtained for biochemical, morphological, immunohistochemical, and Western blot analyses at 8 hours, 24 hours, and 30 days after localized irradiation.

RESULTS

Radiation caused a reduction of saliva secretion, salivary amylase activity, superoxide dismutase, and an elevation of malondialdehyde. Administration of RES reversed the reduction of saliva secretion induced by irradiation and restored salivary amylase and superoxide dismutase activity. In addition, RES could inhibit increases in transforming growth factor-β1 expression induced by radiation.

CONCLUSIONS

RES can protect salivary glands against the negative effects of irradiation and has great potential as a treatment for successful radiotherapy in clinical practice.

Novel drugs to ameliorate gastrointestinal normal tissue radiation toxicity in clinical practice: what is emerging from the laboratory?

PURPOSE OF REVIEW

To give an overview of promising novel agents under development for the prevention and reduction of gastrointestinal radiation injury.

RECENT FINDINGS

Currently, several novel agents are being tested as drugs to prevent or reduce gastrointestinal radiation injury. These drugs may not only prevent injury, but also mitigate toxicity, that is, reduce injury after radiation exposure has occurred. Promising novel agents include the somatostatin analogue SOM230, growth factors, agents acting on the toll-like receptor 5 pathway, endothelial protectants, and the vitamin E analogue γ-tocotrienol.

SUMMARY

Gastrointestinal radiation injury is the most important dose-limiting factor during radiotherapy of the abdomen or pelvis. It may severely affect the quality of life both during radiotherapy treatment and in cancer survivors. To date, there are no agents that can prevent or reduce intestinal radiation injury. Hence, there is an urgent need for the development of novel drugs to ameliorate intestinal toxicity during and after radiotherapy. This review summarizes the several agents that have been shown to reduce intestinal radiation injury in animals. Further research is needed to investigate their safety and efficacy in patients receiving radiotherapy for abdominal or pelvic tumours.

Mechanisms underlying the radioprotective properties of γ-tocotrienol: comparative gene expression profiling in tocol-treated endothelial cells

Among the eight naturally occurring vitamin E analogs, γ-tocotrienol (GT3) is a particularly potent radioprophylactic agent in vivo. Moreover, GT3 protects endothelial cells from radiation injury not only by virtue of its antioxidant properties but also by inhibition of 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase and by improving the availability of the nitric oxide synthase cofactor tetrahydrobiopterin. Nevertheless, the precise mechanisms underlying the superior radioprotective properties of GT3 compared with other tocols are not known. This study, therefore, examined the differences in gene expression profiles between GT3 and its tocopherol counterpart, γ-tocopherol, as well as between GT3 and α-tocopherol in human endothelial cells. Cells were treated with vehicle or the appropriate tocol for 24 h, after which total RNA was isolated and genome-wide gene expression profiles were obtained using the Illumina platform. GT3 was far more potent in inducing gene-expression changes than α-tocopherol or γ-tocopherol. In particular, GT3 induced multiple changes in pathways known to be of importance in the cellular response to radiation exposure. Affected GO functional clusters included response to oxidative stress, response to DNA damage stimuli, cell cycle phase, regulation of cell death, regulation of cell proliferation, hematopoiesis, and blood vessel development. These results form the basis for further studies to determine the exact importance of differentially affected GO functional clusters in endothelial radioprotection by GT3.

gamma-Tocotrienol ameliorates intestinal radiation injury and reduces vascular oxidative stress after total-body irradiation by an HMG-CoA reductase-dependent mechanism

Analogs of vitamin E (tocols) are under development as radioprophylactic agents because of their high efficacy and lack of toxicity. Gamma-tocotrienol (GT3) is of particular interest because, in addition to being an antioxidant, it also inhibits 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase and accumulates to greater extent in endothelial cells than other tocols. We addressed in vivo whether HMG-CoA reductase inhibition contributes to the radioprotection conferred by GT3. Groups of mice were treated with vehicle, mevalonate (the product of the reaction catalyzed by HMG-CoA reductase), GT3 alone or GT3 in combination with mevalonate. Lethality and standard parameters of injury to the hematopoietic, intestinal and vascular/endothelial systems were assessed after exposure to total-body irradiation. GT3 improved postirradiation survival and decreased radiation-induced vascular oxidative stress, an effect that was reversible by mevalonate. GT3 also enhanced hematopoietic recovery, reduced intestinal radiation injury, and accelerated the recovery of soluble markers of endothelial function. These parameters were not reversed by mevalonate co-administration. Our data confirm GT3's radioprophylactic properties against hematopoietic injury and, for the first time, demonstrate benefits in terms of protection against gastrointestinal and vascular injury. The radioprotective efficacy of GT3 against vascular injury is related to its properties as an HMG-CoA reductase inhibitor.