Antioxidant and Cytoprotective Effects of Kukoamines A and B: Comparison and Positional Isomeric Effect

Ethnobotany and phytochemistry of plants used to treat musculoskeletal disorders among Skaw Karen, Thailand

CONTEXT

Musculoskeletal system disorders (MSD) are prevalent around the world affecting the health of people, especially farmers who work hard in the field. Karen farmers use many medicinal plants to treat MSD.

OBJECTIVE

This study collects traditional plant-based remedies used by the Skaw Karen to treat MSD and evaluates their active phytochemical compounds.

MATERIALS AND METHODS

The ethnobotanical study was conducted in six Karen villages in Chiang Mai province using semi-structured interviews were of 120 informants. The data were analyzed using ethnobotanical indices including use values (UV), choice value (CV), and informant consensus factor (ICF). Consequently, the 20 most important species, according to the indices, were selected for phytochemical analysis using LC-MS/MS.

RESULTS

A total of 3731 use reports were obtained for 139 species used in MSD treatment. The most common ailments treated with those plants were muscular pain. A total of 172 high-potential active compounds for MSD treatment were identified. Most of them were flavonoids, terpenoids, alkaloids, and steroids. The prevalent phytochemical compounds related to treat MSD were 9-hydroxycalabaxanthone, dihydrovaltrate, morroniside, isoacteoside, lithocholic acid, pomiferin, cucurbitacin E, leonuriside A, liriodendrin, and physalin E. Sambucus javanica Reinw. ex Blume (Adoxaceae), Betula alnoides Buch.-Ham. ex D.Don (Betulaceae), Blumea balsamifera (L.) DC. (Asteraceae), Plantago major L. (Plantaginaceae) and Flacourtia jangomas (Lour.) Raeusch. (Salicaceae) all had high ethnobotanical index values and many active compounds.

DISCUSSION AND CONCLUSIONS

This study provides valuable information, demonstrating low-cost medicine plants that are locally available. It is a choice of treatment for people living in remote areas.

Potential of Lycii Radicis Cortex as an Ameliorative Agent for Skeletal Muscle Atrophy

Lycii Radicis Cortex (LRC) is a traditional medicine in East Asia with various beneficial effects, including antioxidant, anti-inflammatory, anti-tumor, anti-diabetic, and anti-depressant properties. However, its potential effects on skeletal muscle atrophy have not been studied. In this study, the protective effects of LRC extract (LRCE) on dexamethasone (DEX)-induced muscle atrophy were investigated in C2C12 myotubes and mice. We evaluated the effect of LRCE on improving muscle atrophy using a variety of methods, including immunofluorescence staining, quantitative polymerase chain reaction (qPCR), Western blot, measurements of oxidative stress, apoptosis, ATP levels, and muscle tissue analysis. The results showed that LRCE improved myotube diameter, fusion index, superoxide dismutase (SOD) activity, mitochondrial content, ATP levels, expression of myogenin and myosin heavy chain (MHC), and reduced reactive oxygen species (ROS) production in dexamethasone-induced C2C12 myotubes. LRCE also enhanced protein synthesis and reduced protein degradation in the myotubes. In mice treated with DEX, LRCE restored calf thickness, decreased mRNA levels of muscle-specific RING finger protein 1 (MuRF1) and atrogin-1, and increased insulin-like growth factor 1 (IGF-1) mRNA level. Moreover, LRCE also repaired gastrocnemius muscle atrophy caused by DEX. Although human studies are not available, various preclinical studies have identified potential protective effects of LRCE against muscle atrophy, suggesting that it could be utilized in the prevention and treatment of muscle atrophy.

