Background and aimType 2 diabetes mellitus (T2DM) is one of the major diseases confronting the health care systems. In diabetes mellitus (DM), combined use of oral hypoglycemic medications has been shown to be more effective than metformin (Met) alone in glycemic control. This study determined the effects of Ginkgo biloba (GKB) extract as an adjuvant to Met in patients with uncontrolled T2DM.Subjects and methodsSixty T2DM patients were recruited in a randomized, placebo-controlled, double-blinded, and multicenter trial. The patients, currently using Met, were randomly grouped into those treated with either GKB extract (120 mg/day) or placebo (starch, 120 mg/day) for 90 days. Blood glycated hemoglobin (HbA1c), fasting serum glucose, serum insulin, body mass index (BMI), waist circumference (WC), insulin resistance, and visceral adiposity index (VAI) were determined before (baseline) and after 90 days of GKB extract treatment.ResultsGKB extract significantly decreased blood HbA1c (7.7%±1.2% vs baseline 8.6%±1.6%, P<0.001), fasting serum glucose (154.7±36.1 mg/dL vs baseline 194.4±66.1 mg/dL, P<0.001) and insulin (13.4±7.8 μU/mL vs baseline 18.5±8.9 μU/mL, P=0.006) levels, BMI (31.6±5.1 kg/m2 vs baseline 34.0±6.0 kg/m2, P<0.001), waist WC (102.6±10.5 cm vs baseline 106.0±10.9 cm, P<0.001), and VAI (158.9±67.2 vs baseline 192.0±86.2, P=0.007). GKB extract did not negatively impact the liver, kidney, or hematopoietic functions.ConclusionGKB extract as an adjuvant was effective in improving Met treatment outcomes in T2DM patients. Thus, it is suggested that GKB extract is an effective dietary supplement for the control of DM in humans.

Postprandial hyperglycemia is a major risk factor for diabetic complications leading to disabilities and mortality in diabetics. Quercetin, a flavonoid, has been tried in traditional medicine for treating diabetes. The present study was designed to evaluate the potential of quercetin to control postprandial blood glucose level after maltose and glucose loading in normal and STZ-induced diabetic rats. Normal male Albino wistar rats and STZ-induced diabetic rats were treated with 300 and 600 mg/kg quercetin orally to evaluate the effect on postprandial hyperglycemia after carbohydrate loading, using acarbose as comparator. The results clearly showed ameliorated postprandial hyperglycemia due to the use of quercetin (300 and 600 mg/kg), it significantly dampened the postprandial hyperglycemia by 32.0% and 64.0% respectively, in maltose loaded diabetic rats, and 30.3% after 300 mg/kg dose in normal rats, compared to control; while acarbose produced 51% and 54% decrease in this respect in the two models respecttively. Quercetin in 600 mg/kg dose produces significantly more reduction in postprandial hyperglycemia compared to acarbose, while in rats that received glucose and quercetin, postprandial hyperglycemia was not significantly affected. In conclusion, quercetin effectively suppresses postprandial hyperglycemia in STZ-induced diabetic rats loaded with maltose, which may be attributed to α-glucosidase inhibition. Quercetin could be used as a potential supplement for treating postprandial hyperglycemia

ObjectiveThis study aimed to evaluate the effect of quercetin and/or sitagliptin on testicular damage induced by doxorubicin (DOX).MethodologyTwenty-five male Wistar rats, weighing 240±20 g, were randomly divided into five groups as follows: a negative control group; that was treated with 1 mL of 0.9% sodium chloride; a DOX-treated group received Intraperitoneal (I.P.) DOX injection (3 mg/kg); a group treated with quercetin 80 mg/kg + sitagliptin 10 mg/kg + DOX; a group treated with quercetin 80 mg/kg + DOX; and a group treated with sitagliptin 10 mg/kg+ DOX. All treatment were given orally daily for 21 days with I.P. DOX 3 mg/kg injection for the treatment groups at days 8, 10, 12, 15, 17, and 19. On day 22, blood was collected for analysis of testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), glutathione peroxidase (GPx), and total antioxidant capacity (TAOC). The testes were also removed and sent for histopathological examination.ResultsThe study revealed that the combination of quercetin with sitagliptin produced a significant increase in testosterone and FSH levels with a non-significant increase in LH level. This combination also non-significantly decreased the level of ALP and LDH and restored the GPx level with enhancing TAOC.ConclusionThe results suggest quercetin/sitagliptin combination as a promising therapeutic modality for attenuation of DOX-induced testicular toxicity in rats, and the main mechanism involved in such effect could be due to the antioxidant and anti-inflammatory properties of both agents.

Objective: A previous study revealed a pronounced protective effect of combining quercetin (QC) with sitagliptin (STN) in testicular tissue. Accordingly, this study was designed to evaluate the cardioprotective effects of QC and STN each alone or in combination in doxorubicin (DOX)-induced cardiotoxicity in the rats. Methodology: Thirty male adult Wistar rats were divided into five groups: the first group (control) treated with sodium chloride, the second group treated with DOX (3 mg/kg I. P. injection), the third group treated with DOX with a combination of QC (80 mg/kg), and STN (10 mg/kg), the fourth group treated with DOX and QC and the fifth group treated with DOX and STN. Blood was collected on day 22 and used for assessment of serum troponin, lactate dehydrogenase (LDH), creatine phosphokinase (CPK), total lipid profile, C-reactive protein (CRP), and total antioxidant capacity (TAOC). Atherogenic indices were also calculated. Cardiac tissue was sent for histopathological analysis. Results: DOX produced a significant increase in the level of troponin, LDH, CKP, CRP, total cholesterol (TC), low-density lipoprotein (LDL), triglycerides (TG), and atherogenic index of plasma; and significantly decreased TAOC. The combination of quercetin and sitagliptin was more effective than each treatment alone in restoring the level of troponin, LDH, CKP, CRP, Cholesterol, LDL, TG, atherogenic index of plasma and significantly increased TAOC compared to DOX treated group. The histopathological finding also supports the biochemical results. Conclusion: The study revealed the cardioprotective effects of the combination of QC and STN which could be attributed to the additive effects of this combination through antioxidant, anti-inflammatory, lipid lowering and anti-atherogenic activities; suggesting it as a good therapeutic candidate to be tested in the clinical setting.

Background and aimGinkgo biloba (GKB) extract has shown to be beneficial in experimental models of metabolic and inflammatory disorders such as diabetes and metabolic syndrome (MTS). The objective of this pilot clinical study was to evaluate the effects of GKB extract as an “add-on” treatment with metformin (Met) in MTS patients.Patients and methodsWe performed a randomized, placebo-controlled, double-blinded clinical study in subjects with MTS. Forty patients completed the 90-day clinical trial and were randomly allocated to administer either GKB extract (120 mg capsule/day) or placebo (120 mg starch/day) as an add-on treatment with their currently used doses of Met for 90 days. During the study, body mass index (BMI), waist circumference (WC), serum leptin, glycated hemoglobin (HbA1c), fasting serum glucose (FSG), insulin, insulin resistance (IR), visceral adiposity index (VAI), lipid profile, and the inflammatory markers high sensitive C-reactive protein (hsCRP), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) were evaluated.ResultsGKB extract significantly decreases HbA1c, FSG and insulin levels, IR, BMI, WC, VAI, serum leptin, and the inflammatory markers compared to baseline values. Simultaneously, GKB did not negatively affect the functions of the liver, kidney, and hematopoietic system.ConclusionThe use of GKB extract as an adjuvant with Met was effective in improving the outcome of patients with MTS.