New Labdane-type diterpenoids and anti-inflammatory constituents from Hedychium coronarium

Role of Bioactive Compounds, Novel Drug Delivery Systems, and Polyherbal Formulations in the Management of Rheumatoid Arthritis

Rheumatoid Arthritis (RA) is an autoimmune disorder that generally causes joint synovial inflammation as well as gradual cartilage and degenerative changes, resulting in progressive immobility. Cartilage destruction induces synovial inflammation, including synovial cell hyperplasia, increased synovial fluid, and synovial pane development. This phenomenon causes articular cartilage damage and joint alkalosis. Traditional medicinal system exerts their effect through several cellular mechanisms, including inhibition of inflammatory mediators, oxidative stress suppression, cartilage degradation inhibition, increasing antioxidants and decreasing rheumatic biomarkers. The medicinal plants have yielded a variety of active constituents from various chemical categories, including alkaloids, triterpenoids, steroids, glycosides, volatile oils, flavonoids, lignans, coumarins, terpenes, sesquiterpene lactones, anthocyanins, and anthraquinones. This review sheds light on the utilization of medicinal plants in the treatment of RA. It explains various phytoconstituents present in medicinal plants and their mechanism of action against RA. It also briefs about the uses of polyherbal formulations (PHF), which are currently in the market and the toxicity associated with the use of medicinal plants and PHF, along with the limitations and research gaps in the field of PHF. This review paper is an attempt to understand various mechanistic approaches employed by several medicinal plants, their possible drug delivery systems and synergistic effects for curing RA with minimum side effects.

Terpenoids as Human Neutrophil Elastase (HNE) Inhibitors: A Comprehensive Review of Natural Anti-inflammatory Isoprenoids

Human neutrophil elastase (HNE) is an enzyme that plays a key role in the body's inflammatory response. It has been linked to several diseases such as chronic obstructive pulmonary disease (COPD), emphysema, and cystic fibrosis. As potential treatments for these diseases, HNE inhibitors are of great interest. Metabolites derived from plants, particularly terpenoids such as β-caryophyllene found in black pepper and other plants, and geraniol present in several essential oils, are recognized as significant sources of inhibitors for HNE. Because of their ability to inhibit HNE, terpenoids are considered promising candidates for developing novel therapies to treat inflammatory conditions such as COPD and emphysema. Furthermore, nature can serve as an excellent designer, and it may offer a safer drug candidate for inhibiting HNE production and activity in the future. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses were searched to get relevant and up-to-date literature on terpenoids as human neutrophil elastase inhibitors. This review focuses on the isolation, chemical diversity, and inhibition of human neutrophil elastase (HNE) of various terpenoids reported from natural sources up to 2022. A total of 251 compounds from various terpenoids classes have been reported. Further, it also provides a summary of HNE inhibitors and includes a thorough discussion on the structure-activity relationship.

A Comprehensive Review on Pharmacologically Active Phyto-Constituents from Hedychium species

In this review, we describe and discuss the phytoconstituents present in Hedychium species and emphasize their potential as drug candidates. Though they are widely validated in vitro and in vivo models, to date, no efforts have been made to compile in a single review all the pharmacologically active phytoconstituents from Hedychium species, and their pharmacological and toxicity profile. In this study, we present a reinvestigation of the chemical constituents present in Hedychium species obtained from the essential oil and solvent extraction of the flowers, leaves and rhizomes under consideration. Key databases such as PubMed, Science Direct, Scopus, and Google Scholar amongst others were probed for a systematic search using keywords to retrieve relevant publications on this plant. An exhaustive electronic survey of the related literature on Hedychium species resulted in around 200 articles. Articles published between the years 1975-2021 were included. The studies conducted on either crude extracts, solvent fractions or isolated pure compounds from Hedychium species reported with a varied range of biological effects such as anti-inflammatory, analgesic, antidiabetic, potentially anti-asthmatic, and cytotoxic, among other related activities of the chemical constituents present in its essential oil and solvent extract deployed in this review. Traditional and herbal medication around the world that uses different parts of Hedychium species were considered for anti-inflammatory, skincare, analgesic, anti-asthmatic, anti-diabetic, antidotal uses, among others. These uses support the idea that chemical constituents obtained from solvent extraction may also exert the same action individually or in a synergistic manner. The review concluded that there is scope for computation and biological study to find out possible new targets for strengthening the potency and selectivity of the relevant compounds, and to find a commercial method for extraction of active pharmaceutical ingredients.

