Lignans from the root of Wikstroemia indica and their cytotoxic activity against PANC-1 human pancreatic cancer cells

Wikstroemia: A Review on its Phytochemistry and Pharmacology

BACKGROUND

Wikstroemia (the family Thymelaeaceae) consists of medicinal plants which established great value in traditional medicines for many years. For instance, W. indica is always recommended for treatments of syphilis, arthritis, whooping cough, and cancer. No systematic review of bioactive compounds from this genus has been recorded to date.

OBJECTIVES

The objective of the current study is to review phytochemical investigations and pharmacological effects of Wikstroemia plant extracts and isolates.

METHODS

By searching on the internet, the relevant data about Wikstroemia medicinal plants were retrieved from internationally renowned scientific databases, such as Web of Science, Google Scholar, Sci-Finder, Pubmed, and so on.

RESULTS

More than 290 structurally diverse metabolites were separated and identified from this genus. They include terpenoids, lignans, flavonoids, coumarins, mono-phenols, diarylpentanoids, fatty acids, phytosterols, anthraquinones, and others. Pharmacological records indicated that Wikstroemia plant crude extracts and their isolated compounds bring out various beneficial effects, such as anticancer, antiinflammatory, anti-aging, anti-viral, antimicrobacterial, antimalarial, neuroprotective, and hepatoprotective activities.

CONCLUSION

Wikstroemia has been regarded as a worthy genus with numerous phytochemicals and various pharmacological potentials. Modern pharmacological studies have successfully provided evidence for traditional uses. Nonetheless, their action mechanisms need to be further investigated. Although various secondary metabolites were identified from Wikstroemia plants, the current pharmacological research mainly concentrated on terpenoids, lignans, flavonoids, and coumarins.

Matairesinol Induces Mitochondrial Dysfunction and Exerts Synergistic Anticancer Effects with 5-Fluorouracil in Pancreatic Cancer Cells

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive types of cancer and exhibits a devastating 5-year survival rate. The most recent procedure for the treatment of PDAC is a combination of several conventional chemotherapeutic agents, termed FOLFIRINOX, that includes irinotecan, leucovorin, oxaliplatin, and 5-fluorouracil (5-FU). However, ongoing treatment using these agents is challenging due to their severe side effects and limitations on the range of patients available for PDAC. Therefore, safer and more innovative anticancer agents must be developed. The anticarcinoma activity of matairesinol that can be extracted from seagrass has been reported in various types of cancer, including prostate, breast, cervical, and pancreatic cancer. However, the molecular mechanism of effective anticancer activity of matairesinol against pancreatic cancer remains unclear. In the present study, we confirmed the inhibition of cell proliferation and progression induced by matairesinol in representative human pancreatic cancer cell lines (MIA PaCa-2 and PANC-1). Additionally, matairesinol triggers apoptosis and causes mitochondrial impairment as evidenced by the depolarization of the mitochondrial membrane, disruption of calcium, and suppression of cell migration and related intracellular signaling pathways. Finally, matairesinol exerts a synergistic effect with 5-FU, a standard anticancer agent for PDAC. These results demonstrate the therapeutic potential of matairesinol in the treatment of PDAC.

The Application of UHPLC-HRMS for Quality Control of Traditional Chinese Medicine

UHPLC-HRMS (ultra-high-performance liquid chromatography-high resolution mass spectrometry) is a new technique that unifies the application of UHPLC with HRMS. Because of the high sensitivity and good separation ability of UHPLC and the sensitivity of HRMS, this technique has been widely used for structure identification, quantitative determination, fingerprint analysis, and elucidation of the mechanisms of action of traditional Chinese medicines (TCMs) in recent years. This review mainly outlines the advantages of using UHPLC-HRMS and provides a survey of the research advances on UHPLC-HRMS for the quality control of TCMs.

