Antidiabetic and in vitro antioxidant effects of hydromethanol extract of Paullinia pinnata root bark in alloxan-induced diabetic rat

Abstract

Background The study evaluated phytochemical composition, antidiabetic, oral glucose tolerance test and in vitro antioxidant activities of hydromethanol extract of Paullinia pinnata root bark. Methods Cold maceration method was used in extract preparation and scavenging of 2,2-diphenyl-1-picrylhydrazyl radicals was used to evaluate antioxidant properties of the extract. Diabetes was induced with alloxan at the dose of 160 mg/kg. The antidiabetic activity of the extract was tested at doses of 50, 100 and 200 mg/kg, and glibenclamide was used as reference drug. Results Phytochemical analysis of the extract showed the presence of alkaloids, flavonoids, glycosides, tannins, saponins and terpenes/sterols. The extract produced a significant (p<0.05) time-dependent decrease in the fasting blood glucose (FBG) levels in the treated rats when compared with the distilled water treated rats, but did not produce dose-dependent effects. The extract 50, 100 and 200 mg/kg and glibenclamide (2 mg/kg) caused 83.62 %, 60.66 %, 47.77 % and 68.52 % reduction respectively in FBG at 6 h post-treatment while the distilled water (5 mL/kg) produced 8.12 % reduction in FBG at 6 h post treatment. The extract (50 mg/kg) and glibenclamide (2 mg/kg) produced a significant (p<0.05) oral glucose tolerance effect in both normoglycemic and diabetic rats. The extract produced concentration-dependent increase in antioxidant activity and had its optimum effect at 400 µg/mL concentration. Conclusions This study suggests that P. pinnata root bark has potent antidiabetic and antioxidant activities and also validates its use in folkloric medicine in the management of diabetes-related conditions.

Hypolipidemic, hepatoprotective, nephroprotective and anti-lipid peroxidation properties of a methanol extract of Paullinia pinnata root-bark, in alloxan-induced hyperglycemic rats

“…Ozioko. The plant material was processed, extracted using a cold maceration method with 80% methanol and concentrated in hot air oven at 40°C as reported by Okwudili et al [9]. Experimental animals.…”

“…The animals were housed in cages (6 per cage) in a well-ventilated room at ambient temperature (25-27°C). They were served feed and tap water ad libitum except when fasted is recommended, as reported by Okwudili et al [9], in line with the published guidelines of the National Research Council [15]. The experimental protocol was approved by the institutional ethic committee.…”

“…Flavone glycoside [14], pinnatoside [13] and Lupane triterpenoid [12], moreover, have been isolated from P. pinnata. In addition, Okwudili and co-researchers [9], have reported the effects of a single dose of P. pinnata root-bark on fasting blood glucose (FBG) of alloxan-induced diabetes. There is, however, no information on the effects of the extract on the serum biochemical and histopathological changes of alloxan-induced diabetes.…”

“…In recent times, there is increasing interest in the ethnomedical management of diabetes with natural products of plant origin. One of such plant is Paullinia pinnata -used especially in South Eastern Nigerian medicine [8,9]. Paullinia pinnata L., commonly called "Bread and Cheese", belongs to the family Sapindaceae.…”

Antihyperglycemic, antidyslipidemic and antioxidant properties of hydromethanol extract of Eremomastax speciosa leaf in alloxan monohydrate-induced hyperglycemic rats

“…The induction of diabetes and experimental protocol were conducted as modified by Okwudili et al [22]. Briefly, 30 diabetic rats were randomly separated into 5 groups (I-V) (n = 6).…”