Comparative Study on the Impact of Different Extraction Technologies on Structural Characteristics, Physicochemical Properties, and Biological Activities of Polysaccharides from Seedless Chestnut Rose (Rosa sterilis) Fruit.

Seedless chestnut rose (Rosa sterilis S. D. Shi, RS) is a fresh type of R. roxburghii Tratt with copious functional components in its fruit. Polysaccharides are recognized as one of the vital bioactive compounds in RS fruits, but their antioxidant and hypoglycemic properties have not been extensively explored. Hence, in this study, accelerated solvent extraction (RSP-W), citric acid (RSP-C), 5% sodium hydroxide/0.05% sodium borohydride (RSP-A), and 0.9% sodium chloride (RSP-S) solution extraction were individually utilized to obtain RS fruit polysaccharides. The physicochemical properties, structural characteristics, and biological activities were then compared. Results indicated that extraction methods had significant influences on the extraction yield, uronic acid content, monosaccharide composition, molecular weight, particle size, thermal stability, triple-helical structure, and surface morphology of RSPs apart from the major linkage bands and crystalline characteristics. The bioactivity tests showed that the RSP-S, which had the greatest amount of uronic acid and a comparatively lower molecular weight, exhibited more potent antioxidant and α-glucosidase inhibitory property. Furthermore, all RSPs inhibited α-glucosidase through a mixed-type manner and quenched their fluorescence predominantly via a static quenching mechanism, with RSP-S showing the highest binding efficiency. Our findings provide a theoretical basis for utilizing RSPs as functional ingredients in food industries.

Gut microbiota-derived tryptophan metabolites alleviate liver injury via AhR/Nrf2 activation in pyrrolizidine alkaloids-induced sinusoidal obstruction syndrome.

BACKGROUND AND AIMS: Hepatic sinusoidal obstruction syndrome (HSOS) is caused by toxic injury, such as pyrrolizidine alkaloids, to the liver sinusoidal endothelial cells, and the gut microbiota may be involved. However, the specific role and underlying mechanism of gut microbiota in HSOS is unknown. METHODS: HSOS model was established by gavage of monocrotaline (MCT) in rats. Fecal microbiota transplantation (FMT) with HSOS-derived or healthy gut flora was also conducted to validate the role of gut microflora in MCT-induced liver injury. The microbial 16 s rRNA analysis and untargeted metabolomics analysis in the faeces were performed to identify HSOS-related flora and metabolites. Finally, by supplementation with specific tryptophan metabolites, such as indole-3-acetaldehyde (IAAld) and indole acetic acid (IAA), we further confirmed the role of tryptophan metabolism in HSOS and the role of the AhR/Nrf2 pathway in MCT-induced liver injury. RESULTS: MCT induced HSOS-like liver injury in rats with significantly altered gut microbiota. Particularly, some tryptophan-metabolizing bacteria reduced in MCT-treated rats, such as Bacteroides, Bifidobacterium, Lactobacillus and Clostridium, and accompanied by a decrease in microbial tryptophan metabolic activity and a series of tryptophan derivatives. Restoring the gut microbiota via FMT improved MCT-induced liver damage, while HSOS-derived gut microbiota aggravated the liver injury induced by MCT. Supplementation with microbial tryptophan derivatives (IAAld or IAA), or 6-formylindolo(3,2-b)carbazole (Ficz, an AhR agonist) could activate the AhR/Nrf2 signaling pathway, thereby attenuating the MCT-induced liver oxidative stress and liver sinusoidal endothelial cells injury. CONCLUSIONS: Gut microbiota plays a critical role in MCT-induced HSOS, with inadequate microbial tryptophan metabolism in the gut and consequently a lower activity of the AhR/Nrf2 signaling pathway in the liver, which should be a potential target for the management of HSOS.

Modulation of the microbiota across different intestinal segments by Rifaximin in PI-IBS mice.

