A review on pharmacology and toxicology of Elephantopus scaber Linn

The specialized sesquiterpenoids produced by the genus Elephantopus L.: Chemistry, biological activities and structure-activity relationship exploration

The genus Elephantopus L. is a valuable resource rich in sesquiterpenoids with structural diversity and various bioactivities, showing great potential for applications in medicinal field and biological industry. Up to now, over 129 sesquiterpenoids have been isolated and identified from this plant genus, including 114 germacrane-type, 7 guaianolide-type, 5 eudesmane-type, 1 elemanolide-type, and 2 bis-sesquiterpenoids. These sesquiterpenoids were reported to show a diverse range of pharmacological properties, including cytotoxic, anti-tumor, anti-inflammatory, antimicrobial, and antiprotozoal. Consequently, some of them were identified as active scaffolds in the design and development of drugs. Considering that there is currently no overview available that covers the sesquiterpenoids and their biological activities in the Elephantopus genus, this article aims to comprehensively review the chemical structures, biosynthetic pathways, pharmacological properties, and structure-activity relationship of sesquiterpenoids found in the Elephantopus genus, which will establish a theoretical framework that can guide further research and exploration of sesquiterpenoids from Elephantopus plants as promising therapeutic agents.

Deoxyelephantopin, a germacrane-type sesquiterpene lactone from Elephantopus scaber, induces mitochondrial apoptosis of hepatocarcinoma cells by targeting Hsp90α in vitro and in vivo

Hepatocellular carcinoma has been known as the most frequent subtype of liver cancer with a high rate of spread, metastases, and recurrence, also dismal treatment effects. However, effective therapies for HCC are still required. Nowadays, natural products have been known as a valuable source for drug discovery. In this research, 44 sesquiterpene lactones isolated from the Elephantopus scaber Linn. (Asteraceae) were tested by MTT assay for the antitumor activities. Deoxyelephantopin (DET) was found to exert significant cytotoxicity on HepG2 and Hep3B cells. Moreover, we found that DET treatment markedly reduced the growth of HCC cells in a concentration-dependent manner, which was better than sorafenib. Furthermore, DET induced mitochondrial dysfunction, oxidative stress, and cellular apoptosis. Additionally, we found that DET and sorafenib synergistically induced apoptosis and mitochondrial dysfunction in HCC cells. DET combined with sorafenib was also efficacious in tumor xenograft model. Molecular docking experiments revealed that DET had a potentially high binding affinity with Hsp90α. Moreover, Drug Affinity Responsive Target Stability assay suggested that DET could directly target Hsp90α. Additionally, the expression of Hsp90α was both decreased in vitro and in vivo. Altogether, this study revealed that DET might be a promising agent for HCC therapy by targeting Hsp90α.

Deoxyelephantopin alleviates lipopolysaccharide-induced septic lung injury through inhibiting NF-ĸB/STAT3 axis

Sepsis induces multiple organ dysfunction syndromes, such as acute kidney, liver, or lung injury. Septic lung injury is associated with excessive apoptosis and inflammatory responses in hepatocytes. Deoxyelephantopin is a sesquiterpene lactone found in Elephantopus scaber L, and has immunomodulatory, antibacterial, anti-inflammatory, and antifungal properties. The role of deoxyelephantopin in sepsis-associated lung injury was investigated. First, human bronchial epithelial cells (BEAS-2B) and human pulmonary artery endothelial cells (HPAEC) were treated with lipopolysaccharide to induce cytotoxicity. Treatment with lipopolysaccharide reduced cell viability of BEAS-2B and HPAEC, and promoted cell apoptosis through down-regulation of poly (ADP-ribose) polymerase (PARP) and B-cell lymphoma 2 (Bcl-2), and up-regulation of cleaved PARP and B-cell lymphoma-associated X protein (Bax). Second, lipopolysaccharide-treated BEAS-2B and HPAEC were incubated with increasing concentrations of deoxyelephantopin, that is, 1, 5, or 10 μM. Deoxyelephantopin enhanced cell viability and reduced cell apoptosis of lipopolysaccharide-treated BEAS-2B and HPAEC. Third, deoxyelephantopin attenuated lipopolysaccharide-induced decrease of superoxide dismutase and glutathione, and increase of malondialdehyde and myeloperoxidase in BEAS-2B and HPAEC. Moreover, deoxyelephantopin also weakened lipopolysaccharide-induced increase of tumor necrosis factor-α, interleukin (IL)-1β, and IL-6. Finally, deoxyelephantopin decreased protein expression of p-p65 and p-signal transducer and activator of transcription 3 (STAT3) in lipopolysaccharide-treated BEAS-2B and HPAEC. In conclusion, deoxyelephantopin exhibited anti-oxidative and anti-inflammatory effects against lipopolysaccharide-treated BEAS-2B and HPAEC through inactivation of nuclear factor kappa B/STAT3 signaling.

