Phenolic Compounds in Extracts of Hibiscus acetosella (Cranberry Hibiscus) and Their Antioxidant and Antibacterial Properties

Natural products - Dawn of keloid treatment

Keloids are prevalent pathological scars, often leading to cosmetic deformities and hindering joint mobility.They cause discomfort, including burning and itching, while gradually expanding and potentially posing a risk of cancer.Developing effective drugs and treatments for keloids has been a persistent challenge in the medical field. Natural products are an important source of innovative drugs and a breakthrough for many knotty disease.Herein, keywords of "natural, plant, compound, extract" were combined with "keloid" and searched in PubMed and Google Scholar, respectively. A total of 32 natural products as well as 9 extracts possessing the potential for treating keloids were ultimately identified.Current research in this field faces a significant challenge due to the lack of suitable animal models, resulting in a predominant reliance on in vitro studies.In vivo and clinical studies are notably scarce as a result.Moreover, there is a notable deficiency in research focusing on the role of nutrients in keloid formation and treatment.The appropriate dosage form (oral, topical, injectable) is crucial for the development of natural product drugs. Finally, the conclusion was hereby made that natural products, when used as adjuncts to other treatments, hold significant potential in the management of keloids.By summarizing the natural products and elucidating their mechanisms in keloid treatment, the present study aims to stimulate further discoveries and research in drug development for effectively addressing this challenging condition.

Aptamers for the Delivery of Plant-Based Compounds: A Review

Natural compounds have a high potential for the treatment of various conditions, including infections, inflammatory diseases, and cancer. However, they usually present poor pharmacokinetics, low specificity, and even toxicity, which limits their use. Therefore, targeted drug delivery systems, typically composed of a carrier and a targeting ligand, can enhance natural product selectivity and effectiveness. Notably, aptamers-short RNA or single-stranded DNA molecules-have gained attention as promising ligands in targeted drug delivery since they are simple to synthesize and modify, and they present high tissue permeability, stability, and a wide array of available targets. The combination of natural products, namely plant-based compounds, with a drug delivery system utilizing aptamers as targeting agents represents an emerging strategy that has the potential to broaden its applications. This review discusses the potential of aptamers as targeting agents in the delivery of natural compounds, as well as new trends and developments in their utilization in the field of medicine.

Protective effects of vanillic acid on letrozole-induced polycystic ovarian syndrome: A comprehensive study in female wistar rats

Background

Polycystic ovarian syndrome (PCOS) is one of the known causes of anovulatory fertility in the world. Previous research has linked oxidative stress could contribute to PCOS, and vanillic acid has shown antioxidant potential. Hence, the present study evaluated the effect of vanillic acid on letrozole-induced polycystic ovarian syndrome in female rats.

Materials and methods

PCOS was induced in Wistar female rats with letrozole (1 mg/kg, orally) in carboxymethoxycellulose (1 % w/v), administered for 21 days. After induction, the standard group received clomiphene citrate (1 mg/kg, orally) while other treatment groups were administered with vanillic acid at doses 25, 50, and 100 mg/kg, orally for 15 days, and without treatment was considered a negative control group. Different parameters studied were body weight, ovary weight, blood glucose, lipid profile, hormonal levels [luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone], markers for oxidative stress (superoxide dismutase, reduced glutathione, catalase, and malonaldehyde), and histopathology of the ovary. Statistical analysis was done for the results and p < 0.05 was considered to indicate the significance.

Results

Vanillic acid-treated animals showed a concentration-dependent activity on the tested parameters. The highest tested dose (100 mg/kg) produced a more prominent effect in significantly (P < 0.001) decreasing the body weight, and ovary weight and improving the hormonal imbalance. Also, vanillic acid significantly (P < 0.01) reduced elevated blood sugar and lipid levels. Additionally, vanillic acid reduced oxidative stress significantly (P < 0.001) in the ovaries of female rats. Histopathological reports showed a reduction in cystic follicles and appearance of normal healthy follicles at different stages of development after the administration of vanillic acid. Furthermore, these effects were observed to be comparable with those recorded for standard drug, clomiphene.

Conclusion

The current study data suggests that vanillic acid has protected the letrozole-induced polycystic ovarian syndrome. In the event of several side effects associated with conventional treatments used for PCOS, the findings of this study suggest the promising role of vanillic acid. More research in this direction might identify the true potency of vanillic acid in the treatment of PCOS.

