An extract of the root of Lithospermun erythrorhison accelerates wound healing in diabetic mice

Herbal Oils for Treatment of Chronic and Diabetic Wounds: A Systematic Review

BACKGROUND

In the present scenario, diabetes is a growing health challenge, and its occurrence is growing across the globe. Diabetes, with its complications like diabetic wounds, vasculopathy, neuropathy, wound infections, and oxidative stress, is a serious cause of mortality worldwide.

INTRODUCTION

Among the various complications, treatment of diabetic foot and ulcers is one of the major concerns in patients who are suffering from diabetes. The causative factors for this condition include increased oxidative stress, high blood glucose levels, vascular insufficiency, and microbial infections, and many a time, if left untreated, it may even lead to amputations of the lower extremities. The present therapy for the treatment of diabetic wounds mainly involves the use of synthetic moieties and other biotechnology-derived biomolecules, including growth factors. Few plant products are also useful in the treatment of wounds.

METHODS

Essential oils derived from various herbs are reported to possess significant wound healing potential and promote blood clotting, help to fight infections, and accelerate the wound healing process. Hence, the present review is a systematic analysis of all the available data on the use of the natural oils with their biological source, active phytochemical constituents present, and the probable mechanism of action for the treatment of chronic and diabetic wounds in suitable animal models. A methodical collection of data was performed, and information was searched up to April 2020 in entirety. Key phrases used for the data search include the pathophysiology of wounds, diabetic foot wound and its complications, natural oils for chronic and diabetic wound treatment.

RESULTS

This review summarizes the natural oils which are reported in the literature to be beneficial in the treatment of chronic wounds, while some oils have been specifically also studied against wounds in diabetic rats. Essential oils are said to interact with the body pharmacologically, physiologically and psychologically and help in rapid wound healing. However, the majority of the literature studies have demonstrated wound healing activity only in animal models (preclinical data), and further clinical studies are necessary.

CONCLUSION

This review provides a platform for further studies on the effective utilization of natural oils in the treatment of chronic and diabetic wounds, especially if oils are to receive credibility in the management of chronic wounds.

Limited Treatment Options for Diabetic Wounds: Barriers to Clinical Translation Despite Therapeutic Success in Murine Models

Significance: Millions of people worldwide suffer from diabetes mellitus and its complications, including chronic diabetic wounds. To date, there are few widely successful clinical therapies specific to diabetic wounds beyond general wound care, despite the vast number of scientific discoveries in the pathogenesis of defective healing in diabetes. Recent Advances: In recent years, murine animal models of diabetes have enabled the investigation of many possible therapeutics for diabetic wound care. These include specific cell types, growth factors, cytokines, peptides, small molecules, plant extracts, microRNAs, extracellular vesicles, novel wound dressings, mechanical interventions, bioengineered materials, and more. Critical Issues: Despite many research discoveries, few have been translated from their success in murine models to clinical use in humans. This massive gap between bench discovery and bedside application begs the simple and critical question: what is still missing? The complexity and multiplicity of the diabetic wound makes it an immensely challenging therapeutic target, and this lopsided progress highlights the need for new methods to overcome the bench-to-bedside barrier. How can laboratory discoveries in animal models be effectively translated to novel clinical therapies for human patients? Future Directions: As research continues to decipher deficient healing in diabetes, new approaches and considerations are required to ensure that these discoveries can become translational, clinically usable therapies. Clinical progress requires the development of new, more accurate models of the human disease state, multifaceted investigations that address multiple critical components in wound repair, and more innovative research strategies that harness both the existing knowledge and the potential of new advances across disciplines.