Chemical structures and anti-tyrosinase activity of the constituents from Elephantopus scaber L

Four undescribed compounds including one germacrane-type sesquiterpene lactones (1), alkaloid (2) along with two neolignans (3-4) were isolated from Elephantopus scaber L. Their structures and absolute configurations were elucidated unambiguously by means of 1D and 2D NMR spectroscopic data analysis, and quantum chemical electronic circular dichroism calculations, as well as single-crystal X-ray crystallography. Their anti-tyrosinase activities have been evaluated in vitro and compound 2 exhibited significant inhibitory activity. Furthermore, molecular docking was performed to study the interaction patterns between 2 and the tyrosinase.

New caffeoyl derivatives from Elephantopus scaber

Three new caffeoyl derivatives (1-3), together with two known ones (4-5), were isolated from the whole plant of Elephantopus scaber Linn. The structures of the new compounds were elucidated using detailed spectroscopic analysis. Compound 4 was obtained and its NMR data were given for the first time. All isolates were evaluated for their anti-inflammatory activity against lipopolysaccharide (LPS)-stimulated nitric oxide (NO) production and pro-inflammatory cytokines release in RAW 264.7 cells. Compounds 2-5 showed mild inhibitory activities with IC₅₀ values ranging from 64.78 to 87.21 μM, and 3-4 could inhibit LPS-induced tumor necrosis factor-α (TNF-α) production.

Effects of Elephantopus scaber extract on growth, proximate composition, immunity, intestinal microbiota and resistance of the GIFT strain of Nile tilapia Oreochromis niloticus to Streptococcus agalactiae

This study aimed to investigate the effects of Elephantopus scaber extract on the GIFT (genetic improvement of farmed tilapia) strain of Nile tilapia Oreochromis niloticus. A total of 800 tilapia with an initial body weight of 1.34 ± 0.09 g each were randomly divided into five groups. The tilapia in the control group (E0 group) were fed on a basal diet only. Meanwhile, tilapia in the four experimental groups were fed on a basal diet supplemented with 1 g/kg (E1 group), 3 g/kg (E2 group), 5 g/kg (E3 group), and 7 g/kg (E4 group) of E. scaber extract for 10 weeks. Results showed that the survival rate was higher in the experimental groups than in the control group. Compared with the control group, some growth parameters (FW, WGR, SGR, VSI, and HSI) were significantly improved in the E1 group and E2 group. The crude lipid content in the dorsal muscle and liver was lower in the E1 group than in the control group. After E. scaber extract supplementation, activities of immunity-related enzymes (ACP, AKP, T-AOC, SOD, CAT, GSH-Px and LZM) in plasma, liver, spleen and head kidney, and expressions of immunity-related genes (IL-1β, IFN-γ, TNF-α, and CCL-3) in liver, spleen and head kidney showed various degrees of improvement, while MDA content and Hsp70 expression level were decreased. The survival rate of tilapia increased in all the supplementation groups after Streptococcus agalactiae treatment. E. scaber extract addition changed the species composition, abundance, and diversity of intestinal microbiota in tilapia. These results demonstrate that E. scaber extract supplementation in diet can improve the growth, immunity, and disease resistance of GIFT against S. agalactiae. E. scaber extract supplementation can also change intestinal microbiota and reduce crude lipid content in dorsal muscle and liver. The above indicators show that the optimal dose of E. scaber extract for GIFT is 1 g/kg.

