Herbal remedies improve the strength of repairing ligament in a rat model.

Herbal remedies have been reported to be effective in controlling inflammation for acute soft tissue injuries. There exist, however, no reports of their effects on collagen production and remodeling; thus mechanical strength studies of the tissues have not been reported. This study tested the effects of a herbal remedy on the strength of healing medial collateral ligaments (MCL) in rats. Sixteen rats receiving surgical transection to their right MCLs and eight receiving sham operation were tested. Eight of the MCL-injured animals were treated with an adhesive herbal plaster application to their right knees, while the other eight in the MCL injured group and the sham group were treated with plain adhesive plaster to their right knees. The MCLs were harvested and tested at either 3 or 6 weeks post-operation. The ultimate tensile strength (UTS) and stiffness normalized to the uninjured side of each animal of the herb and sham groups were significantly larger than those of the control at both 3 and 6 weeks (p = 0.001). No significant difference was found in stiffness between the herb and sham groups (p > 0.05). We concluded that the herbal remedy improves the UTS and stiffness of repairing MCLs at 3 and 6 weeks after injury.