Acute, Sub-Acute and Cell Toxicity of Verbascoside

Identification of anti-inflammatory and anti-cancer compounds targeting the NF-κB-NLRP3 inflammasome pathway from a phytochemical library of the Sideritis genus

ETHNOBOTANICAL RELEVANCE

For centuries, the aerial parts of Sideritis species have been known for their medicinal properties as herbal teas. Although the antioxidant and anti-inflammatory properties of the genus have been widely documented, the underlying mechanisms are yet to be sufficiently clarified.

AIM OF THE STUDY

We investigated the anti-inflammatory and anticancer activities of phytochemicals of the Sideritis genus.

MATERIAL AND METHODS

Through literature mining, a chemical library containing 657 components of the Sideritis genus was formed. We studied these compounds for binding to NLRP3 and NF-κB proteins in silico by virtual drug screening and molecular docking, and in vitro by microscale thermophoresis (MST). Liquid chromatography-high-resolution mass spectrometry analysis (LC-HRMS) was performed in the Sideritis extracts. One of the identified compounds, verbascoside, was investigated for its cytotoxic activity by mining a panel of 49 tumor cell lines in the data repository of the National Cancer Institute (NCI, USA).

RESULTS

Virtual screening and molecular docking results highlighted two compounds targeting both proteins of interest, i.e., verbascoside (acteoside) and apigenin 7,4'-bis(trans-p-coumarate), as both had lowest binding energies of less than -10 kcal/mol. Using MST, we then verified that both compounds bound to the target proteins. Verbascoside bound to NLRP3 and NF-κB with Kd values of 0.67 ± 0.18 μM and 0.01 ± 0.08 μM, while apigenin 7,4'-bis(trans-p-coumarate) had Kd values of 4.60 ± 1.66 μM and 0.27 ± 0.75 μM, respectively. Verbascoside was abundant in the Sideritis extracts, according to LC-HRMS analysis. Since inflammation is strongly related to carcinogenesis, we investigated the anticancer activity of verbascoside in the second part of this study. We investigated the activity of verbascoside in 49 tumor cell lines of the NCI. Comparing its activity with 81 standard anticancer drugs revealed numerous interactions with DNA-damaging agents (alkylators, topoisomerase I/II inhibitors, antimetabolites), indicating that verbascoside may also affect the DNA of tumor cells. We further investigated the involvement of verbascoside in several main drug resistance mechanisms, i.e., ABC transporters, oncogenes, tumor suppressors, cellular proliferation rates, and other parameters. Except for the correlation to the mutational status of NRAS, no other significant relationships were found, indicating that verbascoside is not involved in most of the common drug resistance mechanisms. Two-dimensional cluster analysis-based heatmap generation of a proteomic profile from 40 out of 3171 proteins revealed a significant correlation between the expression of these proteins in 49 tumor cell lines, and the cellular response to verbascoside. This indicates that the presence of these proteins is a determinant for sensitivity or resistance to this natural product.

CONCLUSION

The database established here represents a valuable resource for the screening of bioactivites of the Sideritis genus. The experimental validation of the anti-inflammatory and cytotoxic activities of selected compounds proved that virtual drug screening and molecular docking are suitable tools for the identification of putative drug candidates. Verbascoside was among the top 10 compounds binding to two key anti-inflammatory proteins, NLRP3 and NF-kB. Additionally, data from the NCI indicate that verbascoside is not linked to main drug resistance mechanisms.

Verbascoside: comprehensive review of a phenylethanoid macromolecule and its journey from nature to bench

Polyphenolic compounds are among the most widely researched compounds for various therapeutic applications. However, naturally occurring phenylethanoid glycosides are least explored under this class of compounds. One such phenylethanoid glycoside, verbascoside (Vb), abundantly found among 200 species of 23 families, has gained recent attention due to its wide-spectrum therapeutic properties such as antioxidant, antimicrobial, anti-inflammatory, neuroprotective, cardioprotective, skin-protective, and anti-cancer. Despite having multiple therapeutic benefits, due to its large size, the compound has poor bioavailability for oral and topical applications. To meet these limitations, current research on Vb focuses on delivering it through nanoformulations. Presently, most developed formulations are liposome based for various applications, such as corneal epithelial wound healing, anti-neuropathic, anti-wrinkle, anti-hyperalgesia, atopic dermatitis, alopecia, and cutaneous wound healing. Multiple studies have confirmed the least acute and sub-acute toxicity for Vb. Few clinical studies have been performed for the therapeutic application of Vb to manage COVID-19, nephropathy, platelet aggregation, chronic primary glomerulonephritis, and acute hepatitis. Recent studies have shown the immense therapeutic potential of Vb in wound healing, dermatitis, neuroprotection, and anti-cancer activities, which creates a need for developing novel formulations for their respective uses. Long-term toxicity studies and techniques for scaling up Vb production by biotechnological approaches should be emphasized.

