Renoprotective effect of umbelliferone in high-fat diet/streptozotocin-induced type 2 diabetic rats

Objective: To evaluate the renoprotective effect of umbelliferone in high-fat diet/streptozotocin-induced type 2 diabetic rats. Methods: We established a streptozotocin-induced type 2 diabetic model in male Wistar rats. The rats were fed with high-fat diet (45 kcal％ lard fat) and injected with 35 mg/kg streptozotocin. Diabetic rats were treated with umbelliferone for 8 weeks. At the end of the experimental period, the serum and kidney were used for measuring biochemical parameters, protein expression and histological analysis. Results: After 8-week treatment, umbelliferone decreased fasting plasma glucose, concentrations of malondialdehyde and monocyte chemoattractant protein-1 in the plasma and tissues. It also significantly reduced serum creatinine, blood urea nitrogen, serum advanced glycation end products, as well as kidney weight in type 2 diabetic rats (P<0.05). Moreover, umbelliferone reduced the 24-h urine albumin, but increased 24-h urine creatinine excretion (P<0.05). In renal protein expression, umbelliferone decreased the levels of transforming growth factor-β1 and fibronectin while increasing the levels of superoxide dismutase and catalase (P<0.05). Renal histological examination revealed an enlarged glomerular size in diabetic rats, which was smaller in umbelliferone-treated diabetic rats. Conclusions: Umbelliferone alleviates renal dysfunction in diabetes via decreasing hyperglycemia, oxidative stress, inflammation and glycation.

Pandanus amaryllifolius leaf extract increases insulin sensitivity in high-fat diet-induced obese mice

Objective: To examine the effect of Pandanus amaryllifolius (P. amaryllifolius) leaf extract on the insulin resistance state in obese ICR mice. Methods: Obesity was induced in mice fed with high-fat diet (45%fat) for 12 weeks. After the first six weeks on the diet, the obese mice were administered with the water extract of P. amaryllifolius leaf at 125 and 250 mg/kg/day, respectively for another six weeks. At the 5th week of treatment, oral glucose tolerance test was conducted. After six weeks of treat-ment, the levels of blood glucose, serum insulin, leptin, adiponectin, and lipid profiles were determined. The liver, muscle and epididymal fat tissues were removed for measuring the biochemical parameters and protein expression, as well as histological examination. Results: Six weeks of treatment with P. amaryllifolius led to a significant reduction in the blood glucose level as well as improvement in the insulin resistance. P. amaryllifolius also increased the liver glycogen storage and serum adiponectin and decreased the serum leptin levels. A reduction in the serum and hepatic triglyceride, and non-esterified fatty acid levels was also observed. The histological examination showed that the obese mice treated with P. amaryllifolius reduced the lipid droplet in liver tissue and adipocyte size in epididymal fat tissue. The treatment also increased the protein expression of glucose transporter 4 in the muscle and fat tissues. Conclusions: The treatment with P. amaryllifolius could decrease several parameters of impaired glucose and lipid metabolism. To the best of our knowledge, this is the first report on the role of P. amaryllifolius leaf extract in alleviating the insulin dysfunction in obesity state.

An investigation of antimicrobial and wound healing potential of Allium ascalonicum Linn.

BACKGROUND: The pharmacological properties of Allium ascalonicum Linn., commonly called shallot, have been reported as including those that are antibacterial and antioxidant. OBJECTIVE: The present study aimed to evaluate the antimicrobial effect and wound-healing activity ofthe ethanolic extracts of Allium ascalonicum Linn. (AAE). MATERIAL AND METHOD: The antimicrobial activity of AAE was tested in vitro against using the disc diffusion method and a broth micro-dilution technique to determine the minimal inhibition concentrations (MIC) and the minimal microbicidal concentrations (MMC). Wound-healing activity of the extract was performed on rat test subjects. RESULTS: The AAE showed potential antimicrobial activity by inhibiting gram-positive bacteria Staphylococcus epidermidis and Bacillus subtilis ATCC 6633. MIC and MMC varied from 25-50 mg/ml and 25-200 mg/ml, respectively. After surgery 14 days, wound contractions oftreated groups and standard group were 78.61 +/- 1.20%, 78.55 +/- 1.93% and 100%, respectively; but, in the control group, wound contraction was 64.90 +/- 3.55%. Histological studies showed the complete epidermis and found the collagen fibers and fibroblasts as similar appearance as standard group in dermis. The results of histological evaluation have confirmed remarkable wound-healing activities of AAE. CONCLUSION: Taken together the present study provides evidence that AAE extract processes antimicrobial and wound-healing activities.