Hairy root culture: a potent method for improved secondary metabolite production of Solanaceous plants

Secondary metabolites synthesized by the Solanaceous plants are of major therapeutic and pharmaceutical importance, many of which are commonly obtained from the roots of these plants. 'Hairy roots', mirroring the same phytochemical pattern of the corresponding root of the parent plant with higher growth rate and productivity, are therefore extensively studied as an effective alternative for the in vitro production of these metabolites. Hairy roots are the transformed roots, generated from the infection site of the wounded plants with Agrobacterium rhizogenes. With their fast growth, being free from pathogen and herbicide contamination, genetic stability, and autotrophic nature for plant hormones, hairy roots are considered as useful bioproduction systems for specialized metabolites. Lately, several elicitation methods have been employed to enhance the accumulation of these compounds in the hairy root cultures for both small and large-scale production. Nevertheless, in the latter case, the cultivation of hairy roots in bioreactors should still be optimized. Hairy roots can also be utilized for metabolic engineering of the regulatory genes in the metabolic pathways leading to enhanced production of metabolites. The present study summarizes the updated and modern biotechnological aspects for enhanced production of secondary metabolites in the hairy root cultures of the plants of Solanaceae and their respective importance.

Clinical Development and Evaluation of a Multi-Component Dissolving Microneedle Patch for Skin Pigmentation Disorders

Excessive melanin deposition in the skin leads to various skin pigmentation diseases, such as chloasma and age spots. The deposition is induced by several factors, including tyrosinase activities and ultraviolet-induced oxidative stress. Herein, we propose a multi-component, multi-pathway drug combination, with glabridin, 3-O-ethyl-L-ascorbic acid, and tranexamic acid employed as, respectively, a tyrosinase inhibitor, an antioxidant, and a melanin transmission inhibitor. Considering the poor skin permeability associated with topical application, dissolving microneedles (MNs) prepared with hyaluronic acid/poly(vinyl alcohol)/poly(vinylpyrrolidone) were developed to load the drug combination. The drug-loaded microneedles (DMNs) presented outstanding skin insertion, dissolution, and drug delivery properties. In vitro experiments confirmed that DMNs loaded with active ingredients had significant antioxidant and inhibitory effects on tyrosinase activity. Furthermore, the production of melanin both in melanoma cells (B16-F10) and in zebrafish was directly reduced after using DMNs. Clinical studies demonstrated the DMNs' safety and showed that they have the ability to effectively reduce chloasma and age spots. This study indicated that a complex DMN based on a multifunctional combination is a valuable depigmentation product worthy of clinical application.

Kukoamine B from Lycii Radicis Cortex Protects Human Keratinocyte HaCaT Cells through Covalent Modification by Trans-2-Nonenal

The unsaturated aldehyde trans-2-nonenal is known to be generated by lipid peroxidation at the surface of the skin in an aging-related manner and has harmful effects on keratinocytes in the skin. In this study, the protective effect of a Lycii Radicis Cortex (LRC) extract against trans-2-nonenal-induced cell damage on human keratinocyte cell lines (HaCaT) was investigated. Notably, treatment with the LRC extract resulted in an increase in cell survival, while trans-2-nonenal decreased the viability of HaCaT cells. For identification of interaction between the LRC extract and trans-2-nonenal, this mixture was incubated in simulated physiological conditions, showing a strong decrease in the amount of trans-2-nonenal by the LRC extract. Subsequent LC-ESI-MS analysis revealed that kukoamine B (KB) formed Schiff base-derived pyridinium adducts with trans-2-nonenal. Thus, these results suggest that KB could be a potential agent that may protect HaCaT cells by forming new products with trans-2-nonenal.

Influence of oral administration of kukoamine A on blood pressure in a rat hypertension model

The benefits of lowering blood pressure (BP) are well established for the prevention of cardiovascular disease. While there are a number of pharmaceuticals available for lowering BP, there is considerable interest in using dietary modifications, lifestyle and behaviour changes as alternative strategies. Kukoamines, caffeic acid derivatives of polyamines present in solanaceous plants, have been reported to reduce BP. We investigated the effect of orally administered synthetic kukoamine A on BP in the Spontaneously Hypertensive Rat (SHR) laboratory animal model of hypertension. Prior to the hypertension study, we determined the safety of the synthetic kukoamine A in a single oral dose (5 or 10 mg kg^-1 bodyweight) 14-day observational study in mice. No negative effects of the oral administration of kukoamine A were observed. We subsequently investigated the effect of daily oral doses of kukoamine A (0, 5, 10 mg kg^-1 bodyweight) for 35 days using the SHR rat model of hypertension. The normotensive control Wistar Kyoto (WKY) strain was used to provide a baseline for normal BP in rats. We observed no effect of orally administered synthetic kukoamine A on arterial hypertension in this laboratory animal model of hypertension.

