Chemical Composition and Future Perspectives of Essential Oil Obtained from a Wild Population of Stachys germanica L. Distributed in the Balkan Mountains in Bulgaria

Stachys germanica L. (Lamiaceae) is a plant associated with a rich history in the traditional medicine of Iran, Turkey, and Serbia. However, researchers have not fully investigated the pharmacological potential of the herb, and scientific data on this plant species are limited. The aim of the current study was to evaluate the chemical composition of the essential oil (EO) obtained from the aerial parts of S. germanica L. growing wild in Bulgaria and to perform a comparative analysis of the chemical composition of EOs obtained from the same plant species from other geographical regions. For the evaluation of the chemical profile of the isolated EO, gas chromatographic analysis with mass spectrometry was performed. The most abundant terpene class was oxygenated monoterpenes, which accounted for 59.30% of the total EO composition. The bicyclic monoterpene camphor, as a compound of this class, was identified as the major constituent in the EO, accounting for 52.96% of the total oil composition. The chemical profile of Bulgarian EO is quite different compared to that of EOs from other regions. It is the only one to contain more than 50% camphor. In addition, EO contains significant amounts of the diterpene geranyl p-cymene (10.49%). This is the first study describing the chemical composition of EO from Bulgarian Stachys germanica L., and our results reveal some future perspectives for the evaluation of the biological activity of EO from the studied plant species as a new therapeutic agent or natural remedy targeting different medical conditions. The EO has a promising potential to be used as a biopesticide and repellent as well, an environmentally friendly and safer alternative to standard pesticides.

Antitumor and Immunomodulatory Properties of the Bulgarian Endemic Plant Betonica bulgarica Degen et Neič. (Lamiaceae)

Background: Extracts obtained from different Betonica species have been shown to possess important biological properties. The present study aimed to investigate the cytotoxicity, antitumor and immunomodulatory potential of the endemic plant Betonica bulgarica (Lamiaceae) and thus, reveal new aspects of its biological activity. Methods: Methanolic extract obtained from inflorescences was analyzed for cytotoxicity against mammalian cell lines. The antitumor potential of the sample was determined using human cervical and lung adenocarcinoma cells (HeLa and A549). Programmed cell death-inducing effects against HeLa cells and peripheral blood lymphocytes, as well as immunomodulatory properties of the extract were determined by flow cytometry analysis. Results: The research results demonstrated that the extract has significant inhibitory potential against HeLa cells (mean IC50 value 119.2 μg/mL). The sample selectively induced apoptotic death in tumor cells. Cytotoxic effects towards mouse cell lines were detected following treatment with high concentrations of Betonica bulgarica extract (200 and 250 μg/mL). Twenty-four-hour ex vivo incubation of peripheral blood leucocytes in growth medium containing plant extract induced prominent effects in distinct immune cell populations. They included elevated levels of CD25+ and CD56+ T cells’ lymphocytes, particularly CD4+CD25+ and CD8+CD56+ cells. Conclusions: The present study demonstrates that Betonica bulgarica inflorescence extract possesses potential beneficial antitumor and immunomodulatory activity and could serve as a source of bioactive compounds with biomedical application.

Biological Activity and NMR-Fingerprinting of Balkan Endemic Species Stachys thracica Davidov

Stachys thracica Davidov is a Balkan endemic species distributed in Bulgaria, Greece, and Turkey. In Bulgaria, it is classified as “rare” and is under the protection of the Bulgarian biodiversity law. The aim of our study was to develop an efficient protocol for ex situ conservation of S. thracica and to perform comparative NMR-based metabolite profiling and bioactivity assays of extracts from in situ grown, in vitro cultivated, and ex vitro acclimated plants. Micropropagation of S. thracica was achieved by in vitro cultivation of mono-nodal segments on basal MS medium. Ex vitro adaptation was accomplished in the experimental field with 83% survival while conserved genetic identity between in vitro and ex vitro plants as shown by the overall sequence-related amplified polymorphism marker patterns was established. Verbascoside, chlorogenic acid, and trigonelline appeared the main secondary metabolites in in situ, in vitro cultivated, and ex vitro acclimated S. thracica. High total phenolic and flavonoid content as well as antioxidant and radical scavenging activity were observed in in situ and ex vitro plants. Further, the anti-inflammatory activity of S. thracica was tested by hemolytic assay and a high inhibition of the complement system was observed. Initiated in vitro and ex vitro cultures offer an effective tool for the management and better exploitation of the Stachys secondary metabolism and the selection of lines with high content of bioactive molecules and nutraceuticals.