Effects of Bilayer Nanofibrous Scaffolds Containing Curcumin/Lithospermi Radix Extract on Wound Healing in Streptozotocin-Induced Diabetic Rats

Impaired growth factor production, angiogenic response, macrophage function, and collagen accumulation have been shown to delay wound healing. Delayed wound healing is a debilitating complication of diabetes that leads to significant morbidity. In this study, curcumin and Lithospermi radix (LR) extract, which are used in traditional Chinese herbal medicine, were added within nanofibrous membranes to improve wound healing in a streptozotocin (STZ)-induced diabetic rat model. Gelatin-based nanofibers, which were constructed with curcumin and LR extract at a flow rate of 0.1 mL/hour and an applied voltage of 20 kV, were electrospun onto chitosan scaffolds to produce bilayer nanofibrous scaffolds (GC/L/C). The wounds treated with GC/L/C exhibited a higher recovery rate and transforming growth factor-beta (TGF-β) expression in Western blot assays. The decreased levels of pro-inflammatory markers, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), provided evidence for the anti-inflammatory effects of GC/L/C treatment. Chronic wounds treated with GC/L/C achieved better performance with a 58 ± 7% increase in recovery rate on the seventh day. Based on its anti-inflammatory and wound-healing effects, the GC/L/C bilayer nanofibrous scaffolds can be potential materials for chronic wound treatment.

Molecular Concept of Diabetic Wound Healing: Effective Role of Herbal Remedies

The incidence of diabetes mellitus (DM) is on the rise, worldwide. One of the main complications in DM is delayed wound healing and it often requires amputation. Various drugs were used to treat DM but they presented with adverse effects. Often, patients failed to comply with such treatment. This opened the door for complementary and alternative medicine. In the present review, we explored the molecular concept of wound healing occurring in different stages with special emphasis to DM. We also highlighted the potential herbal products such as NF3 (Chinese 2-Herb Formula), Zicao, Jing Wan Hong ointment, Aleo vera, mixture of Adiantum capillus-veneris, Commiphora molmol, Aloe vera, and henna, Phenol-rich compound sweet gel, Jinchuang ointment, San-huang-sheng-fu (S) oil, Yi Bu A Jie extract, Astragali Radix (AR) and Rehmanniae Radix (RR), Yiqi Huayu, Tangzu yuyang ointment, Shengji Huayu recipe, Angelica sinensis, Lithospermun erythrorhison, Hippophae rhamnoides L., Curcuma longa and Momordica charantia that could be used effectively to treat DM wounds. Future clinical trials are needed for designing potential drugs which may be effective in treating DM wounds.

Mechanistic insight into diabetic wounds: Pathogenesis, molecular targets and treatment strategies to pace wound healing

Wound management in diabetic patient is of an extreme clinical and social concern. The delayed and impaired healing makes it more critical for research focus. The research on impaired healing process is proceeding hastily evident by new therapeutic approaches other than conventional such as single growth factor, dual growth factor, skin substitutes, cytokine stimulators, cytokine inhibitors, matrix metalloproteinase inhibitors, gene and stem cell therapy, extracellular matrix and angiogenesis stimulators. Although numerous studies are available that support delayed wound healing in diabetes but detailed mechanistic insight including factors involved and their role still needs to be revealed. This review mainly focuses on the molecular cascades of cytokines (with growth factors) and erstwhile factors responsible for delayed wound healing, molecular targets and recent advancements in complete healing and its cure. Present article briefed recent pioneering information on possible molecular targets and treatment strategies including clinical trials to clinicians and researchers working in similar area.

The Relationship Between Inflammation and Impaired Wound Healing in a Diabetic Rat Burn Model

