Leaves and stem bark from Allophylus africanus P. Beauv.: An approach to anti-inflammatory properties and characterization of their flavonoid profile

Anti-inflammatory effects of naringenin 8-sulphonate from Parinari excelsa Sabine stem bark and its semi-synthetic derivatives

The inflammatory response is a vital mechanism for repairing damage induced by aberrant health states or external insults; however, persistent activation can be linked to numerous chronic diseases. The nuclear factor kappa β (NF-κB) inflammatory pathway and its associated mediators have emerged as critical targets for therapeutic interventions aimed at modulating inflammation, necessitating ongoing drug development. Previous studies have reported the inhibitory effect of a hydroethanol extract derived from Parinari excelsa Sabine (Chrysobalanaceae) on tumour necrosis factor-alpha (TNF-α), but the phytoconstituents and mechanisms of action remained elusive. The primary objective of this study was to elucidate the phytochemical composition of P. excelsa stem bark and its role in the mechanisms underpinning its biological activity. Two compounds were detected via HPLC-DAD-ESI(Ion Trap)-MS2 analysis. The predominant compound was isolated and identified as naringenin-8-sulphonate (1), while the identity of the second compound (compound 2) could not be determined. Both compound 1 and the extract were assessed for anti-inflammatory properties using a cell-based inflammation model, in which THP-1-derived macrophages were stimulated with LPS to examine the treatments' effects on various stages of the NF-κB pathway. Compound 1, whose biological activity is reported here for the first time, demonstrated inhibition of NF-κB activity, reduction in interleukin 6 (IL-6), TNF-α, and interleukin 1 beta (IL-1β) production, as well as a decrease in p65 nuclear translocation in THP-1 cells, thus highlighting the potential role of sulphur substituents in the activity of naringenin (3). To explore the influence of sulphation on the anti-inflammatory properties of naringenin derivatives, we synthesized naringenin-4'-O-sulphate (4) and naringenin-7-O-sulphate (5) and evaluated their anti-inflammatory effects. Naringenin derivatives 4 and 5 did not display potent anti-inflammatory activities; however, compound 4 reduced IL-1β production, and compound 5 diminished p65 translocation, with both exhibiting the capacity to inhibit TNF-α and IL-6 production. Collectively, the findings demonstrated that the P. excelsa extract was more efficacious than all tested compounds, while providing insights into the role of sulphation in the anti-inflammatory activity of naringenin derivatives.

Allophylus africanus Stem Bark Extract Modulates the Mitochondrial Apoptotic Pathway in Human Stomach Cancer Cells

The present work aimed to detail the mechanisms elicited by Allophylus africanus P. Beauv. stem bark extract in human stomach cancer cells and to identify the bioactives underlying the cytotoxicity. MTT reduction and LDH leakage assays allowed characterizing the cytotoxic effects in AGS cells, which were further detailed by morphological analysis using phalloidin and Hoechst 33258. Proapoptotic mechanisms were elucidated through a mitochondrial membrane potential assay and by assessing the impact upon the activity of caspase-9 and -3. The extract displayed selective cytotoxicity against AGS cells. The absence of plasma membrane permeabilization, along with apoptotic body formation, suggested that pro-apoptotic effects triggered cell death. Intrinsic apoptosis pathway activation was verified, as mitochondrial membrane potential decrease and activation of caspase-9 and -3 were observed. HPLC-DAD profiling enabled the identification of two apigenin-di-C-glycosides, vicenin-2 (1) and apigenin-6-C-hexoside-8-C-pentoside (3), as well as three mono-C-glycosides-O-glycosylated derivatives, apigenin-7-O-hexoside-8-C-hexoside (2), apigenin-8-C-(2-rhamnosyl)hexoside (4) and apigenin-6-C-(2-rhamnosyl)hexoside (5). Isovitexin-2″-O-rhamnoside (5) is the main constituent, accounting for nearly 40% of the total quantifiable flavonoid content. Our results allowed us to establish the relationship between the presence of vicenin-2 and other apigenin derivatives with the contribution to the cytotoxic effects on the presented AGS cells. Our findings attest the anticancer potential of A. africanus stem bark against gastric adenocarcinoma, calling for studies to develop herbal-based products and/or the use of apigenin derivatives in chemotherapeutic drug development.

