Anti-Inflammatory and Wound Healing Properties of Leaf and Rhizome Extracts from the Medicinal Plant Peucedanum ostruthium (L.) W. D. J. Koch

Phlomis crinita Cav. From Algeria: A source of bioactive compounds possessing antioxidant and wound healing activities

ETHNOPHARMACOLOGICAL RELEVANCE

Phlomis crinita Cav. (Lamiaceae), locally known as "El Khayata" or "Kayat El Adjarah", is traditionally used in Algeria for its wound-healing properties.

AIM OF THE STUDY

Investigate, for the first time, the phytochemical profile, safety, antioxidant and wound-healing activities of the flowering tops methanolic extract of P. crinita (PCME) collected from Bouira Province in the North of Algeria.

MATERIALS AND METHODS

Preliminary phytochemical assays were carried out on PCME to quantify the main classes of bioactive compounds, such as total phenols, flavonoids, and tannins. An in-depth LC-DAD-ESI-MS analysis was carried out to elucidate the phytochemical profile of this plant species. Antioxidant activity was investigated by several colorimetric and fluorimetric assays (DPPH, TEAC, FRAP, ORAC, β-carotene bleaching and ferrozine assay). The acute oral toxicity of PCME (2000 mg/kg b.w.) was tested in vivo on Swiss albino mice, whereas the acute dermal toxicity and wound-healing properties of the PCME ointment (1-5% PCMO) were tested in vivo on Wistar albino rats. Biochemical and histological analyses were carried out on biological samples.

RESULTS

The phytochemical screening highlighted a high content of phenolic compounds (175.49 ± 0.8 mg of gallic acid equivalents/g of dry extract), mainly flavonoids (82.28 ± 0.44 mg of quercetin equivalents/g of dry extract). Fifty-seven compounds were identified by LC-DAD-ESI-MS analysis, belonging mainly to the class of flavones (32.27%), with luteolin 7-(6″-acetylglucoside) as the most abundant compound and phenolic acids (32.54%), with salvianolic acid C as the most abundant compound. A conspicuous presence of phenylethanoids (15.26%) was also found, of which the major constituent is forsythoside B. PCME showed a strong antioxidant activity with half-inhibitory activity (IC50) ranging from 1.88 to 37.88 μg/mL and a moderate iron chelating activity (IC50 327.44 μg/mL). PCME appears to be safe with Lethal Dose 50 (LD50) ≥ 2000 mg/kg b.w. No mortality or toxicity signs, including any statistically significant changes in body weight gain and relative organs' weight with respect to the control group, were recorded. A significant (p < 0.001) wound contraction was observed in the 5% PCMO-treated group with respect to the untreated and petroleum jelly groups between 8 and 20 days, whereas no statistically significant results were observed at the two lower doses (1 and 2% PCMO). In addition, the 5% PCMO-treated group showed a statistically significant (p < 0.05) wound healing activity with respect to the reference drug-treated group, showing, at the end of the study, the highest wound contraction percentage (88.00 ± 0.16%).

CONCLUSION

PCME was safe and showed strong antioxidant and wound-healing properties, suggesting new interesting pharmaceutical applications for P. crinita based on its traditional use.

A critical overview of challenging roles of medicinal plants in improvement of wound healing technology

PURPOSE

Chronic diseases often hinder the natural healing process, making wound infections a prevalent clinical concern. In severe cases, complications can arise, potentially leading to fatal outcomes. While allopathic treatments offer numerous options for wound repair and management, the enduring popularity of herbal medications may be attributed to their perceived minimal side effects. Hence, this review aims to investigate the potential of herbal remedies in efficiently treating wounds, presenting a promising alternative for consideration.

METHODS

A literature search was done including research, reviews, systematic literature review, meta-analysis, and clinical trials considered. Search engines such as Pubmed, Google Scholar, and Scopus were used while retrieving data. Keywords like Wound healing 'Wound healing and herbal combinations', 'Herbal wound dressing', Nanotechnology and Wound dressing were used.

RESULT

This review provides valuable insights into the role of natural products and technology-based formulations in the treatment of wound infections. It evaluates the use of herbal remedies as an effective approach. Various active principles from herbs, categorized as flavonoids, glycosides, saponins, and phenolic compounds, have shown effectiveness in promoting wound closure. A multitude of herbal remedies have demonstrated significant efficacy in wound management, offering an additional avenue for care. The review encompasses a total of 72 studies, involving 127 distinct herbs (excluding any common herbs shared between studies), primarily belonging to the families Asteraceae, Fabaceae, and Apiaceae. In research, rat models were predominantly utilized to assess wound healing activities. Furthermore, advancements in herbal-based formulations using nanotechnology-based wound dressing materials, such as nanofibers, nanoemulsions, nanofiber mats, polymeric fibers, and hydrogel-based microneedles, are underway. These innovations aim to enhance targeted drug delivery and expedite recovery. Several clinical-based experimental studies have already been documented, evaluating the efficacy of various natural products for wound care and management. This signifies a promising direction in the field of wound treatment.

