Beneficial effects of natural eggshell membrane (NEM) on multiple indices of arthritis in collagen-induced arthritic rats

Abstract

Objectives: This study was performed to evaluate the potential efficacy of natural eggshell membrane (NEM) in collagen-induced arthritic rats, a well-established rodent model of inflammation and rheumatoid arthritis.

Methods: Rats with developing type II collagen-induced arthritis (CIA) were treated once daily by oral gavage on study days –14 to 17 with vehicle or NEM (52 mg/kg body weight). Rats were euthanized on study day 17. Efficacy was assessed by daily ankle caliper measurements, ankle diameter expressed as area under the curve (AUC_d0–17), and histopathologic evaluation of ankles and knees. Serum biomarkers of cartilage function and inflammation [collagen type II C-telopeptide (CTXII), cartilage oligomeric matrix protein (COMP), and alpha-2-macroglobulin (A2M)] were measured by ELISA.

Results: Treatment with NEM resulted in significant beneficial effects on the daily ankle diameter measurements and ankle diameter AUC. Ankle and knee histopathology scores were significantly reduced (36% and 43% reduction of summed individual histopathology scores for ankle and knee, respectively; p < 0.05) toward normal for rats given NEM compared to vehicle controls. The percent reduction of serum CTXII, COMP, and A2M in NEM-treated rats ranged from 30% to 72% (p < 0.05).

Conclusions: NEM significantly improved multiple aspects of inflammatory arthritis including inflammation, pannus, cartilage damage, bone resorption, and periosteal bone formation. This study provides further support for the use of CTXII, COMP, and A2M as relevant biomarkers that were responsive to NEM.

Keywords:

• A2M
• COMP
• CTXII
• Methotrexate
• Rheumatoid

Acknowledgments

The authors gratefully acknowledge the participation, dedication, and expertise of the animal care and technical staffs of Bolder BioPATH and HistoTox Labs.

Conflict of interest

KJW, CAA, and JLE are employees of Novus International (St. Charles, MO) which co-markets NEM® (with ESM Technologies, Carthage, MO) through its Stratum Nutrition business unit. KJR is an employee of ESM Technologies which manufactures and co-markets NEM with Stratum Nutrition. AB is an employee of Bolder BioPATH (Boulder, CO), an independent contract research organization that was contracted by Novus International to perform this study. Funding for this study was provided by Novus International (St. Charles, MO) and ESM Technologies (Carthage, MO). These relationships are provided in the spirit of transparency; none of the authors benefit financially (e.g. royalties, commissions, bonuses, etc.) from the sale of any intervention used in this study.