The role of Cistanches Herba and its ingredients in improving reproductive outcomes: A comprehensive review

BACKGROUND

Infertility patients account for an astonishing proportion of individuals worldwide. Due to its complex etiology and challenging treatment, infertility has imposed significant psychological and economic burdens on many patients. C. Herba (Cistanche tubulosa (Schenk) Wight and Cistanche deserticola Ma), renowned as one of the most prominent Chinese herbal medicines (CHMs), is abundant in diverse bioactive compounds that exhibit therapeutic effects on many diseases related to oxidative stress (OS) and disorders of sex hormone levels.

OBJECTIVE

Due to the limited drugs currently used in clinical practice to improve reproductive outcomes and their inevitable side effects, developing safe and effective new medications for infertility is of significance. This article comprehensively reviewed the phytochemicals of C. Herba, focusing on their efficacy and mechanisms on infertility and their safety for the first time, aiming to offer valuable insights for the development and application of C. Herba, and for developing novel strategies for treating infertility.

METHODS

We used "Cistanche" and its known bioactive components in combination with "sperm", "testicles", "epididymis", "ovaries", "uterus", and "infertility" as keywords to search in PubMed, Web of Science, Scopus and CNKI up to November 2023. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guideline was followed.

RESULTS

The therapeutic effects of C. Herba on infertility are mainly attributed to echinacoside (ECH), verbascoside (VB), salidroside (SAL), polysaccharides, and betaine. They can effectively improve spermatogenic dysfunction, gonadal dysfunction and erectile dysfunction (ED) by exerting anti-oxidation, sex hormones regulation and anti-hypoxia. Moreover, they can also improve premature ovarian failure (POF), ovarian and uterine cancer, oocyte maturation by exerting anti-oxidation, anti-apoptosis, and anti-cancer. C. Herba and its active ingredients also exhibit pleasing safety.

CONCLUSION

C. Herba is a promising source of natural medicine for infertility. Additionally, compared to current therapeutic drugs, its favorable safety also supports its development as a nutritional supplement. However, high-quality clinical studies are required to validate its effectiveness for the development of novel therapeutic strategies.

Verbascoside: A neuroprotective phenylethanoid glycosides with anti-depressive properties

BACKGROUND

Verbascoside is a natural and water-soluble phenylethanoid glycoside found in several medicinal plants. It has extensive pharmacological effects, including antioxidative and antineoplastic actions, and a wide range of therapeutic effects against depression.

PURPOSE

In this review, we appraised preclinical and limited clinical evidence to fully discuss the anti-depression capacity of verbascoside and its holistic characteristics that can contribute to better management of depression in vivo and in vitro models, as well as, its toxicities and medicinal value.

METHODS

This review was prepared according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). A systematic review of 32 preclinical trials published up to April 2023, combined with a comprehensive bioinformatics analysis of network pharmacology and molecular docking, was conducted to elucidate the antidepressant mechanism of action of verbascoside. Studies included in the systematic review were obtained from 7 electronic databases: PubMed, Scopus, Web of Science, Cochrane, ResearchGate, ScienceDirect, and Google Scholar.

RESULTS

Studies on the antidepressant effects of verbascoside showed that various pharmacological mechanisms and pathways, such as modulating the levels of monoamine neurotransmitters, inhibiting hypothalamic-pituitary-adrenal (HPA) axis hyperfunction and promoting neuroprotection may be involved in the process of its action against depression. Verbascoside promotes dopamine (DA) biosynthesis by promoting the expression of tyrosine hydroxylase mRNA and protein, upregulates the expression of 5-hydroxytryptamine receptor 1B (5-HT1B), prominence protein, microtubule-associated protein 2 (MAP2), hemeoxygenase-1 (HO-1), SQSTM1, Recombinant Autophagy Related Protein 5 (ATG5) and Beclin-1, and decreases the expression of caspase-3 and a-synuclein, thus exerting antidepressant effects. We identified seven targets (CCL2, FOS, GABARAPL1, CA9, TYR, CA12, and SQSTM1) and three signaling pathways (glutathione metabolism, metabolism of xenobiotics by cytochrome P450, fluid shear stress and atherosclerosis) as potential molecular biological sites for verbascoside.