Deoxyelephantopin and Its Isomer Isodeoxyelephantopin: Anti-Cancer Natural Products with Multiple Modes of Action

Cancer is a leading cause of morbidity and mortality worldwide. The development of cancer involves aberrations in multiple pathways, representing promising targets for anti-cancer drug discovery. Natural products are regarded as a rich source for developing anti-cancer therapies due to their unique structures and favorable pharmacology and toxicology profiles. Deoxyelephantopin and isodeoxyelephantopin, sesquiterpene lactone compounds, are major components of Elephantopus scaber and Elephantopus carolinianus, which have long been used as traditional medicines to treat multiple ailments, including liver diseases, diabetes, bronchitis, fever, diarrhea, dysentery, cancer, renal disorders, and inflammation-associated diseases. Recently, deoxyelephantopin and isodeoxyelephantopin have been extensively explored for their anti-cancer activities. This review summarizes and discusses the anti-cancer activities of deoxyelephantopin and isodeoxyelephantopin, with an emphasis on their modes of action and molecular targets. Both compounds disrupt several processes involved in cancer progression by targeting multiple signaling pathways deregulated in cancers, including cell cycle and proliferation, cell survival, autophagy, and invasion pathways. Future directions of research on these two compounds towards anti-cancer drug development are discussed.

Semisynthesis and Non-Small-Cell Lung Cancer Cytotoxicity Evaluation of Germacrane-Type Sesquiterpene Lactones from Elephantopus scaber

Two series of germacrane-type sesquiterpene lactones were produced by semisynthetic modulation of scaberol C, which was prepared by a standard chemical transformation from an Elephantopus scaber extract. Their inhibition activities against non-small-cell lung cancer cells were screened, and preliminary structure-activity relationships were also established. Among them, monomeric analog 1u and dimeric analog 3d exhibited superior anti-non-small-cell lung cancer cytotoxic potencies with IC₅₀ values of 4.3 and 0.7 μM against A549 cells, respectively, and were more active than cisplatin and the standard sesquiterpene lactones, parthenolide and scabertopin. Further studies revealed that compounds 1u and 3d cause G2/M phase arrest and induce apoptosis through the activation of mitochondrial pathways in A549 cells. Collectively, the results obtained suggest that compounds 1u and 3d are promising anti-non-small-cell lung cancer lead compounds.

Ethnobotanical Survey on Bitter Tea in Taiwan

Ethnopharmacological evidence: In Taiwan, herbal tea is considered a traditional medicine and has been consumed for hundreds of years. In contrast to regular tea, herbal teas are prepared using plants other than the regular tea plant, Camellia sinensis (L.) Kuntze. Bitter tea (kǔ-chá), a series of herbal teas prepared in response to common diseases in Taiwan, is often made from local Taiwanese plants. However, the raw materials and formulations have been kept secret and verbally passed down by store owners across generations without a fixed recipe, and the constituent plant materials have not been disclosed.

Aim of the study: The aim was to determine the herbal composition of bitter tea sold in Taiwan, which can facilitate further studies on pharmacological applications and conserve cultural resources.

Materials and methods: Interviews were conducted through a semi-structured questionnaire. The surveyed respondents were traditional sellers of traditional herbal tea. The relevant literature was collated for a systematic analysis of the composition, characteristics, and traditional and modern applications of the plant materials used in bitter tea. We also conducted an association analysis of the composition of Taiwanese bitter tea with green herb tea (qing-cao-cha tea), another commonly consumed herbal tea in Taiwan, as well as herbal teas in neighboring areas outside Taiwan.

Results: After visiting a total of 59 stores, we identified 32 bitter tea formulations and 73 plant materials. Asteraceae was the most commonly used family, and most stores used whole plants. According to a network analysis of nine plant materials used in high frequency as drug pairs, Tithonia diversifolia and Ajuga nipponensis were found to be the core plant materials used in Taiwanese bitter tea.

Conclusion: Plant materials used in Taiwanese bitter tea were distinct, with multiple therapeutic functions. Further research is required to clarify their efficacy and mechanisms.