Chemical Composition and Biological Activity of Commelina erecta: An Edible Wild Plant Consumed in Brazil

In recent years, the interest in products of natural origin has boosted the exploitation and use of plants as food and sources of bioactive compounds, especially wild plants widely used in different cultures for several purposes. Commelina erecta is a wild edible plant (WEP) traditionally used as food and medicine, about which few studies exist. Thus, this study aimed at enhancing the knowledge about its nutritional, chemical and bioactive profile, considering different plant parts and development stages, in order to increase its inclusion in the diet of South American communities. The nutritional profile was found to be similar to other WEP frequently consumed in Brazil. Thirteen phenolic compounds (HPLC-DAD-ESI/MS) were tentatively identified, with apigenin, luteolin and quercetin derivatives being the most abundant. Fructose and oxalic acid were the major sugar and organic acid, respectively, in the aerial parts of C. erecta, and four isoforms of tocopherols were also identified. Regarding the plant's antioxidant activity, the EC₅₀ values varied between 18.4 and 1060 µg/mL in the inhibition of lipid peroxidation assay (TBARS) and between 53 and 115 µg/mL in the oxidative haemolysis inhibition (OxHLIA) assay. The hydroethanolic extract obtained from stems at the flowering stage also presented anti-inflammatory activity. In general, all the extracts evidenced promising antimicrobial activity. Altogether, these results reinforce the traditional use of this plant species as food and medicine to support the diet of needier populations and also promote food sovereignty and sustainability.

Phlomis fruticosa L. exerts in vitro antineurodegenerative and antioxidant activities and induces prooxidant effect in glioblastoma cell line

Despite the significant advances in drug development we are witnessing the inability of health systems to combat both neurodegenerative diseases and cancers, especially glioblastoma. Hence, natural products are comprehensively studied in order to provide novel therapeutic options. This study aimed to explore anti-neurodegenerative and anti-glioblastoma potential of extract of Phlomis fruticosa L. using in vitro model systems. It was found that the methanol extract of P. fruticosa was able to efficiently reduce activities of enzymes linked to neurodegenerative disease including acetylcholinesterase, butyrylcholinesterase and tyrosinase. Furthermore, P. fruticosa extract has shown excellent antioxidant potential, as evidenced by six different methods. Analysis of cytotoxic effect of P. fruticosa extract on A172 glioblastoma cell line revealed that the concentration of the extract necessary for 50 % inhibition of A172 growth (IC₅₀) was 710 μg/mL. The extract did not induce changes in proliferation and morphology of A172 glioblastoma cells. On the other side, production of ROS was increased in A172 cells treated with the extract. Observed cytotoxic effect of P. fruticosa extract might be based on increase in ROS generation upon treatment. Quantitative chemical analysis revealed the presence of twelve different polyphenols with the cis 3-O-caffeoylquinic acid being the most abundant. This study provided scientific evidence for further exploration of P. fruticosa as a promising natural anti-neurodegenerative therapeutic option.

Topical Fixed-Dose Combinations: Current in vitro methodologies for pre-clinical development

The combination of two or more active pharmaceutical ingredients in the same dosage form - fixed-dose combination products - for topical administration represents a promising therapeutic approach for treating several pathologies, including pain. The pre-clinical development of fixed-dose combination products aims to characterize the interactions between the different APIs and ensure that the final medicinal product has the required safety characteristics. To this end, there are several regulatory accepted in vitro tests to assess the safety of medicinal products intended for cutaneous administration. In turn, the evaluation of anti-inflammatory activity should be based on models described in the scientific literature, as there are no models fully validated by competent entities. Therefore, the present work presents the information regarding accepted in vitro tests to assess the safety of topical products and the most used methods to assess anti-inflammatory activity. Additionally, a new approach to select a fixed-dose combination product with the potential to enhance the therapeutic effects of the individual active pharmaceutical ingredients is rationalized by integrating the overall effects on several targets relevant for inflammation and pain management in one numeric index.

