S Dwajani, T Shanbhag
breaking strength, dexamethasone, epithelization, michelia champaca, wound healing
S Dwajani, T Shanbhag. Michelia Champaca: Wound Healing Activity In Immunosuppressed Rats. The Internet Journal of Alternative Medicine. 2008 Volume 7 Number 2.
A wound is a disruption in the normal anatomical structure and function of living tissue that can be caused by physical, chemical, microbiological or immunological injury. Wound healing is essentially a survival mechanism and represents an attempt to maintain normal anatomical structure and function. When healing takes place in a direction away from its normal course, it may result in non-healing, under-healing or over healing. Therefore attempts have been made to accelerate wound healing either when it is progressing normally1 or when it is suppressed by corticosteroids2, anti-neoplastic3 and non-steroidal anti-inflammatory agents4. Treatment is aimed at either shortening the time required for healing or minimizing the undesired consequences.
A large section of world population relies on traditional remedies to treat a plethora of diseases. Medicinal herbs are an indispensable part of traditional medicine practiced all over the world due to low cost, easy access and ancestral experience. The greatest contribution of plant kingdom to mankind is that it has provided a large variety of potent drugs to alleviate suffering from disease. The plant
Materials and Methods
Ethical clearance: Institutional Animal Ethics Committee cleared all the protocol of the study.
Twelve-week-old healthy Wistar rats weighing 150-200g of either sex, bred locally in the animal house of Kasturba Medical College, Manipal, were selected for the study. They were housed under controlled conditions of temperature (23±2oc), humidity (50±5%) and 10-14 hours of light and dark cycles. The animals were housed individually in polypropylene cages containing sterile paddy husk bedding and free access to food and water
The animals were randomly allocated into four groups of six animals each.
Group I received 2ml gum acacia.
Group II received alcoholic extract of
Group III received Dexamethasone intramuscularly
Group IV received Dexamethasone + alcoholic extract of
Gum acacia and alcoholic extract of
For assessment of wound healing activity, excision, incision and dead space wound model were used. All wounding procedures were carried out under ketamine anaesthesia i.m. In the present study no animals showed visible signs of infection.
Incision wound model: Two long paravertebral straight incisions of 6cm each were made 1cm lateral to the vertebral column on the either side of the depilated back of the animal, cutting through the entire thickness of the skin11. The wounds were closed with the sutures 1cm apart with No.4 black silk thread and straight needle12. The sutures were removed on the 7th post wounding day and breaking strength was measured on the 10th day by continuous constant water flow technique of Lee4.
Excision wound model: An excision wound was made by cutting away a circular area of full thickness of skin measuring 500mm2 on the depilated back of the rat, in the dorsal interscapular region, 5cm away from the ears13. Period of epithelization was noted as the number of days after wound healing required for the eschar to fall off leaving no raw wound behind. Wound contraction rate was monitored by planimetric measurement of wound area on alternate days. This was done by tracing the wound area on a graph paper. Reduction in the wound size was expressed as percentage of original wound size14.
Dead space wound model: Dead space wounds were created by implanting 2.5x0.5cm polypropylene tubes subcutaneously in the lumbar region, beneath the dorsal paravertebral lumbar skin, through a small transverse incision15. Granulation tissue formed on the tube was harvested by careful dissection on the 10th post wounding day and breaking strength of granulation tissue was measured. The granulation tissue was dried in an oven at 60oC for 24 hours and the dry weight was noted. Acid hydrolysate of the dry tissue was used for determination of hydroxyproline content by the method of Neuman and Logan16.
The results were analyzed by One way Analysis of Variance (ANOVA) followed by Scheffe’s test, as applicable,using SPSS computer package version 10.
Incision wound model: The mean breaking strength in the Group 1 was 204.58±8.04g and it was increased to 236.66±16.10g in the Group 2. In Group 3, the breaking strength was significantly reduced to 164.58±9.16g as compared to Group 1, and significantly (p<0.028) increased in Group 4 (217.08±9.1g) compared to Group1 and Group 3
Excision wound model: The percentage of wound contraction in the group 1 was 25.46±5.3, 51.16±0.58, 92.20±1.24 and 98.06±0.39 as measured on the 4th, 8th, 12th 16th day respectively. The wound contraction rate was not significantly altered in groups 2 & 4 as compared to group 1. The mean period of epithelization in the group 1 was 21.00±0.68 days. The rate of wound contraction was not significantly altered in animals treated with both Dexamethasone and
Dead space wound model: The mean breaking strength of the granulation tissue in the group 1 was 230.83±21.11g. An increase in the breaking strength of granulation tissue was observed in the
There was increase in breaking strength of granulation tissue in group 4 when compared to group 3 (table-3)
The mean dry weight of granulation tissue in the group 1 was 0.060±0.012mg. This was increased to 0.065±0.061mg in the group 2. The mean dry weight of granulation tissue in group 3 was 0.070±0.015mg (statistically significant) (table 3)
The mean hydroxyproline content of granulation tissue of the group 1 was 926.6±239.6mg/g of the tissue. It was significantly altered in group 4
In the present study, the breaking strength of the incision wound was not significantly increased in the
Dexamethasone inhibits wound contraction, granulation tissue and collagen formation2. This is the cause of suppressed wound healing in the Dexamethasone treated group in all wound models. The effect of Dexamethasone was reversed by
Oxidative stress has been implicated in a variety of degenerative processes and diseases including wound healing17. This could contribute to its pro-healing effects.
The enhanced wound contraction effect and epithelization by