BACKGROUND: Rifaximin has been increasingly applied in irritable bowel syndrome (IBS) treatment. Whether there were differences in the effects of rifaximin on microbiota from different intestinal segments, especially the small intestine where rifaximin predominantly acted, has not been confirmed. METHODS: In this study, we used Trichinella spiralis infection to induce post infectious irritable bowel syndrome (PI-IBS) and measured visceral sensitivity of mice by means of abdominal withdrawal reflex (AWR) tests to colorectal distention (CRD). We compared the effects of rifaximin on the composition of ileal, colonic mucosal and fecal microbiota in PI-IBS mice. RESULTS: Rifaximin significantly reduced AWR scores and increased pain threshold in PI-IBS mice, and this effect was associated with the change in the relative abundance of ileal mucosal microbiota. Rifaximin could obviously decrease ileum mucosal microbiota alpha diversity assessed by Shannon microbial diversity index. Meanwhile, the analysis of beta diversity and relative abundance of microbiota at phylum, family and genus levels showed that rifaximin could improve the microbiota structure of ileal mucosa. However, for colonic mucosal and fecal microbiota, this effect of rifaximin was not obvious. Rifaximin could reshape the correlation of genera between different intestinal segments. CONCLUSION: Rifaximin improved visceral hypersensitivity in PI-IBS mice. Rifaximin mainly affected ileal mucosal microbiota, and its improvement effect on IBS might be closely related to the improvement of ileal microbiota structure.

Zhizhu Kuanzhong, a traditional Chinese medicine, alleviates gastric hypersensitivity and motor dysfunction on a rat model of functional dyspepsia.

Ethnopharmacological relevance: Zhizhu Kuanzhong (ZZKZ) is a traditional Chinese medicine modified from classic formula Zhizhu decoction in "Synopsis of Golden Chamber" (Han Dynasty in the 3rd century) and the Zhizhu pill in "Differentiation on Endogenous" in Jin Dynasty (1,115-1,234). ZZKZ contains four botanical drugs, including Citrus × Aurantium L [Rutaceae; Aurantii Fructus Immaturus], Atractylodes Macrocephala Koidz. [Compositae; Rhizoma Atractylodis Macrocephalae], Bupleurum Chinense DC [Apiaceae; Radix Bupleuri Chinensis], and Crataegus Pinnatifida Bunge [Rosaceae; Fructus Crataegi Pinnatifidae], which have been widely used in clinical therapy for functional dyspepsia (FD). Aim of the study: This study aimed to evaluate the pharmacological effects and mechanisms of action of ZZKZ on gastric hypersensitivity and motor dysfunction in a rat model of FD. Materials and methods: FD was induced in Sprague-Dawley rats by neonatal gastric irritation with 0.1% iodoacetamide. The FD rats were treated with ZZKZ (0.5 g/kg, 1.0 g/kg, or 1.5 g/kg respectively) by gavage for 7 days, while domperidone (3 mg/kg) acted as treatment control. Body weight gain, food intake, gastric emptying, and intestinal propulsion were also measured. Ex vivo gastric smooth muscle activity recordings and greater splanchnic afferent (GSN) firing recordings were employed to evaluate gastric motility and sensation. Particularly, the role of 5-HT in the action of ZZKZ in improving gastric dysmotility and hypersensitivity was explored. Results: ZZKZ promoted weight gain, food intake, gastric emptying, and intestinal propulsion in FD rats. ZZKZ promoted spontaneous and ACh-induced contractions of gastric smooth muscle strips in FD rats, alleviated spontaneous activity, and chemical (acid perfusion) and mechanical (intragastric distension) stimulated GSN firing in FD rats. ZZKZ ameliorated gastric smooth muscle contraction and GSN firing induced by 5-HT in FD rats. ZZKZ stimulated the release of serum 5-HT, with reduced 5-HT3 receptor and increased 5-HT4 receptor mRNA expression in the guts of FD rats. Conclusion: This study demonstrated that ZZKZ improves FD-related gastric hypersensitivity and motor dysfunction and should be an effective compound for relieving FD symptoms. The gastric 5-HT system with lower 5-HT3 activity and increased 5-HT4 distribution is involved in the mechanisms of ZZKZ underlying the treatment of FD.