Comparative Study of Metabolomic Profile and Antioxidant Content of Adult and In Vitro Leaves of Aristotelia chilensis

This work aimed to identify the bioactive compounds present in adult maqui (Aristotelia chilensis) leaves from different stages of development and seasons of the year and compare them with leaves obtained from maqui plants grown in vitro. The qualitative and quantitative analysis of maqui leaf extracts by HPLC-DAD-ESI-MSn showed the presence of different polyphenolic compounds classified into galloyl and caffeoyl quinic acids, ellagitannins and ellagic acid- and flavonoid-derivatives. In general, the total phenolic content of the in vitro samples was higher than that of ex vitro samples, whereas the total flavonoid content was higher in winter basal leaves. Additionally, the analysis by HPLC-MS showed that the extract from spring basal leaves was enriched in quercetin, catechin, kaempferol and 3-caffeoyl quinic acids, while in the in vitro leaves extract, quercetin was not present. As regards lipophilic compounds identified by GC/MS, the samples of in vitro leaves showed a high presence of α-tocopherol and β-sitosterol. In contrast, the samples of adult leaves presented a hight level of linolenic and linoleic acids. These results suggest that maqui leaves could be an excellent source of antioxidants and lipophilic compounds for many industries, such as the nutraceutical and pharmaceutical industries.

Cassia sieberiana DC. leaves modulate LPS-induced inflammatory response in THP-1 cells and inhibit eicosanoid-metabolizing enzymes

ETHNOPHARMACOLOGICAL RELEVANCE

According to ethnobotanical surveys, Cassia sieberiana DC. (1825) is a particularly reputed species in African folk Medicine, namely due to the application of its leaves and roots for the treatment of diseases and symptomatology that appear to be related with an inflammatory background. In contrast with the roots of the plant, the leaves remain to be investigated, which prompted us to further detail mechanisms underlying their anti-inflammatory properties, by using in vitro models of disease.

AIM OF THE STUDY

Considering its use in the amelioration and treatment of conditions that frequently underlie an inflammatory response, C. sieberiana leaves extract was prioritized amongst a collection of extracts obtained from plants collected in Guinea-Bissau. As such, this work aims to deliver experimental data on the anti-inflammatory properties of C. sieberiana leaf and to establish possible associations with its chemical composition, thus providing a rationale on its use in folk Medicine.

MATERIALS AND METHODS

The chemical profile of an hydroethanol extract obtained from the leaves of the plant was established by HPLC-DAD-ESI/MSⁿ in order to identify bioactives. The extract and its main compound were tested towards a series of inflammatory mediators, both in enzymatic and cell-based models. The capacity to interfere with the eicosanoid-metabolizing enzymes 5-lipoxygenase (5-LOX), cyclooxygenase-1 (COX-1) and -2 (COX-2) was evaluated in cell-free systems, while the effects in interleukin 6 (IL-6) and tumour necrosis factor-α (TNF-α) levels produced by THP-1 derived macrophages were assessed through ELISA.

RESULTS

HPLC-DAD-ESI/MSⁿ analysis of the extract elucidated a chemical profile qualitatively characterized by a series of anthraquinones, particularly rhein derivatives, and nine flavonols, most of which 3-O-glycosylated. Considering the concentrations of the identified compounds, quercetin was detached as the main component. Effects of the hydroethanol extract obtained from C. sieberiana leaves against key enzymes of the arachidonic acid cascade were recorded, namely a concentration-dependent inhibition against 5-LOX, at concentrations ranging from 16 to 250 μg mL^-1 and a selective inhibitory action upon COX-2 (IC₅₀ = 3.58 μg mL^-1) in comparison with the isoform COX-1 (IC₅₀ = 9.10 μg mL^-1). Impact on inflammatory cytokines was also noted, C. sieberiana leaf extract significantly decreasing IL-6 levels in THP-1 derived macrophages at 250 and 500 μg mL^-1. In contrast, TNF-α levels were found to be increased in the same model. Quercetin appears to partially account for the observed effects, namely due to the significant inhibitory effects on the activity of the arachidonic acid metabolizing enzymes COX-2 and 5-LOX.

