Investigation of the extracts from Bidens pilosa Linn. var. radiata Sch. Bip. for antioxidant activities and cytotoxicity against human tumor cells

Inhibition of DNA Topoisomerase Ι by Flavonoids and Polyacetylenes Isolated from Bidens pilosa L

Human DNA topoisomerase I (Topo I) is an essential enzyme in regulating DNA supercoiling during transcription and replication, and it is an important therapeutic target for anti-tumor agents. Bidens pilosa L. is a medicinal herb that is used as a folk medicine for cancers in China. A new flavonoid (1) and a new polyacetylene (20), along with eighteen flavonoids (2-19) and nine polyacetylenes (21-29), were isolated and identified from the methanol extract of the whole plant of B. pilosa, and some of the compounds (4, 5, 6 and 7) exhibited potent cytotoxicity against a panel of five human cancer cell lines. The DNA relaxation assay revealed that some flavonoids and polyacetylenes exerted inhibitory activities on human DNA Topo I, among them compounds 1, 2, 5, 6, 7, 8, 15, 19, 20, 22, and 24 were the most active ones, with IC50 values of 393.5, 328.98, 145.57, 239.27, 224.38, 189.84, 89.91, 47.5, 301.32, 178.03, and 218.27 μM, respectively. The structure-activity analysis of flavonoids was performed according to the results from the Topo I inhibition assay. The DNA content analysis revealed that 5, 6, and 7 potently arrested cell cycle at the G1/S and G2/M phases in human colon cancer cell DLD-1 depending on the concentration of the inhibitors. The levels of protein expression related to the G1/S and G2/M cell cycle checkpoints were in accordance with the results from the DNA content analysis. These findings suggest that flavonoids are one of the key active ingredients accounting for the anti-tumor effect of B. pilosa.

Flow cytometry as an alternative method to evaluate genotoxicity of natural cosmetic actives

Alternative in vitro methods are important, as there is a call to ban the use of animals in cosmetics research.

AIM

To suggest the expansion of the use of in vitro safety techniques recommended by the OECD guidelines and to propose the use of the automation of the in vitro mammalian micronucleus test method by flow cytometry to assess the genotoxic potential of Centella asiatica, Horse Chestnut, Witch Hazel, Blend, Ecoblend, and Caffeine extracts due to their widespread use in commercial products.

METHODS

Flow cytometer analysis was performed using the Accuri™ C6 equipment and analyzed using the FlowJo software. Cytotoxicity tests followed OECD 129 guidelines and Phototoxicity followed OECD/GD 432 guidelines.

RESULTS

The results showed that the cytotoxicity assay presented a decrease in cell viability when cells were exposed to Centella asiatica from a concentration of 5.0%, horse chestnut 2.5%, Witch hazel 2.5%, Blend 3.13%, and Caffeine 3%, while Ecoblend at the tested concentrations did not show cytotoxicity. In the phototoxicity test, the samples at the tested concentrations showed a PIF <2 being considered potentially non-phototoxic. Finally, in the genotoxicity automated assay, samples were considered potentially non-genotoxic.

CONCLUSION

In vitro methods are of paramount importance for the development of pre-clinical tests and the use of test automation helps to reduce the time for analysis and dissemination of results, being a determining factor for the prospect of new compounds.

Separation of chemical constituents in Bidens pilosa Linn. var. radiata Sch. Bip. by elution-extrusion counter-current chromatography using two new three-phase solvent systems