Dietary Supplementation With Didancao (Elephantopus scaber L.) Improves Meat Quality and Intestinal Development in Jiaji Ducks

Didancao (Elephantopus scaber L.) has been used as a traditional herbal medicine and has exhibited a beneficial role in animal health. This study aimed to investigate the effects of dietary supplementation with E. scaber on growth performance, meat quality, intestinal morphology, and microbiota composition in ducks. A total of 480 Jiaji ducks (42 days old, male:female ratio = 1:1) were randomly assigned to one of four treatments. There were six replicates per treatment, with 20 ducks per replicate. The ducks in the control group (Con) were fed a basal diet; the three experimental groups were fed a basal diet supplementation with 30 (T1), 80 (T2), and 130 mg/kg (T3) of E. scaber. After a 48-day period of supplementation, growth performance, meat quality, intestinal morphology, and microbiota composition were evaluated. The results showed that no differences were observed in the final body weight, average daily feed intake, and average daily gain among the four groups. Compared with that in the Con group, the feed conversion in the T1 and T2 groups was increased significantly; the T2 group was shown to decrease the concentration of alanine aminotransferase in serum; the T3 group was lower than the Con group in the concentration of aspartate aminotransferase and was higher than the Con group in the concentration of high-density lipoprotein-cholesterol. The highest concentration of creatinine was observed in the T1 group. The T2 group was higher than the Con group in the contents of Phe, Ala, Gly, Glu, Arg, Lys, Tyr, Leu, Ser, Thr, Asp, and total amino acids in the breast muscle. Moreover, the T2 group was higher than the Con group in the contents of meat C18:2n−6 and polyunsaturated fatty acid. The concentration of inosinic acid in the T1, T2, and T3 groups was significantly higher than that in the Con group. However, the Con group was higher than the T2 or T3 group in the Zn content. The T2 group was lower than the Con group in the jejunal crypt depth. The T3 group was higher than the Con group in the ileal villus height and the ratio of villus height to crypt depth. In addition, the T3 group had a trend to significantly increase the abundance of Fusobacteria. Compared with the Con group, the T1 and T2 groups displayed a higher abundance of Subdoligranulum. Collectively, dietary supplementation with 80 mg/kg of E. scaber improves meat quality and intestinal development in ducks.

Characterisation of inverse agonism of the orphan-G protein-coupled receptor GPR52 by cannabinoid ligands Cannabidiol and O-1918

The identification of cannabinoid ligands Cannabidiol and O-1918 as inverse agonists of the orphan receptor GPR52 is reported. Detailed characterisation of GPR52 pharmacology and modelling of the proposed receptor interaction is described. The identification of a novel and further CNS pharmacology for the polypharmacological agent and marketed drug Cannabidiol is noteworthy.

Three new sesquiterpene lactones from the whole plants of Elephantopus scaber

Three new sesquiterpene lactones, named scabertopinolides H - J (1 - 3), along with four known ones, desacylisodeoxyelephantopin 2-methylbutyrate (4), iso-17,19-dihydrodeoxyelephantopin (5), scabertopinolide D (6) and (2R,6R,7R,8S)-8-tigloyloxy-1(10),4(5),11(13)-germacratrien-2,15,6,12-diolide (7) were isolated from the whole plants of Elephantopus scaber. Their structures were elucidated by extensive analysis of spectroscopic data (including IR, UV, HRESIMS, 1 D and 2 D NMR) and single-crystal X-ray. These isolated compounds showed effective anti-inflammatory effects on LPS-stimulated RAW 264.7 cells with IC₅₀ values of 6.27 ± 0.18 to 18.31 ± 1.38 μM.

Medicinal plants as a potential source of Phosphodiesterase-5 inhibitors: A review

ETHNOPHARMACOLOGICAL RELEVANCE

The prevalence and distress caused by erectile dysfunction (ED) to both male and female partners are increasing at a steady rate. ED has now become the most treated sexual disorder for men among young and old age groups due to varying physical and psychological factors. The treatment with synthetic Phosphodiesterase-5 (PDE5) inhibitors are cost-effective but due to adverse effects such as priapism, loss of vision, heart attack and syncope, the daily life patterns of these patients are distressed and hence the need for alternative medicaments or sources are of utmost important. Therefore, the exploration of medicinal plants as PDE5 inhibitors will be worthwhile in tackling the problems as many plant extracts and fractions have been long used as aphrodisiacs and sexual stimulants which may be found to be active against PDE5 enzyme.

