Verbascoside is not genotoxic in the ST and HB crosses of the Drosophila wing spot test, and its constituent, caffeic acid, decreases the spontaneous mutation rate in the ST cross

In Vitro Characterization of Antioxidant, Antibacterial and Antimutagenic Activities of the Green Microalga Ettlia pseudoalveolaris

Recently, green microalgae have gained importance due to their nutritional and bioactive compounds, which makes them some of the most promising and innovative functional foods. The aim of this study was to evaluate the chemical profile and the in vitro antioxidant, antimicrobial and antimutagenic activity of an aqueous extract of the green microalga Ettlia pseudoalveolaris, obtained from the freshwater lakes of the Ecuadorian Highlands. Human microvascular endothelial cells (HMEC-1) were used to determine the ability of the microalga to reduce the endothelial damage caused by hydrogen peroxide-induced oxidative stress. Furthermore, the eukaryotic system Saccharomyces cerevisiae was used to evaluate the possible cytotoxic, mutagenic and antimutagenic effect of E. pseudoalveolaris. The extract showed a notable antioxidant capacity and a moderate antibacterial activity mostly due to the high content in polyphenolic compounds. It is likely that the antioxidant compounds present in the extract were also responsible for the observed reduction in endothelial damage of HMEC-1 cells. An antimutagenic effect through a direct antioxidant mechanism was also found. Based on the results of in vitro assays, E. pseudoalveolaris proved to be a good source of bioactive compounds and antioxidant, antibacterial and antimutagenic capacities making it a potential functional food.

The pharmacokinetic property and pharmacological activity of acteoside: A review

Acteoside (AC), a phenylpropanoid glycoside isolated from many dicotyledonous plants, has been demonstrated various pharmacological activities, including anti-oxidation, anti-inflammation, anti-cancer, neuroprotection, cardiovascular protection, anti-diabetes, bone and cartilage protection, hepatoprotection, and anti-microorganism. However, AC has a poor bioavailability, which can be potentially improved by different strategies. The health-promoting characteristics of AC can be attributed to its mediation in many signaling pathways, such as MAPK, NF-κB, PI3K/AKT, TGFβ/Smad, and AMPK/mTOR. Interestingly, docking simulation study indicates that AC can be an effective candidate to inhibit the activity of SARS-CoV2 main protease and protect against COVID-19. Many clinical trials for AC have been investigated, and it shows great potentials in drug development.

Leucosceptoside A from Devil's Claw Modulates Psoriasis-like Inflammation via Suppression of the PI3K/AKT Signaling Pathway in Keratinocytes

Psoriasis is a chronic inflammatory skin condition characterized by abnormal keratinocyte proliferation and differentiation that is accompanied with dysregulated immune response and abnormal vascularization. Devil’s claw (Harpagophytum procumbens (Burch.) DC. ex Meisn.) tubers extract has been used both systemically and topically for treatment of chronic inflammatory diseases such as arthritis, osteoporosis, inflammatory bowel disease, among others. However, its potential mechanisms of action against psoriasis remains poorly investigated. The human keratinocyte HaCaT cell line is a well-accepted in vitro model system for inflammatory skin disorders such as psoriasis. The present study involved an exploration of the effect of biotechnologically produced H. procumbens (HP) cell suspension extract and pure phenylethanoid glycosides verbascoside (VER) and leucosceptoside A (LEU) in interferon (IFN)-γ/interleukin (IL)-17A/IL-22-stimulated HaCaT cells as a model of psoriasis-like inflammation. Changes in key inflammatory signaling pathways related to psoriasis development were detected by reverse transcription polymerase chain reaction and western blotting. Treatment with LEU, but not VER and HP extract improved psoriasis-related inflammation via suppression of the PI3K/AKT signaling in IFN-γ/IL-17A/IL-22-stimulated HaCaT cells. Our results suggest that LEU may exhibit therapeutic potential against psoriasis by regulating keratinocyte differentiation through inhibition of the PI3K/AKT pathway.