Two new three-phase solvent systems combined with elution-extrusion counter-current chromatography mode were used to study the chemical constituents in Bidens pilosa Linn. var. radiata Sch. Bip. The first novel solvent system consisted of n-hexane, acetonitrile, chloroform, and water in a ratio of 5:5:1:5, which was selected for elution-extrusion counter-current chromatography to separate the n-hexane extraction part. A total of six constituents were obtained from this part in the up phase as the stationary phase and the middle phase as the mobile phase. The second novel solvent system, composed of n-hexane-butyl acetate-acetonitrile-water (3:1:4:3, v/v/v/v), was used for separating ethyl acetate extract of Bidens pilosa Linn. var. radiata Sch. Bip. Eight compounds were successfully isolated using elution-extrusion counter-current chromatography elution-extrusion mode. Fourteen chemical constituents were identified as 2-β-D-glucopyranosytoxy-1-hydroxy-5(E)-tridecene-7,9,11-triyne (Y1), 3-β-D-glucopyranosyloxy -1-hydroxy-6(E)-tetradecene-8,10,12-triyne (Y2), 1, 2-dihydroxy-5(E)-tridecene-7,9, 11-triyne (Y3), isorhamnetin (Y4), kaempferol (Y5), icthyothereolacetate (Y6), quercetin-3-O-β-D- galactopyranosyl-7-O-β-D-glucopyranoside (W1), quercetin 3-O-β-L-rhamnopyranoside (W2), neosperidin dihydrochalcone (W3), quercetin (W4), quercetagetin-3,6,4' -trimethoxyl- 7-O-β-D-glucopyranoside (W5), taxifolin (W6), luteolin (W7), and apigenin (W8) by spectra of ¹ H-NMR and ¹³ C-NMR data. Among them, compounds Y1, Y2, Y3, and Y6 belong to polyacetylene compounds, and the rest were flavonoids. In addition, counter-current chromatography has been used to separate polyacetylene compounds for the first time. All compounds in this method were isolated from Bidens pilosa Linn. var. radiata Sch. Bip. for the first time.

Biological effects of formulation containing curcuminoids and Bidens Pilosa L. in oral carcinoma cell line

FITOPROT, which contains curcuminoids and Bidens pilosa L. extract, is an innovative mucoadhesive formulation indicated for the topical treatment of chemoradiotherapy-induced oral mucositis (OM) in patients with advanced and visible oral squamous cell carcinoma. The formulation is used as a mouthwash directly on tumor tissue of patients with advanced neoplasms, without triggering cancer cell proliferation or tumor invasiveness. Thus, the aim of this study was to evaluate the biological effects of FITOPROT on an oral squamous cell carcinoma cell line (SCC-4). The viability of SCC-4 cells was assessed after exposure to FITOPROT using MTT reduction assay. The effects of the mucoadhesive formulation on cell cycle progression and cell death parameters were evaluated using flow cytometry. In addition, the inflammatory profile of the tumor cells was evaluated using the cytometric bead array (CBA) assay. FITOPROT promoted a concentration-dependent decrease in cell viability and cell cycle arrest at the G2/M phase (p < 0.05). Mitochondrial membrane potential was also altered after exposure to the formulation (p < 0.05), in parallel with a reduction in VEGF and IL-8 production (p = 0.01 and p = 0.05, respectively). In summary, the results indicate that FITOPROT reduces SCC-4 cell viability, promotes cell cycle arrest, modulates mitochondrial membrane potential, and exhibits antiangiogenic and anti-inflammatory properties, thus indicating its potential for topical use in patients with OM and visible tumors in the mouth.

Anti-Inflammatory Activity and Mechanism of Isookanin, Isolated by Bioassay-Guided Fractionation from Bidens pilosa L

Bidens pilosa L. (Asteraceae) has been used historically in traditional Asian medicine and is known to have a variety of biological effects. However, the specific active compounds responsible for the individual pharmacological effects of Bidens pilosa L. (B. pilosa) extract have not yet been made clear. This study aimed to investigate the anti-inflammatory phytochemicals obtained from B. pilosa. We isolated a flavonoids-type phytochemical, isookanin, from B. pilosa through bioassay-guided fractionation based on its capacity to inhibit inflammation. Some of isookanin’s biological properties have been reported; however, the anti-inflammatory mechanism of isookanin has not yet been studied. In the present study, we evaluated the anti-inflammatory activities of isookanin using lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. We have shown that isookanin reduces the production of proinflammatory mediators (nitric oxide, prostaglandin E₂) by inhibiting the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in LPS-stimulated macrophages. Isookanin also inhibited the expression of activator protein 1 (AP-1) and downregulated the LPS-induced phosphorylation of p38 mitogen-activated protein kinase (MAPK) and c-jun NH₂-terminal kinase (JNK) in the MAPK signaling pathway. Additionally, isookanin inhibited proinflammatory cytokines (tumor necrosis factor-a (TNF-α), interleukin-6 (IL-6), interleukin-8 (IL-8), and interleukin-1β (IL-1β)) in LPS-induced THP-1 cells. These results demonstrate that isookanin could be a potential therapeutic candidate for inflammatory disease.

