Aqueous Extracts of <i>Morus alba</i> Root Bark and <i>Cornus officinalis</i> Fruit Protect against Osteoarthritis Symptoms in Testosterone-Deficient and Osteoarthritis-Induced Rats

• Main Authors: Sunmin Park, Bo Reum Moon, Ji Eun Kim, Hyun Joo Kim, Ting Zhang
• Format: Article
• Language: English
• Published: MDPI AG 2020-12-01
• Series: Pharmaceutics
• Subjects: bone mineral density; lean body mass; articular cartilage; inflammation; pain behavior; testosterone deficiency
• Online Access: https://www.mdpi.com/1999-4923/12/12/1245

Water extracts of both <i>Morus alba</i> L. root bark (MBW) and <i>Cornus officinalis</i> Siebold and Zucc fruit (CFW) have traditionally been used to promote men’s health in the elderly in Asia. We determined that the 12-week consumption of MBW and CFW could alleviate testosterone-deficiency syndrome and osteoarthritis (OA) symptoms in testosterone-deficient rats, and the action mechanisms were explored. Rats with bilateral orchiectomy (ORX) were fed a 45% fat diet containing either 0.5% MBW (ORX-MBW), 0.5% CFW(ORX-CFW), or 0.5% dextrin (ORX-CON). Sham-operated rats also received 0.5% dextrin (Non-ORX-CON). After 8 weeks of treatment, all rats had an injection of monoiodoacetate (MIA) into the left knee, and they continued the same diet for the additional 4 weeks. ORX-CFW and ORX-MBW partially prevented the reduction of serum testosterone concentrations and decreased insulin resistance, compared to the ORX-CON. ORX-CFW and ORX-MBW protected against the reduction of bone mineral density (BMD) and lean body mass (LBM) compared to the ORX-CON. The limping and edema scores were lower in the order of the ORX-CON, ORX-CRF = ORX-MBW, and Non-ORX-CON (<i>p</i> < 0.05). The scores for pain behaviors, measured by weight-distribution on the OA leg and maximum running velocity on a treadmill, significantly decreased in the same order as limping scores. ORX-MBW protected against the increased expression of matrix metalloproteinase (MMP)-3 and MMP-13 and reduced the production of inflammatory markers such as TNF-α and IL-1β, by MIA in the articular cartilage, compared to the ORX-CON (<i>p</i> < 0.05). The cartilage damage near the tidemark of the knee and proteoglycan loss was significantly less in ORX-MBW than ORX-CON. In conclusion, MBW, possibly CFW, could be effective alternative therapeutic agents for preventing osteoarthritis in testosterone-deficient elderly men.