Evaluation of Antidiabetic and Antioxidant Activities of Fruit Pulp Extracts of Cucurbita moschata Duchesne and Cucurbita maxima Duchesne.

Objective: To evaluate and compare the antidiabetic and antioxidant activities of fruit pulp extracts from Cucurbita moschata (PCMOS) and Cucurbita maxima (PCMAX). Methods: The antidiabetic activity was carried out in vivo by orally and daily giving the extracts at a dose of 500 mg/kg·b.w. to the streptozotocin-induced diabetic male albino Wistar rats for six weeks. After the period of administration, blood glucose levels, body weight, serum insulin, morphology of islets of Langerhans, biochemical parameters, and haematological values of the rats were determined. Meanwhile, the antioxidant activity was carried out in vitro by determination of total phenolic and flavonoid contents, DPPH radical scavenging activity, and ferric reducing antioxidant power. Results: PCMAX significantly (p < 0.05) reduced blood glucose levels but increased the body weight, serum insulin levels, size and number of islets of Langerhans, and ß-cell number of the treated diabetic rats more than PCMOS did. However, they did not alter biochemical parameters and haematological values of the treated diabetic rats. PCMAX possessed total phenolic and flavonoid contents and showed DPPH scavenging and FRAP reducing antioxidant power more significantly (p < 0.05) than PCMOS. Conclusions: According to the obtained results, it is indicated that PCMOS and PCMAX possess antidiabetic and antioxidant activities. PCMAX possesses more potent antidiabetic and antioxidant activities than PCMOS. These are probably due to PCMAX providing polysaccharide and total phenolic and flavonoid contents more than PCMOS.

Toxicity and antidiabetic activity of ethanolic extract of Sphagneticola trilobata (L.) Pruski flower in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Plants are the source of medication for preventive, curative, protective or promotive purposes. Medicinal plants are an important source for generating of novel phytomedicine. They provide profound therapeutic benefits, more affordable treatments, effectiveness, less side effects and relatively low cost or less expensive and globally competitive. Using plant derived medicine is also relatively safe compared to synthetic medicines. Many plants have proved to successfully aid in the treatment of ailments including Sphagneticola triolobata (L.) Pruski. AIM OF STUDY: This study was therefore, designed to investigate acute and subacute toxicities, antidiabetic activity and also antioxidant activity of flower extract from S. triolobata (L.) Pruski. METHODS: This research investigates the toxicity and antidiabetic activity of Sphagnelicola trilobata (L.) Pruski flower ethanolic extract in rats. Acute toxicity was determined by a single oral administration of S. trilobata extract of 1500, 2000, and 2500 mg/kg body weight; and subacute toxicity by oral administration every two days for 14 days. Signs of toxicity and mortality were observed during 24 h and for 14 days. Hematological values and blood chemistry were also characterized. The antidiabetic activity was examined by orally administering S. trilobata extract of 250 mg/kg body weight to streptozotocin-induced diabetic rats on a daily basis for eight weeks; and the body weight, blood glucose, serum insulin, and lipid profiles were determined. The antioxidant activity of the extract was assessed by 1, 1-diphenyl-2-picryl-hydrazyl free radical scavenging assay. RESULTS AND CONCLUSION: The results demonstrated a median lethal dose (LD50) greater than 2500 mg/kg since there was no sign of toxicity and mortality in acute and subacute toxicity testing. The high LD50 indicated that S. trilobata flower ethanolic extract is safe for treatment of diabetes. There was no significant change in the body weight, hematological values, and blood chemistry of treated rats, compared with the control group. The diabetes-induced rats showed a significant reduction in blood glucose and triglyceride (p < 0.05). Meanwhile, the antioxidant activity of S. trilobata extract was lower than that of standard ascorbic acid.

Hypoglycemic and Hypolipidemic Effects of Seed Extract from Antidesma bunius (L.) Spreng in Streptozotocin-induced Diabetic Rats.