Brazilian sunberry (Solanum oocarpum Sendtn): Alkaloid composition and improvement of mitochondrial functionality and insulin secretion of INS-1E cells

Chronic high-glucose levels induce the generation of reactive oxygen species leading to mitochondrial dysfunction, which is one of the pathological triggers in the development of diabetes. This study investigated the alkaloid composition of two fruits of the genus Solanum, fruta-do-lobo (Solanum lycocarpum) and juá-açu (Solanum oocarpum), and their capacity to protect against oxidative damage and defective insulin secretion induced by chronic high-glucose levels. LC-MS and molecular network of fruit crude extracts reveals that juá-açu and fruta-do-lobo contain kukoamines and glycoalkaloids, respectively. Two purification processes were used to enrich those alkaloids. Fruta-do-lobo extract rich in glycoalkaloids showed a strong cytotoxicity effect, however the juá-açu enriched extract was able to protect mitochondrial functionality against glucotoxicity and stimulate insulin secretion even under conditions of hyperglycemia. These results are promising and suggest that juá-açu is a potential source of bioactive compounds for adjuvant/co-adjuvant therapy for diabetes.

Ferroptosis-Inhibitory Difference between Chebulagic Acid and Chebulinic Acid Indicates Beneficial Role of HHDP

The search for a safe and effective inhibitor of ferroptosis, a recently described cell death pathway, has attracted increasing interest from scientists. Two hydrolyzable tannins, chebulagic acid and chebulinic acid, were selected for the study. Their optimized conformations were calculated using computational chemistry at the B3LYP-D3(BJ)/6-31G and B3LYP-D3(BJ)/6-311 + G(d,p) levels. The results suggested that (1) chebulagic acid presented a chair conformation, while chebulinic acid presented a skew-boat conformation; (2) the formation of chebulagic acid requires 762.1729 kcal/mol more molecular energy than chebulinic acid; and (3) the 3,6-HHDP (hexahydroxydiphenoyl) moiety was shown to be in an (R)- absolute stereoconfiguration. Subsequently, the ferroptosis inhibition of both tannins was determined using a erastin-treated bone marrow-derived mesenchymal stem cells (bmMSCs) model and compared to that of ferrostatin-1 (Fer-1). The relative inhibitory levels decreased in the following order: Fer-1 > chebulagic acid > chebulinic acid, as also revealed by the in vitro antioxidant assays. The UHPLC-ESI-Q-TOF-MS analysis suggested that, when treated with 16-(2-(14-carboxytetradecyl)-2-ethyl-4,4-dimethyl-3-oxazolidinyloxy free radicals, Fer-1 generated dimeric products, whereas the two acids did not. In conclusion, two hydrolyzable tannins, chebulagic acid and chebulinic acid, can act as natural ferroptosis inhibitors. Their ferroptosis inhibition is mediated by regular antioxidant pathways (ROS scavenging and iron chelation), rather than the redox-based catalytic recycling pathway exhibited by Fer-1. Through antioxidant pathways, the HHDP moiety in chebulagic acid enables ferroptosis-inhibitory action of hydrolyzable tannins.

Synthesis and Biological Activities of Naturally Functionalized Polyamines: An Overview

Recently, extensive researches have emphasized the fact that polyamine conjugates are becoming important in all biological and medicinal fields. In this review, we will focus our attention on natural polyamines and highlight recent progress in both fundamental mechanism studies and interests in the development and application for the therapeutic use of polyamine derivatives.