1H‑NMR‑based metabolic profiling of rat urine to assess the toxicity‑attenuating effect of the sweat‑soaking method on Radix Wikstroemia indica

Radix Wikstroemia indica (L.) C.A. Mey. (RWI) is a toxic medicinal species primarily present in the Miao area of China. The toxicity of RWI is effectively reduced whilst maintaining the therapeutic effect when processed using the ‘sweat-soaking method’, which is a common method of Traditional Chinese Medicine preparation. However, there is a lack of scientific and medical evidence to explain the potential mechanisms by which the toxicity of RWI is reduced after preparation using this method, and the endogenous systemic metabolic effect of RWI remains uncertain. The aim of the present study was to explore the endogetnous metabolic alterations caused by RWI and to examine the possibility of reducing the toxicity of RWI using the sweat-soaking method using proton nuclear magnetic resonance (NMR) metabolomic analysis in rats. Principal Component Analysis, Partial Least Squares-Discriminant Analysis (PLS-DA) and Orthogonal PLS-DA were used to assess individual proton NMR spectra. A total of 34 metabolic products were altered after delivering raw RWI, and 32 endogenous metabolites were induced by processed RWI. The metabolic pathways that lead to a significant impact on energy and carbohydrate, amino acid, organic acids and lipid metabolism following raw and processed RWI use were identified. The mitochondria of hepatic and renal tubules of rats were injured in the raw RWI group, whereas the processed product reduced or interfered with energy substrate, carbohydrate and amino acid metabolism, whilst reducing the levels of metabolic markers of hepatotoxicity and nephrotoxicity, without causing damage to the mitochondria. Our previous study showed that the median lethal dose (LD₅₀) value of raw RWI was 4.05 g/kg in rats after oral administration; however, the LD₅₀ value of the processed RWI could not be measured. The maximum tolerated dose and minimum lethal dose were 20 and 30 g/kg for the processed RWI, respectively, corresponding to 109 and 164 times the clinical daily dose (0.029 g/kg). Thus, the sweat-soaking method reduced the toxicity of RWI. Moreover, after processing, the toxic component YH-10 was converted into a YH-10 + OH compound, reducing the content of the toxic YH-10 by 48%, whilst also reducing the contents of the toxic components YH-12 and YH-15 by 44 and 65%, respectively. In conclusion, the present study showed that the sweat-soaking method reduced the toxicity of RWI, as evidenced by the reduction of the levels of metabolic markers and the activity of metabolic pathways, thus providing a basis for processing of RWI for clinical use.

Therapeutic potential of naturally occurring lignans as anticancer agents

Cancer as a long-lasting and dramatic pandemic affects almost a third of the human being worldwide. At present, chemotherapy is the main clinical treatment strategy, but it is difficult to achieve satisfactory efficacy due to drug resistance and side effects. Natural products are becoming increasingly popular in cancer therapy due to their potent broad-spectrum anticancer potency and slight side effects. Lignans are complex diphenolic compounds, comprising a family of secondary metabolites existing widely in plants. Naturally occurring lignans have the potential to act on cancer cells by a range of mechanisms of action and could inhibit the colony formation, arrest the cell cycle in different phases, induce apoptosis, and suppress migration, providing privileged scaffolds for the discovery of novel anticancer agents. In recent five years, a variety of naturally occurring lignans were isolated and screened for their in vitro and/or in vivo anticancer efficacy, and some of them exhibited promising potential. This review has systematically summarized the resources, anticancer activity, and mechanisms of action of naturally occurring lignans, covering articles published between January 2017 and January 2022.

Herbals and Plants in the Treatment of Pancreatic Cancer: A Systematic Review of Experimental and Clinical Studies

Background: Pancreatic cancer represents the most lethal malignancy among all digestive cancers. Despite the therapeutic advances achieved during recent years, the prognosis of this neoplasm remains disappointing. An enormous amount of experimental (mainly) and clinical research has recently emerged referring to the effectiveness of various plants administered either alone or in combination with chemotherapeutic agents. Apart from Asian countries, the use of these plants and herbals in the treatment of digestive cancer is also increasing in a number of Western countries as well. The aim of this study is to review the available literature regarding the efficacy of plants and herbals in pancreatic cancer. Methods: The authors have reviewed all the experimental and clinical studies published in Medline and Embase, up to June 2021. Results: More than 100 plants and herbals were thoroughly investigated. Favorable effects concerning the inhibition of cancer cell lines in the experimental studies and a favorable clinical outcome after combining various plants with established chemotherapeutic agents were observed. These herbals and plants exerted their activity against pancreatic cancer via a number of mechanisms. The number and severity of side-effects are generally of a mild degree. Conclusion: A quite high number of clinical and experimental studies confirmed the beneficial effect of many plants and herbals in pancreatic cancer. More large, double-blind clinical studies assessing these natural products, either alone or in combination with chemotherapeutic agents should be conducted.

