THE EFFICIENCY OF POLYSACCHARIDE GEL EXTRACTED FROM FRUIT-HULLS OF DURIAN (DURIO ZIBETHINUS L.) FOR WOUND HEALING IN PIG SKIN

Polysaccharide gel (PG) extracted from fruit-hulls of durian (Durio zibethinus L.) was prepared as a preparation of dressing film. Efficacy of PG film for the treatment of full-thickness excisional wounds was performed in swine. Six youngfemale, cross-bred pigs, weighing 18-20 kg were used. Three full-thickness excisional wounds 2.45 cm in diameter were operated along both sides of dorsal midline area in each pig. Thirty-six wounds were randomly devided into 3 groups of 12 wounds. All wounds in group 1 were applied 1% Lugol’s solution and covered with sterile gauze dressing (control). The wounds in group 2 and 3 were treated with PG dressing film (treatment 1) and applied 1% Lugol’s solution and covered with PG dressing film (treatment 2), respectively. The wounds were examined for performance of wound healing on day 3, 6, 9, 12 and 15 postoperation and each group were re-treated with the same procedure. On day 18, skin samples from each wound were taken for histopathological study. The results demonstrated that PG dressing film treated wounds (treatment 1) showed more rapid wound closure, slightly and less tissue reactions than those in the control and the treatment 2 groups. The results suggest that PG dressing film seems to have beneficial property on wound healing in pig skin in this study. INTRODUCTION Plants having structural substance associated with their cellulose structures usually contain commercially valuable pectin supplies for food and pharmaceutical industries (Whistler and BeMiller, 1959). In Thailand, there are many reports on the utilization of plant waste as a source of valuable materials of commercial importance. Durian (Durio zibethinus L.) is one of the most favorite fruit of Thailand. The polysaccharide gel (PG) is isolated from fruit-hulls of durian by deriving the process of Pongsamart and Panmaung (1998). PG is a water soluble component of five sugars such as glucose, rhamnose, fructose, arabinose and galacturonic acid and it is useful in preparation of food and pharmaceutical products such as jelly, tablet, suspension and emulsion (Griddit et al., 2001). Toxicity test of PG was determined, a high oral dose (2 g/kg) did not induced severe toxicity in male mice and rats (Pongsamart et al., 2001). Subchronic toxicity test also has not induced toxic effect in male and female mice after longterm feeding at 0.5 g/kg/d for 60-100 days (Pongsamart et al., 2002). Furthermore, Griddit et al. (2001) found that PG can be use as a good film forming agent and used to prepare as a satisfactory film dressing. In a recent study, PG showed antibacterial properties against Staphylococcus aureus and Staphylococcus epidermidis, which found on skin and caused wound infection (Nantawanit et al., 2001). According to the properties of film forming and antibacterial Proc. WOCMAP III, Vol. 5: Quality, Efficacy, Safety, Processing & Trade in MAPs Eds. E. Brovelli, S. Chansakaow, D. Farias, T. Hongratanaworakit, M. Botero Omary, S. Vejabhikul, L.E. Craker and Z.E. Gardner Acta Hort. 679, ISHS 2005 38 activity of PG, it is expected to be applied for treatment of wounds. Therefore, the purpose of this study was to evaluate the efficiency of PG dressing film on wound healing compared with conventional treatment using 1% Lugol’s solution and treatment with 1% Lugol’s solution plus PG dressing film. MATERIALS AND METHODS Preparation of PG Dressing Film PG was isolated from dried fruit-hulls of durian (Durio zibethinus L.) (Pongsamart and Panmaung, 1998). The PG dressing film was prepared by casting/solvent evaporation method (Remunan-Lopez and Bodmeier, 1996). The formulation of PG dressing films composed of 2% PG powder were dissolved in deionized water at room temperature and 15% propylene glycol was added as plasticizer (Girddit et al., 2001). The solutions were warmed and stirred until homogeneously mixed and poured into a plastic casting area 10.2 x 24.8 cm, solid content of PG as 4.42 mg/cm. The films were dried for 3 hrs at room temperature and oven dried for 8 hrs at 50°C. The PG dressing films were cut into 3x3 cm and were steriled as follows; (1) moist sterile by autoclave at 121°C, 15 min.; (2) dry sterile at 121°C, 45 min. (Autoclave, Model HA-300MD, HIRAYA Corp, Japan). The PG dressing films were kept in desiccator until use. Operation and Treatment of Wound Six young female, cross-bred pigs, weighing 18-20 kg were used. The animals were kept separately in each cage and fed a standard swine diet (ad libitum). All pigs were acclimatized for at least 7 days before the experiment started. On experiment day (day 0), all pigs were sedated by intramuscular injection of 4 mg/kg azaperone (Stresnil, Janssen Pharmaceutica, Belgium) and anesthetized with 20 mg/kg pentobarbital sodium (Nembutal, Sanofi, France) by intravenous injection. The dorsal aspects (back) of all pigs were clipped and cleansed with povidone iodine and 70% alcohol solution. Three full-thickness excisional wounds 2.45 cm in diameter were operated along both sides of dorsal midline area in each pig. Thirty-six wounds were randomly divided into 3 groups of 12 wounds. All wounds in group 1 were treated with applied 1% Lugol’s solution (control), while the wounds in group 2 and 3 were treated with PG dressing film (treatment 1) and 1% Lugol’s solution plus PG dressing film (treatment 2), respectively. All wounds were covered with sterile gauze dressing on the top and fixed into the skin at the edges by nylon sutures. On day 3, 6, 9, 12 and 15 postoperation, all animals were sedated and anesthetized by the same protocol. The wounds in each treatment were observed and the areas of wound closure were measured by tracing the wound boundaries using sterile transparent sheets with permanent marker. Wound were cleaned with sterile normal saline and treated by the same treatment as day 0. On day 18 postoperation, the animals were euthanized and the skin tissues in the area of operation were removed size 1x1 in deep in epidermal and dermal layers. Some selected tissues were fixed in 10% neutral buffered formalin, embedded in paraffin wax, sectioned at 5 μm, and stained with hematoxylin and eosin. Histopathological lesions in each treatment were evaluated by veterinarian pathologist. Histopathology Evaluation Histopathological lesions were evaluated by the criteria as follows; (1) epidermal hyperkeratosis and epidermal hyperplasia; (2) subacute dermatitis; (3) chronic dermatitis; (4) dermal fibrosis; and (5) dermal granuloma. They were given a score ranging from 0 (no remarkable lesions), 1 (mild), 2 (moderate) and 3 (severe). The values of the histopathological scores were averaged and expressed as the mean ± standard deviation. All statistical evaluations were performed by ANOVA. The results were considered significant at p < 0.05.