Effects of Cymbopogon citratus Stapf water extract on rat antioxidant defense system.

BACKGROUND: Cymbopogon citratus, Stapf(CCS) is commonly known as lemon grass. Previous studies showed that it has a strong antioxidant property and have been traditionally used as analgesic, antipyretic, antiseptic in SoutheastAsia. However, the effect of CCS on antioxidant defense system has not been demonstrated. OBJECTIVE: The present study was conducted to investigate the effects of CCS water extract on rat antioxidant defense system, especially on the expression of y-glutamylcysteine ligase (γ-GCL) and heme oxygenase-1 (HO-1). MATERIAL AND METHOD: The CCS water extract was screenedfor its phytochemical contents and antioxidant activity in vitro. Moreover, the extract was studied in rats to evaluate its effects in vivo. Male Sprague-Dawley rats aged eight weeks (250±20 g) were orally administered with CCS at 250, 500 and 1,000 mg/kg/day for one month. RESULTS: The extract contained flavonoids (496.17 mg gallic acid/g CCS extract) and phenolic compounds (4,020.18 mg catechin/g CCS extract). The scavenging activity (DPPH assay) of the extract was demonstrated by EC50 of 917.76±86.89 µg/ ml whereas the EC50 of the potent antioxidant, vitamin C was 31.22±1.84 µg/ml. In the animals, the protein expression of antioxidant enzymes, γGCL and HO-1 was significantly increased in the high dose-treated animals (1,000 mg/kg/day). This was consistent with elevation ofserum total antioxidant capacity. CONCLUSION: Taken together the present study provides evidence that CCS water extract exhibits antioxidant activity and antioxidant enzymes induction in vivo.

Antioxidant, antimicrobial and wound healing activities of Boesenbergia rotunda.

The ethanolic extract of Boesenbergia rotunda (L.) Mansf was studied for its wound-healing potential. Since wound healing is interrelated with microbial infection and reactive oxygen species (ROS), this study was conducted to evaluate the antimicrobial and antioxidant activity of B. rotunda. The antimicrobial activity of B. rotunda was studied against six bacterial and two yeast strains using disc diffusion, minimum inhibitory concentration (MIC), and minimum microbicidal concentration (MMC). The B. rotunda extract displayed potential antimicrobial and antifungal activities by inhibiting the Gram-positive bacteria Staphylococcus aureus (ATCC 25923), S. epidermidis, and Bacillus subtilis (ATCC 6633), and the yeasts Candida albicans (ATCC 10231), and Saccharomyces cerevisiae. MIC and MMC values varied from 0.04 to 25 mg/mL and from 0.16 to 25 mg/mL, respectively. The antioxidant activity of B. rotunda was evaluated by measuring the Ferric Reducing/Antioxidant Power (FRAP) and DPPH free radical scavenging activity. The FRAP and DPPH values were 22.2 microM/microg and 76.3 mg/mL, respectively. In the wound-healing studies, the topical application of the B. rotunda extract indicated a significantly increased percentage of wound contraction on day 12 compared with the control group. Histological studies showed the complete epidermis and found collagen fibers and hair follicles in the dermis. The results of the present study support the continued and expanded utilization of B. rotunda in Thai folk medicine.