Diarylpentanones from the root of Wikstroemia indica and their cytotoxic activity against human lung A549 cells

One new diarylpentanone, 4(S)-hydroxy-1, 5-diphenyl -2(E)-en-1-pentanone (1), two diarylpentanones isolated from Wikstroemia indica for the first time (3 and 5) and two other known diarylpentanones were isolated from petroleum ether fraction of root of Wikstroemia indica. The structure of the new compound including absolute configuration was elucidated by extensive spectroscopic techniques, including 1D, 2D NMR, HR-ESI-MS and ECD spectroscopy. All isolated compounds were tested for their cytotoxic activity against cancer-derived cell lines A549. Compound 5 exhibited remarkable cytotoxic activity comparable to that of positive control cisplatin.

Panduratins Q-Y, dimeric metabolites from Boesenbergia rotunda and their antiausterity activities against the PANC-1 human pancreatic cancer cell line

A methanolic extract of the rhizomes of Boesenbergia rotunda showed potent preferential cytotoxicity against PANC-1 human pancreatic cancer cells under nutrient deficiency conditions with a PC₅₀ value of 6.6 μg/mL. Bioactivity-guided phytochemical investigation of the rhizomes of B. rotunda led to the isolation of nine undescribed dimeric metabolites, panduratins Q-Y. Their structures were elucidated based on NMR, MS, and ECD spectroscopic data interpretation. Panduratins Q-S and U-W exhibited potent cytotoxicity towards PANC-1 cell line with the PC₅₀ values ranging from 0.8 to 6.3 μM. Panduratin W, which possessed a cyclohexenylchalcone-linked flavanone skeleton, showed the most cytotoxicity with a PC₅₀ value of 0.8 μM under nutrient-deprived medium.

Curcumin and wikstroflavone B, a new biflavonoid isolated from Wikstroemia indica, synergistically suppress the proliferation and metastasis of nasopharyngeal carcinoma cells via blocking FAK/STAT3 signaling pathway

BACKGROUND

Curcumin (CUR) is a natural diarylheptanoid with marked anti-tumor activities. Recent investigations demonstrate that CUR combines with some other phytochemicals exerts advantages over its single application manifested as lower toxicity, higher efficacy or more significant reversal of multidrug resistance.

PURPOSE

This study aimed to elucidate a new biflavonoid (wikstroflavone B, WFB) isolated from Wikstroemia indica and to assess the synergistic inhibition of combined CUR and WFB (CUR/WFB) on human nasopharyngeal carcinoma (NPC) cell lines proliferation and metastasis.

METHODS

WFB was obtained through sequential chromatographic methods including silica gel, Sephadex LH-20 and preparative HPLC. Its structure was determined by HRESIMS, 1D and 2D NMR spectroscopic analysis. The absolute configuration of WFB was assigned through comparison of experimental and calculated optical rotation (OR) values. Changes in cellular viability, migration and invasion were assessed by MTT, colony formation, wound healing and Transwell assays. The nature of synergistic interaction of CUR/WFB was determined through the combination index (CI) method under the median-effect analysis. Expression levels of indicated mRNAs and proteins were measured by qRT-PCR and Western blotting assays, respectively.