Activities and Molecular Mechanisms of Diterpenes, Diterpenoids, and Their Derivatives in Rheumatoid Arthritis

Diterpenes and their derivatives have many biological activities, including anti-inflammatory and immunomodulatory effects. To date, several diterpenes, diterpenoids, and their laboratory-derived products have been demonstrated for antiarthritic activities. This study summarizes the literature about diterpenes and their derivatives acting against rheumatoid arthritis (RA) depending on the database reports until 31 August 2021. For this, we have conducted an extensive search in databases such as PubMed, Science Direct, Google Scholar, and Clinicaltrials.gov using specific relevant keywords. The search yielded 2708 published records, among which 48 have been included in this study. The findings offer several potential diterpenes and their derivatives as anti-RA in various test models. Among the diterpenes and their derivatives, andrographolide, triptolide, and tanshinone IIA have been found to exhibit anti-RA activity through diverse pathways. In addition, some important derivatives of triptolide and tanshinone IIA have also been shown to have anti-RA effects. Overall, findings suggest that these substances could reduce arthritis score, downregulate oxidative, proinflammatory, and inflammatory biomarkers, modulate various arthritis pathways, and improve joint destruction and clinical arthritic conditions, signs, symptoms, and physical functions in humans and numerous experimental animals, mainly through cytokine and chemokine as well as several physiological protein interaction pathways. Taken all together, diterpenes, diterpenoids, and their derivatives may be promising tools for RA management.

Genome-wide identification and expression pattern of SnRK gene family under several hormone treatments and its role in floral scent emission in Hedychium coronarium

The SnRK (Snf1-Related protein Kinase) gene family plays crucial roles in various plant signaling pathways and stress-adaptive responses including biotic and abiotic stresses via activating protein phosphorylation pathways. However, there is no information available on the role of the SnRK gene family in Hedychium coronarium. H. coronarium is an important crop widely cultivated as an ornamental plant, herb, spice, or condiment. In this study, 60 HcSnRK genes were identified from the H. coronarium genomic and transcriptome data. Phylogenetic and gene structure analysis showed that the HcSnRK genes were divided into three groups (HcSnRK1, HcSnRK2 and HcSnRK3) and among them HcSnRK3 subfamily was further subdivided into two clades according to the number of introns. Chromosome localization analysis showed that HcSnRK genes were unevenly mapped onto all chromosomes, and the Ka/Ks ratio of 24 paralogues includes four tandems and 20 segmental duplications indicated that the HcSnRK gene family underwent a purifying selection. Cis-regulatory elements analysis suggested that the HcSnRK genes respond to multiple hormones and other stresses. The responsiveness of HcSnRK genes to several hormones was analyzed by quantitative real-time PCR. Based on the different transcriptome data, two candidates HcSnRK genes (HcSnRK2.2 and HcSnRK2.9) were screened out for further characterization . The subcellular localization experiment revealed that both genes were located in the nucleus and cytoplasm. Moreover, virus-induced gene silencing (VIGS) of HcSnRK2.2 and HcSnRK2.9 significantly reduced the floral volatile contents by suppressing the expression of terpene synthase genes (HcTPS1, HcTPS3, and HcTPS5), indicating that HcSnRK2.2 and HcSnRK2.9 genes play an important role in the regulatory mechanism of floral aroma. These results will provide novel insights into the functional dissection of H. coronarium SnRK gene family.

Bioactive Compounds from Medicinal Plants in Myanmar

Myanmar is a country with rich natural resources and of these, medicinal plants play a vital role in the primary health care of its population. The people of Myanmar have used their own system of traditional medicine inclusive of the use of medicinal plants for 2000 years. However, systematic and scientific studies have only recently begun to be reported. Researchers from Japan, Germany, and Korea have collaborated with researchers in Myanmar on medicinal plants since 2000. During the past two decades, over 50 publications have been published in peer-reviewed journals. Altogether, 433 phytoconstituents, including 147 new and 286 known compounds from 26 plant species consisting of 29 samples native to Myanmar, have been collated. In this contribution, phytochemical and biological investigations of these plants, including information on traditional knowledge are compiled and discussed.

