Investigations on the in vivo wound healing potential of Hypericum perforatum L.

Ethnopharmacological relevance

Olive oil extract of the flowering aerial parts of Hypericum perforatum L. (Hypericaceae) is a popular folk remedy for the treatment of wounds in Turkey.

Aim of the study

In order to prove the claimed utilization of the plant, the effects of the extracts and the fractions were investigated by using bioassay-guided procedures. For the wound healing activity assessment, in vivo excision and incision wound models were applied. For the anti-inflammatory activity, an in vivo model, based on the inhibition of acetic acid-induced increase in capillary permeability was used as well. Moreover, a parallel study was run on Hypericum scabrum L., which is a widespread species of the gender but not known as a folk remedy for wound healing, to provide a preliminary data to compare and emphasize the selection of correct plant species.

Results

Initial investigations proved that the olive oil extract of Hypericum perforatum has a significant wound healing effect on excision (5.1–82.6% inhibition) and circular incision (20.2–100.0% inhibition) wound models. In order to determine the active wound healing ingredient(s), aerial parts of the plant was extracted with ethanol, noteworthy wound healing activity profile was observed with the wound models; between 18.3% and 95.6% in excision model and from 13.9% to 100.0% inhibitions in incision model were determined. The ethanolic extract was then submitted to successive solvent extractions with n-hexane, chloroform and ethyl acetate (EtOAc). Each solvent extract was also applied on the same wound models, consequently, EtOAc subextract was found to be the most active one by inhibiting wounds between 17.9% and 100.0% in excision model, subsequently between 9.4% and 100.0% in incision model. However, all subfractions obtained from the EtOAc subextract using Sephadex LH-20 column chromatography showed wound healing activity not more than the whole EtOAc subextract, which revealed that a possible synergistic activity that might be questioned. Among the active Sephadex fractions, Fr. A further yielded hyperoside, isoquercitrin, rutin and (−)-epicatechin and Fr. B yielded hypericin as the major components. Moreover, a dose-dependent anti-inflammatory activity was found for the ethanol extract, EtOAc subextract and Sephadex fractions of Hypericum perforatum. These results suggest that anti-inflammatory activity of the active fractions might have a contributory role in the wound healing effect of the plant.

Conclusion

Results of the present study have proved that aerial parts of Hypericum perforatum possess remarkable wound healing and anti-inflammatory activities supporting the folkloric assertion of the plant in Turkish folk medicine. Flavonoids [hyperoside, isoquercitrin, rutin and (−)-epicatechin] and naphthoquinones (hypericins) were found as the active components of Hypericum perforatum. On the other hand, ethanol extract of Hypericum scabrum showed neither remarkable wound healing nor anti-inflammatory activity demonstrating the importance of correct plant species selection in therapeutic applications.     

A novel wound healing ointment: a formulation of Hypericum perforatum oil and sage and oregano essential oils based on traditional Turkish knowledge

Aim of the study

Hypericum perforatum L. (Hypericaceae), olive oil (Oleaceae), Origanum Tourn ex L. and Salvia L. species (Lamiaceae) are used against inflammatory disorders and for healing of skin wounds in traditional Turkish medicine. A new ointment formulation was developed to provide more efficient wound healing activity. The content of the formulation was as follows; olive oil extract of flowering aerial parts of Hypericum perforatum L., olive oil, an equivalent mixture of Origanum majorana L. and Origanum minutiflorum Schwrd. et Davis essential oils (Origani aetheroleum), Salvia triloba L. essential oil. The aim of the present study is to assess the wound healing potential of this new formulation by using in vivo and in vitro models as well as histopathological methods.

Materials and methods

For the evaluation of wound healing potential of this formulation (HPP crème mit Rotöl ointment) in vivo wound healing experimental models were employed on rats and mice and the efficiency was comparatively assessed against a reference ointment Madecassol^®. Tissue sections were also evaluated histopathologically. Furthermore, the wound healing activity of each component was also investigated individually to determine the improvement in the healing capacity of the formulation.