AIM OF THE STUDY

To provide a review on the different medicinal herbs traditionally used as natural aphrodisiacs, libido or sexual enhancers which are proven for their PDE5 inhibitory effect.

MATERIALS AND METHODS

Ethnobotanical and scientific information was procured, reviewed and compiled from the literature search of electronic databases and search engines.

RESULTS

A total of 97 medicinal plants exhibiting PDE5 inhibitory effect are reviewed in this paper which is supported by preclinical experimental evidence. Among them, 77 plants have been selected according to their traditional and ethnobotanical uses as aphrodisiacs and the rest are screened according to their effectiveness against predisposing factors responsible for ED and sexual dysfunction such as diabetes and hypertension or due to the presence of phytochemicals having structural similarity towards the identified natural PDE5 inhibitors. In addition, sixteen alkaloids, sixty-one phenolics and eight polycyclic aromatic hydrocarbons have been isolated or identified from active extracts or fractions that are exhibiting PDE5 inhibitory activity. Among them, isoflavones and biflavones are the major active constituents responsible for action, where the presence of prenyl group for isoflavones; and the methoxy group at C-5 position of flavones are considered essential for the inhibitory effect. However, the prenylated flavonol glycoside, Icariin and Icariside II isolated from Epimedium brevicornum Maxim (hory goat weed) are the most effective inhibitor, till date from natural sources. Traditional medicines or formulations containing extracts of Ginkgo biloba L., Kaempferia parviflora Wall. ex Baker, Clerodendrum colebrookianum Walp., Eurycoma longifolia Jack and Vitis vinifera L. are also found to be inhibitors of PDE5 enzyme.

CONCLUSION

The review suggests and supports the rational use of traditional medicines that can be further studied for the development of potential PDE5 inhibitors. Many traditional medicines are still used in various regions of Africa, Asia and South America that are poorly characterized and experimented. Despite the availability of a vast majority of traditional formulations as aphrodisiacs or sexual stimulants, there exists a need for systemic evaluation on the efficacy as well as the mechanism of action of the herbal constituents for the identification of novel chemical moieties that can be further developed for maximum efficacy.

Germacranolides from Elephantopus scaber L. and their cytotoxic activities

Seven undescribed germacranolides, named as scabertopinolide A-G were obtained from whole herbs of Elephantopus scaber L. The determination of their structures was conducted via comprehensive spectroscopic analyses combined with experimental electronic circular dichroism (ECD) spectroscopic data and quantum mechanical ECD calculations. The absolute configuration of scabertopinolide A was determined by X-ray crystallography data analysis. The cytotoxicity of all compounds was evaluated against three human cancer cell lines HepG2, Hep3B (human hepatocellular carcinoma cell lines), and MCF-7 (human breast adenocarcinoma cell line). Scabertopinolide G exhibited the most significant cytotoxic activities against the three cancer cell lines with IC₅₀ values between 7.0 and 10.3 μM. Furthermore, flow cytometry analysis has suggested that scabertopinolide G may cause death of cancer cells through apoptosis induction.

Huaier Restrains Cholangiocarcinoma Progression in vitro and in vivo Through Modulating lncRNA TP73-AS1 and Inducing Oxidative Stress

Purpose

Huaier, the fruiting body of Trametes robiniophila Murr, is a kind of traditional Chinese medicine. Recently, many studies have confirmed that Huaier has antitumor effects on various malignancies. Moreover, studies have demonstrated that long noncoding RNAs play an important regulatory role in the occurrence and progression of malignancies. Our present study was to explore whether Huaier has a potential antitumor effect in cholangiocarcinoma and reveal the relationship between lncRNAs and Huaier-induced tumor inhibition.

Methods

Microarray assay was performed to identify the candidate lncRNAs regulated by Huaier. Quantitative real-time PCR was applied to assess the effect of Huaier on TP73-AS1 expression. The effect of Huaier on the cell viability, proliferation, migration and invasion was evaluated by CCK-8, colony formation, wound healing and Transwell assays, respectively. The ratio of cell apoptosis was determined using AO/EB, Hoechst 33342 and flow cytometry. The effect of Huaier on oxidative stress was revealed using DCFH-DA, mito-SOX, JC-1 probes and Western blotting. In addition, the effect of Huaier on tumor growth and metastasis was explored using subcutaneous tumor model and lung metastatic tumor model in nude mice.