Secoiridoid Glucosides and Anti-Inflammatory Constituents from the Stem Bark of Fraxinus chinensis

Qin Pi (Fraxinus chinensis Roxb.) is commercially used in healthcare products for the improvement of intestinal function and gouty arthritis in many countries. Three new secoiridoid glucosides, (8E)-4′′-O-methylligstroside (1), (8E)-4′′-O-methyldemethylligstroside (2), and 3′′,4′′-di-O-methyl-demethyloleuropein (3), have been isolated from the stem bark of Fraxinus chinensis, together with 23 known compounds (4–26). The structures of the new compounds were established by spectroscopic analyses (1D, 2D NMR, IR, UV, and HRESIMS). Among the isolated compounds, (8E)-4′′-O-methylligstroside (1), (8E)-4′′-O-methyldemethylligstroside (2), 3′′,4′′-di-O-methyldemethyloleuropein (3), oleuropein (6), aesculetin (9), isoscopoletin (11), aesculetin dimethyl ester (12), fraxetin (14), tyrosol (21), 4-hydroxyphenethyl acetate (22), and (+)-pinoresinol (24) exhibited inhibition (IC₅₀ ≤ 7.65 μg/mL) of superoxide anion generation by human neutrophils in response to formyl-L-methionyl-L-leuckyl-L-phenylalanine/cytochalasin B (fMLP/CB). Compounds 1, 9, 11, 14, 21, and 22 inhibited fMLP/CB-induced elastase release with IC₅₀ ≤ 3.23 μg/mL. In addition, compounds 2, 9, 11, 14, and 21 showed potent inhibition with IC₅₀ values ≤ 27.11 μM, against lipopolysaccharide (LPS)-induced nitric oxide (NO) generation. The well-known proinflammatory cytokines, tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6), were also inhibited by compounds 1, 9, and 14. Compounds 1, 9, and 14 displayed an anti-inflammatory effect against NO, TNF-α, and IL-6 through the inhibition of activation of MAPKs and IκBα in LPS-activated macrophages. In addition, compounds 1, 9, and 14 stimulated anti-inflammatory M2 phenotype by elevating the expression of arginase 1 and Krüppel-like factor 4 (KLF4). The above results suggested that compounds 1, 9, and 14 could be considered as potential compounds for further development of NO production-targeted anti-inflammatory agents.

New diterpenoids from the rhizomes of Hedychium forrestii

A novel hexanorditerpenoid, hedychin C (1), and a new diterpenoid, hedychin D (2), were isolated from the rhizomes of Hedychium forrestii. Their structures and absolute configurations were unambiguously established by means of extensive spectroscopic data (IR, UV, HRMS, and NMR) and electronic circular dichroism (ECD) calculations. This is the first report of naturally occurring labdane-type hexanorditerpenoid. Compound 1 was proved to have moderate cytotoxicity against XWLC-05 cell line with an IC₅₀ value of 53.6 μM.

Hedychium coronarium extract arrests cell cycle progression, induces apoptosis, and impairs migration and invasion in HeLa cervical cancer cells

Background

Hedychium coronarium Koen. (Zingiberaceae) is traditionally used as medicine in countries such as India, China, and Vietnam for treatment of various ailments including cancer. However, in spite of its implied significance in cancer treatment regimes, there are no reports so far involving the anticancerous attributes of H, coronarium ethanol extract (HCEE) on cancer cells and a more comprehensive study on its mechanism is still lacking.

Materials and methods

The cytotoxicity of HCEE was evaluated by MTT and clonogenic survival assay. Annexin V/propidium iodide (PI), Hoechst 33342 staining, and TUNEL assay were performed to detect apoptosis. Cell cycle analysis was performed using PI staining. JC-1 and 2′,7′-dichlorodihydrofluorescein diacetate assay were used to check the levels of MMP and ROS, respectively. Western blot analysis was carried out to measure the expression levels of proteins. Migration and invasion activity were assessed by wound healing and Transwell membrane assay, respectively.

Results

Antiproliferative effect of HCEE was investigated in various cancerous and normal cell lines. Among these, HCEE significantly inhibited the survival of HeLa cells without affecting the viability of normal human umbilical vein endothelial cells. Annexin V/PI, Hoechst staining, and TUNEL assay showed HCEE induced apoptosis in HeLa cells in a dose-dependent manner. HCEE promoted cell cycle arrest at G1 phase in HeLa cells by upregulating the levels of p53 and p21 and downregulating the levels of cyclin D1, CDK-4, and CDK-6. Moreover, HCEE treatment upregulated the expression of Bax and downregulated the expression of Bcl-2. Additionally, HCEE activated the caspase cascade by increasing the activities of caspase-9, caspase-8, and caspase-3. The expression levels of Fas ligand and Fas were also upregulated. Further, HCEE inhibited the migratory potential of HeLa cells by downregulating MMP-2 and MMP-9 expression levels.

Conclusion

Our results indicate H. coronarium exerts antiproliferative and apoptotic effects against HeLa cells, and therefore may be used for treatment against cervical cancer.