Association of stress and functional gastrointestinal disorders in high school graduates.

BACKGROUND: Psychosocial factors are seemed as important causes of functional gastrointestinal disorders (FGIDs). However, the role of stress in FGIDs in high school students under the pressure of college entrance examination is largely unknown. The aim of this study is to investigate the association between the stress and FGIDs in high school graduates. METHODS: A cross-sectional survey was conducted in randomly selected high school fresh graduates. Questionnaires concerned health condition, living habits, gastrointestinal symptoms and life stress were given out and be finished voluntarily. Participants were diagnosed as FGIDs based on the Rome IV criteria. RESULTS: Stress level of FGIDs population was higher than control group and stress was independent predicted factor of high risk of FGIDs. The stressor "changes" was significantly correlated with functional gastroduodenal disorders (OR1.118(1.011-1.238)). Stressor "frustration" was significantly correlated with functional bowel disorders (OR1.038(1.006-1.071)). "Physiological reaction" was correlated with functional bowel disease and functional gastroduodenal disorders + functional bowel disorders (OR1.027(1.007-1.046) and OR1.055(1.000-1.113)). Students with more than one gastrointestinal symptom exhibited higher stress level. Moreover, there was mediation effect of stress in the association between gender, sleep quality, allergies and FGIDs. LIMITATIONS: This was a cross-section study and the sample included in the study were only from Wuhan, China. CONCLUSIONS: Our findings illustrated the predicted and mediated role of stress in FGIDs in high school fresh graduates. Different stressors and reactions to stressors contributed to different FGIDs. Intervening measures aimed at stress coping strategies were warranted for students in daily school life.

Diarrhea and altered inflammatory cytokine pattern in severe coronavirus disease 2019: Impact on disease course and in-hospital mortality.

BACKGROUND AND AIM: Dynamic changes of immunocyte subsets and inflammatory profiles in coronavirus disease 2019 (COVID-19) patients with gastrointestinal symptoms were undetermined. METHODS: A single-center retrospective analysis of 409 severe, hospitalized COVID-19 patients from 20 January to 29 February 2020 was performed. The longitudinal characteristics of immune inflammatory cytokines in patients with/without diarrhea were analyzed. The relations of diarrhea and immuno-inflammatory factors with illness course and clinical outcomes were further explored. RESULTS: Diarrhea was more common and more serious with longer duration (4.9 ± 1.5 vs 4.2 ± 1.5 days, P = 0.039) and higher frequency (5.5 ± 2.1 vs 4.0 ± 2.0 times/day, P = 0.001) in deceased patients than in the survivors. Also, diarrhea patients were more inclined to develop multi-organ damage: survivors have longer illness course (media 41.0 vs 36.0 days, P = 0.052) and hospital stays (media 27.0 vs 23.0 days, P = 0.041), and the deceased patients had higher mortality (33.0% vs 22.6%, P = 0.045) and earlier death (media 20.0 vs 25.0 days, P = 0.038). Progressively, neutrophilia and lymphopenia, especially the declined CD8+ T cells, were demonstrated in diarrhea patients relative to the non-diarrhea cases. The inflammatory cytokines including IL-6, IL-10, and TNF-α were intensively increased in patients with diarrhea. The multivariable logistic analysis showed longer duration of diarrhea (P = 0.036), higher neutrophil counts (P = 0.011), and lower lymphocyte counts (P < 0.001) were independent risk factors of in-hospital death. The proportional hazards model indicated that longer duration of diarrhea (P = 0.002), higher frequency of diarrhea (P = 0.058), higher neutrophil counts (P = 0.001), lower lymphocyte counts (P = 0.035), and decreased proportion of CD8+ T cells (P < 0.001) were independently associated with longer illness course of the survivors. CONCLUSIONS: Diarrhea patients were more likely to present with neutrophilia, lymphopenia, and cytokine storm and to develop multi-organ damage. The inflammatory patterns were independent factors associated with illness course of the survivors and in-hospital death of severe COVID-19.

