Effect of green tea on the second degree burn wounds in rats

The Potential of Medicinal Plants and Natural Products in the Treatment of Burns and Sunburn-A Review

Treating burns remains a challenge for modern medicine, especially in developing countries that cannot afford expensive, advanced therapies. This review article summarises clinical and animal model studies of botanical preparations and their mixtures in treating burn wounds and sunburn. Articles available in electronic databases such as PubMed, Scopus, Web of Science, Science Direct and Google Scholar, published in English in 2010-2022, were considered. In the described clinical trials, it was shown that some herbal preparations have better effectiveness in treating burn wounds, including shortening the healing time and reducing inflammation, than the conventional treatment used hitherto. These herbal preparations contained extracts from Albizia julibrissin, Alkanna tinctoria, Aloe vera, Arnebia euchroma, Betula pendula and Betula pubescens, Centella asiatica, Hippophaë rhamnoides, Juglans regia, Lawsonia inermis, and mixtures of Matricaria chamomilla and Rosa canina. Research on animal models shows that many extracts may potentially benefit the treatment of burn wounds and sunburn. Due to the diverse mechanism of action, antibacterial activity, the safety of use and cost-effectiveness, herbal preparations can compete with conventional treatment. The growing interest in alternative medicine and herbal medicine encourages further research. Not only single preparations but also their mixtures should be taken into account because the research conducted so far often suggests a synergistic effect of the ingredients.

Wound healing in second-degree burns in rats treated with silver sulfadiazine: a systematic review and meta-analysis

Objective:

This study aims to assess the wound healing efficacy in second-degree burns in rats treated with 1% silver sulfadiazine (SSD)—a sulfonamide antibiotic.

Method:

This is a systematic literature review and meta-analysis performed according to the PICO (Population, Intervention, Comparison and Outcomes) strategy.

Results:

The review found 100 studies in PubMed, Web of Science and other search engines. Of these, 70 studies were pre-selected after removing duplicates. After independent analysis by two reviewers, only seven studies met the inclusion criteria for meta-analysis. All studies except one showed faster wound closure by the application of silver sulfadiazine ointment. Using a random effects model, healing was faster in SSD-treated groups when compared to the control group on day 21, with a statistically significant mean difference of –2.72 days (95% confidence interval: –4.99, –0.45) between treatment and control groups (p<0.01).

Conclusion:

The results of this meta-analysis revealed that SSD aided in faster healing of second-degree burns.

Rational selection of bioactive principles for wound healing applications: Growth factors and antioxidants

Wound healing is a complex process of communication between growth factors, reactive species of oxygen, cells, signalling pathways, and cytokines in the extracellular matrix, in which growth factors are the key regulators. In humans, the main regulators of the cellular responses in wound healing are five growth factors, namely EGF, bFGF, VEGF, and TGF-β1. On the other hand, antioxidants such as astaxanthin, beta-carotene, epigallocatechin gallate, delphinidin, and curcumin have been demonstrated to stimulate cell proliferation, migration and angiogenesis, and control inflammation, to suggest a practical approach to design new strategies to treat non-healing cutaneous conditions. Based on the individual effects of growth factors and antioxidants, it may be envisioned that the use of both types of bioactives in wound healing formulations may have an additive or synergistic effect on the healing potential. This review addresses the effect of growth factors and antioxidants on wound healing-related processes. Furthermore, a prospective on their potential additive or synergistic effect on wound healing formulations, based on their individual effects, is presented. This may serve as a guide for the development of a new generation of wound healing formulations.

Alternative Wound Management: Translating Science into Practice

GENERAL PURPOSE

To present a scoping review of preclinical and clinical trial evidence supporting the efficacy and/or safety of major alternative wound care agents to summarize their effects on validated elements of wound bed preparation and wound management paradigms.

TARGET AUDIENCE

This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care.

LEARNING OBJECTIVES/OUTCOMES

After participating in this educational activity, the participant will:1. Differentiate the effectiveness of the topical wound care agents included in this review.2. Compare the preventive efficacy of intravenous agents administered to trauma and surgical patients.3. Select the effectiveness of products in this review that are left in place after surgical procedures.4. Identify an oral agent that can be helpful in mitigating the effects of COVID-19.