CONCLUSION

In recent years, scientists have increasingly utilized evidence-based medicine and advanced scientific techniques to validate the efficacy of herbal medicines and delve into the underlying mechanisms of their actions. However, there remains a critical need for further research to thoroughly understand how isolated chemicals extracted from herbs contribute to the healing process of intricate wounds, which may have life-threatening consequences. This ongoing research endeavor holds great promise in not only advancing our understanding but also in the development of innovative formulations that expedite the recovery process.

Electrospun nanofibers synthesized from polymers incorporated with bioactive compounds for wound healing

The development of innovative wound dressing materials is crucial for effective wound care. It's an active area of research driven by a better understanding of chronic wound pathogenesis. Addressing wound care properly is a clinical challenge, but there is a growing demand for advancements in this field. The synergy of medicinal plants and nanotechnology offers a promising approach to expedite the healing process for both acute and chronic wounds by facilitating the appropriate progression through various healing phases. Metal nanoparticles play an increasingly pivotal role in promoting efficient wound healing and preventing secondary bacterial infections. Their small size and high surface area facilitate enhanced biological interaction and penetration at the wound site. Specifically designed for topical drug delivery, these nanoparticles enable the sustained release of therapeutic molecules, such as growth factors and antibiotics. This targeted approach ensures optimal cell-to-cell interactions, proliferation, and vascularization, fostering effective and controlled wound healing. Nanoscale scaffolds have significant attention due to their attractive properties, including delivery capacity, high porosity and high surface area. They mimic the Extracellular matrix (ECM) and hence biocompatible. In response to the alarming rise of antibiotic-resistant, biohybrid nanofibrous wound dressings are gradually replacing conventional antibiotic delivery systems. This emerging class of wound dressings comprises biopolymeric nanofibers with inherent antibacterial properties, nature-derived compounds, and biofunctional agents. Nanotechnology, diminutive nanomaterials, nanoscaffolds, nanofibers, and biomaterials are harnessed for targeted drug delivery aimed at wound healing. This review article discusses the effects of nanofibrous scaffolds loaded with nanoparticles on wound healing, including biological (in vivo and in vitro) and mechanical outcomes.

Hydrogels based on lignin extracted from cashew apple bagasse and its application in antimicrobial wound dressings

Hydrogels are versatile materials with a three-dimensional network structure that can retain water and release bioactive compounds. They have found applications in various fields, including agriculture, biomaterial synthesis, and pharmaceuticals. Incorporating natural antimicrobial compounds into hydrogels is a promising approach to developing non-toxic biomedical materials, particularly for wound healing dressings. It was evaluated the extraction and use of cashew apple bagasse lignin (CAB-Lig) due to its healing, anti-inflammatory, and antimicrobial properties for producing a hydrogel-based bandage. The extraction process involved acid and alkali treatments followed by precipitation. The antimicrobial potential of CAB-Lig was evaluated at different concentrations for formulating hydrogels. Hydrogels containing 0.1 % and 3 % lignin showed high swelling and liquid retention abilities. The 3 % lignin hydrogel exhibited effectiveness against Escherichia coli and Staphylococcus aureus. Incorporating CAB-Lig into the hydrogel structure improved its mechanical properties, making it more suitable for application as a bandage. Moreover, the extracted lignin showed low toxicity, indicating its safe use. A bandage was formulated by combining the CAB-Lig-based hydrogel with polyester, which possessed antimicrobial properties and demonstrated biocompatibility (L929 and HaCat cells). The results confirmed the potential of CAB-Lig for synthesizing hydrogels and dressings with antimicrobial properties, offering a sustainable solution for utilizing lignocellulosic biomass.