Gastroenterologists Reveal More Digestive Symptoms in COVID-19 Patients than Nongastroenterologists in Fever Clinic.

The incidence of digestive symptoms may vary depending on doctors' professional backgrounds when they inquired suspected COVID-19 patients in a fever clinic. We sought to understand the characteristics of inquiries about digestive symptoms by doctors in different specialties; therefore, inquiry records of 2 gastroenterologists and 6 nongastroenterologists were reviewed. We compared the difference in inquiry of digestive symptoms (diarrhea, vomit, distension, anorexia, and abdominal pain) between these two groups among identified COVID-19 patients. And we further compared the difference of digestive symptoms between confirmed patients and suspected cases who excluded from COVID-19. Among 495 confirmed COVID-19 cases (254 cases by gastroenterologists and 241 cases by nongastroenterologists), 22.83% patients experienced various digestive symptoms in the gastroenterologists' group, while only 4.47% reported digestive symptoms by nongastroenterologists (p < 0.0001). Additionally, among initially suspected 611 patients who presented with similar respiratory symptoms inquired by gastroenterologists, confirmed cases presented far more frequency of digestive symptoms than excluded cases (22.8% vs. 3.64%, p < 0.0001). Furthermore, confirmed patients reported more percentage of watery diarrhea (56% vs. 36%, p < 0.0001) and higher frequent vomit (2.77 ± 0.97 vs. 1.80 ± 0.45 per day, p = 0.041) than excluded cases. We concluded that gastroenterologists could detect a greater proportion of gastrointestinal symptoms in COVID-19 patients during fever clinic inquiries. Moreover, confirmed COVID-19 patients are more likely to have higher severity in digestive symptoms than excluded cases. Therefore, physicians in fever clinic should pay more attention to the triage of gastrointestinal symptoms.

Immuno-Inflammatory Characteristics in Low Severity COVID-19 Patients with Digestive Symptoms.

AIM: The outbreak of Coronavirus Disease 2019 (COVID-19) has resulted in a global pandemic, with the main manifestations being of respiratory nature, including pneumonia. It is noteworthy that digestive symptoms are also observed in COVID-19 patients. In this article, we describe the immuno-inflammatory characteristics of low severity COVID-19 patients with digestive symptoms. METHODS: Patients with mild symptoms of COVID-19 were split into three groups based on the patients' symptoms. The first group displayed digestive symptoms only, the second group displayed respiratory symptoms only, and the last group displayed both digestive and respiratory symptoms. Patients were discharged based on negative results of rRT-PCR testing for SARS-CoV-2 from at least two sequential respiratory tract specimens collected ≥24 hours apart. Multiorgan function and immuno-inflammatory characteristics were analyzed for all of the three groups. RESULTS: Mild liver damage and activation of the immuno-inflammatory system were the most common abnormalities observed in patients with mild COVID-19 symptoms but no significant differences were found (P > 0.05). Patients with digestive symptoms were more likely to have slightly higher and later peak values of inflammatory cytokines during the subsequent course of disease (P < 0.05). In addition, a significant correlation between IL-2 and TNF level was found in the first group which included patients with digestive symptoms only (P < 0.05). CONCLUSIONS: Patients with mild cases of COVID-19 only displaying digestive symptoms are a special subtype. Patients in this group were more likely to have slightly higher and delayed peak values of inflammatory cytokines during the subsequent course of the disease. Prevention and clinical management of this type should be taken into consideration.