New Anti-Inflammatory Aporphine and Lignan Derivatives from the Root Wood of Hernandia nymphaeifolia

A new aporphine, 3-hydroxyhernandonine (1) and a new lignin, 4′-O-demethyl-7-O-methyldehydropodophyllotoxin (2), have been isolated from the root wood of Hernanadia nymphaeifolia, together with thirteen known compounds (3–15). The structures of these compounds were determined through mass spectrometry (MS) and spectroscopic analyses. The known isolate, 2-O-methyl-7-oxolaetine (3), was first isolated from natural sources. Among the isolated compounds, 3-hydroxyhernandonine (1), 4′-O-demethyl-7-O-methyldehydropodophyllotoxin (2), hernandonine (4), oxohernangerine (5), and oxohernagine (6) displayed inhibition (IC₅₀ values ≤5.72 μg/mL) of superoxide anion production by human neutrophils in response to formyl-l-methionyl-l-leucyl-l-phenylalanine/cytochalasin B (fMLP/CB). In addition, 3-hydroxyhernandonine (1), 4′-O-demethyl-7-O-methyldehydropodophyllotoxin (2), oxohernangerine (5), and oxohernagine (6) suppressed fMLP/CB-induced elastase release with IC₅₀ values ≤5.40 μg/mL.

Labdane diterpenoids from Curcuma amada rhizomes collected in Myanmar and their antiproliferative activities

Four new labdane diterpenoids, 12β-hydroxy-15-norlabda-8(17),13(14)-dien-16-oic acid (1), (E)-15-ethoxy-15-methoxylabda-8(17),12-dien-16-al (2), (E)-15α-ethoxy-14α-hydroxylabda-8(17),12-dien-16-olide (3), and 15-ethoxy-12β-hydroxylabda-8(17),13(14)-dien-16,15-olide (4) were isolated from the methanol extract of Curcuma amada rhizomes collected in Myanmar, together with 13 known analogs. Their structures were elucidated by extensive spectroscopic techniques. All of the isolates were evaluated for their antiproliferative activities against a small panel of five different human cancer cell lines (A549, human lung cancer; HeLa, human cervical cancer; MCF7, human breast cancer; PANC-1 and PSN-1, human pancreatic cancer). Among the isolates, compounds 2-4, 7, 8, 12, and 17 showed mild antiproliferative activities with IC₅₀ values ranging from 19.7 to 96.1μM. (E)-14-Hydroxy-15-norlabda-8(17),12-dien-16-al (11) exhibited strong antiproliferative activities selectively against HeLa, PANC-1, and PSN-1 cells, with IC₅₀ values of 5.88, 1.00, and 3.98μM, respectively. These potencies were comparable to those of the positive control, 5-fluorouracil.

New Flavones, a 2-(2-Phenylethyl)-4H-chromen-4-one Derivative, and Anti-Inflammatory Constituents from the Stem Barks of Aquilaria sinensis

In the current study, two new flavones, 4′-O-geranyltricin (1) and 3′-O-geranylpolloin (2), and a new 2-(2-phenylethyl)-4H-chromen-4-one derivative, 7-hydroxyl-6-methoxy-2-(2-phenylethyl)chromone (3), have been isolated from the stem barks of A. sinensis, together with 21 known compounds 4–24. The structures of new compounds 1–3 were determined through spectroscopic and MS analyses. Compounds 2, 3, 5, 6, and 8–10 exhibited inhibition (IC₅₀ ≤ 12.51 μM) of superoxide anion generation by human neutrophils in response to formyl-l-methionyl-l-leucyl-l-phenylalanine/cytochalasin B (fMLP/CB). Compounds 3, 6, 8, 10, and 19 inhibited fMLP/CB-induced elastase release with IC₅₀ values ≤ 15.25 μM. This investigation reveals bioactive isolates (especially 2, 3, 5, 6, 8, 9, 10, and 19) could be further developed as potential candidates for the treatment or prevention of various inflammatory diseases.

Phytochemistry and pharmacology of ornamental gingers, Hedychium coronarium and Alpinia purpurata: a review

In this review, the phytochemistry and pharmacology of two ornamental gingers, Hedychium coronarium (butterfly ginger) and Alpinia purpurata (red ginger), are updated, and their botany and uses are described. Flowers of H. coronarium are large, showy, white, yellow or white with a yellow centre and highly fragrant. Inflorescences of A. purpurata are erect spikes with attractive red or pink bracts. Phytochemical investigations on the rhizomes of H. coronarium generated research interest globally. This resulted in the isolation of 53 labdane-type diterpenes, with little work done on the leaves and flowers. Pharmacological properties of H. coronarium included antioxidant, antibacterial, antifungal, cytotoxic, chemopreventive, anti-allergic, larvicidal, anthelminthic, analgesic, anti-inflammatory, anti-urolithiatic, anti-angiogenic, neuro-pharmacological, fibrinogenolytic, coagulant and hepatoprotective activities. On the contrary, little is known on the phytochemistry of A. purpurata with pharmacological properties of antioxidant, antibacterial, larvicidal, cytotoxic and vasodilator activities reported in the leaves and rhizomes. There is much disparity in terms of research effort within and between these two ornamental gingers.