Results

In vitro, Huaier inhibited the proliferation, migration and invasion of cholangiocarcinoma cells by down-regulating TP73-AS1 and induced apoptosis through mitochondrial apoptotic pathway. In vivo, Huaier suppressed the growth and metastasis of cholangiocarcinoma by modulating the expression of proliferation and EMT-associated proteins.

Conclusion

Huaier could inhibit cell proliferation, invasion and metastasis by modulating the expression of TP73-AS1, meanwhile promote apoptosis of CCA cells through disturbing mitochondrial function, inducing oxidative stress and activating caspases in vitro. In addition, Huaier could suppress tumor growth and metastasis by regulating the expression of proliferation and EMT-related proteins. In the meantime, Huaier prolonged the survival of nude mice in lung metastatic model with acceptable drug safety.

Deoxyelephantopin induces apoptosis via oxidative stress and enhances gemcitabine sensitivity in vitro and in vivo through targeting the NF-κB signaling pathway in pancreatic cancer

Pancreatic cancer is a highly invasive malignant tumor of the digestive system with an unfavorable prognosis worldwide. This trait is thought to be largely attributed to chemoresistance. Chemotherapy is the only hope for patients with advanced pancreatic cancer. Therefore, seeking new effective chemotherapy drugs has become an urgent need. The purpose of our study was to explore whether deoxyelephantopin (DET), a sesquiterpene lactone, has a potential antitumor effect in pancreatic cancer. Additionally, the antitumor effects of DET alone or in combination with gemcitabine (GEM) and the potential mechanism of this combination were revealed. In vitro experiments showed that DET suppressed the proliferation, invasion and metastasis of pancreatic cancer cells, induced cell apoptosis via oxidative stress, and enhanced GEM sensitivity by inhibiting the NF-κB signaling pathway. Beyond that, in vivo experiments showed that DET not only inhibited pancreatic tumor growth and metastasis but also amplified the antitumor capacity of GEM, which was related to the downregulation of NF-κB and its downstream gene products. In summary, it is possible that DET could be developed as a single agent or combined with conventional chemotherapy drugs to improve the treatment of pancreatic cancer.

New phenolic acids from the whole herb of Elephantopus scaber Linn. and their anti-inflammatory activity

Two new phenolic acids, ethyl 3,3',4,4'-tetrahydroxy-δ-truxinate (1), 3-O-p-coumaroyl-4-O-caffeoyl quinic acid methyl ester (2), together with three known compounds (3-5) were isolated from the whole plant of Elephantopus scaber Linn. The structures of the new compounds were elucidated using detailed spectroscopic analysis. Compound 3 was obtained and given its NMR data for the first time. All isolates were evaluated for their anti-inflammatory activity via inhibiting the production of nitric oxide (NO) in lipopolysaccharide (LPS)-stimulated murine macrophage RAW 264.7 cells, and 1, 4 and 5 showed a moderate inhibition with IC₅₀ values ranging from 11.85 to 20.62 μM.

Chemical Composition, Antimicrobial and Antiparasitic Screening of the Essential Oil from Phania matricarioides (Spreng.) Griseb

Essential oils (EOs) have gained increasing attention due to their pharmacological effectiveness, and they also constitute some of the most popular natural products. In this study, we present the chemical characterization of the EO from Phania matricarioides and the in vitro activity/selectivity against a wide panel of bacteria, fungi and parasitic protozoa. Forty-five compounds were identified in the studied EO, of which lavandulyl acetate (40.1%) and thymyl isobutyrate (13.9%) were the major components. The EO did not inhibit bacterial or fungal growth at the maximum concentration tested (64 µg/mL), although it displayed activity on all evaluated protozoa (IC₅₀ values ranging from 2.2 to 56.6 µg/mL). In parallel, the EO demonstrated a noteworthy cytotoxic activity against peritoneal macrophages (CC₅₀ values of 28.0 µg/mL). The most sensitive microorganism was Trypanosoma cruzi, which had a superior activity (IC₅₀ = 2.2 µg/mL) and selectivity (SI = 13) in respect to other parasitic protozoa and the reference drug (p < 0.05). Further in vivo studies are needed to evaluate the potential use of this EO and the main compounds as antitrypanosomal agents. To our knowledge, this is the first report of chemical characterization and antimicrobial assessment of the EO from P. matricarioides.