RENISUS Plants and Their Potential Antitumor Effects in Clinical Trials and Registered Patents

Cancer is a significant cause of morbidity and mortality. Scientific advances, coupled with potential flaws in current treatments, are driving research into the discovery of new bioactive molecules. This systematic review focused on scientific studies with clinical trials and patents registered on the National Relation of Medicinal Plants of Interest to the Unified Health System (RENISUS) plants (or derivative compounds) with antitumor potential. Studies with 19 different forms of cancer were found, the prostate being the organ with the highest research incidence and the species Glycine max, Curcuma longa, and Zingiber officinale, beside the phytochemicals curcumin and soy isoflavone were the most tested in clinical trials/patents.

An Ethnobotanical Study on Qīng-Căo-Chá Tea in Taiwan

Herbal tea, a beverage prepared from a variety of plant materials excluding the leaves of the tea plant Camellia sinensis (L.) Kuntze of the family Theaceae, for a long time, has been consumed by most Chinese people for preventive and/or therapeutic health care. Usually, it is brewed or prepared as a decoction of local plants in water. The qīng-căo-chá tea, a commercial herbal tea, is the most common among many differently formulated herbal teas in Taiwan. For hundreds of years, qīng-căo-chá tea has played an important role in the prevention and treatment of diseases associated with the environmental conditions in Taiwan. However, research studies in this field have been insufficient. The raw material formulas of qīng-căo-chá tea have always been passed down from “masters” to “apprentices.” Hence, there is no systematic collation or record, and, therefore, there is a need to assess and confirm the composition, safety, and effectiveness of the raw materials. This study aimed to document the uses of Taiwan's qīng-căo-chá tea through a semi-structured interview survey and investigate the background of traditional practitioners, tea compositions, and plant origins and uses. This will improve our understanding of the knowledge inherited by the practitioners and the theoretical basis of the medicinal uses of these teas. In our field investigation, we visited 86 shops and assessed 71 raw ingredients of qīng-căo-chá tea. A semi-structured questionnaire was used to conduct the interviews. During the interviews, in addition to written records, audio and video recordings were made, and photographs were taken with the permission of the interviewees. The qīng-căo-chá raw materials have long been used as herbal teas, although more research should clarify their efficacy and safety. Traditional sellers of qīng-căo-chá tea were mainly males, and most shops have been in operation for more than 71 years. Some of the raw materials were derived from multiple sources, including different plants, and were often mixed without any safety concerns. To our knowledge, this is the first systematic ethnobotanical study on qīng-căo-chá tea that assesses and confirms its herbal ingredients. Our study represents a reference for herbal teas in Taiwan that can be used by the public and regulatory agencies.

3, 3-Dimethylquercetin Inhibits the Proliferation of Human Colon Cancer RKO Cells through Inducing G2/M Cell Cycle Arrest and Apoptosis

Background:

Our previous study successfully identified that 3,3-Dimethylquercetin (DMQ) acted as a potent anticancer agent against human colon cancer cell lines RKO. Thus, this study was conducted to investigate the underlying mechanism by which DMQ displayed inhibitory activity in RKO cells.

Methods:

Flow cytometry was used to evaluate the effect of DMQ on the cell cycle arrest, as well as the mitochondrial membrane potential in RKO cells. DAPI staining and DNA fragmentation ladder assays were performed to assess the apoptosis inducing activity of DMQ. Furthermore, western blot analysis was conducted to examine the expression of related proteins responsible for the cell cycle arrest and apoptosis.