CONCLUSIONS

The anti-inflammatory effects herein reported provide a rationale for the use of C. sieberiana leaves in African folk practices, such as in the treatment of arthritis, rheumatism and body aches. Considering the occurrence of flavonoidic and anthraquinonic constituents, as well as the observed anti-inflammatory properties of quercetin, recorded effects must be related with the presence of several bioactives.

Phenolic Compounds and Bioactive Properties of Ruscus aculeatus L. (Asparagaceae): The Pharmacological Potential of an Underexploited Subshrub

Ruscus aculeatus L. is a subshrub used in traditional medicine in different parts of the world, namely in Europe and the Iberian Peninsula. According to reported folk knowledge, the aerial parts are mainly used as diuretics and the underground organs are used for the treatment of disorders of the urinary system and as a laxative. In this work, the aerial part and the roots and rhizomes of R. aculeatus were chemically characterized with regard to the content of phenolic compounds and bioactive properties. Aqueous (infusions and decoctions) preparations and hydroethanolic extracts from the two mentioned parts of the plant were prepared. Nine phenolic compounds were detected in all the extracts. Apigenin-C-hexoside-C-pentoside isomer II was the major compound in aqueous extracts and, in the hydroethanolic extract was quercetin-O-deoxyhexoside-hexoside followed by apigenin-C-hexoside-C-pentoside isomer II. All extracts revealed antioxidant activity and potential to inhibit some of the assayed bacteria; aqueous extracts of the aerial part and infusions of roots and rhizomes did not show cytotoxic effects on a non-tumor primary cell culture. This preliminary study provides suggestions of the biological potential associated with the empirical uses and knowledge of this species, in particular its bioactivities.

Variation in essential oil components and anti-inflammatory activity of Allophylus edulis leaves collected in central-western Brazil

ETHNOPHARMACOLOGICAL RELEVANCE

An infusion obtained from the leaves of "chal-chal" (Allophylus edulis Radlk.) is used for popular treatment of intestinal disorders and as an anti-inflammatory throat treatment. Because of the anti-inflammatory medicinal folk use, a previous work reported scientific research confirming the anti-inflammatory activity of A. edulis essential oil collected in Dourados, MS, Brazil, in March 2015.

AIM OF THE STUDY

The aim of this study was to evaluate the variation in the chemical profile of the essential oil of A. edulis plants collected in Dourados (EOAE-D) and Bonito (EOAE-B), two cities in Mato Grosso do Sul State, Brazil. Additionally, we evaluated the anti-inflammatory effects of the essential oil, as well as that of the major compounds (caryophyllene oxide and α-zingiberene), in experimental in vivo models of inflammation in mice.

MATERIALS AND METHODS

Leaves were collected from plants at both sites in July 2018. The composition of the essential oil (EOAE-D and EOAE-B) was determined by GC/MS, and major compounds (caryophyllene oxide and α-zingiberene) were isolated and identified by chromatographic methods and NMR spectroscopy. Anti-inflammatory capacities were assessed using two classical models of inflammatory models, carrageenan- and CFA-induced paw inflammation (mechanical and thermal hyperalgesia).

RESULTS

Both EOAE-D and EOAE-B showed sesquiterpenes as a major constituent, namely, caryophyllene oxide (29.5%) and α-zingiberene (45.0%), respectively. In tests, EOAE, caryophyllene oxide and α-zingiberene-induced antiedematogenic and antihyperalgesic effects were found in the different utilized models.

CONCLUSIONS

The results indicate that samples from the two cities differed in chemical composition but not in their anti-inflammatory and antihyperalgesic effects. This finding corroborates the use of A. edulis as a medicinal plant and indicates its potential in the therapy of inflammatory conditions.

Lipoxygenase Inhibition by Plant Extracts

Lipoxygenases are widespread enzymes that catalyze oxidation of polyunsaturated fatty acids (linoleic, linolenic, and arachidonic acid) to produce hydroperoxides. Lipoxygenase reactions can be desirable, but also lipoxygenases can react in undesirable ways. Most of the products of lipoxygenase reactions are aromatic compounds that can affect food properties, especially during long-term storage. Lipoxygenase action on unsaturated fatty acids could result in off-flavor/off-odor development, causing food spoilage. In addition, lipoxygenases are present in the human body and play an important role in stimulation of inflammatory reactions. Inflammation is linked to many diseases, such as cancer, stroke, and cardiovascular and neurodegenerative diseases. This review summarized recent research on plant families and species that can inhibit lipoxygenase activity.

