EFFECTS OF ACEMANNAN, A COMPLEX CARBOHYDRATE, ON WOUND-HEALING IN YOUNG AND AGED RATS

Acemannan is an acetylated, B(1,4)-linked mannan derived from the clea r gel of the Aloe vera leaf. Studies were undertaken to determine if i t had an effect on the rate of wound healing in rats. When a solution containing 30mug acemannan was injected into tissues surrounding biops y punch wounds in young (three-month old) rats, a reduction in wound h ealing time of approximately four days when compared to untreated woun ds was observed. When used to treat biopsy punch wounds in two-year ol d rats, it resulted in a reduction in wound healing time from 21 days in untreated wounds to 14 days in treated wounds. This enhancement in the rate of wound healing was observed in both ad libitum-fed and calo rie-reduced aged rats. Acceleration in wound healing was also observed when acemannan was administered by either the intraperitoneal or intr acardiac routes. Acemannan is believed to exert its effects on the wou nd healing process by two mechanisms. First, it is a potent macrophage -activating agent and may therefore stimulate the release of fibrogeni c cytokines. Macrophage function is known to be a limiting factor in t he healing of wounds in aged animals. Alternatively, growth factors ma y bind directly to acemannan, promoting their stability and possibly p rolonging their stimulating effects on granulation tissue formation.