Verbascoside-enriched fraction from Buddleja cordata Kunth ameliorates the effects of diabetic embryopathy in an animal model

BACKGROUND

The deleterious effects of diabetes mellitus (DM) over development are apparently due to an increase in oxidative stress. Some antioxidants could prevent developmental alterations produced by diabetic state. Extracts of plants of the genus Buddleja are used traditionally for Mexican indigens to ameliorate some diseases. The purpose of this work was to evaluate the effect of the extract of Buddleja cordata over diabetic embryopathy.

METHODS

Two experimental approaches were used: an in vivo study and an in vitro model. In the first, rats were treated with streptozotocin, streptozotocin plus methanolic extract of B. cordata, or none. Females were sacrificed at gestational day (GD) 19, and biochemical clinical parameters were measured; also, the fetuses were obtained and morphologically analyzed. In the in vitro model, a verbascoside-enriched fraction (VEF) of the extract was used in whole embryo culture in order to search for the mechanisms for embryoprotection effect over hyperglycemia-induced malformations.

RESULTS

In the in vivo experiments, B. cordata extract reduces the frequency and severity of fetal malformations produced by chemically induced diabetes, and additionally partially ameliorates the diabetic condition; in the in vitro model, both severity and frequency of embryo dysmorphogenesis were reduced by the VEF; also, this fraction reduces lipoperoxidation without affecting the activity of the antioxidant enzymes.

CONCLUSION

The results suggest that verbascoside of methanolic extract and enriched fraction can directly affect the redox state, and thus, prevents the embryotoxicity mediated by oxidative stress, in embryos of diabetic pregnancy.

Acteoside Counteracts Interleukin-1β-Induced Catabolic Processes through the Modulation of Mitogen-Activated Protein Kinases and the NFκB Cellular Signaling Pathway

Osteoarthritis (OA) is the most common degenerative joint disease with chronic joint pain caused by progressive degeneration of articular cartilage at synovial joints. Acteoside, a caffeoylphenylethanoid glycoside, has various biological activities such as antimicrobial, anti-inflammatory, anticancer, antioxidative, cytoprotective, and neuroprotective effect. Further, oral administration of acteoside at high dosage does not cause genotoxicity. Therefore, the aim of present study is to verify the anticatabolic effects of acteoside against osteoarthritis and its anticatabolic signaling pathway. Acteoside did not decrease the viabilities of mouse fibroblast L929 cells used as normal cells and primary rat chondrocytes. Acteoside counteracted the IL-1β-induced proteoglycan loss in the chondrocytes and articular cartilage through suppressing the expression and activation of cartilage-degrading enzyme such as matrix metalloproteinase- (MMP-) 13, MMP-1, and MMP-3. Furthermore, acteoside suppressed the expression of inflammatory mediators such as inducible nitric oxide synthase, cyclooxygenase-2, nitric oxide, and prostaglandin E2 in the primary rat chondrocytes treated with IL-1β. Subsequently, the expression of proinflammatory cytokines was decreased by acteoside in the primary rat chondrocytes treated with IL-1β. Moreover, acteoside suppressed not only the phosphorylation of mitogen-activated protein kinases in primary rat chondrocytes treated with IL-1β but also the translocation of NFκB from the cytosol to the nucleus through suppression of its phosphorylation. Oral administration of 5 and 10 mg/kg acteoside attenuated the progressive degeneration of articular cartilage in the osteoarthritic mouse model generated by destabilization of the medial meniscus. Our findings indicate that acteoside is a promising potential anticatabolic agent or supplement to attenuate or prevent progressive degeneration of articular cartilage.