Total urinary polyphenols and longitudinal changes of bone properties. The InCHIANTI study

The aim of this study was to evaluate the association of levels of urinary total polyphenols considered as a proxy measure of polyphenol intake, with longitudinal changes of bone properties, in the InCHIANTI study. Dietary intake of polyphenols appears to be associated with future accelerated deterioration of bone health.

INTRODUCTION

Polyphenols, micronutrients ingested through plant-based foods, have antioxidant and anti-inflammatory properties and may contribute to osteoporosis prevention. We evaluated associations of high levels of urinary total polyphenols (UTP), a proxy measure of polyphenol intake, with longitudinal changes of bone properties in a representative cohort of free-living participants of the InCHIANTI study.

METHODS

The InCHIANTI study enrolled representative samples from the registry list of two towns in Tuscany, Italy. Baseline data were collected in 1998 and follow-up visits in 2001 and 2004. Of the 1453 participants enrolled, 956 consented to donate a 24-h urine sample used to assess UTP, had dietary assessment, a physical examination, and underwent a quantitative computerized tomography (pQCT) of the tibia. From pQCT images, we estimated markers of bone mass (BM), diaphyseal design (DD), and material quality (MQ). Mixed models were used to study the relationship between baseline tertiles of UTP with changes of the bone characteristics over the follow-up.

RESULTS

At baseline, higher levels of UTP were positively correlated with markers of BM, DD, and MQ. Compared with lower tertile of UTP, participants in the intermediate and highest tertiles had higher cortical bone area, cortical mineral content, and cortical thickness. However, participants in the intermediate and highest UTP tertiles experienced accelerated deterioration of these same parameters over the follow-up compared with those in the lowest UTP tertile.

CONCLUSIONS

Dietary intake of polyphenols estimated by UTP and dietary questionnaire was associated with long-term accelerated deterioration of bone health. Our study does not support the recommendation of increasing polyphenol intake for osteoporosis prevention.

Phenolamides: Plant specialized metabolites with a wide range of promising pharmacological and health-promoting interests

Phenolamides constitute a family of metabolites, widely represented in the plant kingdom, that can be found in all plant organs with a predominance in flowers and pollen grains. They represent a large and structurally diverse family, resulting from the association of phenolic acids with aliphatic or aromatic amines. Initially revealed as active compounds in several medicinal plant extracts, phenolamides have been extensively studied for their health-promoting and pharmacological properties. Indeed, phenolamides have been shown to exhibit antioxidant, anti-inflammatory, anti-cancer and antimicrobial properties, but also protective effects against metabolic syndrome and neurodegenerative diseases. The purpose of this review is to summarise this large body of literature, including in vitro and in vivo studies, by describing the diversity of their biological properties and our actual knowledge of the molecular mechanisms behind them. With regard to their considerable pharmacological interest, the question of industrial production is also tackled through chemical and biological syntheses in engineered microorganisms. The diversity of biological activities already described, together with the active discovery of the broad structural diversity of this metabolite family, make phenolamides a promising source of new active compounds on which future studies should be focused.

The Chemistry and Health Benefits of Dietary Phenolamides

Phenolamides, also known as hydroxycinnamic acid amides or phenylamides, have been reported throughout the plant kingdom, while a few of these amine-conjugated hydroxycinnamic acids are unique in foods. The current knowledge of their specific functions in plant development and defense is readily available as is their biosynthesis; however, their functionality in humans is still largely unknown. Of the currently known phenolamides, the most common are avenanthramides, which are unique in oats and similar to the well-known drug Tranilast, which possess anti-inflammatory, antioxidant, anti-itch, and antiatherogenic activities. While recent data have brought to light more information regarding the other known phenolamides, such as hordatines, dimers of agmatine conjugated to hydroxycinnamic acid, and kukoamines, spermine-derived phenolamides, the information is still severely limited, leaving their potential health benefits to speculation. Herein, to highlight the importance of dietary phenolamides to human health, we review and summarize the four major subgroups of phenolamides, including their chemical structures, dietary sources, and reported health benefits. We believe that the studies on phenolamides are still in the infancy stage and additional health benefits of these phenolamides may yet be identified.