Comparative Pharmacognosy, Chemical Profile and Antioxidant Activity of Extracts from Phania matricarioides (Spreng.) Griseb. Collected from Different Localities in Cuba

Phania matricarioides (Spreng.) Griseb. is a traditionally used plant with various pharmacological properties. However, there are only scarce reports about the phytochemistry and biological activity of this plant. In this work, P. matricarioides was collected from three different localities of Cuba: PmB (collected in Bauta, Artemisa), PmC (collected in Cangrejeras, Artemisa), and PmI (collected in La Lisa, Havana), extracted with aqueous ethanol, and analyzed macroscopically and microscopically. The extracts were screened for phytochemical contents, analyzed by TLC and HPLC, and screened for antioxidant activity using the FRAP and DPPH assays. Macroscopic analysis showed similar results for all samples; however, microscopic, physicochemical and phytochemical studies showed appreciable differences. In particular, the total solid of PmC extract was higher (1.94 ± 0.03%) than the other samples. In HPLC profiles, quercetin was identified in the three samples and a greater similarity between samples PmB and PmI was observed. All samples demonstrated radical-scavenging antioxidant activity by the DPPH assay, which PmC also demonstrated the smaller (p < 0.05) value (IC₅₀ = 27.4 ± 0.1 µg/mL), but was statistically superior (p < 0.05) to vitamin C (IC₅₀ = 23.7 ± 0 µg/mL). Also, in the FRAP assay, a higher vitamin C equivalent of PmC was significantly superior (p < 0.05) to the other extracts at the evaluated concentrations, which is likely due to a higher concentration of quercetin. In conclusion, P. matricarioides could constitute a potential resource in the field of phytotherapeutic products, and the results obtained can contribute to the development of the quality control norms for this species.

Evaluation of extracts prepared from 16 plants used in Yao ethnomedicine as potential anticancer agents

ETHNOPHARMACOLOGICAL RELEVANCE

Medicines of the Yao ethnic group in China are a special branch of traditional Chinese medicine (TCM) and are well documented for use in disease prevention. According to an ethnopharmacological survey, there are 1392 species of medicinal plants that have been documented as Yao ethnomedicines and 104 of these species are used routinely. This study evaluated a partial collection of these 104 core plant species for their potential as anticancer agents.

MATERIAL AND METHODS

A literature study of scientific journals and books in the local language was conducted. Based on an ethnopharmacological survey, 16 plant species widely used in Yao ethnomedicine were collected and 64 plant extracts were prepared from these plants. in vitro cytotoxicity screening was conducted with a panel of four human cancer cell lines, lung cancer A549, breast cancer BT20 and MCF-7, bone cancer U2OS. The potential toxicity of the extracts was evaluated using two normal human cell lines, human peripheral lung epithelial cells (HPL1A) and human umbilical vein endothelial cells (HUVEC). Additionally, the 10 extracts that demonstrated cytotoxicity in cancer cells with an IC₅₀ of less than 25.0µg/mL were examined for the ability to induce apoptosis in U2OS cells.

RESULTS

The up-to-date information regarding the traditional uses, pharmacological and biological activities, as well as the chemical constituents of the 16 plants are presented. Extracts from all 16 plants showed cytotoxicity against one to four of the human cancer cell lines and the cytotoxic effects of extracts from Melaleuca leucadendra, Stephania longa, Microsorium fortune and Bidens biternata were demonstrated for the first time. The highest anticancer potential was observed for extracts prepared from Melaleuca leucadendra Linn against all tested cancer cells (BT20, A549, U2OS, and MCF7) with an IC₅₀ range of 3.1-32.7µg/mL. The selectivity index of the active samples varied from 0.1 to 25, and five extracts from Bidens biternata, Wedelia calendulacea, Stephania longa and Achras zapota showed significant selectivity against cancer cell lines versus normal cell lines. All tested extracts induced apoptosis in U2OS cells, and for the first time extracts from Melaleuca leucadendra and Microsorium fortune were shown to induce apoptosis.