Verbascoside production in long-term Buddleja cordata Kunth cell suspension cultures

Previously, our group reported the establishment of a white callus cell line of Buddleja cordata Kunth that is a high producer of the secondary metabolite, verbascoside (VB, also named acteoside), under suspension culture conditions. Here, we present experimental evidence of the sustained ability of that cellular line to grow and produce high amounts of VB for 5 years of continuous culture. Cellular line profiles were determined at the early (at the beginning) and late stages (at the end of 5 years of continuous subculturing) by analyzing relevant parameters of culture growth, i.e., specific growth rate [µ], doubling time [dt], and growth index [GI], as well as VB production. Late-stage cultures exhibited a 61% faster growth rate than early-stage subcultures, and 25 and 3% lower doubling time and growth index. The extents of growth phases were found to be different. Similar amounts of biomass were found (9.5 g and 9.4 g L-1). Verbascoside production increased parallel to cell growth; maximal yield level occurred in the mid-exponential phase and lasted until the end of the stationary phase (i.e., from the 15th to the 25th day and from the 9th to the 21st day for the early and late stages, correspondingly). The content of VB was higher in the late-stage culture (1.43 ± 0945 g L-1) than in the early-stage culture (1.21 ± 0.0286 g L-1). Productivity values point out the potential use of B. cordata cell line in the biotechnological production of VB and for research focused on the biochemistry of secondary metabolism.

Antimutagenic, antigenotoxic and antiproliferative activities of Fraxinus angustifolia Vahl. leaves and stem bark extracts and their phytochemical composition

In recent years, chronic degenerative diseases such as certain types of cancers, are becoming an evident issue. DNA damage has been for long recognized as a causal factor for cancer development because mutations or chromosomal aberrations affect oncogenes and tumor suppressor genes leading cells to malignant transformation and to the subsequent cancerous growth. Medicinal plants are often used for the prevention or treatment of various diseases with great scientific interest. Among the medicinal plants distributed in the Mediterranean region, Fraxinus angustifolia Vahl. has been used in traditional medicine for its remarkable curative properties. However, in spite of this popularity, little works have been performed on the activity so that further studies should be performed to investigate in depth the antimutagenic, antigenotoxic and antiproliferative activities of the plant. Thus, the present study was aimed to the evaluation of the potential antimutagenic, antigenotoxic and antiproliferative properties of leaves and stem bark extracts of this well-known tree. Antimutagenic activity was evaluated by Salmonella mutagenicity assay in Salmonella typhimurium TA98 and TA100 strains. The antigenotoxic potential was assessed by umu test in the strain of S. typhimurium TA1535/pSK1002. Antiproliferative activity was studied on human hepatoblastoma (HepG-2) and on breast adenocarcinoma (MCF-7) cell lines by MTT assay. Furthermore, the antiproliferative activity observed on cancer cells was compared with that on the human normal-like fibroblasts (TelCOFS02MA) and the selectivity index was calculated to understand if extracts were able to exert selective toxicity towards cancer cells. Moreover, phenolic compounds are plant substances with a large spectrum of biochemical activities with antioxidant, antimutagenic and anticarcinogenic effects. Based on the strong evidence of biological activities of phenolic compounds, the study was focused on the determination of total phenolics and flavonoids contents, and the phytochemical composition of the extracts assessed by LC/MS. The ethanol extracts of both leaves and stem barks showed significant from moderate to strong antimutagenic and antigenotoxic effects. In addition, selective cytotoxicity towards cancer cells was shown by ethanolic leaves extract and aqueous/chloroform leaves and stem bark extracts. The latter showed high levels of total phenolic contents among all the other extracts. Identified phenylethanoids (calceolariosides, verbascoside) and secoiridoids (oleuropein and ligstroside) could be responsible for the demonstrated broad spectrum of healthy properties.

Toxicological evaluation of a standardized hydroethanolic extract from leaves of Plantago australis and its major compound, verbascoside

ETHNOPHARMACOLOGICAL RELEVANCE

Plantago australis is a perennial plant widely distributed in Latin America, and its seeds and leaves are used in folk medicine to treat many diseases and conditions. Among its various chemical compounds, verbascoside is one of the most present, and has several pharmacological activities described, but there is not much information about its toxicity.

AIMS OF THE STUDY

The aims of this study were to optimize the extraction of verbascoside from P. australis leaves with ultrasound methods, to develop a validated HPLC method to quantify verbascoside, and to evaluate the toxicological safety of the extract and verbascoside using in vitro and in vivo assays.