Harpagide: Occurrence in plants and biological activities - A review

In this review article, the occurrence of harpagide in the plant kingdom and its associated biological activities are presented and detailed for the first time. The presence of harpagide has been reported in several botanical families within Asteridae, and harpagide has been observed to exert a wide number of biological activities such as cytotoxic, anti-inflammatory, and neuroprotective. These results show how harpagide can be recovered from several natural sources for several pharmacological purposes even if there is a lot to still be studied. Nowadays, the interest is related to its presence in phytomedicines. Threfore, these studies are useful to support and validate the large use of several plants in the folklore medicine.

Valorisation of stachysetin from cultivated Stachys iva Griseb. as anti-diabetic agent: a multi-spectroscopic and molecular docking approach

Stachys species are considered as important medicinal plants with numerous health benefit effects. In continuation of our research on the Greek Stachys species, the chemical profile of the aerial parts of cultivated S. iva Griseb. has been explored. The NMR profiles of the plant extract/infusion were used to guide the isolation process, leading to the targeted isolation of seventeen known compounds. The rare acylated flavonoid, stachysetin, was isolated for the third time from plant species in the international literature. Identification of the characteristic signals of stachysetin in the 1D ¹H-NMR spectrum of the crude extract was presented. In order to evaluate the potential of the identified chemical space in Stachys to bear possible bioactivity against diabetes, we performed an in silico screening against 17 proteins implicated in diabetes, as also ligand based similarity metrics against established anti-diabetic drugs. The results capitalized the anti-diabetic potency of stachysetin. Its binding profile to the major drug carrier plasma protein serum albumin was also explored along with its photophysical properties suggesting that stachysetin could be recognized and delivered in plasma through serum albumin and also could be tracked through near-infrared imaging. Communicated by Ramaswamy H. Sarma.

New Rare Ent-Clerodane Diterpene Peroxides from Egyptian Mountain Tea (Qourtom) and Its Chemosystem as Herbal Remedies and Phytonutrients Agents

Genus Stachys, the largest genera of the family Lamiaceae, and its species are frequently used as herbal teas due to their essential oils. Tubers of some Stachys species are also consumed as important nutrients for humans and animals due to their carbohydrate contents. Three new neo-clerodane diterpene peroxides, named stachaegyptin F-H (1, 2, and 4), together with two known compounds, stachysperoxide (3) and stachaegyptin A (5), were isolated from Stachys aegyptiaca aerial parts. Their structures were determined using a combination of spectroscopic techniques, including HR-FAB-MS and extensive 1D and 2D NMR (¹H, ¹³C NMR, DEPT, ¹H-¹H COSY, HMQC, HMBC and NOESY) analyses. Additionally, a biosynthetic pathway for the isolated compounds (1-5) was discussed. The chemotaxonomic significance of the isolated diterpenoids of S. aegyptiaca in comparison to the previous reported ones from other Stachys species was also studied.

Effects of Stachys sylvatica hydroalcoholic extract on the ovary and hypophysis-gonadal axis in a rat with polycystic ovary syndrome

Background

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy affecting women. The purpose of this study is to evaluate the effects of Stachys sylvatica hydroalcoholic extract on biochemical and histological parameters in a rat model of polycystic ovary syndrome. Thirty adult female Wistar rats with an average weight of 180 g were divided into five groups of six rats. Animals were divided into groups of control, PCOS (intramuscular injection of 2 mg estradiol valerate, Aburaihan Co., Iran/rat, once), and treated with hydroalcoholic extract of Stachys sylvatica. After 60 days of PCOS induction, 100, 250, and 500 mg/kg BW Stachys sylvatica hydroalcoholic extract were injected intraperitoneally. The control group was just injected with olive oil as a solvent. After 10 days of treatment, animals were weighed and then sacrificed and blood samples were taken from their heart for hormonal studies. Ovaries of all groups were cut for histological studies and fixed in formaldehyde, and 7-μm sections were prepared by microtome and stained using hematoxylin–eosin. The data were analyzed by one-way ANOVA and Tukey-Kramer post hoc test with the SPSS software. The significant level was p < 0.05.

