Analgesic Effects of a Standardized Bioflavonoid Composition from Scutellaria baicalensis and Acacia catechu

Mesfin Yimam,Lidia Brownell,Mandee Hodges,Qi Jia

doi:10.3109/19390211.2012.708713

Abstract

ABSTRACTAnti-inflammatory properties of both baicalin and catechins have been widely reported. However, the reports of analgesic effects of baicalin and catechins are limited. Three commonly used pain-related animal models were employed to evaluate the analgesic activity of UP446, a standardized bioflavonoid composition of baicalin and catechins. Carrageenan-induced paw edema, formalin test, and abdominal constriction assays were used to evaluate antinociceptive activity of 150 mg/kg or 100 mg/kg oral doses of UP446. Ibuprofen was used as a reference compound in each test. Pretreatment of carrageenan-induced hyperalgesic animals with UP446 at 150 mg/kg oral dosage reduced the hypersensitivity of pain by 39.5%. Similarly, a single dose of UP446, given orally at 100 mg/kg, exhibited 58% and 71.9% inhibition in pain sensitivity compared to vehicle-treated control in writhing and formalin tests, respectively. These findings suggest that the standardized anti-inflammatory bioflavonoid composition, UP446, could also be employed to inhibit nociception.

Highlights

Current use of prescription and over the counter non-steroidal anti-inflammatory drugs (NSAIDs) has been limited due to untoward gastrointestinal and cardiovascular-related side effects
UP446, a standardized bioflavonoid composition with primarily baicalin from the roots of Scutellaria baicalensis (S. baicalensis) and (+)-catechin from the heartwoods of Acacia catechu (A. catechu), has been used in both over the counter joint care dietary supplements and a prescription medical food
The primary objective of this study is to document the analgesic ability of a standardized bioflavonoid composition with a combination of baicalin and catechins on three different animal models

Summary

Introduction

Current use of prescription and over the counter non-steroidal anti-inflammatory drugs (NSAIDs) has been limited due to untoward gastrointestinal and cardiovascular-related side effects. UP446, a standardized bioflavonoid composition with primarily baicalin from the roots of Scutellaria baicalensis (S. baicalensis) and (+)-catechin from the heartwoods of Acacia catechu (A. catechu), has been used in both over the counter joint care dietary supplements and a prescription medical food This natural flavonoid composition reduces production of eicosanoids through inhibition of cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), and 5-lipoxygenase (5-LOX) enzymes (Burnett, Jia, Zhao, & Levy, 2007) and decreases expressions of inducible nitric oxide synthase (iNOS), nuclear factor-kappaB (NF-kB), and tumor necrosis factor-alpha (TNF-α) (Altavilla et al, 2009). The initial phase lasting for 30–60 min after carrageenan injection is dominated by the release of histamine, serotonin, and kinins and mediated by prostaglandin and leukotrienes, which act relatively late in the development of inflammation response. NSAIDs are known to prevent hyperalgesia of inflammation by blocking the prostaglandin pathway (Flower, 1974)

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