1. Free radical scavenging profile and myeloperoxidase inhibition of extracts from antidiabetic plants: Bauhinia forficata and Cissus sicyoides.

Khalil NM, Pepato MT, Brunetti IL.

Biol Res. 2008;41(2):165-71. Epub 2008 Oct 8.

Clinical Analysis Department, School of Pharmaceutical Sciences, Araraquara-UNESP-São Paulo StateUniversity, São Paulo, Brazil.

There is abundant evidence that reactive oxygen species are implicated in several physiological and pathological processes. To protect biological targets from oxidative damage, antioxidants must react with radicals and other reactive species faster than biological substrates do. The aim of the present study was to determine the in vitro antioxidant activity of aqueous extracts from leaves of Bauhinia forficata Link (Fabaceae-Caesalpinioideae) and Cissus sicyoides L. (Vitaceae) (two medicinal plants used popularly in the control of diabetes mellitus), using several different assay systems, namely, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) decolorization, superoxide anion radical (O2(.-)) scavenging and myeloperoxidase (MPO) activity. In the ABTS assay for total antioxidant activity, B. forficata showed IC50 = 8.00+/-0.07 microg/mL, while C. sicyoides showed IC50 = 13.0+/-0.2 microg/mL. However, the extract of C. sicyoides had a stronger effect on O2(.-) (IC50 = 60.0+/-2.3 microg/mL) than the extract of B. forficata (IC50 = 90.0+/-4.4 microg/mL). B. forficata also had a stronger inhibitory effect on MPO activity, as measured by guaiacol oxidation, than C. sicyoides. These results indicate that aqueous extracts of leaves of B. forficata and C. sicyoides are a potential source of natural antioxidants and may be helpful in the prevention of diabetic complications associated with oxidative stress.

PMID: 18949134 [PubMed - in process]

2. Effect of Bauhinia forficata aqueous extract on the maternal-fetal outcome and oxidative stress biomarkers of streptozotocin-induced diabetic rats.

Volpato GT, Damasceno DC, Rudge MV, Padovani CR, Calderon IM.

J Ethnopharmacol. 2008 Feb 28;116(1):131-7. Epub 2007 Nov 19.

Laboratório de Pesquisa Experimental de Ginecologia e Obstetrícia, Departamento de Ginecologia e Obstetrícia, Faculdade de Medicina de Botucatu, UNESP, Distrito de Rubião Jr s/n, 18610-000 Botucatu, SP, Brazil. gtvolpato@yahoo.com

ETHNOPHARMACOLOGICAL RELEVANCE: Bauhinia forficata Link, commonly known as "paw-of-cow", is widely used in Brazilian folk medicine for the treatment of diabetes. AIM OF THIS STUDY: To evaluate the effect of Bauhinia forficata treatment on maternal-fetal outcome and antioxidant systems of streptozotocin-induced diabetic rats. MATERIALS AND METHODS: Virgin female Wistar rats were injected with 40 mg/kg streptozotocin before mating. Oral administration of an aqueous extract of Bauhinia forficata leaves was given to non-diabetic and diabetic pregnant rats at increasing doses: 500 mg/kg from 0 to 4th day of pregnancy, 600 mg/kg from 5th to 14th day and 1000 mg/kg from 15th to 20th day. At day 21 of pregnancy the rats were anaesthetized with ether and a maternal blood sample was collected for the determination superoxide dismutase (SOD) and reduced glutathione (GSH). The gravid uterus was weighed with its contents and fetuses were analyzed. RESULTS AND CONCLUSION: The data showed that the diabetic dams presented an increased glycemic level, resorption, placental weight, placental index, and fetal anomalies, and reduced GSH and SOD determinations, live fetuses, maternal weight gain, gravid uterine weight, and fetal weight. It was also verified that Bauhinia forficata treatment had no hypoglycemic effect, did not improve maternal outcomes in diabetic rats, but it contributed to maintain GSH concentration similarly to non-diabetic groups, suggesting relation with the decreased incidence of visceral anomalies.

PMID: 18155864 [PubMed - indexed for MEDLINE]

3. Antidiabetic activity of Bauhinia forficata extracts in alloxan-diabetic rats.

Lino Cde S, Diógenes JP, Pereira BA, Faria RA, Andrade Neto M, Alves RS, de Queiroz MG, de Sousa FC, Viana GS.

Biol Pharm Bull. 2004 Jan;27(1):125-7.

Department of Physiology and Pharmacology, Federal University of Ceará, Coronel Nunes de Melo 1127, 60430-270 Fortaleza, Ceará, Brazil. cleidelino@yahoo.com.br

The antidiabetic activity of aqueous, ethanolic and hexanic extracts of Bauhinia forficata was investigated in a model of alloxan-induced diabetes in rats. The biochemical parameters studied were: plasma glucose, serum triglycerides, cholesterol, high density lipoprotein (HDL), and low density lipoprotein (LDL). Extracts were administered daily for 7 d at doses of 200 and 400 mg/kg, p.o., 48 h after alloxan injection (60 mg/kg, i.v.). The alloxan-diabetic rats showed significant reductions in plasma glucose, triglycerides, total cholesterol and HDL-cholesterol after treatment with the extracts and glibenclamide (used as standard) as compared to the diabetic controls. Levels of LDL were not altered. In conclusion, our results showed that the plant extracts when administered by gavage may reduce glucose, triglycerides, total cholesterol and HDL-cholesterol levels. These results suggest the validity of the clinical use of B. forficata in the treatment of diabetes mellitus type II.

PMID: 14709915 [PubMed - indexed for MEDLINE]