Results

The Stachys sylvatica extract can improve obesity in the PCOS group. The histological and hormonal results showed that PCOS induction can decrease the number of preantral, antral, and Graafian follicles as well as corpus luteum in comparison with the control (p < 0.001), whereas the number of cystic follicles increased significantly (p < 0.001). After treatment with Stachys sylvatica hydroalcoholic extract (500 mg/kg), a significant increase was observed in all these parameters. In addition, the number of cystic follicles decreased significantly (p < 0.001). The level of LH and FSH hormones decreased significantly (p < 0.01) in the PCOS group compared with the control. In contrast, the estrogen level increased significantly (p < 0.01). In the 250 and 500 mg/kg group, treatment with the extract could increase FSH and decrease estrogen concentration significantly relative to the PCOS group (p < 0.01). Results of antral follicle morphometry indicated an increase in follicle diameter and theca thickness, but the thickness of the granulosa layer decreased significantly. An improvement in these measurements was observed in the treated PCOS groups with all doses.

Conclusions

It can be concluded that Stachys sylvatica hydroalcoholic extract can improve some symptoms of polycystic ovary syndrome because of components such as iridoids, flavonoids, and sesquiterpenes with antioxidant and anti-inflammatory effects. In this experiment, 500 mg/kg dose of extract was considered as the most effective dose.

Genotoxic properties of Betonica officinalis, Gratiola officinalis, Vincetoxicum luteum and Vincetoxicum hirundinaria extracts

Genotoxicity of B. officinalis, G. officinalis, V. luteum and V. hirundinaria extracts, which demonstrated strong antioxidant capacity, was tested using chromosome aberration, sister chromatid exchange (SCE), cytokinesis-block micronucleus and alkaline single-cell gel electrophoresis (comet) assays in human lymphocytes in vitro and Ames Salmonella/microsome test. All tested extracts were not mutagenic in S. typhimurium strains TA98 and TA100 with and without metabolic activation and did not induce chromosome aberrations in human lymphocytes in vitro. Extract from G. officinalis was the only one, which induced significant increase in micronuclei, indicating possible aneugenic effect. All investigated plant extracts induced DNA damage evaluated by the comet assay, while B. officinalis and V. luteum extracts induced slight increase in SCE values. The determined variation in response might be due to the plant extract tested and donor susceptibility.

Chemical composition, cytotoxic effect and antimicrobial activity of Stachys koelzii Rech.f. essential oil against periodontal pathogen Prevotella intermedia

Prevotella intermedia is associated with periodontal diseases and endodontic infections. Periodontitis can be suppressed by utilizing the antiseptics, which target the infectious bacteria. The member of Stachys sp. has been used traditionally in the form of decoction or infusion for management of infectious diseases. The subject of this article was to evaluate the chemical composition, antimicrobial and cytotoxic effect of Stachys koelzii essential oil and its main components against Prevotella intermedia. GC-FID and GC-MS analysis were used to determine the chemical composition. The antimicrobial effects of S. koelzii essential oil was evaluated by micro-broth dilution assay. Time kill curve assays, leakage of cytoplasmic materials and anti-biofilm effects were determined. Its cytotoxic effect was evaluated by MTT assay. Essential oil with main components of α-pinene, trans-caryophyllene and 1,8-cineole inhibited P. intermedia with MIC and MBC values of 0.1 and 0.2 mg/mL. Its biofilm formation was higher than α-pinene, followed by trans-caryophyllene and 1,8-cineole. Essential oil and its main components increased the leakage of cytoplasmic components. Essential oil showed cytotoxic effect on HeLa cell lines with IC₅₀ 0.06 mg/mL. The cytotoxic effect of α-pinene on healthy cell lines was higher than essential oil. S. koelzii essential oil can be used in mouthwash formulations and its efficacy should be evaluated in large clinical studies.

Preparation of Colon-Targeted Acetylharpagide Tablets and its Release Properties in vivo and in vitro

Ethno Pharmacological Relevance: Acetylharpagide is a monomeric compound extracted from Ajuga decumbens, widely used for remedying infectious and inflammatory diseases in Southern China.

Aim of the Study: The present study designed and investigated the formulation of colon-targeted acetylharpagide tablets according to the dual controlled release mechanisms of time-delay and pH-sensitivity.

Materials and Methods: The core tablets of acetylharpagide were coated with the material used in time-delay systems such as ethyl cellulose and suitable channeling agent, followed by pH-dependent polymers, polyacrylic resin II and III in a combination of 1:4. Furthermore, the release and absorption performance of colon-targets tables were evaluated in vitro and in vivo. In the in vitro tests, the optimized formulation was not released in simulated gastric fluid in 2 h; the release was <5% at pH 6.8 simulated intestinal fluids for 4 h; the drug was completely released within 5 h at pH 7.6 simulated colon fluid. In the in vivo tests, pharmacokinetic characteristics of the colon-targeted tablets were investigated in dogs.

