Immortelle Essential-Oil-Enriched Hydrogel for Diabetic Wound Repair: Development, Characterization, and In Vivo Efficacy Assessment

Background: Alarming data revealed that 19% to 34% of adults with diabetes mellitus develop chronic wounds, which are characterized by impaired healing and a higher risk of infections. Inspired by the traditional use of immortelle for wound healing and the lack of scientific evidence regarding how it thoroughly influences tissue regeneration, we aimed to formulate a hydrogel loaded with immortelle essential oil and assess its effectiveness on diabetic excision wounds. Methods: The rheological properties of the hydrogel, an in vivo safety test, as well as wound healing capacity, were determined in rats with induced diabetes and excision wounds. Diabetic rats were divided into four groups: untreated, treated with 1% silver sulfadiazine ointment, treated with a gel base, and treated with the immortelle essential oil-based hydrogel. Results: It was revealed that the hydrogel exerts pseudoplastic behavior and has no potential to act as an irritant, thus highlighting its suitability for skin application. Moreover, analysis of macroscopic, biochemical, and histopathological data revealed that the immortelle essential oil-based hydrogel significantly improves wound repair. Superior re-epithelialization, scar maturation, and increased collagen fiber density were achieved after immortelle essential oil-based gel application. Conclusions: These findings suggest that the immortelle essential oil-based hydrogel could be a natural, safe, and effective wound-healing dressing.

Anti-inflammatory and Antiphytopathogenic Fungal Activity of 2,3-seco-Tirucallane Triterpenoids Meliadubins A and B from Melia dubia Cav. Barks with ChemGPS-NP and In Silico Prediction

Two new rearranged 2,3-seco-tirucallane triterpenoids, meliadubins A (1) and B (2), along with four known compounds, 3-6, were isolated from the barks of Melia dubia Cav. Compound 2 exhibited a significant inflammatory inhibition effect toward superoxide anion generation in human neutrophils (EC50 at 5.54 ± 0.36 μM). It bound to active sites of a human inducible nitric oxide synthase (3E7G) through interactions with the residues of GLU377 and PRO350, which may benefit in reducing the neutrophilic inflammation effect. The ChemGPS-NP interpretation combined with bioactivity assay and in silico prediction results suggested 2 to be an agent for targeting iNOS with different mechanisms as compared to a selected set of current approved drugs. Moreover, compounds 1 and 2 showed remarkable inhibition against the rice pathogenic fungus Magnaporthe oryzae in a dose-dependent manner with IC50 values of 137.20 ± 9.55 and 182.50 ± 18.27 μM, respectively. Both 1 and 2 displayed interactions with the residue of TYR223, a key active site of trihydroxynaphthalene reductase (1YBV). The interpretation of 1 and 2 in the ChemGPS-NP physical-chemical property space indicated that both compounds are quite different compared to all members of a selected set of reference compounds. In light of demonstrated biological activity and in silico prediction experiments, both compounds possibly exhibited activity against phytopathogenic fungi via a novel mode of action.

Immortelle essential oil-based ointment improves wound healing in a diabetic rat model

The phytochemical analysis of the investigated Immortelle essential oil revealed the presence of monoterpenes and sesquiterpenes as major components that might be efficient as a wound healing potential agent. The present study aimed to develop an ointment based on the Immortelle essential oil and investigate its wound healing effects on excision wounds in diabetic rats. The topical formulated Immortelle ointment was subjected to pharmaco-technical characterization. Thirty-two diabetic rats with the induced excision wound were used to evaluate in vivo wound healing effects of ointment. The animals were randomly divided into four groups untreated or topically treated with either a 1% silver sulfadiazine, the ointment base, or Immortelle ointment. The response to the treatment was assessed by macroscopic, biochemical and histopathological analysis. The ointment, compatible with the skin remained stable for 6 months. Topical application of the Immortelle ointment showed the highest wound contraction with the highest content of hydroxyproline in comparison to the all examined groups. The Immortelle ointment showed significant wound contraction from day 7 to day 21 as compared to other groups. On the day 21, there was an average of 99.32% wound contraction in the Immortelle group, whereas the mean wound contraction in the negative control and ointment base group was 71.36% and 81.26% respectively. The histopathological results validated the potential wound healing effect of Immortelle ointment with evident post-excision scar maturation and increased collagen fibers density. Our findings revealed that the Immortelle ointment approach might serve as a promising and innovative tool for wound healing.

Formulation and Evaluation of Helichrysum italicum Essential Oil-Based Topical Formulations for Wound Healing in Diabetic Rats

As proper wound management is crucial to reducing morbidity and improving quality of life, this study evaluated for the first time the wound healing potential of H. italicum essential oil (HIEO) prepared in the form of ointment and gel in streptozotocin-induced diabetic wound models in rats. After creating full-thickness cutaneous wounds, forty-eight diabetic rats were divided into six groups: (1) negative control; (2) positive control; (3) ointment base; (4) gel base; (5) 0.5% HIEO ointment (6) 0.5% HIEO gel. Wound healing potential was determined by the percentage of wound contraction, hydroxyproline content, redox status, and histological observation. A significant decrease in the wound size was observed in animals treated with HIEO formulations compared with other groups. The HIEO groups also showed a higher level of total hydroxyproline content, and more pronounced restitution of adnexal structures with only the underlying muscle defect indicating the incision site. Hence, our results legitimate the traditional data of the pro-healing effect of HIEO because HIEO in both formulations such as gel and ointment exhibited the significant wound repairing effect in the incision wound model.

Exosomes Derived from Human Umbilical Cord Mesenchymal Stem Cells Accelerate Cutaneous Wound Healing by Enhancing Angiogenesis through Delivering Angiopoietin-2

The underlying mechanisms of human umbilical cord mesenchymal stem cells (hucMSCs) and their exosomes (hucMSC-Exs), which play significant roles in skin wound healing, remain poorly understood. By using a rat model of deep second-degree burn injury, the roles of hucMSC-Exs in angiogenesis and cutaneous wound healing in vivo were investigated. We found that hucMSC-Exs accelerated skin wound healing and angiogenesis, inducing a higher wound-closure rate and increased expression of CD31 in vivo. We also discovered that hucMSC-Exs contained angiopoietin-2 (Ang-2), and treatment with hucMSC-Exs enhanced the expression of the Ang-2 protein in the wound area and human umbilical vein endothelial cells (HUVECs) through exosomal-mediated Ang-2 transfer. Moreover, hucMSC-Exs promoted the proliferative, migratory, and tube-forming ability of HUVECs. Furthermore, overexpression of Ang-2 in hucMSC-Exs further enhanced HUVEC migration and tube formation and exerted therapeutic and proangiogenic effects in cutaneous wounds in rats, whereas knockdown of Ang-2 in hucMSC-Exs abrogated these therapeutic and proangiogenic effects. Taken together, our results indicated that hucMSC-Ex-derived Ang-2 plays a significant role in tube formation of HUVECs and promotion of angiogenesis, and further suggested that hucMSC-Ex-based therapy may serve as a promising therapeutic approach for promoting cutaneous wound healing.