The Antioxidant Capability of Higenamine: Insights from Theory

Density functional theory was employed to highlight the antioxidant working mechanism of higenamine in aqueous and lipid-like environments. Different reaction mechanisms were considered for the reaction of higenamine with the •OOH radical. The pH values and the molar fraction at physiological pH were determined in aqueous solution. The results show that the preferred reaction mechanism was the hydrogen atom transfer from the catecholic ring. The computed kinetic constants revealed that, in order to obtain reliable results, it is important to consider all the species present in water solution derived from acid-base equilibria. From the present investigation, it emerges that at physiological pH (7.4), the scavenging activity of higenamine against the •OOH radical is higher than that of Trolox, chosen as a reference antioxidant. Furthermore, higenamine results to be more efficient for that purpose than melatonin and caffeine, whose protective action against oxidative stress is frequently associated with their reactive oxygen species (ROS) scavenging activity.

Simultaneous Study of Anti-Ferroptosis and Antioxidant Mechanisms of Butein and (S)-Butin

To elucidate the mechanism of anti-ferroptosis and examine structural optimization in natural phenolics, cellular and chemical assays were performed with 2'-hydroxy chalcone butein and dihydroflavone (S)-butin. C11-BODIPY staining and flow cytometric assays suggest that butein more effectively inhibits ferroptosis in erastin-treated bone marrow-derived mesenchymal stem cells than (S)-butin. Butein also exhibited higher antioxidant percentages than (S)-butin in five antioxidant assays: linoleic acid emulsion assay, Fe3+-reducing antioxidant power assay, Cu2+-reducing antioxidant power assay, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide radical (PTIO•)-trapping assay, and α,α-diphenyl-β-picrylhydrazyl radical (DPPH•)-trapping assay. Their reaction products with DPPH• were further analyzed using ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-ESI-Q-TOF-MS). Butein and (S)-butin produced a butein 5,5-dimer (m/z 542, 271, 253, 225, 135, and 91) and a (S)-butin 5',5'-dimer (m/z 542, 389, 269, 253, and 151), respectively. Interestingly, butein forms a cross dimer with (S)-butin (m/z 542, 523, 433, 419, 415, 406, and 375). Therefore, we conclude that butein and (S)-butin exert anti-ferroptotic action via an antioxidant pathway (especially the hydrogen atom transfer pathway). Following this pathway, butein and (S)-butin yield both self-dimers and cross dimers. Butein displays superior antioxidant or anti-ferroptosis action to (S)-butin. This can be attributed the decrease in π-π conjugation in butein due to saturation of its α,β-double bond and loss of its 2'-hydroxy group upon biocatalytical isomerization.

Kukoamine B Ameliorate Insulin Resistance, Oxidative Stress, Inflammation and Other Metabolic Abnormalities in High-Fat/High-Fructose-Fed Rats

BACKGROUND

Obesity is characterized by excessive body fat, insulin resistance and dyslipidemia, which increases the chances of developing chronic diseases like type 2 diabetes, cardiovascular diseases, hypertension, nonalcoholic fatty liver diseases, some types of cancers and neurodegenerative diseases. Kukoamine B (Kuk B) is a spermine alkaloid obtained from Lycium chinense, and it has been shown to possess antidiabetic, antioxidant and anti-inflammatory properties. In this study, we evaluated the therapeutic effect of Kuk B on high-fat diet/high-fructose (HFDFr)-induced insulin resistance and obesity in experimental rats.

MATERIALS AND METHODS

Rats were fed with either normal rat diet or HFDFr for 10 consecutive weeks. The groups that were fed with HFDFr received Kuk B (25 and 50 mg/kg) from the beginning of the 6th week to the 10th week. After treatment, the effect of Kuk B on body weight, food, water intake, insulin, blood glucose, serum biochemical parameters, hepatic oxidative stress (malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and proinflammatory cytokine (interleukin (IL)-6, interleukin (IL)-1β and tumor necrosis factor alpha (TNF-α)) levels was determined. Histopathological analysis of the liver tissues was also performed.