Outcomes and implications of diarrhea in patients with SARS-CoV-2 infection.

BACKGROUND AND AIMS: Diarrhea was not uncommon in patients with coronavirus disease 2019 (COVID-19), but the significance remains undetermined. METHODS: This retrospective study included 157 diarrhea cases form 564 hospitalized COVID-19 patients who were admitted to Wuhan Union Hospital from January 20 to February 29, 2020. Clinical characteristics, the course and the outcome of patients with diarrhea were analyzed. The correlation between diarrhea and fecal presence of coronavirus was also determined. RESULTS: The overall morbidity of diarrhea was 27.8% (157/564) in COVID-19 patients. Among them, 38 cases presented only with diarrhea, and 119 cases in both diarrhea and respiratory symptoms. Patients with diarrhea and respiratory symptoms had higher levels of inflammatory activity, longer hospital stay (27.5 vs. 23.0 vs. 22.0 days, p = .029) and higher odds ratio of mortality (3.2 times and 2.2 times, respectively) than those with diarrhea only or respiratory symptoms only. However, patients with diarrhea had longer time from onset to admission (14.5 days vs. 11.0 days, p = .04), higher positive viral RNA in stool (80.0% vs. 52.4%, p = .016) than those with both diarrhea and respiratory symptoms. CONCLUSIONS: Diarrhea caused by high enteric viral burden may lead to long course and poor outcome in COVID-19 patients. The patients with diarrhea and respiratory symptoms were prone to serious condition, and had worse outcomes. However, the patients with diarrhea alone showed mild illness but delayed health-seeking.

Digestive Symptoms in COVID-19 Patients With Mild Disease Severity: Clinical Presentation, Stool Viral RNA Testing, and Outcomes.

OBJECTIVES: Coronavirus disease 2019 (COVID-19) most commonly presents with respiratory symptoms, including cough, shortness of breath, and sore throat. However, digestive symptoms also occur in patients with COVID-19 and are often described in outpatients with less severe disease. In this study, we sought to describe the clinical characteristics of COVID-19 patients with digestive symptoms and mild disease severity. METHODS: We identified COVID-19 patients with mild disease and one or more digestive symptoms (diarrhea, nausea, and vomiting), with or without respiratory symptoms, and compared them with a group presenting solely with respiratory symptoms. We followed up patients clinically until they tested negative for COVID-19 on at least 2 sequential respiratory tract specimens collected ≥24 hours apart. We then compared the clinical features between those with digestive symptoms and those with respiratory symptoms. RESULTS: There were 206 patients with low severity COVID-19, including 48 presenting with a digestive symptom alone, 69 with both digestive and respiratory symptoms, and 89 with respiratory symptoms alone. Between the 2 groups with digestive symptoms, 67 presented with diarrhea, of whom 19.4% experienced diarrhea as the first symptom in their illness course. The diarrhea lasted from 1 to 14 days, with an average duration of 5.4 ± 3.1 days and a frequency of 4.3 ± 2.2 bowel movements per day. Concurrent fever was found in 62.4% of patients with a digestive symptom. Patients with digestive symptoms presented for care later than those with respiratory symptoms (16.0 ± 7.7 vs 11.6 ± 5.1 days, P < 0.001). Nevertheless, patients with digestive symptoms had a longer duration between symptom onset and viral clearance (P < 0.001) and were more likely to be fecal virus positive (73.3% vs 14.3%, P = 0.033) than those with respiratory symptoms. DISCUSSION: We describe a unique subgroup of COVID-19 patients with mild disease severity marked by the presence of digestive symptoms. These patients are more likely to test positive for viral RNA in stool, to have a longer delay before viral clearance, and to experience delayed diagnosis compared with patients with only respiratory symptoms.

Preparation and Reactivation of Heterogeneous Palladium Catalysts and Applications in Sonogashira, Suzuki, and Heck Reactions in Aqueous Media.