CONCLUSIONS

These findings provide strong evidence that verbascoside exerts its antidepressant effects through various pharmacological mechanisms. However, further multicentre clinical case-control and molecularly targeted fishing studies are required to confirm the clinical efficacy of verbascoside and its underlying direct targets.

Antibacterial and Anti-inflammatory Activity of Extracts and Major Constituents Derived from Stachytarpheta indica Linn. Leaves and Their Potential Implications for Wound Healing

Wounds of various types continue to have a severe socioeconomic impact on the cost of health care. Globally, there has been increased interest surrounding the identification of bioactive compounds that promote or modulate the wound healing process. Stachytarpheta indica Linn. is traditionally used to heal wounds and relieve inflammation; however, the theorised pharmacological properties have not yet been scientifically validated. In this study, dried and ground plant leaves were extracted with water and methanol, which were then subjected to various analyses. The antimicrobial activity of the plant extracts and isolated compounds was determined using well diffusion assays, while the minimum inhibitory concentrations were determined with a colorimetric assay. Morphological changes of human keratinocytes in response to plant extracts were observed with differential interference contrast microscope imaging. Cell viability, proliferation, and migratory effects post-treatment with the plant extracts were also evaluated via colorimetric cytotoxicity assays and a real-time cell analyser protocol. Anti-inflammatory effects of plant extracts and isolated compounds were evaluated by flow cytometry and cyclooxygenase and lipoxygenase enzyme inhibition assays. Three active compounds, i.e. ipolamiide, verbascoside and iso-verbascoside, were isolated from S. indica leaves. Verbascoside demonstrated broad-range antibacterial activity and imposed strong inhibition at 9.77 μg/mL against Staphylococci spp. S. indica extracts (0.1-0.2 mg/mL) were shown to improve human keratinocyte proliferation up to 60% and induce morphological changes by producing cytoplasmic projections at concentrations higher than 0.4 mg/mL. Plant extracts (6.25-100 μg/mL) and individual compounds (3.125-50 μg/mL) elicited strong anti-inflammatory effects by suppressing the expression of interleukin-8 and inhibiting cyclooxygenase-1 and 5-lipoxygenase enzymes. Collectively, these results indicate that plant extracts and isolated compounds derived from S. indica have the potential to inhibit bacterial growth, promote tissue regeneration and reduce inflammation, hence, potentially providing the basis for a novel therapeutic for the treatment of wounds.

Verbascoside inhibits paraquate-induced pulmonary toxicity via modulating oxidative stress, inflammation, apoptosis and DNA damage in A549 cell

Paraquat (PQ), one of the most frequently used herbicides, can cause serious health problems in an exposed individual. In the present study, we investigated the protective effect of verbascoside (VB), a phenylpropanoid glycoside from lemon verbena, against PQ-induced A549 cell injury with a particular focus on the possible molecular pathways involved. A549 cells were exposed to PQ (300 µM) and different concentrations of VB (12.5, 25, and 50 µM). Cell viability, ROS content, the level of antioxidant enzymes (SOD, CAT and GPx) and inflammatory markers (IL-6 and TNF-α), as well as 8-OHdG, were detected using MTT assay and an ELISA kit. Western blotting and qRT-PCR were performed to measure the levels of caspase3 and NF-κB mRNA and protein expression. Exposure of cells to PQ caused viability loss and ROS increase. PQ also increased the levels of IL-6, TNF-α and 8-OHdG and decreased the antioxidant enzymes content. PQ treatment resulted in cell death by increasing the gene and protein expression level of caspase 3 and NF-κB. Treatment with VB notably increased cell survival, antioxidant enzymes activity, which concomitantly attenuated ROS, NF-κB and inflammatory mediator production. VB also inhibited apoptosis expression markers. These results indicated that VB could protect A549 cells against PQ induced cell injury by attenuation of ROS and inflammatory marker production and modulation of antioxidant enzymes. VB efficiently suppressed increased NF-κB and caspase-3 activity and formation of 8-OHdG and ultimately improved cell viability. Therefore, VB may be useful in the development of a new therapy for PQ-induced pulmonary toxicity.