A comprehensive review of medicinal Toxicodendron (Anacardiaceae): Botany, traditional uses, phytochemistry and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Comprising of about 30 species, the genus Toxicodendron (Anacardiaceae) are mainly distributed in East Asia and North America. Among them, 13 species have been traditionally used as folk medicines in Asia and other parts of the world to treat blood diseases, abnormal bleeding, skin diseases, gastrointestinal diseases, liver diseases, bone injury, lung diseases, neurological diseases, cardiovascular diseases, tonic, cancer, eye diseases, menstrual irregularities, inflammation, rheumatism, diabetes mellitus, rattlesnake bite, internal parasites, contraceptive, vomiting and diarrhea.

AIM OF THE STUDY

To date, no comprehensive review on Toxicodendron has been published and the scientific basis of the traditional medicinal benefits of Toxicodendron have been less reported. Therefore, this review aims to provide a reference for further research and development on medicinal purpose of Toxicodendron by summarizing the works (from 1980 to 2023), and focusing on its botany, traditional uses, phytochemistry and pharmacology.

MATERIALS AND METHODS

The names of the species were from The Plant List Database (http://www.theplantlist.org), World Flora Online (http://www.worldfloraonline.org), Catalogue of Life Database (https://www.catalogueoflife.org/) and Plants for A Future Database (https://pfaf.org/user/Default.aspx). And the search terms "Toxicodendron" and "the names of 31 species and their synonyms" were used to search for information from electronic databases such as Web of Science, Scopus, Google Scholar, Science Direct, PubMed, Baidu Scholar, Springer, and Wiley Online Library. Moreover, PhD and MSc dissertations were also used to support this work.

RESULTS

These species on Toxicodendron are widely used in folkloric medicine and modern pharmacological activities. So far, approximately 238 compounds, mainly phenolic acids and their derivatives, urushiols, flavonoids and terpenoids, are extracted and isolated from Toxicodendron plants, commonly, T. trichocarpum, T. vernicifluum, T. succedaneum, and T. radicans. Among them, phenolic acids and flavonoids are the main compound classes that show pharmacological activities in Toxicodendron plants both in vitro and in vivo. Furthermore, the extracts and single compounds of these species show a wide range of activities, such as antioxidant, antibacterial, anti-inflammatory, anti-tumor, liver protection, fat reduction, nerve protection, and treatment of blood diseases.

CONCLUSIONS

Selected species of Toxicodendron have been used as herbal medicines in the Southeast Asian for a long time. Furthermore, some bioactive constituents have been identified from them, so plants in this genus may be potential new drugs. The existing research on Toxicodendron has been reviewed, and the phytochemistry and pharmacology provide theoretical basis for some of the traditional medicinal uses. Therefore, in this review, the traditional medicinal, phytochemical and modern pharmacology of Toxicodendron plants are summarized to help future researchers to find new drug leads or to get a better understanding of structure-activity relationships.

Back to Nature: Medicinal Plants as Promising Sources for Antibacterial Drugs in the Post-Antibiotic Era

Undoubtedly, the advent of antibiotics in the 19th century had a substantial impact, increasing human life expectancy. However, a multitude of scientific investigations now indicate that we are currently experiencing a phase known as the post-antibiotic era. There is a genuine concern that we might regress to a time before antibiotics and confront widespread outbreaks of severe epidemic diseases, particularly those caused by bacterial infections. These investigations have demonstrated that epidemics thrive under environmental stressors such as climate change, the depletion of natural resources, and detrimental human activities such as wars, conflicts, antibiotic overuse, and pollution. Moreover, bacteria possess a remarkable ability to adapt and mutate. Unfortunately, the current development of antibiotics is insufficient, and the future appears grim unless we abandon our current approach of generating synthetic antibiotics that rapidly lose their effectiveness against multidrug-resistant bacteria. Despite their vital role in modern medicine, medicinal plants have served as the primary source of curative drugs since ancient times. Numerous scientific reports published over the past three decades suggest that medicinal plants could serve as a promising alternative to ineffective antibiotics in combating infectious diseases. Over the past few years, phenolic compounds, alkaloids, saponins, and terpenoids have exhibited noteworthy antibacterial potential, primarily through membrane-disruption mechanisms, protein binding, interference with intermediary metabolism, anti-quorum sensing, and anti-biofilm activity. However, to optimize their utilization as effective antibacterial drugs, further advancements in omics technologies and network pharmacology will be required in order to identify optimal combinations among these compounds or in conjunction with antibiotics.