In vivo wound-healing and antioxidant activity of aqueous extract of Roylea elegans leaves against physically induced burn model in Wistar albino rats

Roylea elegans Wall. ex Benth. is a lemon-scented hoary shrub belonging to the mint family (Lamiaceae). Traditionally, a local tribe of the Himalayan region uses leaves for scabs and skin infections. The aerial parts and leaves are widely used to cure various skin ailments. The plant is well known for two furanoid diterpenes, royeleganin and royelegafuran. The aqueous extract of Roylea elegans (AERE) leaves was investigated for wound-healing effects in rats using a physically induced burn model by assessing different parameters. Animals were divided into four groups (six rats in each group). Group I animals were considered as disease control and topically given base cream. Group II was considered as standard control and treated topically with Framycetin sulphate cream (1% w/w). Group III and IV animals were treated topically with creams containing 5 or 10% of AERE, respectively. Several parameters such as wound contraction rate, epithelialization period, and enzymatic and non-enzymatic antioxidant markers along with pro- and anti-inflammatory cytokines were studied followed by histopathological studies. The animals treated with AERE cream exhibited significant declination in the wound area and increased collagen content as compared to the disease control group. The results showed that the lower dose (5%) of AERE produced a significant decrease in the epithelialization period, wound contraction rate, and collagen content. Increased levels of cytokine production may be one of the mechanisms in accelerating the wound-healing process. The study established the traditional claim as an antioxidant and wound-healing potential of Roylea elegans by promoting the accelerated wound-healing activity against the physically induced burn model.

Identification of Metagenomics Structure and Function Associated With Temporal Changes in Rat (Rattus norvegicus) Skin Microbiome During Health and Cutaneous Burn

The cutaneous skin microbiome is host to a vast ensemble of resident microbes that provide essential capabilities including protection of skin barrier integrity and modulation of the host immune response. Cutaneous burn-injury promotes alteration of cutaneous and systemic immune response that can affect both commensal and pathogenic microbes. A cross-sectional study of a limited number of burn patients revealed a difference in the bacteriome of burned versus control participants. Temporal changes of the skin microbiome during health and cutaneous burn-injury remains largely unknown. Furthermore, how this microbial shift relates to community function in the collective metagenome remain elusive. Due to cost considerations and reduced healing time, rodents are frequently used in burn research, despite inherent physiological differences between rodents and human skin. Using a rat burn model, a longitudinal study was conducted to characterize the rat skin bacterial residents and associated community functions in states of health (n = 30) (sham-burned) and when compromised by burn-injury (n = 24). To address the knowledge gap, traumatic thermal injury and disruption of cutaneous surface is associated with genus-level changes in the microbiota, reduced bacterial richness, and altered representation of bacterial genes and associated predicted functions across different skin microbial communities. These findings demonstrate that, upon burn-injury, there is a shift in diversity of the skin's organismal assemblages, yielding a core microbiome that is distinct at the genome and functional level. Moreover, deviations from the core community correlate with temporal changes post-injury and community transition from the state of cutaneous health to disease (burn-injury).

Histopathological Changes of Organs (Lungs, Liver, Kidney, and Brain) After Using Two Types of AgiCoat and Acticoat Nanosilver Dressings on Deep Second-Degree Burn in Rat

Prevention of infections is a very important issue in treating the burn wounds. The nanosilver dressings have many promising advantages, but absorption of silver ions and its adverse effects to the body were always a question. The aim of this study was to compare Silver serum levels and acute toxic effects of nanosilver on histopathology of organs (lungs, liver, kidney, spleen, and brain) in two types of AgiCoat and Acticoat (nanosilver) dressings on second-degree deep burn in rat. This is an experimental study conducted in our animal laboratory. We divided 24 Sprague-Dawley male rats weighing 300 to 350 randomly into two groups. After anesthesia, a second deep-degree burn was made over dorsal skins of rats by standard method. For group A, Agicoat and, for group B, Acticoat dressings were used. The dressings were changed every 3 days with AgiCoat and Acticoat, respectively. After 14 days, we got blood samples and tissue samples taken from heart, liver, kidneys, spleen, lungs, and brain and a sample from dorsal skin of the rat for histopathological examinations. The results showed that the levels of serum silver in both groups were significantly higher than the standard level (1.22 part per million (PM); AgiCoat, P = .017; Acticoat, P = .000), but there was no significant difference between the groups (P = .551). Examination of the relationship between the level of serum silver and histopathological changes in liver showed that hepatotoxicity of AgiCoat was higher compared with Acticoat and the difference was significant (P = .002). There were no pathological changes in brain, kidneys, spleen, heart, and lungs. Wound healing was faster in Acticoat group. The nanosilver dressings can cause toxicity in liver but not in kidney, brain, spleen, heart, and lungs. Liver pathology and hepatotoxicity were more prominent in AgiCoat group. Wound healing was faster in Acticoat group.

