Hypoglycemic effect of formulation containing hydroethanolic extract of Calophyllum brasiliense in diabetic rats induced by streptozotocin

Vitisin B, a resveratrol tetramer from Vitis thunbergii var. taiwaniana, ameliorates impaired glucose regulations in nicotinamide/streptozotocin-induced type 2 diabetic mice

Background and aim

In Taiwan, Vitis thunbergii var. taiwaniana (VTT) is used in traditional medicine and as a local tea. VTT rich in resveratrol and resveratrol oligomers have been reported to exhibit anti-obesity and anti-hypertensive activities in animal models; however, no studies have investigated type 2 diabetes mellitus (T2DM) treatments. This study aimed to investigate the anti-T2DM effects of resveratrol tetramers isolated from the VTT in nicotinamide/streptozotocin (STZ)-induced Institute of Cancer Research (ICR) mice.

Experimental procedure

The oral glucose tolerance test (OGTT) was used to imitate postprandial blood glucose (BG) regulations in mice by pre-treatment with VTT extracts, resveratrol tetramers of vitisin A, vitisin B, and hopeaphenol 30 min before glucose loads. Vitisin B (50 mg/kg) was administered to treat T2DM-ICR mice once daily for 28 days to investigate its hypoglycemic activity.

Results and conclusion

Mice pre-treated with VTT-S-95EE, or vitisin B (100 mg/kg) 30-min before glucose loading showed significant reductions (P < 0.001) in the area under the curve at 120-min (BG-AUC0-120) than those without pre-treatment with VTT-S-95 E E or vitisin B. Vitisin B-treated T2DM mice showed hypoglycemic activities via a reduction in plasma dipeptidyl peptidase (DPP)-IV activities to maintain insulin actions and differed significantly than those of untreated T2DM mice (P < 0.05), and also reduced BG-AUC0-120 and insulin-AUC0-120 in the OGTT.These in vivo results showed that VTT containing vitisin B would be beneficial for developing nutraceuticals and/or functional foods for glycemic control in patients with T2DM, which should be investigated further.

Co-Treatment of Purified Annatto Oil (Bixa orellana L.) and Its Granules (Chronic®) Improves the Blood Lipid Profile and Bone Protective Effects of Testosterone in the Orchiectomy-Induced Osteoporosis in Wistar Rats

This study aimed to evaluate and compare the effects of co-treatment with purified annatto oil (PAO) or its granules (GRA, Chronic®) with that of testosterone on the orchiectomy-induced osteoporosis in Wistar rats. After surgery, rats were treated from day 7 until day 45 with testosterone only (TES, 7 mg/kg, IM) or TES + PAO or GRA (200 mg/kg, p.o.). The following parameters were evaluated: food/water intake, weight, HDL, LDL, glucose, triglycerides (TG), total cholesterol (TC), alkaline phosphatase levels, blood phosphorus and calcium contents, femur weight, structure (through scanning electron microscopy), and calcium content (through atomic absorption spectrophotometry). Our results show that orchiectomy could significantly change the blood lipid profile and decrease bone integrity parameters. Testosterone reposition alone could improve some endpoints, including LDL, TC, bone weight, and bone calcium concentration. However, other parameters were not significantly improved. Co-treatment with PAO or GRA improved the blood lipid profile and bone integrity more significantly and improved some endpoints not affected by testosterone reposition alone (such as TG levels and trabeculae sizes). The results suggest that co-treatment with annatto products improved the blood lipid profile and the anti-osteoporosis effects of testosterone. Overall, GRA had better results than PAO.