Pharmacognostic Evaluation of Monarda didyma L. Growing in Trentino (Northern Italy) for Cosmeceutical Applications

Monarda didyma L. (Lamiaceae) is a medicinal and aromatic herb native to eastern North America and now is also cultivated in Northern Italy, which shows terminal heads of bright scarlet-red flowers, subtended by a whorl of red-tinged leafy bracts. Starting from 2018, M. didyma flowering tops have been included in the Belfrit List of botanicals. However, to date studies on the crude extract of this plant are still lacking. The aim of the present study was to investigate the morphological and anatomical features of the flowering tops and the phytochemical profile of their ethanolic and hydroglyceric extracts (EE and HGE, respectively). HGE was the richest in total phenols (105.75 ± 5.91 vs. 64.22 ± 3.45 mg/100 mL) and especially in flavonoids (71.60 ± 5.09 vs. 47.70 ± 1.27 mg/100 mL), as confirmed also by LC-DAD-ESI-MS. Fifty-three polyphenols were identified and quantified. Even if they showed a common polyphenolic profile, EE and HGE showed quantitative differences. Flavan-3-ols and anthocyanins were the most expressed metabolites in HGE, whereas flavonols were the most expressed metabolites in EE. These features confer to HGE the highest antioxidant, anti-inflammatory, and anti-angiogenic properties, detected by several in vitro and in vivo assays, highlighting a promising use of this plant extract for skincare applications.

Toxicological profile of the Hymenaea courbaril stem bark hydroalcoholic extract using in vitro bioassays and an alternative in vivo Caenorhabditis elegans model

Hymenaea genus has been used in folk medicine in Brazil, but few studies investigated its toxicity profile. Thus, the aim of this study was to determine toxicological parameters of Hymenaea courbaril stem bark hydroalcoholic extract by utilizing three cell lines including murine macrophages (RAW 264.7), mouse fibroblast cells (L929) and human lung fibroblast (MRC-5), as well as Salmonella/microsome assay, and in vivo Caenorhabditis elegans model. The predominant detected phytoconstituents in the extract were coumarins, flavonoids, phenolics, tannins and saponins and by HPLC analysis, astilbin (AST) was found to be the main component. The DPPH assay demonstrated that H. courbaril hydroalcoholic extract exhibited potent antioxidant activity, with an IC50 of 3.12 μg/ml. The extract at concentrations of 400 and 800 μg/ml decreased cell viability 48 hr after treatment in L929 and MRC-5 cell lines. In the Raw 264.7 strain, just the highest concentration (800 μg/ml) lowered cell viability within 48 hr following exposure. The concentration of 100 μg/ml did not markedly affect cell viability in the trypan blue assay. In the alkaline comet assay the extract was found to be non-genotoxic. In the Ames test, the extract exhibited low mutagenic potential without metabolic activation, since only the highest concentrations produced an effect. H. courbaril extract only affected the survival of C. elegans at concentrations of 800 and 1600 μl/ml. These findings demonstrate that H. courbaril extract appears to exert low toxicity as evidenced in vitro and mutagenicity assays; however, the biological relevance of the response of C. elegans survival to safety assessments needs further studies.

Biochemometry identifies ostruthin as pluripotent antimicrobial and anthelmintic agent from masterwort

The root extract of Peucedanum ostruthium (PO-E) was identified as a promising antibacterial source from a screening of 158 extracts against Staphylococcus aureus. It has also recently been shown to significantly decrease the survival of the nematode Caenorhabditis elegans. We used the biochemometric approach ELINA to investigate the phytochemical characteristics of the multicomponent mixture PO-E to identify the anti-infective constituent(s) targeting S. aureus and C. elegans.1H NMR spectra of PO-E-derived microfractions were correlated with their respective bioactivity data. Heterocovariance analyses unambiguously identified ostruthin as an anti-staphylococcal constituent, which potently also inhibited Enterococcus spp.. ELINA demonstrated that anthelmintic activity was due to a combinatorial effect of ostruthin and isoimperatorin. A C. elegans-based survival and motility assay confirmed that isoimperatorin, imperatorin, and verapamil modulated the susceptibility of ostruthin. The combinatorial effect of these natural products was shown in larvae studies to be related to the function of the nematodes' efflux pump.

Integrative analysis of chloroplast genome, chemicals, and illustrations in Bencao literature provides insights into the medicinal value of Peucedanum huangshanense