A new type of heterogeneous palladium catalyst, PdMgAl-LDH, was facilely prepared by the immobilization of Pd2+ species in the layers of a Mg-Al layered double hydroxide (LDH) with co-precipitation, and then fully characterized by using powder XRD, thermogravimetric differential thermal analysis, TEM, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy techniques. These catalysts can efficiently catalyze copper-free Sonogashira, Suzuki and Heck coupling reactions of various aryl iodides, bromides, and chlorides in aqueous media under phosphine-ligand- and organic-base-free conditions. These catalysts feature easy recovery through simple filtration and could be reused at least six times without a marked loss in activity. Notably, they can be facilely reactivated by a combination of nitrolysis with co-precipitation. The basic LDH skeletons could effectively stabilize the Pd0 species created in situ and donate electron density to the Pd0 center to facilitate the oxidative addition of aryl halides, thus the PdMgAl-LDH catalysts are stable during catalysis.

An efficient and green synthesis of ferrocenyl-quinoline conjugates via a TsOH-catalyzed three-component reaction in water.

An efficient and green synthesis of 4-ferrocenylquinoline derivatives through a TsOH-catalyzed three-component reaction of aromatic aldehydes, amines and ferrocenylacetylene in water has been successfully developed. This strategy is a powerful method for the construction of diverse ferrocenyl-quinoline conjugates from simple available starting materials as it minimized the use of metal catalyst and organic solvent in the reaction process. The conjugates feature unique structures and excellent electronic properties. Moreover, a plausible mechanism for this TsOH-catalyzed three-component reaction was proposed and assessed.

Synergistic antitumor activity of vitamin D3 combined with metformin in human breast carcinoma MDA-MB-231 cells involves m-TOR related signaling pathways.

Metformin is usually used for the treatment of type 2 diabetes. Recently, many studies suggest that metformin and vitamin D have broad-spectrum antitumor activities. Our aim in this research was to study the effects of vitamin D3 combined with metformin on the apoptosis induction and its mechanisms in the human breast cancer cell line MDA-MB-231. Cell proliferation was measured by methylthiazol tetrazolium (MTT) assay. The morphology of cell apoptosis was observed after Hoechst 33342 staining. Here we show that vitamin D3 280 µg/ml or vitamin D3 300 µg/ml or vitamin D3 320 µg/ml seperately combined with metformin 15000 µg/ml exhibited synergistic effects on cell proliferation and apoptosis. The underlying anti-tumor mechanisms may involve m-TOR related pathways, which are related to activating expression of cleaved caspase-3, Bax and p-AMPK, as well as inhibiting expressions of p-Bcl-2, c-Myc, p-IGF-IR, p-mTOR, p-P70S6K, p-S6.

Vitamin D3 enhances antitumor activity of metformin in human bladder carcinoma SW-780 cells.

OBJECTIVE: To study the effects of vitamin D3 combined with metformin on the proliferation and apoptosis in human bladder cancer cell line SW-780 and its possible mechanism. METHODS: MTT assay and fluorescence microscope observations were used to study the effects of vitamin D3 combined with metformin on the proliferation and apoptosis of SW-780 cells in vitro. Western blot was used to detect the expression of apoptosis-related proteins p-Bcl-2, Bax, Cyclin D1, c-Myc and related signaling pathways activated proteins p-IGF-IR, p-mTOR, p-P70S6K, p-S6. RESULTS: MTT results showed that 320 µg/ml vitamin D3 combined with 620 µg/ml metformin acting on cells for 48h had a significant synergistic effect on proliferation. Fluorescence microscope observations showed that compared with negative control group and monotherapy treatment group, the apoptosis features of combination treatment group were obvious and the apoptosis rate increased greatly. Western blot showed that compared with the negative control group and monotherapy treatment group, the expression levels of p-Bcl-2, Cyclin D1 and c-Myc in combination treatment group significantly decreased, whereas the expression level of Bax significantly increased, and the expression levels of p-IGF-IR, p-mTOR, p-P70S6K and p-S6 in combination treatment group significantly decreased. CONCLUSION: Vitamin D3 combined with metformin exhibited obvious inhibitory effects on the cell proliferation and apoptosis induction in SW-780 cells. The underlying anti-tumor mechanism might be related to inhibiting the expressions of p-Bcl-2, Cyclin D1, c-Myc, p-IGF-IR, p-mTOR, p-P70S6K, p-S6 and activating the expression of Bax.