Results:

Treatment with DMQ caused a significant increase in the fraction of G2/M cells, and induced remarkable apoptosis. Furthermore, western blot analysis showed that DMQ arrested cells at G2/M checkpoint by down-regulation of cyclin B1, cdc2 and cdc25c and up-regulation of p21, and induced cell apoptosis via affecting the ratio of Bax/Bcl-2, causing loss of the mitochondrial membrane potential and enhancing the expression of cleaved caspase-9 (C-caspase-9) and cleaved caspase-3 (C-caspase-3).

Conclusion:

These data showed that DMQ could suppress RKO cell growth by arresting RKO cells at G2/M checkpoint and inducing mitochondria-dependent cell apoptosis. Our findings shed light on the potential use of DMQ as a chemotherapeutic agent for CRC.

Pharmacological potential of Bidens pilosa L. and determination of bioactive compounds using UHPLC-QqQLIT-MS/MS and GC/MS

Background

Research of natural products from traditionally used medicinal plants to fight against the human ailments is fetching attention of researchers worldwide. Bidens pilosa Linn. var. Radiata (Asteraceae) is well known for its folkloric medicinal use against various diseases from many decades. Mizoram, North East India, has high plant diversity and the use of this plant as herbal medicine is deep rooted in the local tribes. The present study was executed to understand the pharmacological potential of B. pilosa leaves extract.

Methods

The antimicrobial potential was determined using agar well diffusion and broth microdilution method against bacterial and yeast pathogens. Cytotoxicity was evaluated using MTT and apoptotic DNA fragmentation assays. Further, the antioxidant ability of the extract was analysed using DPPH and ABTS free radical scavenging assay. Mosquitocidal activity was evaluated against third in-star larvae of C. quinquefasciatus using dose response and time response larvicidal bioassay. Additionally, the major phenolic and volatile compounds were determined using UHPLC-QqQ_LIT-MS/MS and GC/MS respectively.

Results

We found that the extract showed highest antimicrobial activity against E. coli (MIC 80 μg/mL and IC₅₀ 110.04 μg/mL) and showed significant cytotoxicity against human epidermoid carcinoma (KB-3-1) cells with IC₅₀ values of 99.56 μg/mL among the tested cancer cell lines.

The IC₅₀ values for scavenging DPPH and ABTS was 80.45 μg/mL and 171.6 μg/mL respectively. The extract also showed the high phenolics (72 μg GAE/mg extract) and flavonoids (123.3 μg Quercetin /mg extract). Lastly, five bioactive and six volatile compounds were detected using UHPLC-QqQ_LIT-MS/MS and GC-MS respectively which may be responsible for the plant’s bioactivities. An anticancerous compound, Paclitaxel was detected and quantified for the first time from B. pilosa leaves extract, which further showed the anticancerous potential of the tested extract.

Conclusion

On the basis of the present investigation, we propose that the leaf extract of B. pilosa might be a good candidate for the search of efficient environment friendly natural bioactive agent and pharmaceutically important compounds.

Development of Certain Protein Kinase Inhibitors with the Components from Traditional Chinese Medicine

Traditional Chinese medicines (TCMs) have been used in China for more than two thousand years, and some of them have been confirmed to be effective in cancer treatment. Protein kinases play critical roles in control of cell growth, proliferation, migration, survival, and angiogenesis and mediate their biological effects through their catalytic activity. In recent years, numerous protein kinase inhibitors have been developed and are being used clinically. Anticancer TCMs represent a large class of bioactive substances, and some of them display anticancer activity via inhibiting protein kinases to affect the phosphoinositide 3-kinase, serine/threonine-specific protein kinases, pechanistic target of rapamycin (PI3K/AKT/mTOR), P38, mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinases (ERK) pathways. In the present article, we comprehensively reviewed several components isolated from anticancer TCMs that exhibited significantly inhibitory activity toward a range of protein kinases. These components, which belong to diverse structural classes, are reviewed herein, based upon the kinases that they inhibit. The prospects and problems in development of the anticancer TCMs are also discussed.