Results

The ointments of HPP crème mit Rotöl and Hypericum perforatum L. demonstrated the highest activities on both wound models when compared to reference ointment Madecassol^®, while the other ingredients did not show any remarkable wound healing effect. However, the efficacy of the formulation was remarkably higher than the Hypericum L. ointment alone which was also confirmed by histopathological evaluation. On the other hand, the formulation did not reduce elastase activity in vitro, but inhibited the collagenase activity. HPP crème mit Rotöl also exerted bactericidal and candicidal activities.

Conclusions

The experimental studies revealed that HPP crème mit Rotöl formulation displays remarkable wound healing activity. To be acting on the different stages of wound healing process could be considered as a beneficial effect of the formulation for the treatment of wounds.     

Exploring the wound healing activity of Arnebia densiflora (Nordm.) Ledeb. by in vivo models

Ethnopharmacological relevance

The roots of Arnebia densiflora (Nordm.) Ledeb. (Boraginaceae), which is an endemic plant for Turkey, have been used for healing of wounds in folk medicine. The extract of the roots in olive oil and mostly the root barks was applied onto open wounds for rapid healing.

Aim of the study

To evaluate the wound healing activity of the roots, extracts were prepared with different solvents; hexane, chloroform, ethyl acetate and methanol, respectively from the roots of Arnebia densiflora.

Materials and methods

Incision by using tensiometer and excision models were employed on mice and rats.

Results

Significant wound healing activity was observed with the ointment formulation prepared by using hexane extract at 1% concentration on the mentioned models. The results of histopathological examination supported the outcome of both incision and excision wound models. The wound healing effect was comparatively evaluated with a reference ointment Madecassol^®.

Conclusion

The experimental data demonstrated that Arnebia densiflora displayed remarkable wound healing activity.     

Inhibitory effect of eupatilin and jaceosidin isolated from Artemisia princeps on carrageenan-induced inflammation in mice

Ethnopharmacological relevance

Artemisia princeps Pampanini (family Asteraceae) is an herbal medicine widely used as a hepatoprotective, antioxidative, anti-inflammatory, and antibacterial agent in Korea, China, and Japan.

Aim of the study

This study aimed to elucidate the anti-inflammatory effect of the main constituents, eupatilin and jaceosidin, isolated from Artemisia princeps.

Materials and methods

We used carrageenan-induced inflammation in an air pouch on the back of mice and carrageenan-induced hind paw edema in rats to determine the anti-inflammatory effects of eupatilin and jaceosidin. Inflammatory makers, such as expression of pro-inflammatory cytokines and cyclooxygenase (COX)-2, and activation of nuclear factor-kappa B (NF-κB), were measured by enzyme-linked immunosorbent assays and immunoblot analyses.

Results

Eupatilin and jaceosidin blocked carrageenan-induced increase in leukocyte number and protein levels in air pouch exudates. Eupatilin and jaceosidin inhibited COX-2 expression and NF-κB activation, and markedly reduced TNF-α, IL-1β, and prostaglandin E2 (PGE₂) levels. They also inhibited hind paw edema induced by carrageenan. Eupatilin and jaceosidin had similar activity.

Conclusions

These findings suggest that eupatilin and jaceosidin may reduce inflammation by inhibiting NF-κB activation, and that Artemisia princeps inhibits inflammation because of these constituents.     

Hypericum grandifolium Choisy: A species native to Macaronesian Region with antidepressant effect

Aim of the study

Various species of Hypericum genus have been used in the Canary Islands as sedative, diuretic, vermifuge, wound healing, antihysteric and antidepressant agent. Studies have shown that methanol extract of Hypericum grandifolium Choisy is active in tetrabenazine-induced ptosis and forced swimming tests. In the current study, the aqueous, butanol and chloroform fractions obtained from the methanol extract as well as three sub-fractions derived from the chloroform fraction were evaluated for their central nervous effects in mice, particularly their antidepressant activity.