Comparative pharmacokinetics of a tumour-targeting therapy candidate rh-IFNα2a-NGR with rh-IFNα2a administered intravenously in mice and rats.

OBJECTIVES: rh-IFNα2a-NGR is a promising anti-tumor candidate. The aim of present study was to compare pharmacokinetics of rh-IFNα2a-NGR with rh-IFNα2a. METHODS: Pharmacokinetics and elimination were investigated after intravenous administration to mice and rats. Compared tumor and tissue distribution profiles between rh-IFNα2a-NGR and rh-IFNα2a were illustrated in the tumor transplanted mice of SP2/0 myeloma. Double antibody sandwich ELISA method was used to assess the level of both rh-IFNα2a-NGR and rh-IFNα2a in serum, tissue, bile and urine. KEY FINDINGS: After a single intravenous administration, the pharmacokinetic characters of rh-IFNα2a-NGR and rh-IFNα2a were described using a two-compartment model. No significant differences were observed between the two drugs in pharmacokinetic and elimination data. However, the concentration of rh-IFNα2a-NGR in tumor was 5.34 times and 1.52 times as high as that of rh-IFNα2a at 0.5 h (P < 0.01) and 1 h. In addition, immunohistochemical stain displayed rh-IFNα2a-NGR was predominantly located in tumor vascular tissues. CONCLUSIONS: rh-IFNα2a-NGR could be an agent for tumor vascular-targeting therapy and these findings provided references for further clinical study.

Effects of simvastatin gel on bone regeneration in alveolar defects in miniature pigs.

BACKGROUND: Currently, the most commonly used treatment methods for repairing alveolar furcation defects are periodontal guided tissue regeneration (GTR) and bone grafting. The objective of this study was to investigate the effects of simvastatin/methylcellulose gel on bone regeneration in alveolar defects in miniature pigs. METHODS: Alveolar defects were produced in 32 teeth (the third and fourth premolars) of 4 miniature pigs. The 32 experimental teeth were divided into 5 groups comprising control (C) and treatment (T) teeth: (1) empty defects without gel (group C0, n = 4); (2) defects injected with methylcellulose gel (group C1, n = 4); (3) defects injected with 0.5 mg/50 µl simvastatin/methylcellulose gel (group T1, n = 8); (4) defects injected with 1.5 mg/50 µl simvastatin/methylcellulose gel (group T2, n = 8); and (5) defects injected with 2.2 mg/50 µl simvastatin/methylcellulose gel (group T3, n = 8). Every week after surgery, the furcation sites were injected once with gel. At the eighth week after surgery, the 4 pigs were sacrificed and underwent macroscopic observation, descriptive histologic examination, and regenerate bone quantitative histologic examination. RESULTS: At 8 weeks after surgery, the defect sites in the treatment groups were completely filled in with new bone and fibrous tissue. There was little new bone in the C0 and C1 groups, and only a small number of osteoblasts and proliferative vessels could be seen on microscopic examination. CONCLUSIONS: Miniature pigs are an ideal experimental animal for establishing a model of alveolar defects using a surgical method. Local application of simvastatin/methylcellulose gel can stimulate the regeneration of alveolar bone in furcation defect sites, because it promotes the proliferation of osteoblasts. The best dose of simvastatin gel to stimulate bone regeneration is 0.5 mg.