Inflammation, initiated by polymorphonuclear neutrophil (PMNs) infiltration, is the first step in wound healing. The aim of this study is to investigate the function of neutrophils in a diabetes-impaired wound healing model and to explore the underlying mechanisms leading to neutrophil dysfunction. Superficial second-degree burns were created in the streptozotocin (STZ)-induced diabetic rat model, and the changes in the levels of advanced glycation end products (AGE), receptor of AGE (RAGE), inflammatory cytokines and oxidative markers, as well as cell apoptosis were determined. The effects of AGE on isolated PMNs were also determined in vitro. We found that deposition of AGE in diabetic rat skin activated the neutrophils before injury. However, the dense inflammatory band failed to form in the diabetic rats after injury. Compared with the controls, enhanced expression of RAGE and accelerated cell apoptosis were observed in the burned skin of diabetic rats. The altered expression pattern of inflammatory cytokines (tumor necrosis factor-alpha and interleukin-8) and oxidative markers (glutathione peroxidase, myeloperoxidase, hydrogen peroxide, and malondialdehyde) between burned skin of diabetic and control rats revealed delayed neutrophil chemotaxis and respiratory burst. Furthermore, the results in vitro showed that exposure to AGE inhibited the viability of PMNs, promoted RAGE production and cell apoptosis, and prevented the migration of PMNs, consistent with the findings in vivo. Besides, AGE-treated neutrophils showed increased secretion of inflammatory cytokines and increased oxidative stress. Combined, our results suggest that an interaction between AGE and its receptors inhibits neutrophil viability and function in the diabetic rat burn model.

Shikonin Induces Apoptosis, Necrosis, and Premature Senescence of Human A549 Lung Cancer Cells through Upregulation of p53 Expression

Shikonin, a natural naphthoquinone pigment isolated from Lithospermum erythrorhizon, has been reported to suppress growth of various cancer cells. This study was aimed to investigate whether this chemical could also inhibit cell growth of lung cancer cells and, if so, works via what molecular mechanism. To fulfill this, A549 lung cancer cells were treated with shikonin and then subjected to microscopic, biochemical, flow cytometric, and molecular analyses. Compared with the controls, shikonin significantly induced cell apoptosis and reduced proliferation in a dose-dependent manner. Specially, lower concentrations of shikonin (1-2.5 μg/mL) cause viability reduction; apoptosis and cellular senescence induction is associated with upregulated expressions of cell cycle- and apoptotic signaling-regulatory proteins, while higher concentrations (5-10 μg/mL) precipitate both apoptosis and necrosis. Treatment of cells with pifithrin-α, a specific inhibitor of p53, suppressed shikonin-induced apoptosis and premature senescence, suggesting the role of p53 in mediating the actions of shikonin on regulation of lung cancer cell proliferation. These results indicate the potential and dose-related cytotoxic actions of shikonin on A549 lung cancer cells via p53-mediated cell fate pathways and raise shikonin a promising adjuvant chemotherapeutic agent for treatment of lung cancer in clinical practice.

Gromwell (Lithospermum erythrorhizon) supplementation enhances epidermal levels of ceramides, glucosylceramides, β-glucocerebrosidase, and acidic sphingomyelinase in NC/Nga mice

We have previously reported that dietary gromwell (Lithospermum erythrorhizon; LE) prevents the development of atopic dermatitis (AD) with increased epidermal levels of total ceramide (Cer), the major lipid maintaining epidermal barrier. In this study, we investigated whether the increased level of total Cer induced by dietary LE would be related to the altered metabolism of glucosylceramide (GlcCer) and sphingomyelin (SM), two major precursor lipids in Cer generation. NC/Nga mice, an animal model of AD, were fed a control diet (group CA: atopic control) or a diet with 70% ethanol LE extracts (1% in diet; group LE) for 10 weeks. Individual species of Cer, GlcCer, and SM were analyzed by high-performance thin layer chromatography. In the epidermis of group CA, total Cer (including Cer2 and Cer5-7) and total GlcCer (including GlcCer-B/C/D) were significantly reduced; these levels in group LE were increased to levels similar to the normal control group of BALB/c mice (group C). In addition, protein expressions and activities of β-glucocerebrosidase (β-GlcCer'ase) and acidic sphingomyelinase (aSMase), enzymes for GlcCer or SM hydrolysis, respectively, were increased in group LE. However, alterations of Cer1, Cer3/4, GlcCer-A, and all SM species (including SM1-3) were not significant among groups C, CA, and LE. Dietary gromwell increases GlcCer-B/C/D, and further enhances the generation of Cer2 and Cer5-7 with high protein expressions and activities of β-GlcCer'ase and aSMase.

