Evaluation of Wound Healing Activity of Ethanolic Extract of Aerva tomentosa Forsk

 

 

Deepak Kumar*1,DN Prasad1, JS Dua1 and SP Bhatnagar2

*1Dept. of Pharmacognosy, Shivalik College of Pharmacy, Nangal, Ropar, Punjab, 140126, (INDIA).

2Department of Pharmaceutical Sciences, B.I.T., Mesra, Ranchi, 835215,(INDIA).

 

 

ABSTRACT

Herbal drugs are already in vouge as therapeutic agents for thousands of years but in present times there is a need to re-valuate their clinical efficacy. Aerva tomentosa Forsk. is recognized by its white axillary bunches of small woolly flowers and traditionaly claimed for its wound healing activity. Wound healing activity of ethanolic extract of Aerva tomentosa Forsk. was evaluated on excision and incision wound using Wistar rats of either sex. Percentage of wound contraction was measured in excision wound, whereas tensile strength of healed wound was measured in incision wound. In excision wound, wound contraction was 93.8 % on 16th day for Aerva tomentosa treated groups. In incision model, significant increase in tensile strength of healed wound was observed in the concentrated ethanolic extract.

 

KEYWORDS: Excision wound, incision wound, framycetin sulphate.

 

 

INTRODUCTION

Aerva tomentosa Forsk. (A.t) (amaranthaceae) is a common wayside weed grown mostly on waste place and found on the plains of the warmer parts of India including Punjab, Central India, Gujarat, Burma, Baluchistan, Ceylon and in tropical Africa. It is commonly known as Perumbulai or Pulaippu in Tamil, Boi kallan in Punjabi and Bur in Gujrati1.The herb contains kaempferol-3-galactoside, kaempferol-3-rhamnogalactoside, β -amyrin and β –sitosterol2. Maher et.al. has isolated and quantified Ecdysteroids from Aerva tomentosa3. A flavonol glycoside viz.kaempferide-3-O-(6’-O-acetyl-4’-O- α-methylsinapyl) neohesperidoside has been isolated from the perianth lobes of the herb. This compound had been found to possess marked hepatoprotective activities4. It is used as a purgative and emetic for horses and camels. The powdered plant is applied externally to ulcers, wounds in domestic animals5.The ethyl acetate fraction of Aerva tomentosa showed significant antimicrobial activity against gm-ve bacteria6.

 

MATERIALS AND METHODS:

Plant material collection:

The aerial parts of Aerva tomentosa were collected from wild source of the state of Punjab during flowering season in the month of November – December and authenticated by Dr. Sumer Chandra, Scientist D, F.R.I. Deemed University, I.P.E., Kaulagarh Road, Dehradun, 248195, Utranchal as Specimen voucher no. SCP- 302.

 

Extraction of plant materials:

The aerial parts were shade dried, powdered and passed through 80 mesh sieve. The powdered material was extracted with ethanol using Soxhlet’s apparatus. The extract obtained was dried in rotary vacuum evaporator at 400 C yielding a yellowish green colored, viscous mass (1.2%). The phytochemical tests of ethanolic extracts of Aerva tomentosa showed the presence of alkaloids, saponin, flavonoid and tannin.

 

 


 


Table 1 Wound healing activity of ethanolic extract of Aerva tomentosa on excision wounds using topical application method

Post wounding days / % contraction

Control

Framycetin sulfate (Stand.gp.)1%

Conc.ethanolic extract of Aerva toment.

Day 4

12.1±0.30

20.8±0.31

17.1±0.27

Day 8

31.2±0.89

59.8±0.90

44.6±0.88

Day 12

72.6±1.05

89.5±0.76٭٭

82.5±0.99٭٭

Day 16

88.6±0.88

97.33±0.66٭٭٭

93.8±1.07٭٭٭

One way ANOVA. Turkey compares.٭٭٭p< 0.001, ٭٭p< 0.01 N=6, values (mean± SEM), expressed as percentage wound healing in each group on the post wounding day.

 

Table 2 Wound breaking strength of Incision wound on 10th day of Ethanolic extract of Aerva tomentosa (gm)

Control

Standard group Framycetin sulfate

Ethanolic extract of Aerva tomentosa

230.5±0.99

512.3±1.22٭٭٭

478.0±1.41٭٭٭

 

 

 

N= 6, values (mean± SEM), ***p< 0.001 considered significant. all p values calculated with respect to  control.

 

 

 


Animals:

Healthy Wister albino rats of either sex weighing about 150-180g were used for wound healing activity. All animal experiments were carried out under the CPCSEA norms, after obtaining the approval of Institutional Animal Ethical Committee (1080/C/07/CPCSEA/2007). All animals were procured from the Institute of Microbial Technology (IMTECH), Sector 39-A, Chandigarh, 160036. Animals were divided into 3 groups of 6 animals each for both models. Group I was untreated group which served as control, group II as standard and was treated with Framycetin sulphate cream (FSC) (1%w/w) in both excision and incision wound models, group III with concentrated ethanolic extract of A.t.  No other topical or systemic therapy was given to animals during the course of wound healing study.