MATERIALS AND METHODS

Dried leaves of P. australis were submitted to different extraction methods (percolation and ultrasound). The optimization of the ultrasound extraction was carried out by complete factorial design (2²) and response surface methodology (RSM), followed by HPLC analysis for marker compounds. HPLC analysis was performed to verify the presence of the marker compounds aucubin, baicalein, oleanolic acid, ursolic acid and verbascoside. Mutagenicity was assessed by Salmonella/microsome mutagenicity assay. Cytotoxicity and genotoxicity were evaluated in V79 cells by reduction of tetrazolium salt (MTT) and neutral red uptake (NRU) assays, and alkaline comet assay, respectively. Verbascoside phototoxicity was assessed in 3T3 cells by the NRU phototoxicity assay. Wistar rats were used to perform the acute and sub-chronic toxicity tests.

RESULTS

Among the marker compounds, only verbascoside was found in the hydroethanolic extract of P. australis leaves (PAHE); its highest concentration was obtained with the ultrasound-assisted extraction (UAE) method, optimized in 40 min and 25 °C, and the method validation was successfully applied. Neither PAHE nor verbascoside showed mutagenic or genotoxic activities. Cytotoxicity assays demonstrated that both PAHE and verbascoside reduced cell viability only at the highest concentrations, and verbascoside had no phototoxic properties. The in vivo toxicity evaluation of PAHE suggested that the LD50 is higher than 5000 mg/Kg, indicating that this extract is safe for use. In addition, no signs of toxicity were found in subchronic exposure.

CONCLUSION

The HPLC method to quantify verbascoside was validated, and the extraction of verbascoside from P. australis leaves through ultrasound method was optimized, yielding an extract with 6% verbascoside. Our results suggest the toxicological safety of PAHE and verbascoside, corroborating the use of P. australis in folk medicine, and also indicate verbascoside as a potential ingredient in topical formulations.

Cytogenetic tests reveal no toxicity in lymphocytes of rabbit (Oryctolagus cuniculus, 2n=44) feed in presence of verbascoside and/or lycopene

Phenylpropanoid glycosides (PPG), like other phenolic compounds, are a powerful antioxidants and the Verbascoside (VB) is one of the most active of them. A previous study, by using in vitro exposure of blood human lymphocytes to Verbascoside, reported a significant increasings of chromosome fragility compared to control. In the present study, four homogeneous groups of rabbits were used to test in vivo the VB and/or Lycopene (LP) by feeding the animals without VB and LP (control), in presence of VB or/and LP for 80 days. Lymphocyte cell cultures were performed in three different times: 0, 40 and 80 days of the experiment and the cytogenetic tests that we used [CA-test (Chromosome Abnormalities in terms of chromosome and chromatid breaks) and Sister Chromatid Exchange (SCE-test)] have revealed no mutagenic effects on chromosomes. Indeed, mean values/cell of CA and SCE decreased during the experiment with some difference among and within groups, with significant decreasing value only for some group. The study shows clear evidence that diets rich in Verbascoside (and/or Lycopene) do not originate any mutagenic activity, resulting no cytotoxic for the animals and, suggesting a possible their use in both animal and human diets.

Inhibition on cholinesterase and tyrosinase by alkaloids and phenolics from Aristotelia chilensis leaves