The genus Peucedanum L. (Apiaceae) is a large group comprising more than 120 species distributed worldwide. Many plants of the genus Peucedanum have been studied and used in traditional Chinese medicine. In 2020, a new species, Peucedanum huangshanense Lu Q. Huang, H. S. Peng & S. S. Chu, was found in the Huangshan Mountains of Anhui Province, China. However, little is known about its medicinal properties. Thus, the objective of this study is to explore the potential medicinal value of P. huangshanense and its relationship with other Peucedanum species. Through textual research on illustrations of Qianhu in Bencao literature, it can be inferred that at least five species of genus Peucedanum have been used in Chinese medicine. Therefore, we chose these five species of Peucedanum and P. huangshanense together for subsequent research. We conducted morphological, chloroplast genome, and chemical analyses of six Peucedanum species, including the newly discovered P. huangshanense. The chloroplast genomes of Peucedanum showed a typical tetrad structure, and the gene structure and content were similar and conservative. There were significant differences in genome size and the expansion of the inverted repeat boundary. Through nucleotide polymorphism analysis, we screened 14 hotspot mutation regions that have the potential to be used as specific molecular markers for the taxonomy of Peucedanum. Our results showed an inversion of the trnD-trnY-trnE gene in the P. huangshanense chloroplast genome, which can be developed as a specific molecular marker for species identification. Phylogenetic analysis showed that the phylogenetic trees had high support and resolution, which strongly supports the view that Peucedanum is not a monophyletic group. P. huangshanense had the closest genetic relationship to P. ampliatum K. T. Fu, followed by P. harry-smithii Fedde ex Wolff. Furthermore, the main coumarins of P. huangshanense were most similar to those of P. japonicum Thunb. and P. harry-smithii. In summary, our research lays a foundation for the systematic classification of Peucedanum and sheds light on the medicinal value of P. huangshanense.

The Influence of Pedo-Climatic Conditions on the Micromorphological, Phytochemical Features, and Biological Properties of Leaves of Saponaria sicula Raf

Saponaria sicula Raf. grows in Sicily, Sardinia, and Algeria on limestone cliffs and volcanic sands 1300-2500 m above sea level. The aim of the present study was to investigate how the pedo-climatic conditions influence the micromorphological, phytochemical, and biological properties of Sicilian S. sicula leaves collected in the Madonie Mountains (SsM) and on Etna Mt (SsE). Micromorphological investigations revealed that leaves from SsM had a higher amount of calcium oxalate druses in the mesophyll and a more intense blue-green staining with Toluidine blue O, indicating a higher content of polyphenols. These data were confirmed by phytochemical analyses carried out on hydroalcoholic extracts, which showed a higher content of total phenols (8.56 ± 0.57 g GAE/100 g DE) and flavonoids (6.09 ± 0.17 g RE/100 g DE) in SsM. Sixty-four compounds were identified by LC-DAD-ESI-MS analysis with propelargonidin dimer as the most abundant compound (10.49% and 10.19% in SsM and SsE, respectively). The higher polyphenol content of SsM leaves matches also with their biological activity, identifying SsM extract as the strongest plant complex (IC₅₀ 2.75-477.30 µg/mL). In conclusion, the present study experimentally demonstrates that not only climatic differences but also soil characteristics affect the micromorphological, phytochemical, and biological features of this plant species.

Antioxidant Biomaterials in Cutaneous Wound Healing and Tissue Regeneration: A Critical Review

Natural-based biomaterials play an important role in developing new products for medical applications, primarily in cutaneous injuries. A large panel of biomaterials with antioxidant properties has revealed an advancement in supporting and expediting tissue regeneration. However, their low bioavailability in preventing cellular oxidative stress through the delivery system limits their therapeutic activity at the injury site. The integration of antioxidant compounds in the implanted biomaterial should be able to maintain their antioxidant activity while facilitating skin tissue recovery. This review summarises the recent literature that reported the role of natural antioxidant-incorporated biomaterials in promoting skin wound healing and tissue regeneration, which is supported by evidence from in vitro, in vivo, and clinical studies. Antioxidant-based therapies for wound healing have shown promising evidence in numerous animal studies, even though clinical studies remain very limited. We also described the underlying mechanism of reactive oxygen species (ROS) generation and provided a comprehensive review of ROS-scavenging biomaterials found in the literature in the last six years.

The Essential Oil of Citrus lumia Risso and Poit. ‘Pyriformis’ Shows Promising Antioxidant, Anti-Inflammatory, and Neuromodulatory Effects

Citrus lumia Risso and Poit. ‘Pyriformis’ are horticultural varieties of Citrus lumia Risso. The fruit is very fragrant and pear-shaped, with a bitter juice, a floral flavor, and a very thick rind. The flavedo shows enlarged (0.74 × 1.16 mm), spherical and ellipsoidal secretory cavities containing the essential oil (EO), visible using light microscopy, and more evident using scanning electron microscopy. The GC-FID and GC-MS analyses of the EO showed a phytochemical profile characterized by the predominance of D-limonene (93.67%). The EO showed interesting antioxidant and anti-inflammatory activities (IC50 0.07–2.06 mg/mL), as evaluated by the in vitro cell-free enzymatic and non-enzymatic assays. To evaluate the effect on the neuronal functional activity, the embryonic cortical neuronal networks grown on multi-electrode array chips were exposed to non-cytotoxic concentrations of the EO (5–200 µg/mL). The spontaneous neuronal activity was recorded and the mean firing rate, mean burst rate, percentage of spikes in a burst, mean burst durations and inter-spike intervals within a burst parameter were calculated. The EO induced strong and concentration-dependent neuroinhibitory effects, with IC50 ranging between 11.4–31.1 µg/mL. Furthermore, it showed an acetylcholinesterase inhibitory activity (IC50 0.19 mg/mL), which is promising for controlling some of the key symptoms of neurodegenerative diseases such as memory and cognitive concerns.