Materials and methods

The central nervous effect of different fractions and sub-fractions of Hypericum grandifolium was evaluated in mice using various behavioural models including locomotor and muscle relaxant activity, forced swimming test, effect on normal body temperature, barbiturate-induced sleep, tetrabenazine-induced syndrome and 5-hydroxytryptohan-induced head twitches and syndrome.

Results

We found that the butanol and chloroform fractions and all sub-fractions showed an antidepressant effect in the forced swimming test, the chloroform fraction being the most active. They produced no effects or only a slight depression of locomotor activity. Chloroform fraction significantly increased the pentobarbital-induced sleeping time, produced a slight but significant hypothermia and antagonized tetrabenazine-induced ptosis, whereas the butanol fraction produced a slight potentiation of 5-HTP-induced head twitches and syndrome.

Conclusions

The present results, together with previous pharmacological and phytochemical data, indicated that Hypericum grandifolium possess antidepressant-like effects in mice and that different constituents, such as the flavonoids and the benzophenone derivatives, could be responsible at least in part for the antidepressant effects observed for this species.     

Determination of the wound healing effect of Calendula extracts using the scratch assay with 3T3 fibroblasts

Pharmacological relevance

Presentation of the scratch assay as a convenient and inexpensive in vitro tool to gain first insights in the wound healing potential of plant extracts and natural compounds.

Aim of the study

The present study deals with the optimization of the scratch assay which can be used as an in vitro model for quantification of fibroblast migration to and proliferation into the wounded area. It is suitable for the first evaluation of the wound re-epithelialization potential of crude herbal extracts, isolated compounds and pharmaceutical preparations. As a proof of concept three preparations from traditional medicinal plants were investigated.

Materials and methods

Swiss 3T3 albino mouse fibroblasts were used in monolayers and platelet derived growth factor as positive control. Hexane and ethanolic extracts from Calendula officinalis and Matricaria recutita, Hypericum oil as well as the triterpenoids faradiol myristate and palmitate were studied. To differentiate between proliferation and migration antimitotic mitomycin C was added.

Results

Both extracts of Calendula officinalis stimulated proliferation and migration of fibroblasts at low concentrations, e.g. 10 μg/ml enhanced cell numbers by 64.35% and 70.53%, respectively. Inhibition of proliferation showed that this effect is mainly due to stimulation of migration. Faradiol myristate and palmitate gave comparable stimulation rates at an almost 50 μg/ml concentration, indicating that they contribute partially, but not most significantly to the wound healing effects of Calendula preparations. Extracts from Matricaria recutita were only moderately active. Hypericum oil was cytotoxic at concentrations higher than 0.5 μg/ml.

Conclusions

The scratch assay in the present form can be used as a promising scientific approach and platform to differentiate between plant extracts known for their wound healing and their anti-inflammatory properties.     

In vivo topical anti-inflammatory and wound healing activities of the fixed oil of Caryocar coriaceum Wittm. seeds

Ethnopharmacological relevance

Caryocar coriaceum Wittm. (Caryocaraceae), popularly known as pequi, is important source of food and used in the folk medicine as wound healing, anti-inflammatory and for the treatment of diseases of the respiratory tract, rheumatic and muscular pains and gastric ulcer.

Aim of the study

To evaluate the effects of fixed oil of Caryocar coriaceum (FOCC) on the topical inflammation and cutaneous wound healing.

Materials and methods

FOCC was purchased commercially and used at 6%, 12%, 25%, 50% and 100% on model of ear edema induced by xylene and ointments formulations at 6% and 12% on wound excision model in mice. Skin lesions were evaluated by planimetry and histological analysis.

Results

FOCC was capable of reducing inflammation in a dose-dependent fashion. FOCC in nature (100%) inhibited the ear edema in 38.01% and 39.20% at time 15 min and 1 h, respectively, after induction of inflammation, when compared to the positive control. The topical administration of FOCC ointment 12% showed a significantly reduction of unhealed wound area, with increased percentage of wound contraction (96.54%) on day 7 when compared to the other groups. The results of histological evaluation supported the outcome of excision wound model.

Conclusion

Caryocar coriaceum inhibits the topical inflammation and accelerate cutaneous wound repair.