Use of Bidens pilosa L. (Asteraceae) and Curcuma longa L. (Zingiberaceae) to treat intestinal mucositis in mice: Toxico-pharmacological evaluations

INTRODUCTION

Several studies towards the development of an effective treatment for intestinal mucositis have been reported, since this condition represents a major problem in clinical oncology practice due to cytotoxic effects of chemotherapy. However standardized protocols and universally accepted treatment options are yet to be established.

OBJECTIVES

Given above, this study evaluated the protective effects of a mucoadhesive formulation containing both Bidens pilosa L. (Asteraceae) (BP) and curcuminoids from Curcuma longa L. (Zingiberaceae) (CL) on intestinal mucositis induced by 5-fluoruoacil (5-FU) in mice.

RESULTS

As expected, animals only treated with 5-FU (200 mg/kg) showed a significant reduction of 60.3 and 42.4% in villi and crypts size, respectively, when compared to control. On the other hand, the proposed therapeutic/prophylactic treatment with mucoadhesive formulations managed to reduce histopathologic changes in mice bearing mucositis, especially at 125 mg/kg BP + 15 mg/kg CL dose. The formulation promoted an increase of 275.5% and 148.7% for villi and crypts size, respectively. Moreover, chemotherapy-related weight loss was reduced by 7.4% following the treatment. In addition, an increase of 10 and 30.5% in red and white blood cells was observed when compared to 5-FU group. Furthermore, treatments with the mucoadhesive formulation containing BP/CL up modulated Ki-67 and Bcl-2 expression while reduced pro-apoptotic regulator Bax. The formulation also modulated inflammatory response triggered by 5-FU through reduction of 68% of myeloperoxidase activity and a 4-fold increase in anti-inflammatory IL-10 levels. In parallel, the oxidative stress via lipid peroxidation was reduced as indicated by decrease of 63% of malondialdehyde concentrations. Additionally, the new formulation presented low acute oral systemic toxicity, being classified in the category 5 (2000 mg/kg < LD₅₀ < 5000 mg/kg) of the Globally Harmonized Classification System.

CONCLUSIONS

This study showed an interesting potential of the mucoadhesive formulation of BP/CL for the treatment of 5-FU-induced intestinal mucositis. Given the perspectives for the development of a new medicine, clinical studies are in progress to better understand the protective effects of this innovative formulation in treating mucositis.

Mucoadhesive formulation of Bidens pilosa L. (Asteraceae) reduces intestinal injury from 5-fluorouracil-induced mucositis in mice

Gastrointestinal mucositis induced during cancer treatment is considered a serious dose-limiting side effect of chemotherapy and/or radiotherapy. Frequently, interruption of the cancer treatment due to this pathology leads to a reduction in cure rates, increase of treatment costs and decrease life quality of the patient. Natural products such as Bidens pilosa L. (Asteraceae), represent a potential alternative for the treatment of mucositis given its anti-inflammatory properties. In this study, B. pilosa glycolic extract was formulated (BPF) with poloxamer, a mucoadhesive copolymer, was used for treatment of 5-fluorouracil (5-FU)-induced mucositis in mice. As expected, animals only treated with 5-FU (200 mg/kg) presented marked weight loss, reduction of intestinal villi, crypts and muscular layer, which was associated with severe disruption of crypts, edema, inflammatory infiltrate and vacuolization in the intestinal tissue, as compared to the control group and healthy animals only treated with BPF. On the other hand, the treatment of intestinal mucositis-bearing mice with BPF (75, 100 or 125 mg/kg) managed to mitigate clinical and pathologic changes, noticeably at 100 mg/kg. This dose led to the restoration of intestinal proliferative activity through increasing Ki-67 levels; modulated the expression of Bax, Bcl2 and p53 apoptotic markers protecting intestinal cells from cell death. Moreover, this treatment regulated lipid peroxidation and inflammatory infiltration. No acute toxic effects were observed with this formulation. This work demonstrated that BPF was safe and effective against 5-FU-induced intestinal mucositis in mice. Additional studies are already in progress to further characterize the mechanisms involved in the protective effects of this technological formulation toward the development of a new medicine for the prevention and treatment of intestinal injury in patients undergoing chemotherapy/radiotherapy.