Recent advances on the development of wound dressings for diabetic foot ulcer treatment--a review

Diabetic foot ulcers (DFUs) are a chronic, non-healing complication of diabetes that lead to high hospital costs and, in extreme cases, to amputation. Diabetic neuropathy, peripheral vascular disease, abnormal cellular and cytokine/chemokine activity are among the main factors that hinder diabetic wound repair. DFUs represent a current and important challenge in the development of novel and efficient wound dressings. In general, an ideal wound dressing should provide a moist wound environment, offer protection from secondary infections, remove wound exudate and promote tissue regeneration. However, no existing dressing fulfills all the requirements associated with DFU treatment and the choice of the correct dressing depends on the wound type and stage, injury extension, patient condition and the tissues involved. Currently, there are different types of commercially available wound dressings that can be used for DFU treatment which differ on their application modes, materials, shape and on the methods employed for production. Dressing materials can include natural, modified and synthetic polymers, as well as their mixtures or combinations, processed in the form of films, foams, hydrocolloids and hydrogels. Moreover, wound dressings may be employed as medicated systems, through the delivery of healing enhancers and therapeutic substances (drugs, growth factors, peptides, stem cells and/or other bioactive substances). This work reviews the state of the art and the most recent advances in the development of wound dressings for DFU treatment. Special emphasis is given to systems employing new polymeric biomaterials, and to the latest and innovative therapeutic strategies and delivery approaches.

Practices in wound healing studies of plants

Wounds are the result of injuries to the skin that disrupt the other soft tissue. Healing of a wound is a complex and protracted process of tissue repair and remodeling in response to injury. Various plant products have been used in treatment of wounds over the years. Wound healing herbal extracts promote blood clotting, fight infection, and accelerate the healing of wounds. Phytoconstituents derived from plants need to be identified and screened for antimicrobial activity for management of wounds. The in vitro assays are useful, quick, and relatively inexpensive. Small animals provide a multitude of model choices for various human wound conditions. The study must be conducted after obtaining approval of the Ethics Committee and according to the guidelines for care and use of animals. The prepared formulations of herbal extract can be evaluated by various physicopharmaceutical parameters. The wound healing efficacies of various herbal extracts have been evaluated in excision, incision, dead space, and burn wound models. In vitro and in vivo assays are stepping stones to well-controlled clinical trials of herbal extracts.

Naturally Occurring Isohexenylnaphthazarins and Wound Healing: Experimental Study in Dogs

Background:

The healing efficacy of isohexenylnaphthazarins (IHN) has been well proved on chronic or contaminated wounds.

Objective:

To evaluate the wound healing activity of an experimental ointment containing IHN on acute and noncontaminated wounds in dogs. Methods: In each of six beagle dogs, four full-thickness skin defects were created bilaterally: one 2 × 2 cm defect on the lateral aspect of each arm for subjective evaluation, laser Doppler flowmetry (LDF), and planimetry and three 1.5 × 1.5 cm defects on opposite sides of the dorsal midline for histologic evaluation. Wounds on the left were treated with an ointment based on IHN and on the right with another based on petroleum jelly (Vaseline) and beeswax.

Results:

Wound size decreased significantly in both sides. The significantly increased percentage of epithelialization was higher ( p = .0274) in the petroleum jelly–treated wounds on day 20. Tissue perfusion (LDF) increased significantly bilaterally in the center of the wound but only in the IHN-treated side cranial to the wound. Histologically, angiogenesis was significantly higher ( p = .0431) on day 5 in the IHN-treated wounds compared with the petroleum jelly–treated wounds. Collagen production increased significantly bilaterally.

Conclusion:

The IHN-based ointment promoted some of the proliferative processes, but it did not enhance the overall wound healing of acute, surgically created wounds in dogs.