Gustavia gracillima Miers. flowers effects on enzymatic targets underlying metabolic disorders and characterization of its polyphenolic content by HPLC-DAD-ESI/MSn

Notwithstanding Gustavia gracillima Miers widespread distribution in neotropical regions, its chemical profile and biological properties remain uninvestigated. A methanol extract obtained from the flowers was characterized through HPLC-DAD-ESI/MSⁿ, nine ellagic acid derivatives and twelve kaempferol 3-O-glycosides being identified and quantitated for the first time at the species and genus. Preliminary cytotoxicity screening did not reveal noticeable effects upon gastrointestinal representative cell lines (AGS, Caco-2 and Hep G2), which further prompted us to evaluate the impact in a series of targets involved in metabolic disorders and associated complications. Despite of the moderate inhibition towards 5-lipoxygense activity, G. gracillima methanol extract displayed significant effects on carbohydrates-hydrolysing enzymes. In contrast with the antidiabetic reference drug acarbose, the extract was able to selectively inhibit yeast α-glucosidase activity (IC₅₀ = 4.72 µg/mL), with negligible inhibitory effects upon α-amylase. Kinetic studies pointed to a model of mixed inhibition with a great binding activity, characterized by an inhibitory constant of 2.91 µg/mL. The notable inhibitory activity was also confirmed in α-glucosidase homogenates isolated from human intestinal cells (IC₅₀ = 34.03 µg/mL). Moreover, the extract obtained from the flowers of G. gracillima displayed significant aldose reductase inhibition (IC₅₀ = 61.88 µg/mL), as well as O₂^- and NO scavenging properties. A moderate inhibitory effect was also recorded against pancreatic lipase (IC₅₀ = 362.17 µg/mL) through a mixed inhibition mode. Recorded data supports the potential incorporation of G. gracillima flowers on antidiabetic herbal formulations and/or supplements, with not only straight action on carbohydrates digestion, but also direct interference with targets involved on subsequent diabetes events, such as triglycerides metabolism, inflammation and radical-mediated stress.

Anti-inflammatory properties of Xylopia aethiopica leaves: Interference with pro-inflammatory cytokines in THP-1-derived macrophages and flavonoid profiling

ETHNOPHARMACOLOGICAL RELEVANCE

Ethnopharmacological surveys on Guinea-Bissauan flora reveal that several species are used to treat or ameliorate the symptomatology of conditions with an inflammatory background. As such, extracts obtained from a series of plants recorded in those surveys were screened for their anti-inflammatory properties, a hydroethanolic extract obtained from the leaves of Xylopia aethiopica (Dunal) A. Rich, (Annonaceae), used on the treatment of headache, muscular pain and rheumatic pain, scoring positively and being further investigated.

AIM OF THE STUDY

In order to identify species with anti-inflammatory properties, extracts were screened for their ability to interfere with LPS-induced TNF-α levels. Since significant effects were recorded upon treatment with the extract of the leaves obtained from X. aethiopica, further assays were conducted to elucidate additional mechanisms underlying its anti-inflammatory potential. Since little is known on the chemical composition of the plant, we also aimed to characterise its phenolic profile.

MATERIALS AND METHODS

Interference with cytokines was evaluated by ELISA assay, through the quantification of TNF-α and IL-6 levels in the culture medium collected from LPS-activated THP-1-derived-macrophages. Inhibition of 5-lipoxygenase was assessed based on the oxidation of linoleic acid to 13-hydroperoxylinoleic acid. Characterization of the phenolic profile was attained by HPLC-DAD.