CONCLUSION

We demonstrated the in vitro anticancer efficacy and safety of 16 medicinal plants that have been historically used in Yao ethnomedicine. This study provides evidence to assist the clinical practice of Yao ethnomedicine and the development of chemotherapeutic agents from extracts prepared from these plants.

The Oils from Stems, Leaves and Roots of Elephantopus scaber Linn

The oil from stems, leaves and roots of Elephantopus scaber Linn. were extracted by solvent macerationtechnique. The percentage yield oil from stems, leaves and roots are 0.001%, 0.003% and 0.04%, respectively.The stem oil gives major constituents of pentacosane (12.3%), lupenyl acetate (11.7%) and fern-7-en-3β-ol(11.0%), while the leaf oil contains isooctyl phthalate (19.2%), hexadecanoic acid (15.0%) and α-linolenic acid(5.0%) as the major components. The major constituents identified in the root oil are hemellitol (11.6%), octylphthalate (6.0%), 1-nonadecanol (5.6%) and 1-octadecanol (5.5%). There were only three compounds detectedand identified in all three parts of the plant, namely decanedioic acid, bis-(2-ethylhexyl)ester, dotriacontane andpentacosane. The oils were analysed by gas chromatography-mass spectrometer and the compounds wereidentified by comparison with the mass spectral fragmentation pattern database.

Novel sesquiterpene lactone analogues as potent anti-breast cancer agents

Triple-negative breast cancer (TNBC) is associated with high grade, metastatic phenotype, younger patient age, and poor prognosis. The discovery of an effective anti-TNBC agent has been a challenge in oncology. In this study, fifty-eight ester derivatives (DETDs) with a novel sesquiterpene dilactone skeleton were organically synthesized from a bioactive natural product deoxyelephantopin (DET). Among them, DETD-35 showed potent antiproliferative activities against a panel of breast cancer cell lines including TNBC cell line MDA-MB-231, without inhibiting normal mammary cells M10. DETD-35 exhibited a better effect than parental DET on inhibiting migration, invasion, and motility of MDA-MB-231 cells in a concentration-dependent manner. Comparative study of DETD-35, DET and chemotherapeutic drug paclitaxel (PTX) showed that PTX mainly caused a typical time-dependent G2/M cell-cycle arrest, while DETD-35 or DET treatment induced cell apoptosis. In vivo efficacy of DETD-35 was evaluated using a lung metastatic MDA-MB-231 xenograft mouse model. DETD-35 significantly suppressed metastatic pulmonary foci information along with the expression level of VEGF and COX-2 in SCID mice. DETD-35 also showed a synergistic antitumor effect with PTX in vitro and in vivo. This study suggests that the novel compound DETD-35 may have a potential to be further developed into a therapeutic or adjuvant agent for chemotherapy against metastatic TNBC.

Phytometabolite Dehydroleucodine Induces Cell Cycle Arrest, Apoptosis, and DNA Damage in Human Astrocytoma Cells through p73/p53 Regulation

Accumulating evidence supports the idea that secondary metabolites obtained from medicinal plants (phytometabolites) may be important contributors in the development of new chemotherapeutic agents to reduce the occurrence or recurrence of cancer. Our study focused on Dehydroleucodine (DhL), a sesquiterpene found in the provinces of Loja and Zamora-Chinchipe. In this study, we showed that DhL displayed cytostatic and cytotoxic activities on the human cerebral astrocytoma D384 cell line. With lactone isolated from Gynoxys verrucosa Wedd, a medicinal plant from Ecuador, we found that DhL induced cell death in D384 cells by triggering cell cycle arrest and inducing apoptosis and DNA damage. We further found that the cell death resulted in the increased expression of CDKN1A and BAX proteins. A marked induction of the levels of total TP73 and phosphorylated TP53, TP73, and γ-H2AX proteins was observed in D384 cells exposed to DhL, but no increase in total TP53 levels was detected. Overall these studies demonstrated the marked effect of DhL on the diminished survival of human astrocytoma cells through the induced expression of TP73 and phosphorylation of TP73 and TP53, suggesting their key roles in the tumor cell response to DhL treatment.