Results: The results indicated that the acetylharpagide tablets with the technology of colon-targeting caused delayed T_max, prolonged absorption time, lower C_max, and AUCINF_obs. Meanwhile, the apparent volume of distribution (Vz_F_bs) of the colon-target tablets was higher than the reference.

Conclusions: These results suggested that colon-targeted acetylharpagide tablets deliver the drug to the colon. The in vitro performance of colon-targeted acetylharpagide tablet was appropriately correlated with its performance in vivo.

Medicinal Plants of the Family Lamiaceae in Pain Therapy: A Review

Recently, numerous side effects of synthetic drugs have lead to using medicinal plants as a reliable source of new therapy. Pain is a global public health problem with a high impact on life quality and a huge economic implication, becoming one of the most important enemies in modern medicine. The medicinal use of plants as analgesic or antinociceptive drugs in traditional therapy is estimated to be about 80% of the world population. The Lamiaceae family, one of the most important herbal families, incorporates a wide variety of plants with biological and medical applications. In this study, the analgesic activity, possible active compounds of Lamiaceae genus, and also the possible mechanism of actions of these plants are presented. The data highlighted in this review paper provide valuable scientific information for the specific implications of Lamiaceae plants in pain modulation that might be used for isolation of potentially active compounds from some of these medicinal plants in future and formulation of commercial therapeutic agents.

Anti-inflammatory Activity of Melampyrum barbatum and Isolation of Iridoid and Flavonoid Compounds

Melampyrum barbatum Waldst. & Kit. ex Willd. (Scrophulariaceae) has been used in traditional medicine for the treatment of rheumatic complaints and different skin diseases. In the course of our study the anti-inflammatory activity of the aerial parts of M. barbatum was evaluated. A MeOH extract was prepared and consecutively partitioned with CHCl3, EtOAc and n-BuOH. The fractions were assayed in in vivo carrageenan-induced rat paw oedema model. The intraperitoneally administered n-BuOH phase exerted marked inhibitory effect (33.6 %, p < 0.01). Multistep chromatographic separation afforded mussaenoside and aucubine from n-BuOH fraction. Moreover, 8-epiloganin, loganic acid and mussaenoside were obtained from EtOAc fraction and apigenin, luteolin, benzoic acid and galactitol from CHCl3 fraction. These data validate the ethnomedicinal use of M. barbatum for the treatment of inflammatory diseases and reveal that iridoids and flavonoids could be responsible for the anti-inflammatory effect of this species.

Italian folk plant-based remedies to heal headache (XIX-XX century)

BACKGROUND

Headache has been recognized since antiquity. From the late nineteenth to the early to mid-twentieth century, Italian folk remedies to treat headache were documented in a vast corpus of literature sources.

AIM

The purpose of this paper is to bring to light the plant-based treatments utilized by Italian folk medicine to heal headache in an attempt to discuss these remedies from a modern pharmacological point of view. Moreover, we compare the medical applications described by Hippocrates, Pliny the Elder, Dioscorides, Galen and Serenus Sammonicus with those utilized by Italian folk medicine to check if they result from a sort of continuity of use by over two thousand years.

RESULTS

A detailed search of the scientific data banks such as Medline and Scopus was undertaken to uncover recent results concerning the anti-inflammatory, anti-nociceptive and analgesic activities of the plants. Fifty-eight (78.4%) plant-based remedies have shown in vivo, in vitro or in human trials a large spectrum of anti-inflammatory, anti-nociceptive and analgesic activities. Moreover, thirty-one of remedies (41.9%) were already included in the pharmacopoeia between the 5th century BC and the 2nd century AD.

CONCLUSION

Italian folk medicine could be a promising source of knowledge and could provide evidences for active principles that have not as of yet been fully used for their potential.

Reassessment of the polar fraction of Stachys alopecuros (L.) Benth. subsp. divulsa (Ten.) Grande (Lamiaceae) from the Monti Sibillini National Park: A potential source of bioactive compounds

BACKGROUND

The phytochemical analysis of Stachys alopecuros subsp. divulsa, an endemic Italian species, has been recently reported and has showed the presence of 8-O-acetylharpagide (2), harpagide (3), allobetonicoside (4), and 4¢-O-galactopyranosyl-teuhircoside (5). In this paper, an in deep study of its glycosidic fraction with the aim to widen the knowledge on its secondary metabolites content is reported.