RESULTS

WFB was isolated and structural elucidated. Compared with CUR or WFB used alone, CUR/WFB treatment inhibited more effectively on the cell viability, colony formation, cell migration and invasion. Both CI and dose reduction index (DRI) values indicated the significant synergistic effects existed between CUR and WFB. Besides, CUR/WFB showed the marked modulation on the genes involved in cell proliferation (survivin, cyclin D1, p53 and p21) and metastasis (MMP-2, MMP-9 and FAK). CUR/WFB treatment was also found to restrain the phosphorylation of FAK and STAT3 proteins. When pretreatment with a FAK inhibitor, the cell viability and metastasis were significantly attenuated.

CONCLUSION

The results indicate that WFB can synergistically increase the inhibitory effects of CUR on NPC cells proliferation and metastasis, and these findings may afford a rational approach for developing the antitumor medications.

Bioactive daphnane diterpenes from Wikstroemia chuii with their potential anti-inflammatory effects and anti-HIV activities

A phytochemical investigation on the stems and leaves of Wikstroemia chuii resulted in the isolation of three new daphnane diterpenes, wikstroechuins A-C (1-3), together with eight known analogues (4-11). The structures of new daphnane diterpenes (1-3) were determined on the basis of extensive spectroscopic methods and the known daphnane diterpenes (4-11) were identified by comparing their observable spectroscopic data with those reported spectral data in the literature. The anti-inflammatory effects as well as anti-HIV activities in vitro of all isolated daphnane diterpenes 1-11 were assessed. As a consequence, daphnane diterpenes 1-11 displayed remarkable inhibitory activities on NO (nitric oxide) production induced by lipopolysaccharide in mouse macrophage RAW 264.7 cells showing IC₅₀ values in the range of 0.12 ± 0.03 to 10.58 ± 0.16 µM. Meanwhile, daphnane diterpenes 1-11 displayed significant anti-HIV-1 reverse transcriptase (RT) effects showing EC₅₀ values ranging from 0.09509 to 8.62356 µM. These research results indicated that the discovery of these new daphnane diterpenes with remarkable anti-inflammatory and anti-HIV activities from W. chuii, especially these new ones, could be extremely meaningful to the discovery of new anti-inflammatory agents and anti-HIV drugs as well as their potential practical values in the health and pharmaceutical products.

Characterization of the complete chloroplast genome of a medicinal plant, Wikstroemia indica (Thymelaeaceae)

The complete chloroplast genome of Wikstroemia indica, a medicinal plant with a variety of medicinal functions in treatment for arthritis, whooping cough, cancer, and bacillosis, was generated by de novo assembly using whole genome next-generation sequencing. The plastome was a quadripartite circular with 151,731 bp in length; containing a large single-copy (LSC) region of 86,523 bp and a small single-copy (SSC) region of 12,384 bp; separated by 2 inverted repeat (IR) regions of 26,403 bp each. The chloroplast genome contained 124 genes, including 79 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. The GC content in the whole cp genome, LSC region, SSC region, and IR region were 37.4, 34.9, 32.4, and 42.6%, respectively. The phylogenetic tree indicated that W. indica has a close relationship with Stellera chamaejasme with 100% support.

Chemical Constituents and Their Activities From the Seeds of Ormosia hosiei

A new cytisine-like alkaloid, hosimonoal (1), with a fused monoterpene group, and 6 known compounds (2-6) were isolated from the seeds of Ormosia hosiei Hemsl. et Wils. The structure of the new compound was confirmed by high resolution electrospray ionization mass spectroscopy (HRESIMS), 1D and 2D nuclear magnetic resonance (NMR) spectroscopy, and electronic circular dichroism, and the others by 1H and 13C NMR spectroscopy and comparison with the literature data. In addition, compounds 1, 2, 3, and 6 showed moderate cytotoxic effects against A2780, A-549, HepG2, and MCF-7 cell lines with IC50 values ranging from 5.7 to 36.5 μM.