In vivo anti-arthritic effect and repeated dose toxicity of standardized methanolic extracts of Buddleja cordata Kunth (Scrophulariaceae) wild plant leaves and cell culture

ETHNOPHARMACOLOGICAL RELEVANCE

Buddleja cordata Humb. Bonpl. & Kunth, known by the population as Tepozán blanco, is a shrub plant used in traditional herbal medicine in Mexico for the treatment of tumors, cancer, sores, skin burns, rheumatic pains and diseases related to inflammatory processes such as arthritis; authors adjudicate this etno-medicinal effect to the presence of secondary metabolites in the plant such as verbascoside, however due to its low concentration in recent years biotechnological tools are applied as cell culture to biosynthesize these pharmacological active metabolites in greater quantities.

AIM OF THE STUDY

Evaluate the possible toxic effect after a daily administration of MeOH extracts from wild plant leaves (Bc-Wp), and cell culture (Bc-Cc) of B. cordata for 28 days, and after their anti-edematous and antioxidant activities in vivo, as well their effect on the cytokines profile during experimental arthritis induced by complete Freund's adjuvant.

MATERIALS AND METHODS

Both extracts were evaluated in CD1 male mice first in a toxicity test of repeated dose administrations (1 g/kg) for 28 days, after which pharmacological activity of both extracts was measure during experimental induced arthritis where three doses were tested, at the end of the study edema formation, body weight gain and antioxidant activity were measure in edema and ganglionic tissues. Finally, dose that exerted the best protective effect (250 mg/kg) was evaluated to quantify its effect over ganglionic tissue concentration of lymphocytes T CD4⁺, and cytokines (IL-1β, TNF-α and IL-10), as well histological analysis in arthritic mice.

RESULTS

Both extracts (Bc-Wp and Bc-Cc) did not exert lethality, however body weight gain and food in-take were lower than in healthy mice administered with vehicles, also extract-treated animals showed a decrease in serum lipid concentration and only Bc-Wp extract treated animals decrease serum alkaline phosphatase after 28 daily administration compared to healthy un-treated mice. During experimental arthritis best inhibition effect over edema development was observed in those animals administered with both extracts at dose of 250 mg/kg (Bc-Wp and Bc-Cc) on day 28, compared to CFA un-treated mice. Also both extracts reduce oxidative damage over lipids and proteins at the same dose, in both ganglionic and edema tissue, as well antioxidant enzymatic response was reduced in both tissues compared to arthritic un-treated group. In ganglionic tissue of arthritic mice, CD4⁺ lymphocytes concentration was reduced by Bc-Wp and Bc-Cc treatment (250 mg/kg) respectively, as well IL-1β, and TNF-α levels. Only arthritic animals treated with Bc-Cc extract at 250 mg/kg generated a significant increase of IL-10 doubling the levels compared to CFA un-treated group. Histological analysis of popliteal ganglion showed that both extracts decrease the incidence of lytic lesions, lipid inclusions and leukocyte infiltration.

CONCLUSION

Methanolic extracts of wild Buddleja cordata and its cell cultures did not generated lethality after a daily administration for 28 days at 1 g/kg, but it was observed that both showed a lipid-lowering effect. Also at dose of 250 mg/kg both extracts exerted anti-edematous, protection against the oxidation of lipid and proteins, regulation on antioxidant enzymatic response, down-regulation on lymphocytes CD4⁺ producers of IL-1β and TNF-α, an increase in IL-10 levels, which caused a decrease in leukocyte infiltration in ganglionic tissue during experimental arthritis.

In Vitro Human Metabolism and Inhibition Potency of Verbascoside for CYP Enzymes

Verbascoside is found in many medicinal plant families such as Verbenaceae. Important biological activities have been ascribed to verbascoside. Investigated in this study is the potential of verbascoside as an adjuvant during tuberculosis treatment. The present study reports on the in vitro metabolism in human hepatic microsomes and cytosol incubations as well as the presence and quantity of verbascoside within Lippia scaberrima. Additionally, studied are the inhibitory properties on human hepatic CYP enzymes together with antioxidant and cytotoxic properties. The results yielded no metabolites in the hydrolysis or cytochrome P450 (CYP) oxidation incubations. However, five different methylated conjugates of verbascoside could be found in S-adenosylmethionine incubation, three different sulphate conjugates with 3'-phosphoadenosine 5'-phosphosulfate (PAPS) incubation with human liver samples, and very low levels of glucuronide metabolites after incubation with recombinant human uridine 5'-diphospho-glucuronosyltransferase (UGT) 1A7, UGT1A8, and UGT1A10. Additionally, verbascoside showed weak inhibitory potency against CYP1A2 and CYP1B1 with IC50 values of 83 µM and 86 µM, respectively. Potent antioxidant and low cytotoxic potential were observed. Based on these data, verbascoside does not possess any clinically relevant CYP-mediated interaction potential, but it has effective biological activity. Therefore, verbascoside could be considered as a lead compound for further drug development and as an adjuvant during tuberculosis treatment.