MATERIALS AND METHODS

Chromatographic techniques were used for the isolation of constituents while spectroscopic and spectrometric techniques were applied for the structures elucidation.

RESULTS

Besides the known constituents, all of them reconfirmed, ajugoside (1), reptoside (6) and 6-O-acetyl-ajugol (7) were also identified among the iridoids while the phenolic components resulted to be chlorogenic acid (8), b-arbutin (9), verbascoside (10), and stachysoside A (11), instead.

CONCLUSION

The iridoid pattern of S. alopecuros subsp. divulsa has been expanded with the identification of not previously reported compounds as well as for the phenolic fraction. Except for the reconfirmed verbascoside (10), the other phenolic compounds were recognized for the first time in the studied species. The complete NMR assignment of compound (1) by means of bidimensional techniques is reported, and both the chemotaxonomic and pharmacological relevance of the isolated compounds is largely discussed.

Constituents of Melittis melissophyllum subsp. albida

In this paper, for the first time, we have reported the analysis of the polar fraction of Melittis melissophyllum subsp. albida, a species with ecological relevance which is also used in traditional medicine of Central-Southern Italy. Iridoid glucosides were mainly identified, together with verbascoside, an ubiquitous phenyl-ethanoid glycoside, with chemotaxonomic implications in Lamiales order. The majority of the isolated compounds is endowed with interesting bio-activities and may justify the traditional uses of this plant also from a chemical point of view. Several peculiarities were also recorded in the metabolic pattern of this subspecies, i.e. the presence of virginioside and geniposidic acid, two rare compounds in the Lamiaceae family. The presence of free cinnamic acid was an additional characteristic of this subspecies which showed a specific secondary metabolites content. These phytochemical peculiarities, together with the morphological differences showed by the subsp. albida in respect to the nominal species, may be a base for a reconsideration of the systematic of Melittis melissophyllum subsp. albida.

Discovery of Anti-inflammatory Ingredients in Chinese Herbal Formula Kouyanqing Granule based on Relevance Analysis between Chemical Characters and Biological Effects

Kouyanqing Granule (KYQG) is a traditional Chinese herbal formula composed of Flos lonicerae (FL), Radix scrophulariae (RS), Radix ophiopogonis (RO), Radix asparagi (RA), and Radix et rhizoma glycyrrhizae (RG). In contrast with the typical method of separating and then biologicalily testing the components individually, this study was designed to establish an approach in order to define the core bioactive ingredients of the anti-inflammatory effects of KYQG based on the relevance analysis between chemical characters and biological effects. Eleven KYQG samples with different ingredients were prepared by changing the ratios of the 5 herbs. Thirty-eight ingredients in KYQG were identified using Ultra-fast liquid chromatography-Diode array detector-Quadrupole-Time-of-flight-Tandem mass spectrometry (UFLC-DAD-Q-TOF-MS/MS) technology. Human oral keratinocytes (HOK) were cultured for 24 hours with 5% of Cigarette smoke extract (CSE) to induce inflammation stress. Interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumour necrosis factor-α (TNF-α) were evaluated after treatment with the eleven KYQG samples. Grey relational analysis(GRA), Pearson’s correlations (PCC), and partial least-squares (PLS) were utilized to evaluate the contribution of each ingredient. The results indicated that KYQG significantly reduced interleukin-1β, interleukin-6, interleukin-8, and tumour necrosis factor-α levels, in which lysine, γ-aminobutyric acid, chelidonic acid, tyrosine, harpagide, neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid, isoquercitrin, luteolin-7-o-glucoside, 3,4-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid, angoroside C, harpagoside, cinnamic acid, and ruscogenin play a vital role.

Radix Scrophulariae extracts (harpagoside) suppresses hypoxia-induced microglial activation and neurotoxicity

Background

Hypoxia could lead to microglia activation and inflammatory mediators’ overproduction. These inflammatory molecules could amplify the neuroinflammatory process and exacerbate neuronal injury. The aim of this study is to find out whether harpagoside could reduce hypoxia-induced microglia activation.

Methods

In this study, primary microglia cells harvested from neonatal ICR mice were activated by exposure to hypoxia (1 % O₂ for 3 h). Harpagoside had been shown to be no cytotoxicity on microglia cells by MTT assay. The scavenger effect of harpagoside on hypoxia-enhanced microglial cells proliferation, associated inflammatory genes expression (COX-II, IL-1β and IL-6 genes) and NO synthesis were also examined.