Biological and pharmacological aspects of tannins and potential biotechnological applications

Secondary metabolites are divided into three classes: phenolic, terpenoid, and nitrogenous compounds. Phenolic compounds are also known as polyphenols and include tannins, classified as hydrolysable or condensed. Herein, we explored tannins for their ROS reduction characteristics and role in homeostasis. These activities are associated with the numbers and degree of polymerisation of reactive hydroxyl groups present in the phenolic rings of tannins. These characteristics are associated with anti-inflammatory, anti-aging, and anti-proliferative health benefits. Tannins can reduce the risk of cancer and neurodegenerative diseases, such as cardiovascular diseases and Alzheimer's, respectively. These biomolecules may be used as nutraceuticals to maintain good gut microbiota. Industrial applications include providing durability to leather, anti-corrosive properties to metals, and substrates for 3D printing and in bio-based foam manufacture. This review updates regarding tannin-based research and highlights its biological and pharmacological relevance and potential applications.

Hibiscus acetosella: An Unconventional Alternative Edible Flower Rich in Bioactive Compounds

The interest in the consumption of edible flowers has increased since they represent a rich source of bioactive compounds, which are significantly beneficial to human health. The objective of this research was to access the bioactive compounds and antioxidant and cytotoxic properties of unconventional alternative edible flowers of Hibiscus acetosella Welw. Ex Hiern. The edible flowers presented pH value of 2.8 ± 0.00, soluble solids content of 3.4 ± 0.0 °Brix, high moisture content of about 91.8 ± 0.3%, carbohydrates (6.9 ± 1.2%), lipids (0.90 ± 0.17%), ashes (0.4 ± 0.0%), and not detectable protein. The evaluation of the scavenging activity of free radicals, such as 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), of the flower extract was better than the results observed for other edible flowers (507.8 ± 2.7 μM TE and 783.9 ± 30.8 μM TE, respectively) as well as the total phenolic composition (TPC) value (568.8 ± 0.8 mg GAE/g). These flowers are rich in organic acids and phenolic compounds, mainly myricetin, and quercetin derivatives, kaempferol, and anthocyanins. The extract showed no cytotoxicity for the cell lineages used, suggesting that the extract has no directly harmful effects to cells. The important bioactive compound identified in this study makes this flower especially relevant in the healthy food area due to its nutraceutical potential without showing cytotoxicity.

Five blueberry anthocyanins and their antioxidant, hypoglycemic, and hypolipidemic effects in vitro

The dual epidemic of obesity and diabetes mellitus is becoming an important worldwide public health issue. "Diabesity" is the term used to describe the combined detrimental health effects of both diabetes mellitus and obesity/overweight. Currently, food-derived bioactive compounds are suggested to alleviate diabesity. Blueberries are rich in bioactive anthocyanins, which are associated with contributing to preventing obesity and diabetes mellitus. However, the accurate active compounds and the underlying mechanism are still unclear. The objective of this study was to investigate the beneficial effects of blueberry anthocyanin on diabesity. In total, five anthocyanins (delphinidin-3-O-galactoside, delphinidin-3-O-glucoside, petunidin-3-O-galactoside, petunidin-3-O-glucoside, and malvidin-3-O-galactoside) were isolated from rabbiteye blueberry (Vaccinium virgatum) cultivar "Garden blue." All these anthocyanins exhibited oxygen radical absorbance capacity (ORAC), scavenging power of ABTS⁺, and DPPH-free radical and inhibitory activity of α-glucosidase in vitro. Moreover, some compounds improved glucose uptake and attenuated lipid accumulation in high glucose and oleic acid-treated HepG2 cells. All these results suggest that blueberry anthocyanins have potential antioxidant, hypoglycemic, and hypolipidemic effects, which may benefit the treatment of diabesity.

Cardioprotective effects of Ferulic acid against various drugs and toxic agents

Background

Homeostatic regulation of cardiomyocytes is indispensable in maintaining the normal physiological activity of cardiac tissue. Cardiotoxicity induced by drugs may lead to cardiac abnormalities such as arrhythmia, myocardial infarction and myocardial hypertrophy. Moreover, drug-induced cardiotoxicity confines the additional use of the implicated drugs. Several studies have reported that consumption of phytochemicals on regular intervals shall protect humans against numerous diseases such as diabetes, cardiovascular disease, inflammatory diseases and cancer.

Main body

Ferulic acid (FA) is a plant derived polyphenol abundantly found in vegetables, fruits and grains. FA is widely known for its antioxidant, anti-inflammatory, anticancer, nephroprotective and hepatoprotective effects. FA has been well documented for its cardioprotective activity against various drugs and toxic agents as well. However, the cardioprotective action of FA have remained a challenge with regard to understanding its mechanism in health and diseases.

Conclusion

The main purpose of this review is to explore the cardioprotective mechanisms of FA against several drugs and chemicals to recommend further studies to investigate the potential protective effect of FA.