The effects of Rosmarinus officinalis L. essential oil and its nanoemulsion on dyslipidemic Wistar rats

Dyslipidemias are lipid metabolism alterations that cause increased levels of serum lipoprotein, cholesterol, and triglycerides. These alterations are associated with a higher incidence of cardiovascular diseases and are a risk factor for atherosclerosis development. This study aimed to evaluate the effect of Rosmarinus officinalis essential oil (EORO, 100 mg/kg) and its nanoemulsion (NEORO, 500 µg/kg) on Triton and coconut saturated-fat-induced (CSF) dyslipidemias using Wistar rats. The phytochemical evaluation of EORO performed by gas chromatography-mass spectroscopy (GC-MS) revealed 1,8-cineole (33.70%), camphor (27.68%), limonene (21.99%), and α-pinene (8.13%) as its major compounds. Triton-induced dyslipidemia significantly increased total cholesterol, LDL, and triglycerides levels. On the other hand, the groups treated with EORO and NEORO had significantly reduced total cholesterol, LDL, and triglycerides compared to the group treated only with Triton. Similar results were observed on the positive control treated with simvastatin. Dyslipidemia induced with coconut saturated-fat (CSF) caused abdominal fat gain, hypercholesterolemia, hypertriglyceridemia, increased LDL levels, and atherogenesis in the aorta. In contrast, the groups treated with EORO, NEORO, and simvastatin had significantly reduced hypercholesterolemia and hypertriglyceridemia, reduced abdominal fat gain, and absence of atherogenesis in the vascular endothelium. Overall, in the Triton-induced dyslipidemia model, EORO treatment had superior values than NEORO's (and simvastatin), although the differences were not too high, while in the CSF model, the values were mixed. In this manner, our results show an anti-dyslipidemic and anti-atherogenic activity effect by EORO and NEORO.

Molecular docking analysis and anti-hyperglycaemic activity of Synacinn™ in streptozotocin-induced rats

Synacinn™ is a standardized polyherbal supplement formulated from Cinnamomum zeylanicum Blume, Curcuma zanthorrhiza Roxb., Syzygium polyanthum (Wight) Walp., Orthosiphon stamineus Benth. and Andrographis paniculata (Burm.f.) Nees. It is designed for the synergistic treatment of diabetes mellitus and its complications. Although the beneficial effects are yet to be verified scientifically, it is traditionally used to improve general health in patients with diabetes. This study aimed to evaluate the anti-hyperglycemic effects of Synacinn™ in a streptozotocin-induced type 1 diabetes rat model. Initially, Synacinn™ was used for in vivo acute oral toxicity tests and 14 day repeated dose toxicity tests to determine the toxicity levels. An efficacy study of Synacinn™ was carried out via the oral administration of 10, 50, 100, 250, and 250 (b.i.d.) mg kg⁻¹ doses to streptozotocin-induced diabetic rats. After 28 days, blood serum was collected to measure the fasting blood glucose, triglyceride, cholesterol, alanine aminotransferase, alkaline phosphatase, creatinine, and uric acid levels. The liver, kidney, and pancreas structures were histopathologically analyzed. In silico binding interaction studies of five phytochemicals in Synacinn™ identified via HPLC with glucokinase were performed using molecular docking analysis. The results showed that although no mortality was observed during the acute oral toxicity tests, notable damage to the liver and kidney occurred during the 14 day repeated dose testing at Synacinn™ levels of 600 mg kg⁻¹ and 2000 mg kg⁻¹. Treatment with 250 mg kg⁻¹ (b.i.d.) Synacinn™ of the streptozotocin-induced type 1 diabetic rats significantly (p < 0.05) improved the fasting blood glucose (59%), triglyceride (58%), cholesterol (47%), alanine aminotransferase (60%), alkaline phosphatase (90%), and creatinine (32%) levels. Synacinn™ also improved the relative weights of liver (35%), kidney (36%), and pancreatic (36%) tissue. Histological analysis showed improvements in the conditions of the central vein of the liver, the kidney Bowman's capsule and glomerulus, and the pancreatic islets of Langerhans. HPLC analysis of a standardized extract identified five active phytochemicals: andrographolide (17.36 mg g⁻¹), gallic acid (11.5 mg g⁻¹), curcumin (2.75 mg g⁻¹), catechin (3.9 mg g⁻¹), and rosmarinic acid (5.54 mg g⁻¹). Molecular docking studies with glucokinase showed that andrographolide yields the highest binding energy (−12.1 kcal mol⁻¹), followed by catechin (−10.2 kcal mol⁻¹), rosmarinic acid (−8.6 kcal mol⁻¹), curcumin (−7.8 kcal mol⁻¹), and gallic acid (−5.6 kcal mol⁻¹). These current findings suggest that Synacinn™ at a dose of 250 mg kg⁻¹ was non-toxic to rats. A twice-daily 250 mg kg⁻¹ dose of Synacinn™ is an effective anti-hyperglycemic agent, lowering blood glucose, triglyceride, and cholesterol levels, and assisting the recovery of organ impairment caused by streptozotocin in type 1 diabetic rats.