Hydrogel with silver nanoparticles synthesized by Mimosa tenuiflora for second-degree burns treatment

In this work we use Mimosa tenuiflora (MtE) extracts as reducing agents to synthesize silver nanoparticles (AgMt NPs) which were characterized by DPPH and Total Polyphenols Assays, UV-visible, X-ray diffractometer (XRD), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and Thermogravimetric analysis (TGA). AgMt NPs possess average sizes of 21 nm and fcc crystalline structure, it was also confirmed that the MtE is present in the AgMt NPs even after the cleaning protocol applied. Subsequently, carbopol hydrogels were made and the MtE and the synthesized AgMt NPs were dispersed in different gels (MtE-G and AgMt NPs-G, respectively) at 100 µg/g concentration. The gels were characterized by UV-Vis, IR, and rheology. Antimicrobial tests were performed using Staphylococcus aureus and Escherichia coli. Burn wound healing was evaluated in a second-degree burn injury on a Wistar rats model for 14 days and additional skin biopsies were examined with histopathological analysis. Gel with commercial silver nanoparticles (Ag NPs) was prepared and employed as a control on the biological assays. Hydrogel system containing silver nanoparticles synthesized with Mimosa tenuiflora (AgMt NPs-G) is a promising therapeutic strategy for burn wound healing, this due to bactericidal and anti-inflammatory effects, which promotes a more effective recovery (in percentage terms) by damaged area.

The efficacy of a traditional medicine preparation on second-degree burn wounds in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Lime Salve (L.S) has been well documented from the 9th to the 19th century AD by traditional Iranian medicine (TIM) as an effective remedy for burn healing.

AIM OF THE STUDY

The present study was undertaken to evaluate the healing effect and related underlying mechanisms of Lime Salve in a model of deep second-degree thermal burn in male Wistar rats.

MATERIALS AND METHOD

L.S was made up of a combination of refined calcium hydroxide powder, beeswax and sesame oil and its quality control was assessed. A deep second-degree burn was created by a hot plate in 48 male Wistar rats. Afterwards, they were randomly divided into four groups including normal saline (C group), L.S (T group), basement of formulation composed of beeswax and sesame oil (B group) and silver sulfadiazine (S group). On days 5, 10, 17 and 24, the wounds were digitally photographed by a camera and after sacrifice of the rats, skin samples were obtained for performing qRT-PCR, immunohistochemistry staining and histological examination.

RESULTS

L.S prominently augmented the wound closure rate, neovascularization on day 10 and collagen formation on days 17 and 24 in comparison with the C group. Furthermore, the Salve-exposed specimens showed a significant higher epithelialization during the experiment with a peak on day 24. qRT-PCR also showed that on day 10, VEGF and TGF-β1 genes were significantly higher in the T group as compared with the C group. Also, MMP-9 and MMP-2 genes had a significant peak of expression on day 17 and rapid reduction of expression on day 24. Expression levels of IL-6 and TNF-α genes peaked on day 10 in the T group, followed by a progressive reduction until the end of the examination.

CONCLUSION

L.S could effectively accelerate the healing process of deep second-degree burn wounds and therefore, it may be recommended as a promising topical medication for treating burn wounds in the future clinical trials.

Epigallocatechin-3-gallate protects Wharton's jelly derived mesenchymal stem cells against in vitro heat stress

The deteriorating effects of heat stress abrogate the therapeutic implications of human Wharton's jelly derived mesenchymal stem cells (hWJMSCs) transplanted in burn wounds. Topically applied green tea extract comprising epigallocatechin-3-gallate (EGCG) is known to repair burn wounds. Here, we investigated the protective role of EGCG priming of hWJMSCs against heat-induced stress in vitro along with the involved underlying mechanism. EGCG ameliorated heat-induced injuries as demonstrated by significantly improved cell morphology, viability, triggered cell migration and enhanced expression of heat shock proteins. In addition, decreased lactate dehydrogenase release and reduced percentage of senescent and apoptotic cells were observed. EGCG priming alleviated the detrimental effects of thermal stress in hWJMSCs as observed by significant down-regulation in expression of BCL2 associated X (BAX), interleukin 6 (IL6), and interleukin 1 beta (IL1β) genes, while proliferating cell nuclear antigen (PCNA), BCL2 like 1 (BCL2L1), vascular endothelial growth factor (VEGF), transforming growth factor beta 1 (TGFβ1), hepatocyte growth factor (HGF) and interleukin 4 (IL4) genes were up-regulated. Accompanying gene expression data, EGCG primed cells exposed to heat stress also exhibited remarkably increased secretion of VEGF, HGF, epidermal growth factor (EGF), stromal-derived factor 1 (SDF1) proteins while the reduced release of IL-6, and tumor necrosis factor-alpha (TNF-α) proteins. Further, synergistic activation of extracellular-signal-regulated kinase (ERK) and protein kinase B (PKB/AKT) proteins was observed. These findings suggest that EGCG priming might enhance the therapeutic efficacy of hWJMSCs in the burnt tissue through regulation of ERK and AKT signaling pathways, and improved cellular responses.