BACKGROUND: Antidesma bunius (L.) Spreng has been reported to possess various beneficial medicinal properties. Scientific information about this plant is limited. This study was therefore, designed to determine hypoglycaemic and hypolipidemic effects of ethanol seed extract from A. bunius (ABSE). Antioxidant activity and also acute toxicity were conducted. METHODOLOGY: The hypoglycaemic and hypolipidemic effects were studied by oral giving ABSE at a dose of 250 mg kg -1 to streptozotocin-induced diabetic rats daily for 6 weeks. Antioxidant activity was studied using DPPH assay. The ABSE at the doses of 500, 1000, 1500 and 2000 mg kg -1 were employed in the acute toxicity study. RESULTS: The results revealed that ABSE significantly (p<0.05) reduced the blood glucose level and recovered the pathology of hematological values, but significantly (p<0.05) increased the body weight and slightly increased serum insulin of the diabetic rats. However, ABSE recovered pathology of hematological values, but affected renal and hepatic functions in the treated rats by producing an alteration of creatinine, albumin, total protein, BUN and ALP. Interestingly, ABSE increased WBC and HDL, but reduced CHOL, LDL and TG both in normal and diabetic ABSE treated rats. The ABSE possessed relatively low antioxidant activity with IC50 of 2174±14.24 mg mL -1 compared to vitamin C (1.48±0.07 µg mL -1). Fortunately, ABSE did not produce any symptoms of acute toxicity and mortality in the rats. CONCLUSION: The ethanol seed extract from A. bunius possesses hypoglycemic and hypolipidemic effects. The ABSE also recovered the pathology of the hematology but may cause renal dysfunction in the diabetic rats. The hypoglycemic and hypolipidemic effects are likely due to its antioxidant and insulin secretion activities.

Inhibitory effects of ginger oil on spontaneous and PGF2alpha-induced contraction of rat myometrium.

Solvent extracts of ginger, the rhizome of Zingiber officinale Roscoe (Zingiberaceae), have been extensively studied for their pharmacological activities in smooth muscles. However, the effects of ginger essential oil on smooth muscle contractility have not been elucidated. The aims of the study were to investigate the effects of ginger oil on rat myometrial contractility. We particularly examined the effects on phasic contractions arising either spontaneously or with PGF (2) (alpha) stimulation. Ginger oil was obtained by hydrodistillation and its constituents analyzed using gas chromatography and mass spectrometry. Rats were humanely killed by asphyxiation with CO (2), and longitudinal uterine smooth muscles were isolated. Isometric force was measured and the effects of ginger oil studied. It was found that citral was the main constituent of ginger oil (24 %). Ginger oil inhibited spontaneous contractions with an IC (50) of 50 microL/100 mL (10 - 150 microL/100 mL). The PGF (2) (alpha)-induced contractions were also significantly reduced by ginger oil. Increases in external calcium concentration completely reversed the relaxant effects of ginger oil. This was the case for both spontaneous and PGF (2) (alpha)-induced contractions. The effects of ginger oil were indistinguishable from those of pure citral. In conclusion, ginger oil is a potent inhibitor of phasic activity in rat uterus, irrespective of how it was produced. Our data suggest that the effects are largely due to citral, and could be via inhibition of L-type Ca channels.

Streptozotocin-induced diabetes modulates presynaptic and postsynaptic function in the rat ileum.

Altered gastrointestinal motility frequently occurs in diabetic patients and also in animal models of diabetes but the underlying causes are not clear. In the present study, contractile responses to agonists and electrical field stimulation (EFS) and the inhibitory actions of an adenosine A(1) receptor agonist were investigated on ilea from 8-week streptozotocin (STZ)-induced diabetic rats. Contractile responses to carbachol, prostaglandin F(2 alpha) (PGF(2 alpha)), the calcium ionophore A23187 and to EFS were increased in diabetic tissues compared to controls. In contrast, the inhibitory effects of a potent and selective adenosine A(1) receptor agonist N(6)-cyclopentyladenosine (CPA) on electrical field stimulation-evoked contractions were decreased in diabetic tissues compared to controls but its ability to relax carbachol-contracted tissues was unaltered. These results suggest that diabetes may cause alterations at both pre- and postsynaptic sites and this may lead in turn to the gastrointestinal complications seen in diabetic patients.