Comparative Metabolomics study of flavonoids in the pericarp of different coloured bitter gourds (Momordica charantia L.)

Bitter gourd (Momordica charantia L.) is a member of Cucurbitaceae family and has long been used as a source of food and medicine for its rich bioactive components or secondary metabolites. However, there are relatively few large-scale detection, identification, and quantitative studies on flavonoids in the pericarp of bitter gourds of different colours. To determine the differences in the diversity and specificity of flavonoids in the pericarp of bitter gourd of different colours, the metabolic profiles in the pericarp of three coloured bitter gourd accessions, dark green (mo), pale green (lv), and white (bai), were analysed by ultra-performance liquid chromatography-tandem mass spectrometry. Priorly, it was confirmed that the different shades of green were caused by the content of chlorophyll. A total of 93 metabolites, including 90 flavonoids and three tannins, were detected in the current study. These 90 flavonoids included three isoflavones, nine dihydroflavones, seven flavanols, 34 flavonols, 26 flavonoids, four chalcones, five flavonoid carbonosides, and two dihydroflavonols. Compared to mo, both lv and bai had 21 and 25 different metabolites, respectively, while there were only nine different metabolites between lv and bai. The relative contents of vitexin and isovitexin increased with the deeper colour of the bitter gourd. Thus, the different metabolites in coloured bitter gourds are mainly involved in the biosynthesis of flavonols, flavonoid carbonosides, and flavonoids. This study enables identification of metabolic differences in the pericarp of bitter gourds of different colours. The results will be helpful for quality breeding of new bitter gourd varieties and shall provide a reference for their medical application.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s12298-022-01210-7.

Ethnobotanical Documentation of Medicinal Plants Used by the Indigenous Panay Bukidnon in Lambunao, Iloilo, Philippines

The Panay Bukidnon is a group of indigenous peoples living in the interior highlands of Panay Island in Western Visayas, Philippines. Little is known about their ethnobotanical knowledge due to limited written records, and no recent research has been conducted on the medicinal plants they used in ethnomedicine. This study aims to document the medicinal plants used by the indigenous Panay Bukidnon in Lambunao, Iloilo, Panay Island. Semi-structured interviews were conducted with 75 key informants from June 2020 to September 2021 to determine the therapeutic use of medicinal plants in traditional medicine. A total of 131 medicinal plant species distributed in 121 genera and 57 families were used to address 91 diseases in 16 different uses or disease categories. The family Fabaceae was best represented with 13 species, followed by Lamiaceae with nine species and Poaceae with eight species. The leaf was the most frequently used plant part and decoction was the most preferred form of preparation. To evaluate the plant importance, use value (UV), relative frequency citation (RFC), relative important index (RI), informant consensus factor (ICF), and fidelity level (FL) were used. Curcuma longa L. had the highest UV (0.79), Artemisia vulgaris L. had the highest RFC value (0.57), and Annona muricata L. had the highest RI value (0.88). Diseases and symptoms or signs involving the respiratory system and injury, poisoning, and certain other consequences of external causes recorded the highest ICF value (0.80). Blumea balsamifera (L.) DC. and Chromolaena odorata (L.) R.M. King & H. Rob were the most relevant and agreed species for the former and latter disease categories, respectively. C. odorata had the highest FL value (100%) and was the most preferred medicinal plant used for cuts and wounds. The results of this study serve as a medium for preserving cultural heritage, ethnopharmacological bases for further drug research and discovery, and preserving biological diversity.

Comparative Study on Phenolic Compounds and Antioxidant Activities of Hop (Humulus lupulus L.) Strobile Extracts

In this study, we investigated the phenolic compounds in hop strobile extracts and evaluated their antioxidant property using DPPH and ABTS assay. The total phenolic compound (TPC) and total flavonoid compound (TFC) estimated in two different solvent extracts considerably varied depending on the extraction solvent. The most abundant phenolic compound in hop strobile was humulones (α-acid) with levels ranging from 50.44 to 193.25 µg/g. El Dorado accession revealed higher antioxidant activity in ethanol extracts (DPPH: IC50 124.3 µg/mL; ABTS: IC50 95.4 µg/mL) when compared with that of the other accessions. Correlations between DPPH (IC50) scavenging TFC in ethanol extract (TFC_E, −0.941), and TPC_E (−0.901), and between ABTS (IC50) scavenging TFC_E (−0.853), and TPC_E (−0.826), were statistically significant at p < 0.01 level, whereas no significant correlation was observed between antioxidant activities, TPC and TFC in water extract. This study is the first to report that variations in the level of phenolic contents and antioxidant activity of various hop cultivars depended on the type of extraction solvent used and the cultivation regions. These results could provide valuable information on developing hop products.