Comparative analysis of root anatomical structure, chemical components and differentially expressed genes between early bolting and unbolting in Peucedanum praeruptorum Dunn

Early bolting of Peucedanum praeruptorum Dunn severely affects its quality. In this study, we compared with the root structure of P. praeruptorum and its four coumarins content between early bolting (CT) and unbolting (WT) at different growth stages. We found that the proportion of area outside the root cambium (Rs) was higher in the WT plants than in the CT plants and correlated positively with the proximity to the root tip. Furthermore, the content of all four coumarins was also higher in the WT plants relative to the CT plants. In addition, we identified 15,524 differentially expressed genes (DEGs) between the two plant varieties. 11 DEGs are involved in the photoperiod and gibberellin pathways that regulate early bolting and 24 genes involved in coumarins biosynthesis were also identified. Nevertheless, early bolting of P. praeruptorum does affect its quality formation, and further studies are needed to confirm its mechanism.

Pedoclimatic Conditions Influence the Morphological, Phytochemical and Biological Features of Mentha pulegium L

In this study, Mentha pulegium leaves and flowers harvested in three different Sicilian areas were investigated from a micromorphological, phytochemical and biological point of view. Light and scanning electron microscopy showed the presence of spherocrystalline masses of diosmin both in the leaf epidermal cells and in thin flower petals. Two different chemotypes were identified (I, kaempferide/rosmarinic acid; II, jaceidin isomer A). Phytochemical screening identified plant from collection site II as the richest in total phenolics (16.74 g GAE/100 g DE) and that from collection site I as the richest in flavonoids (46.56 g RE/100 g DE). Seventy-seven metabolites were identified both in flower and leaf extracts. Plant from site II showed the best antioxidant (0.90-83.72 µg/mL) and anti-inflammatory (27.44-196.31 µg/mL) activity expressed as half-maximal inhibitory concentration (IC₅₀) evaluated by DPPH, TEAC, FRAP, ORAC, BSA denaturation and protease inhibition assays. These data were also corroborated by in vitro cell-based assays on lymphocytes and erythrocytes. Moreover, plant of site II showed the best antiangiogenic properties (IC₅₀ 33.43-33.60 µg/mL) in vivo on a chick chorioallantoic membrane. In conclusion, pedoclimatic conditions influence the chemotype and the biological activity of M. pulegium, with chemotype I showing the most promising biological properties.

New Insights on Phytochemical Features and Biological Properties of Alnus glutinosa Stem Bark

Alnus glutinosa (namely black alder or European alder) is a tree of the Betulaceae family widely spread through Europe, Southeastern Asia, the Caucasus mountains, and Western Siberia. Its bark is traditionally used for medicinal purposes as an astringent, cathartic, febrifuge, emetic, hemostatic, and tonic, suggesting that it may contain bioactive compounds useful to counteract inflammation. The aim of this study was to investigate the phytochemical profile of A. glutinosa stem bark extract (AGE) by LC-DAD-ESI-MS/MS analysis and to validate some biological activities such as antioxidant, anti-inflammatory and anti-angiogenic properties by in vitro and in vivo models (chick chorioallantoic membranes and zebrafish embryos), that can justify its use against inflammatory-based diseases. The AGE showed a high total phenols content expressed as gallic acid equivalents (0.71 g GAE/g of AGE). Diarylheptanoids have been identified as the predominant compounds (0.65 g/g of AGE) with oregonin, which alone constitutes 74.67% of the AGE. The AGE showed a strong and concentration-dependent antioxidant (IC₅₀ 0.15–12.21 µg/mL) and anti-inflammatory (IC₅₀ 5.47–12.97 µg/mL) activity. Furthermore, it showed promising anti-angiogenic activity, inhibiting both the vessel growth (IC₅₀ 23.39 µg/egg) and the release of an endogenous phosphatase alkaline enzyme (IC₅₀ 44.24 µg/embryo). In conclusion, AGE is a promising source of antioxidant, anti-inflammatory and angio-modulator compounds.