Isoquercitrin inhibits the progression of pancreatic cancer in vivo and in vitro by regulating opioid receptors and the mitogen-activated protein kinase signalling pathway

Pancreatic cancer is a common malignant tumour that affects individuals worldwide. In recent years, the incidence and mortality rates of pancreatic cancer have continuously increased. Currently, the primary clinical treatment methods for pancreatic cancer include surgical resection, chemotherapy and radiotherapy. However, these treatment methods rarely produce satisfactory therapeutic outcomes. Extensive research has also proven that the effective components of several traditional Chinese medicines, particularly flavonoids extracted from plants, have significant antitumour effects. Isoquercitrin, which is one of the flavonoids found in Bidens pilosa extracts, has a significant antitumour effect. However, the antitumour effect of isoquercitrin and its mechanism of action remain unclear. The objective of the present study was to investigate the effect of isoquercitrin on the progression of pancreatic cancer and to further understand the biological characteristics of the participation of isoquercitrin in the progression of pancreatic cancer. In vitro, we found that a therapeutic dose of isoquercitrin significantly inhibited proliferation, promoted apoptosis and induced cell cycle arrest within the G1 phase in pancreatic cancer cells. Isoquercitrin activated caspase-3, -8 and -9 and reduced the mitochondrial membrane potential. In addition, isoquercitrin inhibited the expression level of the δ opioid receptor; however, isoquercitrin had no effect on the κ and µ opioid receptors. Furthermore, isoquercitrin inhibited extracellular signal-regulated kinase (ERK) phosphorylation and promoted c-Jun N-terminal kinase (JNK) phosphorylation. In vivo, we found that a therapeutic dose of isoquercitrin significantly inhibited xenograft growth in nude mice. In summary, the present study demonstrated that isoquercitrin inhibits human pancreatic cancer progression in vivo and in vitro and that its molecular mechanism may be closely related to opioid receptors and to the activation of the mitogen-activated protein kinase (MAPK) signalling pathway.

Isoquercitrin inhibits the progression of liver cancer in vivo and in vitro via the MAPK signalling pathway

Liver cancer is a malignant tumour with high morbidity and fatality rates that is common worldwide. At present, the clinical approaches to treating primary liver cancer include partial hepatectomy, systemic or local chemotherapy, radiotherapy, radiofrequency ablative surgery and liver transplantation. However, all of these approaches have shortcomings, including poor prognosis and numerous side-effects. A large number of studies have proven that many effective ingredients in traditional Chinese medicine, particularly the flavonoid compounds extracted from plants, have achieved breakthroughs in terms of enhancing the effects and reducing the toxicity of chemotherapy and radiotherapy, preventing tumour metastasis and relapse after surgery, alleviating the clinical symptoms of advanced tumours, improving the quality of life of the patient with tumours and extending patient long‑term survival. The purpose of the present study was to investigate the impact of isoquercitrin, the flavonoid from Bidens bipinnata L. extract, on the progression of liver cancer and to achieve a deeper understanding of the biological characteristics of isoquercitrin's involvement in the progression of liver cancer. In the in vitro experiments, isoquercitrin was found to strongly inhibit the proliferation of human liver cancer cells, promote the apoptosis of human liver cancer cells, and block the cell cycle in the G1 phase. Isoquercitrin activated caspase-3, -8 and -9, inhibited the expression level of ERK and p38MAPK protein phosphorylation, and promoted the phosphorylation of JNK. Additionally, isoquercitrin reduced the expression level of PKC in human liver cancer cells. In the in vivo experiments, isoquercitrin was also found to significantly inhibit the growth of transplanted tumours in nude mice. The present study confirmed that isoquercitrin could inhibit the progression of human liver cancer in vivo and in vitro, and the molecular mechanism of isoquercitrin may be closely associated with the MAPK and PKC signalling pathways.