RESULTS

Evaluation of TNF-α levels in LPS-challenged THP-1 macrophages evidenced a significant inhibition (>90%) upon treatment with the hydroethanolic extract obtained from X. aethiopica leaves at a concentration of 500 μg/mL. Additional anti-inflammatory effects were recorded, including a significant decrease on IL-6 levels at 250 and 500 μg/mL. The extract proved to be active towards 5-LOX, leading to significant inhibition at concentrations ranging from 16 to 250 μg/mL (IC₅₀ = 85 μg/mL). Phenolic profiling allowed the identification and quantitation of eight constituents, including caffeoylquinic acids (1-3), mono-O-glycosylated flavonols (5-8), and the mono-O-glycosyl flavone luteolin-7-O-glucoside (4). The main phenolic constituent, kaempferol-3-O-rutinoside (8), was found to significantly contribute to the anti-inflammatory effects, namely through the inhibition of 5-LOX. However, no effects on the decrease of TNF-α and IL-6 levels caused by this phenolic compound were found.

CONCLUSION

The anti-inflammatory effects of X. aethiopica leaves are demonstrated experimentally, thus substantiating its use in folk Medicine. Relevantly, the observed anti-inflammatory properties can stimulate further studies in order to fully unveil the therapeutic potential of the plant, namely as a source of phenolic compounds with a significant ability to interfere with conventional inflammatory targets.

A Review of Bark-Extract-Mediated Green Synthesis of Metallic Nanoparticles and Their Applications

Nanoparticles are intensely studied because of their importance in diverse fields of biotechnology, especially in medicine. This paper highlights that waste bark can be a cheap source of biocompounds, with high recovery and functionalization potential in nanoparticle synthesis. Due to their biocompatibility and activity as antioxidant, antimicrobial, and anticancer agents, the green synthesis of metallic nanoparticles is of great importance. This review aims to bring together the diversity of synthesized metallic nanoparticles mediated by bark extracts obtained from different woody vascular plants, the phytoconstituents responsible for the reduction of metal salts, and the activity of metallic nanoparticles as diverse agents in combating the microbial, oxidant, and cancer activity. The literature data highlight the fact that metallic nanoparticles obtained from natural compounds are proven reducing agents with multiple activities. Thus, the activity of natural components in environmental protection and human health is confirmed.

Recent Trends in the Application of Chromatographic Techniques in the Analysis of Luteolin and Its Derivatives

Luteolin is a flavonoid often found in various medicinal plants that exhibits multiple biological effects such as antioxidant, anti-inflammatory and immunomodulatory activity. Commercially available medicinal plants and their preparations containing luteolin are often used in the treatment of hypertension, inflammatory diseases, and even cancer. However, to establish the quality of such preparations, appropriate analytical methods should be used. Therefore, the present paper provides the first comprehensive review of the current analytical methods that were developed and validated for the quantitative determination of luteolin and its C- and O-derivatives including orientin, isoorientin, luteolin 7-O-glucoside and others. It provides a systematic overview of chromatographic analytical techniques including thin layer chromatography (TLC), high performance thin layer chromatography (HPTLC), liquid chromatography (LC), high performance liquid chromatography (HPLC), gas chromatography (GC) and counter-current chromatography (CCC), as well as the conditions used in the determination of luteolin and its derivatives in plant material.

Biological and Chemical Insights of Beech (Fagus sylvatica L.) Bark: A Source of Bioactive Compounds with Functional Properties

The present study aimed, on the one hand, to improve the yield of microwave assisted extraction (MAE) of polyphenols from beech bark by using a design of experiments (DoE) approach. On the other hand, beech bark extracts (BBE) were characterized in terms of their phytochemical profile and evaluated for biological potential (antioxidant, antibacterial, antifungal, antimutagen, anti-α-glucosidase, and anti-tyrosinase). The extraction time varies with the amount of extracted total phenolic content (TPC). The microwave power favors TPC extraction but in different proportions. The optimum conditions which gave the highest TPC (76.57 mg GAE/g dry plant material) were reached when the microwave power was 300 W, extraction time was 4 min, and the solvent was an ethanol–water (50:50) mixture. The practical value of TPC after a controlled experiment was 76.49 mg GAE/g plant material. The identified compounds were vanillic acid, gallic acid, epicatechin, catechin, protocatechuic acid, chlorogenic acid, ferulic acid, and isoquercitrin. The antioxidant potential of BBEs was demonstrated by in vitro experiments. The BBEs were active against Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhimurium, Escherichia coli, and Candida species. All extracts were antimutagenic and expressed an inhibition on α-glucosidase and tyrosinase activity. Regarding antimutagen activity, the assayed extracts may be considered to have low or no antimutagen effects.