 

Excision Wound Model7:

The hair on the skin from dorsal thoracic region were removed by using a suitable depilatory (Anne French hair removing cream).Circular wounds of approximately 10mm diameter were inflicted on the cleared skin by cutting under mild ether anesthesia, 5 cm away from the ears on the depilated part of skin and the entire thickness of skin from the demarcated area was excised to get a wound. For this a round seal of 10mm diameter was impressed on dorsal thoracic region. Area of the wounds were measured immediately in sq. mm by tracing the wounds on to tracing paper and there after on graph paper by using carbon paper, on day of wounding and this was taken as the initial wound area reading.  Standard and test sample were applied once daily topically till complete contraction of the skin takes places directly on wound, starting from day of excision. The wound area was measured subsequently on 4th, 8th, 12th and 16th days post wounding8. The percentage of wound contraction was calculated from the days of measurements of wound area.

 

Incision wound model:

For incision wound model each animal was secured to operation table in its natural position under light ether anesthesia and hairs were removed from back portion using depilator. Light par vertebral straight incisions were made on the cleared surface by cutting the skin of the animals through the entire thickness of skin with a sterilized sharp blade. The wounds were created at a length of about 1.5 cm. After the incision, the parted skin was kept together and sutured with absorbable sterilized surgical needled suture USP, Vicryl (synthetic, 0.5 matric, coated polyglactin 910, made by Ethicon, Baddi, H.P.) thread as interrupted sutures at 0.5cm apart with curved needle (no.11)9. The concentrated ethanolic extract of A.t. was applied once a day for 10 days in a similar manner as control and standard drug. Wound tensile strength was measured on the 10th day by continuous constant water flow technique of Lee10.

 

Measurement of Wound Breaking Strength of Incised Wounds:

Measurement of wound breaking strength was performed following Lee with certain modifications. A board was placed on a raised platform on the table, on which the anaesthetized rat was made to lie on its abdomen. Two clamps were clamped on either sides of healed wound at a distance of 0.5cm.The left clamp was fastened tightly to a stand by means of a thread. The right clamp was connected to a leak proof polythene bag through a pulley, by means of a thread. A reservoir containing water was placed at a suitable height and connected to a polythene bag by means of a rubber tube. The position of the board was adjusted so that, the polythene bag was hanging freely. Water was added to polythene bag rapidly at constant rate from the reservoir until the wound opened. Amount of water in polythene bag was measured in ml and was considered as tensile strength of the wound11.All results are expressed as mean ± S.E.M. The results obtained were compared with the control and analysed using statistical method.

 

RESULTS:

In excision wounds, wound contraction was 97.33 and 93.8 % respectively on 16th day for framycetin SO4 and ethanolic extract of A.t.treated groups. Significant wound contraction was observed on 16th day for A.t. treated groups in comparison with the control group.

 

In incision model, significant increase in tensile strength of healed wounds was observed in Aerva tomentosa ethanolic extract.

 

DISCUSSION:

Wound healing comprises of different phases such as contraction, granulation and collagenation12.It normally involves an initial inflammatory phase followed by fibroblast proliferation, formation of collagen fibers and shrinking, occurring concurrently but independent of one another13.Phytoconstituents such as flavonoid and tannin are reported to be responsible for wound healing activity. Wound healing effect is also attributed to free radical scavenging activity of flavanoids14.Flavonoids are known to reduce lipid peroxidation not only by preventing or


slowing onset of cell necrosis, but also by improving vascularity. Lipid peroxidation is an important process in several types of injuries like burns, infected wounds and skin ulcers. Hence any drug that inhibits lipid peroxidation is believed to increase strength of collagen fibers, by increasing circulation or by preventing cell damage or by promoting DNA synthesis15.Flavonoid and tannin are known to promote wound healing process mainly by their astringent and antimicrobial property. Hence presence of flavonoid and tannin in the ethanolic extract of A.t. may be responsible for its wound healing activity. Hence, the results of present study support the traditional use of Aerva tomentosa in the treatment of wounds. Further, work may be undertaken to isolate and identify the bio-active constituents responsible for this activity.

 

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10.    Lee KH. Studies on the mechanism of action of salicylate II: Retardation of wound healing by Aspirin.J. Pharmacol. Sci.1968; 57; 1042.

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12.    Vidyas SM, Krishna V, Manjunath BK, Singh SD and Mankani KL, Wound healing activity of Leucuas hirta. Indian J.Pharm.Sci.2006; 380.

13.    Ganachari MS, Kumar S and Patel A. Wound healing activity of Saussurea lappa roots.Indian Drugs.2005; 42(5); 295.

14.    Lara OO, Fakoya FA, Agbani EO and Lwalewa EO. Vascular permeability-Increase effect of the leaf essential oil of Ocimum gratissimum Linn. as a mechanism for its wound healing property.Afr.J.Trad Compl. Alt Med, 2005 ;( 2); 253.

15.    Joshi SD, Arvind MB, Ashok K. Veerapur VP and Shastry CS.Wound healing activity of Dodonaea viscose leaves. Indian Drugs.2003 ;( 9); 549.