It is reported in this study the effect of isolates from leaves of Aristotelia chilensis as inhibitors of acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and tyrosinase enzymes. The aim of the paper was to evaluate the activity of A. chilensis towards different enzymes. In addition to pure compounds, extracts rich in alkaloids and phenolics were tested. The most active F5 inhibited AChE (79.5% and 89.8% at 10.0 and 20.0 μg/mL) and against BChE (89.5% and 97.8% at 10.0 and 20.0 μg/mL), showing a strong mixed-type inhibition against AChE and BChE. F3 (a mixture of flavonoids and phenolics acids), showed IC₅₀ of 90.7 and 59.6 μg/mL of inhibitory activity against AChE and BChE, inhibiting the acetylcholinesterase competitively. Additionally, F3 showed and high potency as tyrosinase inhibitor with IC₅₀ at 8.4 μg/mL. Sample F4 (anthocyanidins and phenolic composition) presented a complex, mixed-type inhibition of tyrosinase with a IC₅₀ of 39.8 μg/mL. The findings in this investigation show that this natural resource has a strong potential for future research in the search of new phytotherapeutic treatments for cholinergic deterioration ailments avoiding the side effects of synthetic drugs. This is the first report as cholinesterases and tyrosinase inhibitors of alkaloids and phenolics from A. chilensis leaves.

Gastroprotective potential of Buddleja scordioides Kunth Scrophulariaceae infusions; effects into the modulation of antioxidant enzymes and inflammation markers in an in vivo model

ETHNOPHARMACOLOGICAL RELEVANCE

A common plant used to treat several gastric disorders is Buddleja scordioides Kunth, commonly known as salvilla.

AIM OF THE STUDY

To detect inflammatory markers, in order to evaluate the gastroprotective potential of salvilla infusions, as this could have beneficial impact on the population exposed to gastric ulcers and colitis.

MATERIALS AND METHODS

The present work attempted infusions were prepared with B. scordioides (1% w/w) lyophilized and stored. Total phenolic content and GC-MS analysis were performed. Wistar rats were divided into five groups (n=8), a negative vehicle control, an indomethacin group, and three experimental groups, named preventive, curative, and suppressive. All rats were sacrificed under deep ether anesthesia (6h) after the last oral administration of indomethacin/infusion. The rat stomachs were promptly excised, weighed, and chilled in ice-cold and 0.9% NaCl. Histological analysis, nitrites quantification and immunodetection assays were done.

RESULTS

B. scordioides infusions markedly reduced the visible hemorrhagic lesions induced by indomethacin in rat stomachs, also showed down-regulation of COX2, IL-8 and TNFα and up-regulation of COX-1 with a moderate down-regulation of NFkB and lower amount of nitrites. However, this behavior was dependent on the treatment, showing most down-regulation of COX-2, TNFα and IL-8 in the curative treatment; more down-regulation of NF-kB in the preventive treatment; and more up-regulation of COX-1 for the suppressor and preventive treatments.

CONCLUSION

The anti-inflammatory potential of B. scordioides infusions could be related with the presence of polyphenols as quercetin in the infusion and how this one is consumed.