The Effect of Mentha Pulegium on Healing of Burn Wound Injuries in Rat

BACKGROUND

Burn is one of the most common injuries and the 4th common cause of trauma globally. This study was designed to evaluate the effect of the Mentha pulegium extract on second degree burn injuries in rats assessing histopathologic and macroscopic.

METHODS

M. Pulegium extract dressings was used as a treatment to deep dermal contact burns in rats, compared with two control groups of vaseline dressing and simple dressing by normal saline. After creating second-degree burn on the dorsum of rats, the treatments were applied for 15 min in three groups. Wound dressings were performed on days 1, 3, 7, 14 and 21^st and at the same time macroscopic assessment was performed using a digital camera and software processing of photos. Pathologic evaluation of skin specimens was undertaken on days 1, 3,7, 14 and 21^st. Wound healing parameters such as epithelialization, angiogenesis, granulation tissue formation, inflammatory cells were compared between these 3 groups.

RESULTS

Application of M. Pulegium extract on second degree burn wounds significantly decreased burn surface area and increased fibroblasts in comparison to simple dressing. There was not any statistically significant relationship between M. Pulegium extract treated group and vaseline treated or simple dressing groups on other wound healing parameters.

CONCLUSION

This study delineated that M. Pulegium extract had a positive effect on healing process of second degree burns.

The effect of green tea ointment on episiotomy pain and wound healing in primiparous women: A randomized, double-blind, placebo-controlled clinical trial

The delayed healing of episiotomy wound and its associated pain is a major problem in obstetrics. Because green tea has analgesic and wound-healing properties, the present study was conducted to determine the effect of green tea ointment on episiotomy pain and wound-healing. The green tea extract was also standardized by measuring its Phenolic and flavonoid compounds, antioxidant activity, and one of its active components, that is, Epigallocatechin gallate. The present clinical trial was conducted on 99 primiparous women visiting Afzalipour Hospital in Kerman in 2015. The subjects were randomly divided into 3 groups, including a green tea ointment group, a placebo ointment group, and a routine care group. The 2 ointment groups smeared 2 cm of the green tea or placebo ointments onto their sutured area twice daily for a total of 10 days. The severity of pain was assessed in the subjects using the visual pain scale and wound-healing using the Redness, Edema, Ecchymosis, Discharge, Approximation (REEDA) scale before the intervention and on the 5th and 10th days after delivery. To standardize the extract, Epigallocatechin gallate was measured by high-performance liquid chromatography (HPLC). Phenolic and flavonoid compounds, as well as antioxidant activity of the extract were also determined by spectrometry methods. Before the intervention, no significant differences were observed between the 3 groups in terms of their personal and obstetric details (p > .05), the severity of pain (p = .118), and the REEDA score (p = .212). On the 5th and 10th days after delivery, the severity of pain was significantly lower in the green tea group than in the other 2 groups (p < .0001). The mean REEDA score on the 5th and 10th days showed a better and faster healing in the green tea group compared to the other 2 groups (p < .0001). Total content of phenolic and flavonoids contents of green tea were 74.2 mg/g Gallic acid equivalent and 16.3 mg/g Rutin equivalent, respectively, and its antioxidant capacity was 46% of b-carotene. Green tea ointment appears to be effective in relieving episiotomy pain and improving wound-healing in this study. Further studies are recommended to be conducted on the effectiveness and safety of the different doses of green tea ointment.

Healing activity of Casearia sylvestris Sw. in second-degree scald burns in rodents

BACKGROUND

Every year thousands of people are victims of burns, mainly scald burns. Many of these victims have small size wounds and superficial partial thickness and do not seek specialized medical care. As in Brazil Casearia sylvestris Sw., popularly known as guaçatonga is widely used for its analgesic, antiseptic and anti-inflammatory activities, this study sought to evaluate the effects of its hydroalcoholic extract in healing process of burns injuries.

METHODS

The obtained extract was validated applying a thin layer chromatography and sophisticated validation method using Bothrops jararacussu snake venom that is necrotic and inflammatory, and by which guaçatonga extract was able to neutralize the irreversible neuromuscular blockade induced by the venom. After induction of the scald injury, the animals were treated daily with saline solution spray; spray containing extract; biofilm; or biofilm impregnated with extract.

RESULTS

Significant differences were observed between the four groups studied considering: extension of the healing area, neovascularization, fibroblast proliferation, and epithelialization.

CONCLUSION

The anti-inflammatory and bactericidal effects of C. sylvestris Sw. suggests a potential therapeutic benefit in the treatment of inflammatory conditions in second-degree scald burn injuries, as well as, counteracting against the in vitro paralysis induced by B. jararacussu venom.