Cosmetic formulations containing Lithospermum erythrorhizon root extract show moisturizing effects on human skin

Retention of water in the stratum corneum of skin epidermis plays an important role in regulation of skin function. Loss of water may decline skin appearance gradually and lead to irregular skin disorders. The root extract of Lithospermum erythrorhizon (LES) is known for its various pharmacological activities. However, the potential skin care effect of LES is not clear. The aim of this study was to evaluate the moisturizing efficacy and skin barrier repairing activity of LES. For this study, 30 healthy Asian females (age 20-30) with healthy skin had applied the test emulsions twice daily over a period of 28 days. The skin properties were measured by skin bioengineering techniques. Our preliminary results indicated that LES show moisturizing effect on skin hydration in a time- and dose-dependent pattern, and the maximum increase in skin humidity was 11.77 +/- 1.18% for emulsion LES5.00. Particularly, LES-containing emulsions significantly improve skin barrier function by decreasing the value of transepidermal water loss (TEWL) in a time- and dose-dependent pattern, and the maximum decrease in TEWL value was 7.68 +/- 0.79% for emulsion LES5.00. Taken together, our data demonstrate that LES is more effective in increasing skin humidity and decreasing the TEWL values, indicating the potential skin care effects of LES.

The Effect of Gromwell (Lithospermum erythrorhizon) Extract on the Stratum Corneum Hydration and Ceramides Content in Atopic Dermatitis Patients

BACKGROUND

A disruption of the balance between the water content of the stratum corneum (SC) and skin surface lipids may lead to the clinical manifestation of dryness of skin in patients with atopic dermatitis (AD).

OBJECTIVE

To determine whether supplementation of gromwell (Lithospermum erythrorhizon), one of herbs used in East Asia in remedies for various abnormal skin conditions, may improve the SC level of hydration and ceramides, major lipid in SC in patients with AD.

METHODS

A total of 28 subjects with AD were randomly assigned into two groups: either gromwell group received dextrose contained capsules with 1.5 g of gromwell extracts or placebo group received only dextrose contained capsules for 10 weeks.

RESULTS

In contrast to no alteration of SC hydration and ceramides in placebo group, the SC hydration in gromwell group was significantly increased in parallel with an increase of SC ceramides. Furthermore, % increase of SC hydration in gromwell group bore a positive correlation with the clinical severity, which suggests that the increase of SC hydration in gromwell group was more effective as AD was more severe.

CONCLUSION

Supplementation of gromwell improves SC hydration in parallel with an increase of ceramides in part.

Relationship between the distribution of myofibroblasts, and stellar and circular scar formation due to the contraction of square and circular wound healing

Square skin wounds can heal to form a stellar scar with four protrusions at the four angles, whereas circular wounds can heal to form an ellipsoid scar. It is not clear why these differences occur and the aim of the present study was to clarify this phenomenon. Two square or circular full-thickness skin wounds were made on the dorsum of mice, and covered with hydrocolloid dressing. They were observed from day 0 to 15 after wounding, and used to prepare paraffin sections stained with anti-alpha-smooth muscle actin antibody to detect myofibroblasts. The square wound was transiently enlarged by edema and skin tension on day 3, at which time the angles became round, and thus the square form became more circular. Thereafter, the wound contracted rapidly and the circular form was maintained until day 11. On day 11 distinct angles appeared where the scar formation had progressed further, and there were fewer myofibroblasts than in any other section. A stellar scar with protrusions from the four angles was formed on day 15, when myofibroblasts almost disappeared in the protrusions. This indicates that due to the earlier disappearance of myofibroblasts and earlier scarring in the angles of the square wound, the scar angle cannot be pulled into the center of the wound but residual myofibroblasts on the side can pull the side into the center due to myofibroblastic contraction and consequently a stellar scar is formed. Thus, the earlier disappearance of myofibroblasts in the angles is very important for the formation of stellar scars.