Biopesticides from plants: Calceolaria integrifolia s.l

The effects of persistent organic pollutants (POPs) on humans and biodiversity are multiple and varied. Nowadays environmentally-friendly pesticides are strongly preferred to POPs. It is noteworthy that the crop protection role of pesticides and other techniques, i.e. biopesticides, plant extracts, prevention methods, organic methods, evaluation of plant resistance to certain pests under an integrated pest management (IPM), could improve the risks and benefits which must be assessed on a sound scientific basis. For this directive it is crucial to bring about a significant reduction in the use of chemical pesticides, not least through the promotion of sustainable alternative solutions such as organic farming and IPM. Biopesticides are derived from natural materials such as animals, plants, bacteria, and certain minerals. Most of them are biodegradable in relatively short periods of time. On this regard, substances from Calceolaria species emerge as a strong alternative to the use of POPs. The American genus Calceolaria species are regarded both as a notorious weeds and popular ornamental garden plants. Some have medicinal applications. Other taxa of Calceolaria are toxic to insects and resistant to microbial attack. These properties are probably associated with the presence of terpenes, iridoids, flavonoids, naphthoquinones and phenylpropanoids previously demonstrated to have interesting biological activities. In this article a comprehensive evaluation of the potential utilization of Calceolaria species as a source of biopesticides is made. The chemical profile of selected members of the Chilean Calceolaria integrifolia sensu lato complex represents a significant addition to previous studies. New secondary metabolites were isolated, identified and tested for their antifeedant, insect growth regulation and insecticidal activities against Spodoptera frugiperda and Drosophila melanogaster. These species serve as a model of insect pests using conventional procedures. Additionally, bactericidal and fungicidal activity were determined. Dunnione mixed with gallic acid was the most active fungistatic and fungicidal combination encountered. Several compounds as isorhamnetin, combined with ferulic and gallic acid quickly reduced cell viability, but cell viability was recovered quickly and did not differ from that of the control. The effect of these mixtures on cultures of Aspergillus niger, Fusarium moniliforme, Fusarium sporotrichum, Rhizoctonia solani, and Trichophyton mentagrophytes, was sublethal. However, when fungistatic isorhamnetin and dunnione were combined with sublethal amounts of both ferulic and gallic acid, respectively, strong fungicidal activity against theses strains was observed. Thus, dunnione combined with gallic acid completely restricted the recovery of cell viability. This apparent synergistic effect was probably due to the blockade of the recovery process from induced-stress. The same series of phenolics (iridoids, flavonoids, naphthoquinones and phenylpropanoids) were also tested against the Gram-negative bacteria Escherichia coli, Enterobacter agglomerans, and Salmonella typhi, and against the Gram-positive bacteria Bacillus subtilis, Sarcinia lutea, and Staphylococcus aureus and their effects compared with those that of kanamycin. Mixtures of isorhamnetin/dunnione/kaempferol/ferulic/gallic acid in various combinations were found to have the most potent bactericidal and fungicidal activity with MFC between 10 and 50 μg/ml. Quercetin was found to be the most potent fungistatic single compound with an MIC of 15 µg/ml. A time-kill curve study showed that quercetin was fungicidal against fungi assayed at any growth stage. This antifungal activity was slightly enhanced by combination with gallic acid. The primary antifungal action of the mixtures assayed likely comes from their ability to act as nonionic surfactants that disrupt the function of native membrane-associated proteins. Hence, the antifungal activity of isorhamnetin and other O-methyl flavonols appears to be mediated by biophysical processes. Maximum activity is obtained when the balance between hydrophilic and hydrophobic portions of the molecules of the mixtures becomes the most appropriate. Diterpenes, flavonoids, phenylpropanoids, iridoids and phenolic acids were identified by chromatographic procedures (HPLC-DAD), ESI-MS, and NMR hyphenated techniques.

Quantification of verbascoside in medicinal species of Phlomis and their genetic relationships

Background

The genus Phlomis (Lamiaceae) is introduced by its valuable medicinal species, of which 17 species are growing wildly and ten of them are exclusively endemic of Iran. The main phytochemical characteristic of this genus is presence of iridoid glycosides including ipolamide, auroside, lamiide and also phenylethanoids such as verbascoside (acetoside) found in Lamiales order.

Due to the broad range of biological and pharmacological activities of verbascoside and lack of any report on quantification of this compound within Iranian species of Phlomis, we conducted a research to achieve two main goals, finding a genetic biodiversity by RAPD (Randomly Amplified Polymorphic DNA), as well as detecting and quantifying verbascoside in nine species of Phlomis growing wildly in Iran.

Results

The results showed that various samples of P.olivieri possess different genetic distances from each other. Also, various species of P.olivieri display close relationships to P.anisodonta and P. persica. Phytoanalysis of Phlomis species by means of TLC scanner using verbascoside as a phytochemical marker showed that the highest concentration of verbascoside was found in P. anisodonta, however, P. bruguieri and P. olivieri (from Mazandaran) were in the second and third places. Interestingly, the lowest concentration of verbascoside was detected in P. olivieri (from Azerbayjan), exhibiting the effect of various growing areas and conditions on the measured levels of this compound.

Conclusions

verbascoside can be found in various species of Iranian Phlomis, of which P. anisodonta, P. bruguieri and P. olivieri might be the best choices. In addition, although the concentration of verbascoside in these plants may be affected by the growing areas and conditions, there are a good agreement between genetic relations and verbascoside levels.