Synacinn™, a standardized polyherbal supplement, was shown to improve hyperglycemic conditions and related complications in STZ-induced rats.

The hypoglycemic effect of extract/fractions from Fuzhuan Brick-Tea in streptozotocin-induced diabetic mice and their active components characterized by LC-QTOF-MS/MS

Fuzhuan Brick-Tea is a postfermented product with the hypoglycemic effect, which is prepared from the leaves of Camellia sinensis var. sinensis. However, the material basis associated with the hypoglycemic effect was not clear. The present research was designed to explore the hypoglycemic effect of extract/fractions from Fuzhuan Brick-Tea in streptozotocin-induced type II diabetic mice. Then an ultra-high pressure liquid chromatography along with quadrupole time of flight mass spectrometry was used to analyze the phytochemicals in Fuzhuan Brick-Tea fractions. As a result, the hypoglycemic and hypolipidemic effects were evidently observed from the serum biochemical indexes and liver pathological examination in type II diabetic mice. In addition, there were total of 20 major components including eight lysophosphatidylcholines (Lyso-PCs), five fatty acids, and seven novel theophylline derivatives tentatively identified in the active fraction from water extract. Therefore, these components were assumed to contribute partly to the hypoglycemic effect of Fuzhuan Brick-Tea. These findings also give the evidence that the Lyso-PCs, fatty acids, and novel theophylline derivatives in Fuzhuan Brick-Tea may provide benefits in ameliorating disorders of glucose and lipid metabolism. PRACTICAL APPLICATION: This study suggests that the Lyso-PCs, fatty acids, and novel theophylline derivatives in Fuzhuan Brick-Tea may provide benefits in ameliorating disorders of glucose and lipid metabolism. It can be taken as a beneficial diet additive or nutraceutical.

Dillenia indica L. attenuates diabetic nephropathy via inhibition of advanced glycation end products accumulation in STZ-nicotinamide induced diabetic rats

The present study was aimed to evaluate advanced glycation end products (AGEs) inhibitory activity of alcohol and hydro-alcohol extract (DAE and DHE) of Dillenia indica L. (Family: Dilleniaceae) and its potential in treatment of diabetic nephropathy by targeting markers of oxidative stress. D. indica was evaluated for its in vitro inhibitory activity against formation of AGEs by using bovine serum albumin. Diabetes was induced in male Wistar rats by streptozotocin (65 mg/kg i.p.) 15 min after nicotinamide (230 mg/kg, i.p.) administration. Diabetic rats were treated with different doses of extracts (100, 200 and 400 mg/kg) to analyze their nephroprotective effect. Tissue antioxidant enzymes level was measured along with the formation of AGEs in kidney to assess the effect of D. indica in ameliorating oxidative stress. D. indica showed significant inhibition of AGEs formation in vitro. D. indica produced significant attenuation in the glycemic status, renal parameter, lipid profile and level of antioxidant enzymes proving efficacy in diabetic nephropathy. Moreover, D. indica produced significant reduction in the formation of AGEs in kidneys. The present study concludes that D. indica as a possible therapeutic agent against diabetic nephropathy.