Aloysia citrodora Paláu (Lemon verbena): A review of phytochemistry and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Aloysia citrodora Paláu (Lippia citriodora Kunth), commonly known as "lemon verbena" is a medicinal plant native to South America, North Africa, and South of Europe which is used by native people for several indications such as diarrhea, flatulence, insomnia, and rheumatism.

AIM OF THE REVIEW

Despite the wide biological activities of lemon verbena, there is no current review summarizing medicinal properties of the plant; thus, this paper aims to discuss current state of the art regarding the phytochemistry, pharmacology, and therapeutic applications of A. citrodora considering in vitro, in vivo, and clinical studies.

MATERIALS AND METHODS

Electronic databases including PubMed, Scifinder, Cochrane library, Scopus, and Science direct were searched with the scientific name of the plant and its synonyms, as well as the common name. All studies on the ethnobotany, phytochemistry, pharmacology, and clinical application of the plant until October 2017 were included in this review.

RESULTS

Despite the few number of studies on the ethnopharmacology of the plant, A. citrodora is widely assessed regarding its phytochemistry and biological activities. Neral and geranial are the main ingredients of the essential oil; whereas verbascoside is the most significant component of the extract. Biological activities such as antioxidant, anxiolytic, neuroprotective, anticancer, anesthetic, antimicrobial, and sedative effects are proved in cell cultures, as well as animal studies.

CONCLUSIONS

Several pharmacological activities have been reported for A. citrodora; however, the plant is not fully assessed regarding its safety and efficacy in human. Future well-designed human studies are essential to confirm the therapeutic benefits of this plant in clinical settings.

Anti-inflammatory and toxicological evaluation of Moussonia deppeana (Schldl. & Cham) Hanst and Verbascoside as a main active metabolite

ETHNOPHARMACOLOGICAL RELEVANCE

Moussonia deppeana, known as Tlachichinole, is a Mexican medicinal plant used for treatment of inflammatory diseases, influenza, diarrhea, gastrointestinal disorders and arthritis.

AIM OF THE STUDY

In this paper the antioxidant and anti-inflammatory activities as well as the acute and sub-acute toxicological effects were evaluated for the ethanolic extract from aerial parts of M. deppeana, also its phytochemical analysis is described.

MATERIALS AND METHODS

Phytochemical analysis and compound isolation were performed with thin layer chromatography. The chemical identification of the main compound was performed by (1)H NMR (COSY, NOESY, HSQC and HMBC) spectra. In vitro antioxidant capacity and total phenolic content for the ethanolic extract and its primary fractions was determined by DPPH and Folin-Ciocalteu reagent. Acute and subacute toxicity tests were evaluated on Balb/C mice. Finally acute anti-inflammatory evaluation was tested for a local (TPA) and systemic (carrageenan) murine model.

RESULTS

The main compound isolated from the ethanolic extract of M. deppeana was Verbascoside, which was isolated from F3 and was identified by (1)H NMR and COSY data. Furthermore oleanolic and ursolic acids were isolated from primary fractions F1 and F2. Ethanolic extract showed IC50 = 6.71mg/mL for DPPH test and 664.12µg QE/mL for the total phenolic content. The LD50 value was >2g/kg by i.g. route in male and female mice. Sub-acute administration (28 days) of the ethanolic extract (1g/kg) did not cause lethality or alter any hematological and biochemical parameters, in addition, histological analysis of the major organs exhibited no structural changes. Anti-inflammatory activity of the ethanolic extract showed an ED50 = 1.5mg/ear and 450mg/kg for TPA and carrageenan test, respectively. Primary fractions generated moderate local and systemic anti-inflammatory activity.

CONCLUSION

The ethanolic extract from the aerial parts of M. deppeana did not cause any lethality or adverse effect in either of the acute and sub-acute toxicity tests. This exhibited an important local and systemic anti-inflammatory activity and also moderate antioxidant capacity. Moreover, the primary fraction F2 was more active for the TPA model while the primary fraction F3 was most active in the carrageenan model in vivo. The main compound isolated from F3 was verbascoside; on the other hand also ursolic and oleanolic acids were isolated from F1 and F2.