I would use a split-wound assay, e.g. one half covered with vaseline cream, the other half with your control cream : all other experiments with different wounds in humans are worthless....

There is one suggestion to use polysporin cream which contains painkiller as well as antibiotics.

But it is said that honey can also act like a wound healer. You may try it

• yes you can use honey as medihoney ointtment 

Hidayet, where is the wound anatomically, and is the rat able to scratch or lick at the wound? Are there other animals in the same cave?

Persistence of ointment on the wound: A shielding / protective cover may determine the efficacy of your treatment maybe more than your ointment per se.

Anatomy: Wounds close to the bowel may heal better with a gall acid catching  drug like cholestyramin, which is useless at the head e.g.

What exactly are you trying to look at?  Would "standard wound care" be your preferred control? 

Hidayet, sorry, I overlooked the word "rat" : the rat is last choice in wound healing experiments because even after a third degree burn of the whole back (!) this large wound is fully healed within 3 weeks by contraction ! Rats have a "platysma" over all their back: the panniculus carnosum ! Therefore, use pigs or dogs for wound healing experiments (I had to burn 1000s of rats for cold water experiments in the 1960....)

Dear Doll,

I am gonig to form a 1.5 cm circular and full thickness wound on the ridge of rats. 

Dear Cordrey

I want to evaluate the effects of two plants extract on the wound healing.

Dear Lemperle

I have not apportunity to use pig or dog. I have to use rats for this study. 

Is there a need to use a positive control (commercially ointments). 

Is your plant extract added to another medium, such as a hydrogel or water to make a wet to moist dressing?  I'd recommend doing he same medium, without the extract, for your control.  If you're just adding the extra as is, then you want to keep a moist wound healing environment for the controls. A hydrogel should do the trick. Be sure to get a simple one, without added ingredients, such as silver, zinc, phytonutrients, etc. It's hard to recommend a specific brand, as I'm not sure what's available in Turkey, but you should be able to find one locally. Talking to your local wound clinic can help you identify one if needed. Or, a google search to see which dressing manufacturers are selling in Turkey.

Hidayet, if you need a control you may use to opt for widely available simple products with just wound protective effect - e.g. vaseline, panthenol or hydrogel. Hydrogel needs containment, as it may escape the wound easily (water - like). Panthenol (vitamin) is semifluid , too. And it is with active ingredient, which you may decide to avoid. Vaseline is cheap and really sticky, and contains no acting ingredient, keeps the wound moist under a semifatty cover. It is not sweet, so it may be less eaten / licked off by the animals. Try it out. You are the researcher establishing an interesting model.

Vaseline (petrolatum), however, can delay epithelial migration, so any improvement you see in your extract may be due to cell mobility more than any active property. I would think that you would need some kind of cover (gauze) for both groups, so containing a hydrogel wouldn't be a problem. Hydrogels aren't very watery, actually. They're more like lubricating jelly (eg: KY) than a liquid.

Thank you very much for the advices you give. 

Best regads.