Lignans and Neolignans: Plant secondary metabolites as a reservoir of biologically active substances

Lignans and neolignans are plant secondary metabolites derived from the oxidative coupling of phenylpropanoids. Biological activity of these phenolic compounds ranges from antioxidant, antitumor (terminaloside P, IC₅₀ = 10 nM), anti-inflammatory, anti-neurodegenerative (schibitubin B, IC₅₀ = 3.2 nM) and antiviral (patentiflorin A, IC₅₀ = 14-23 nM) to antimicrobial. In addition, it was observed that several members of this group, namely enterolactone and its biochemical precursors also known as phytoestrogens, possess important protective properties. Most of these lignans and neolignans are presented in reasonable amounts in one's diet and thus the protection they provide against the colon and breast cancer, to name a few, is even more important to note. Similarly, neuroprotective properties were observed (schisanwilsonin G, IC₅₀ = 3.2 nM) These structural motives also serve as an important starting point in the development of anticancer drugs. Presumably the most famous members of this family, etoposide and teniposide, synthetic derivatives of podophyllotoxin, are used in the clinical treatment of lymphocytic leukemia, certain brain tumors, and lung tumors already for nearly 20 years. This review describes 413 lignans and neolignans which have been isolated between 2016 and mid-2018 being reported in more than 300 peer-reviewed articles. It covers their source, structure elucidation, and bioactivity. Within the review, the structure-based overview of compounds as well as the bioactivity-based overview of compounds are described.

Modular Synthesis and Biological Investigation of 5-Hydroxymethyl Dibenzyl Butyrolactones and Related Lignans

Dibenzyl butyrolactone lignans are well known for their excellent biological properties, particularly for their notable anti-proliferative activities. Herein we report a novel, efficient, convergent synthesis of dibenzyl butyrolactone lignans utilizing the acyl-Claisen rearrangement to stereoselectively prepare a key intermediate. The reported synthetic route enables the modification of these lignans to give rise to 5-hydroxymethyl derivatives of these lignans. The biological activities of these analogues were assessed, with derivatives showing an excellent cytotoxic profile which resulted in programmed cell death of Jurkat T-leukemia cells with less than 2% of the incubated cells entering a necrotic cell death pathway.

Exploring the Q-marker of "sweat soaking method" processed radix Wikstroemia indica: Based on the "effect-toxicity-chemicals" study

BACKGROUND

Radix Wikstroemia indica (RWI), named "Liao Ge Wang" in Chinese, is a kind of toxic Chinese herbal medicine (CHM) commonly used in Miao nationality of South China. "Sweat soaking method" processed RWI could effectively decrease its toxicity and preserve therapeutic effect. However, the underlying mechanism of processing is still not clear, and the Q-markers database for processed RWI has not been established.

PURPOSE

Our study is to investigate and establish the quality evaluation system and potential Q-markers based on "effect-toxicity-chemicals" relationship of RWI for quality/safety assessment of "sweat soaking method" processing.

METHODS

The variation of RWI in efficacy and toxicity before and after processing was investigated by pharmacological and toxicological studies. Cytotoxicity test was used to screen the cytotoxicity of components in RWI. The material basis in ethanol extract of raw and processed RWI was studied by UPLC-Q-TOF/MS. And the potential Q-markers were analyzed and predicted according to "effect-toxicity-chemical" relationship.

RESULTS

RWI was processed by "sweat soaking method", which could preserve efficacy and reduce toxicity. Raw RWI and processed RWI did not show significant difference on the antinociceptive and anti-inflammatory effect, however, the injury of liver and kidney by processed RWI was much weaker than that by raw RWI. The 20 compounds were identified from the ethanol extract of raw product and processed product of RWI using UPLC-Q-TOF/MS, including daphnoretin, emodin, triumbelletin, dibutyl phthalate, Methyl Paraben, YH-10 + OH and matairesinol, arctigenin, kaempferol and physcion. Furthermore, 3 diterpenoids (YH-10, YH-12 and YH-15) were proved to possess the high toxicity and decreased by 48%, 44% and 65%, respectively, which could be regarded as the potential Q-markers for quality/safety assessment of "sweat soaking method" processed RWI.

CONCLUSION

A Q-marker database of processed RWI by "sweat soaking method" was established according to the results and relationship of "effect-toxicity-chemicals", which provided a scientific evidence for processing methods, mechanism and the clinical application of RWI, also provided experimental results to explore the application of Q-marker in CHM.