New Coumarin Derivatives and Other Constituents from the Stem Bark of Zanthoxylum avicennae: Effects on Neutrophil Pro-Inflammatory Responses

Three new coumarin derivatives, 8-formylalloxanthoxyletin (1), avicennone (2), and (Z)-avicennone (3), have been isolated from the stem bark of Zanthoxylum avicennae (Z. avicennae), together with 15 known compounds (4–18). The structures of these new compounds were determined through spectroscopic and MS analyses. Compounds 1, 4, 9, 12, and 15 exhibited inhibition (half maximal inhibitory concentration (IC₅₀) values ≤7.65 µg/mL) of superoxide anion generation by human neutrophils in response to formyl-l-methionyl-l-leucyl-l-phenylalanine/cytochalasin B (fMLP/CB). Compounds 1, 2, 4, 8 and 9 inhibited fMLP/CB-induced elastase release with IC₅₀ values ≤8.17 µg/mL. This investigation reveals bioactive isolates (especially 1, 2, 4, 8, 9, 12 and 15) could be further developed as potential candidates for the treatment or prevention of various inflammatory diseases.

Composition of essential oils of four Hedychium species from Vietnam

Background

Vietnam is a country blessed with many medicinal plants widely used as food and for medicinal purposes, and they contain a host of active substances that contribute to health. However, the analysis of chemical constituents of these plant species has not been subject of literature discussion.

Results

In this study, the chemical compositions of essential oils of four Hedychium species, obtained by hydrodistillation, were determined by means of gas chromatography-flame ionization detector (GC-FID) and gas chromatography–mass spectrometry (GC-MS) techniques. Individually, α-pinene (52.5%) and β-pinene (31.8%) were present in the leaf oil of Hedychium stenopetalum Lodd., while linalool (45.2%), (E)-nerolidol (8.7%) and α-pinene (5.0%) were identified in the root. The leaf of Hedychium coronarium J. König was characterized by β-pinene (20.0%), linalool (15.8%), 1,8-cineole (10.7%), α-pinene (10.1%) and α-terpineol (8.6%); while β-pinene (23.6%), α-humulene (17.1%) and β-caryophyllene (13.0%) were identified in the root. Hedychium flavum Roxb., gave oil whose major compounds were β-pinene (22.5%), α-humulene (15.7%) and β-caryophyllene (10.4%) in the leaf; α-humulene (18.9%), β-caryophyllene (11.8%) and β-pinene (11.2%) in the stem, as well as β-pinene (21.8%), linalool (17.5%) and 1,8-cineole (13.5%) in the root. The main constituents of Hedychium ellipticum Buch.-Ham. ex Smith were (E)-nerolidol (15.9%), β-pinene (11.8%) and bornyl acetate (9.2%) in the leaf with 1,8-cineole (40.8%), α-pinene (18.3%) and β-pinene (11.0%) occurring in the root.

Conclusions

Ubiquitous monoterpenes and sesquiterpenes were identified as characteristic markers for Hedychium species. This work is of great importance for the evaluation of Hedychium essential oils grown in Vietnam.

Electronic supplementary material

The online version of this article (doi:10.1186/s13065-014-0054-3) contains supplementary material, which is available to authorized users.

New coumarins and anti-inflammatory constituents from the fruits of Cnidium monnieri

The fruit of Cnidium monnieri is commercially used as healthcare products for the improvement of impotence and skin diseases. Three new coumarins, 3'-O-methylmurraol (1), rel-(1'S,2'S)-1'-O-methylphlojodicarpin (2), and (1'S,2'S)-1'-O-methylvaginol (3), have been isolated from the fruits of C. monnieri, together with 14 known compounds (4–17). The structures of these new compounds were determined through spectroscopic and MS analyses. Compounds 1, 4–12, and 14–17 exhibited inhibition (IC₅₀ ≤ 7.31 µg/mL) of superoxide anion generation by human neutrophils in response to formyl-l-methionyl-l-leucyl-l-phenylalanine/cytochalasin B (fMLP/CB). Compounds 7, 9–11, 15, and 17 inhibited fMLP/CB-induced elastase release with IC₅₀ values ≤7.83 µg/mL. This investigation reveals that bioactive isolates (especially 6, 7, 14, and 17) could be further developed as potential candidates for the treatment or prevention of various inflammatory diseases.