Isoflavonoids as wound healing agents from Ononidis Radix.

ETHNOPHARMACOLOGICAL RELEVANCE: Dried roots of Ononis spinosa L. are traditionally used for their diuretic, anti-inflammatory and wound healing effects.

AIM OF THE STUDY: Isolation of the bioactive compounds of Ononis spinosa L. subsp. leiosperma (Boiss.) Sirj.

MATERIALS AND METHODS: Ethyl acetate extract prepared from the roots of Ononis spinosa L. subsp. leiosperma (Boiss.) Sirj. was subjected to silica gel column. The fractions were tested for their wound healing and anti-inflammatory activities. Linear incision and circular excision wound models and hydroxypyroline estimation assay were used for the wound healing activity. Carrageenan-induced hind paw edema, TPA-induced ear edema and acetic acid-induced increase in capillary permeability tests as acute inflammation; FCA-induced arthritis as chronic inflammation models were used for the assessment of anti-inflammatory activity. Antioxidant capacities of the fractions were tested using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, 2,2-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid (ABTS) scavenging activity assay, reducing power assay and hydroxyl radical (OH- ) scavenging assay. The isolation procedure was continued with the active fraction (Fr-E5).

RESULTS: Fr-E5 exhibited remarkable wound healing activity with the 33.4% tensile strength value on the linear incision wound model and 51.4% reduction of the wound area at the day 12 on the circular excision wound model. Hydroxyproline content of the tissue treated by Fr-E5 was found to be 30.9 ± 0.72μg/mg. Acetic acid induced increase in capillary permeability test results revealed that Fr-E5 inhibited inflammation by the value of 40.3%. Fr-E5 showed 28.1-32.2% inhibition in carrageenan-induced hind paw edema test while did not possess activity on TPA-induced ear edema and FCA-induced arthritis models. Trifolirhizin, ononin, medicarpin-3-O-glucoside, onogenin-7-O-glucoside and sativanone-7-O-glucoside were isolated from Fr-E5 and tested for their wound healing activities using by measuring their inhibition of hyaluronidase, collagenase and elastase enzymes. Ononin and sativanone-7-O-glucoside inhibited hyaluronidase and elastase enzymes by 31.66% and 41.75%; 45.58% and 46.88% values respectively at the dose of 100μg/mL.

CONCLUSION: Among five isolated compounds, ononin and sativanone-7-O-glucoside were found to inhibit hyaluronidase and elastase enzymes. According to the results, these compounds may majorly be responsible for the wound healing activity of the extract.