RESULTS

HFDFr-fed rats showed a significant increase in body weight, fasting blood glucose, insulin, lipid accumulation and liver function enzymes. In addition, HFDFr diet increased hepatic MDA, TNF-α, IL-1β and IL-6 and decreased hepatic SOD, CAT and GSH-Px activities. On the other hand, Kuk B significantly attenuated body weight, insulin resistance, lipid accumulation, oxidative stress and inflammation.

CONCLUSION

These results indicated that Kuk B showed protective effect against HFDFr-induced metabolic disorders by downregulating lipid accumulation, oxidative stress and inflammatory factors.

Comparative Study of the Chemical Constituents and Bioactivities of the Extracts from Fruits, Leaves and Root Barks of Lycium barbarum

The fruits, leaves and root barks of L. barbarum plant are widely used as functional foods and as ingredients in traditional Chinese prescriptions and patent medicines. They are considered to have different pharmacological activities and health benefits because of their diverse constituents. Here, the chemical constituents of the extracts from fruits, leaves and root barks of L. barbarum were compared by ultra-high performance liquid chromatography coupled with high resolution mass spectrometry (UPLC-HR-MS). A total of 131 compounds were identified and seven of them were quantified. Among them, 98, 28 and 35 constituents were detected in fruits, leaves and root barks respectively. Dicaffeoylspermidine/spermine derivatives were the most detected compounds (74/131); among them, dicaffeoylspermine isomers and propionyl-dicaffeoylspermidine were found in root barks in very large amounts (e.g., kukoamine B = 10.90 mg/g dry powder); dicaffeoyl-spermidine isomers were detected in fruits/leaves in a high amount, and many of their glycosylated derivatives were mainly detected in fruits. In addition, six saponins from L. barbarum fruits were reported for the first time, and 5,6-dihydrosolasonine was reported for the first time in plants. The activity assays showed that the root bark extract possessed the strongest antioxidative activity and cytotoxicity, which was presumed due to the large amount of dicaffeoylspermine/spermidines in root barks. Fourteen potential bioactive components from fruits were identified by a target cell-based screening method. These results will help to understand the different biological activities of these three parts of L. barbarum plant and will benefit the discovery of new functional components.

pH Effect and Chemical Mechanisms of Antioxidant Higenamine

In this article, we determine the pH effect and chemical mechanism of antioxidant higenamine by using four spectrophotometric assays: (1) 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide radical (PTIO•)-scavenging assay (at pH 4.5, 6.0, and 7.4); (2) Fe³⁺-reducing power assay; (3) Cu²⁺-reducing power assay; and (4) 1,1-diphenyl-2-picryl-hydrazyl (DPPH•)-scavenging assay. The DPPH•-scavenging reaction product is further analyzed by ultra-performance liquid chromatography, coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-ESI-Q-TOF-MS/MS) technology. In the four spectrophotometric assays, higenamine showed good dose-response curves; however, its IC₅₀ values were always lower than those of Trolox. In UPLC-ESI-Q-TOF-MS/MS analysis, the higenamine reaction product with DPPH• displayed three chromatographic peaks (retention time = 0.969, 1.078, and 1.319 min). The first gave m/z 541.2324 and 542.2372 MS peaks; while the last two generated two similar MS peaks (m/z 663.1580 and 664.1885), and two MS/MS peaks (m/z 195.9997 and 225.9971). In the PTIO•-scavenging assays, higenamine greatly decreased its IC₅₀ values with increasing pH. In conclusion, higenamine is a powerful antioxidant—it yields at least two types of final products (i.e., higenamine-radical adduct and higenamine-higenamine dimer). In aqueous media, higenamine may exert its antioxidant action via electron-transfer and proton-transfer pathways. However, its antioxidant action is markedly affected by pH. This is possibly because lower pH value weakens its proton-transfer pathway via ionization suppression by solution H⁺, and its electron-transfer pathway by withdrawing the inductive effect (-I) from protonated N-atom. These findings will aid the correct use of alkaloid antioxidants.