Phenolic Profiling and Biological Potential of Ficus curtipes Corner Leaves and Stem Bark: 5-Lipoxygenase Inhibition and Interference with NO Levels in LPS-Stimulated RAW 264.7 Macrophages

The economic value of fig trees has been globally acknowledged due to their utilization in the food industry, being also frequently used in traditional medicine. While ubiquitously distributed in Southeast Asia, Ficus curtipes Corner remains uninvestigated concerning its biological properties and chemical profile. HPLC-DAD-ESI/MSⁿ characterization of methanol extracts obtained from the stem bark and leaves allowed the identification and quantitation of 21 phenolic compounds for the first time; the stem bark was predominantly rich in flavan-3-ols and apigenin derivatives, while solely apigenin-di-glycosides have been identified and quantitated on the leaf extract. Both extracts inhibited 5-lipoxygenase (5-LOX) activity in a concentration-dependent manner, the one obtained from the stem bark being significantly more active (IC₅₀ = 10.75 μg/mL). The effect of both extracts on lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages was evaluated, and while the stem bark extract did not lead to a noticeable interference on nitric oxide (NO) levels, the extract obtained from the leaves notably decreased NO and L-citrulline levels at concentrations ranging from 250 to 500 μg/mL. Herein, F. curtipes is valorized due to its modulatory effects on inflammatory mediators and also as a source of bioactive phenols, which may fuel further studies on the development of nutraceuticals.

Flavonoid Composition of Salacia senegalensis (Lam.) DC. Leaves, Evaluation of Antidermatophytic Effects, and Potential Amelioration of the Associated Inflammatory Response

Predominantly spread in West Tropical Africa, the shrub Salacia senegalensis (Lam.) DC. is known because of its medicinal properties, the leaves being used in the treatment of skin diseases. Prompted by the ethnomedicinal use, a hydroethanolic extract obtained from the leaves of the plant was screened against a panel of microbial strains, the majority of which involved in superficial infections. The extract was found to be active against the dermatophytes Trichophyton rubrum and Epidermophyton floccosum. Notable results were also recorded regarding the attenuation of the inflammatory response, namely the inhibitory effects observed against soybean 5-lipoxygenase (IC₅₀ = 71.14 μg mL^-1), no interference being recorded in the cellular viability of RAW 264.7 macrophages and NO levels. Relevantly, the extract did not lead to detrimental effects against the keratinocyte cell line HaCaT, at concentrations displaying antidermatophytic and anti-inflammatory effects. Flavonoid profiling of S. senegalensis leaves was achieved for the first time, allowing the identification and quantitation of myricitrin, three 3-O-substituted quercetin derivatives, and three other flavonoid derivatives, which may contribute, at least partially, to the observed antidermatophytic and anti-inflammatory effects. In the current study, the plant S. senegalensis is assessed concerning its antidermatophytic and anti-inflammatory properties.

A Critical Review of Phenolic Compounds Extracted from the Bark of Woody Vascular Plants and Their Potential Biological Activity

Polyphenols are one of the largest and most widespread groups of secondary metabolites in the plants world. These compounds are of particular interest due to their occurrence and the properties they possess. The main sources of phenolic compounds are fruits and vegetables, but lately, more and more studies refer to woody vascular plants, especially to bark, as an important source of phenolic compounds with a potential biological effect. This study aims to bring together information on the phenolic compounds present in the bark of woody vascular plants by discussing extraction methods, the chemical composition of the extracts and potential biological effects. The literature data used in this paper were collected via PubMed (2004⁻2019). Search terms were: bark, rhytidome, woody vascular plant, polyphenols, phenolic compounds, biologic activity, antioxidant, immunostimulatory, antimutagenic, antibacterial, anti-inflammatory, and antitumoral. This paper intends to highlight the fact that the polyphenolic extracts obtained from the bark of woody vascular plants represent sources of bioactive compounds with antioxidant, immunostimulatory, antimutagenic, antibacterial properties, etc. Future research directions should be directed towards identification and isolation of bioactive compounds. Consequently, biologically active compounds obtained from the bark of woody plants could be exploited on an industrial scale.