Encapsulation of bioactive compounds extracted from plants of genus Hibiscus: A review of selected techniques and applications

The genus Hibiscus includes more than 250 species, and many studies showed that these plants contain bioactive compounds with technological potential to be used in the development of functional foods. However, the instability of these compounds during typical food processing conditions, such as exposure to high temperatures, pH changes and presence of light and oxygen have stimulated the use of encapsulation techniques to increase their stability and applicability. Among the existing Hibiscus species, only H. sabdariffa, H. cannabinus, and H. acetosella have been investigated in encapsulation studies, being spray drying the most common method approached. Considering the high technological potential offered by the incorporation of encapsulated bioactive compounds from plants of the genus Hibiscus in food formulations, this review discusses key information of selected encapsulation techniques, which represents promising alternatives to increase food systems' stability and stimulate the design of new functional foods. Relevant gaps in the literature were also noticed, mainly the lack of systematic studies regarding the composition of bioactive compounds after encapsulation, instead of total determinations, and biological activities in different analytical systems, such as antioxidant, antimicrobial and anti-inflammatory properties as well as bioaccessibility and bioavailability.

Bioactive Compounds, Antioxidant, and Antibacterial Properties of Lonicera caerulea Berries: Evaluation of 11 Cultivars

The aim of the study was to evaluate 11 cultivars of blue honeysuckle (Lonicera caerulea L.) for bioactive compounds, antioxidant capacity, and the antibacterial activity of berries. Total phenolic contents (TPCs) and total anthocyanin contents (TACs) were established by using ethanolic extracts. For contents of organic acids and saccharides, aqueous extracts were used, and vitamin C was determined by using oxalic acid solution. DPPH^• radical scavenging capacity was evaluated by using ethanolic extracts; antibacterial activity was assessed by using both ethanolic and aqueous extracts. The TPC varied from 364.02 ± 0.41 mg/100 g in ‘Vostorg’ to 784.5 ± 0.3 mg/100 g in ‘Obilnaja’, and TAC ranged from 277.8 ± 1.1 mg/100 g in ‘Čelnočnaja’ to 394.1 ± 8.4 mg/100 g in ‘Nimfa’. Anthocyanins comprised 53.8% of total phenolic contents on average. Among organic acids, citric acid was predominant, averaging 769.41 ± 5.34 mg/100 g, with malic and quinic acids amounting to 289.90 ± 2.64 and 45.00 ± 0.37 mg/100 g on average, respectively. Contents of vitamin C were 34.26 ± 0.25 mg/100 g on average. Organic acids were most effective in the inhibition of both Gram-positive and Gram-negative bacteria tested. In conclusion, berries of L. caerulea are beneficial not only for fresh consumption, but also as a raw material or ingredients of foods with high health-promoting value.

Phenolic Compounds from Leaves and Flowers of Hibiscus roseus: Potential Skin Cosmetic Applications of an Under-Investigated Species

The use of plant extracts in skin-care cosmetics is a modern trend due to their richness in polyphenols that act as anti-aging molecules. Hibiscus roseus is a perennial species naturalized in Italy, with beautiful soft pink flowers; its phenolic composition and biological activities have not been studied yet. The aim of this study was to characterize and quantify the phenolics and to evaluate the antioxidant, sun protection factor (SPF), and anti-collagenase activities of the ethanolic extracts of H. roseus leaves (HL) and flowers (HF). p-Coumaric, chlorogenic, and trans-ferulic acids derivatives as well as quercetin and kaempferol flavonoids were the main phenolic compounds detected. Catechin, epicatechin, kaempferol-3-O-rutinoside, kaempferol-3-O-glucoside, kaempferol-7-O-glucoside, tiliroside, oenin, and peonidin-3-O-glucoside were detected only in HF, while phloridzin was exclusive from HL, which also showed greater amounts of hydroxycinnamic acid derivatives. HF was richer in flavonoids and total phenolics, also exhibiting greater antioxidant capacity. The SPF and anti-collagenase activity of both extracts were similar and comparable to those of synthetic standards. The overall results demonstrate that H. roseus extracts are promising sources of bioactive phenolic compounds that could be potentially applied as anti-aging agents in skin-care cosmetics.

Editorial to the Special Issue "Biological and Pharmacological Activity of Plant Natural Compounds"

Plant natural products are a valuable source of compounds with a healthy potential effect on living organisms, including animals and humans [...].