Anti-inflammatory effects of polyphenolic-enriched red raspberry extract in an antigen-induced arthritis rat model.

Abstract

The red raspberry ( Rubus idaeus ) fruit contains bioactive polyphenols including anthocyanins and ellagitannins with reported anti-inflammatory properties. This study sought to investigate the cartilage-protecting and anti-inflammatory effects of a polyphenolic-enriched red raspberry extract (RRE; standardized to total polyphenol, anthocyanin, and ellagitannin contents) using (1) an in vitro bovine nasal explant cell culture model and (2) an in vivo adjuvant-induced arthritis rat model. RRE contained 20% total polyphenols (as gallic acid equivalents), 5% anthocyanins (as cyanidin-3-glucoside equivalents), and 9.25% ellagitannins (as ellagic acid equivalents). In the in vitro studies, bovine nasal explants were stimulated with 10 ng/mL IL-1β to induce the release of proteoglycan and type II collagen. On treatment with RRE (50 μg/mL), there was a decrease in the rate of degradation of both proteoglycan and type II collagen. In the in vivo antigen-induced arthritis rat model, animals were gavaged daily with RRE (at doses of 30 and 120 mg/kg, respectively) for 30 days after adjuvant injection (750 μg of Mycobacterium tuberculosis suspension in squalene). At the higher dose, animals treated with RRE had a lower incidence and severity of arthritis compared to control animals. Also, histological analyses revealed significant inhibition of inflammation, pannus formation, cartilage damage, and bone resorption by RRE. This study suggests that red raspberry polyphenols may afford cartilage protection and/or modulate the onset and severity of arthritis.

• Authors: Dinorah Jean-Gilles, Liya Li, Hang Ma, Tao Yuan, Clinton O Chichester 3rd, Navindra P Seeram
• Journal: Journal of agricultural and food chemistry (J Agric Food Chem) Vol. 60 Issue 23 Pg. 5755-62 (Jun 13 2012) ISSN: 1520-5118 [Electronic] United States
• PMID: 22111586 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Anti-Inflammatory Agents
• Collagen Type II
• Phytochemicals
• Plant Extracts
• Polyphenols
• Proteoglycans

Topics

• Animals
• Anti-Inflammatory Agents (pharmacology)
• Arthritis, Experimental (drug therapy, prevention & control)
• Cartilage (drug effects, metabolism)
• Cell Line
• Collagen Type II (metabolism)
• Dose-Response Relationship, Drug
• Male
• Phytochemicals (pharmacology)
• Plant Extracts (pharmacology)
• Polyphenols (pharmacology)
• Proteoglycans (metabolism)
• Rats
• Rats, Inbred Lew
• Rosaceae (chemistry)