Results

Hypoxia enhances active proliferation of microglial cells, while harpagoside can scavenge this effect. We find that harpagoside could scavenge hypoxia-enhanced inflammatory genes expression (COX-2, IL-1β and IL-6 genes) and NO synthesis of microglial cells. Under 3 h’ hypoxic stimulation, the nuclear contents of p65 and hypoxia inducible factor-1α (HIF-1α) significantly increase, while the cytosol IκB-α content decreases; these effects can be reversed by 1 h’s pre-incubation of 10⁻⁸ M harpagoside. Harpagoside could decrease IκB-α protein phosphorylation and inhibit p65 protein translocation from the cytosol to the nucleus, thus suppress NF-κB activation and reduce the HIF-1α generation.

Conclusion

These results suggested that the anti-inflammatory mechanism of harpagoside might be associated with the NF-κB signaling pathway. Harpagoside protect against hypoxia-induced toxicity on microglial cells through HIF-α pathway.

Inhibitory effects of harpagoside on TNF-α-induced pro-inflammatory adipokine expression through PPAR-γ activation in 3T3-L1 adipocytes

Obesity is closely associated with increased production of pro-inflammatory adipokines, including interleukin (IL)-6, plasminogen activator inhibitor (PAI)-1, and adipose-tissue-derived monocyte chemoattractant protein (MCP)-1, which contribute to chronic and low-grade inflammation in adipose tissue. Harpagoside, a major iridoid glycoside present in devil's claw, has been reported to show anti-inflammatory activities by suppression of lipopolysaccharide (LPS)-induced production of inflammatory cytokines in murine macrophages. The present study is aimed to investigate the effects of harpagoside on both tumor necrosis factor (TNF)-α-induced inflammatory adipokine expression and its underlying signaling pathways in differentiated 3T3-L1 cells. Harpagoside significantly inhibited TNF-α-induced mRNA synthesis and protein production of the atherogenic adipokines including IL-6, PAI-1, and MCP-1. Further investigation of the molecular mechanism revealed that pretreatment with harpagoside activated peroxisome proliferator-activated receptor (PPAR)-γ. These findings suggest that the clinical application of medicinal plants which contain harpagoside may lead to a partial prevention of obesity-induced atherosclerosis by attenuating inflammatory responses.

Phytochemical composition of the essential oil of different populations of Stachys lavandulifolia Vahl

OBJECTIVE

To examine the chemical variability in inflorescences of wild populations of Stachys lavandulifolia Vahl (S. lavandulifolia) collected throughout two provinces (Isfahan and Chaharmahal va Bakhtiary), Southwest Iran.

METHODS

The essential oils of S. lavandulifolia Vahl from seven locations were obtained by hydro-distillation and analysed by gas chromatography and gas chromatography-mass spectrometry.

RESULTS

The results revealed that distinct differences in the content of compounds depending on region of sample collection. The main constituents of the essential oils were α-thujone (0.3%-32.3%), α-pinene (trace to 37.3%), myrcene (0.5%-15.9%), β-phellandrene (1.1%-37.9%), germacrene D (0.4%-11.3%), Δ-cadinene (trace to 11.6%) and 1, 4-methano-1 H-indene (trace to 10.1%).

CONCLUSIONS

The results of the present study indicated that essential oil components of S. lavandulifolia Vahl can be varied with genetic (ecotype), environmental conditions and geographic origin. In general, the essential oils of various populations of S. lavandulifolia Vahl were rich in monoterpenoids and sesquiterpenoids.

Pharmacological insight into the anti-inflammatory activity of sesquiterpene lactones from Neurolaena lobata (L.) R.Br. ex Cass

PURPOSE

Neurolaena lobata is a Caribbean medicinal plant used for the treatment of several conditions including inflammation. Recent data regarding potent anti-inflammatory activity of the plant and isolated sesquiterpene lactones raised our interest in further pharmacological studies. The present work aimed at providing a mechanistic insight into the anti-inflammatory activity of N. lobata and eight isolated sesquiterpene lactones, as well as a structure-activity relationship and in vivo anti-inflammatory data.

METHODS

The effect of the extract and its compounds on the generation of pro-inflammatory proteins was assessed in vitro in endothelial and monocytic cells by enzyme-linked immunosorbent assay. Their potential to modulate the expression of inflammatory genes was further studied at the mRNA level. In vivo anti-inflammatory activity of the chemically characterized extract was evaluated using carrageenan-induced paw edema model in rats.

RESULTS

The compounds and extract inhibited LPS- and TNF-α-induced upregulation of the pro-inflammatory molecules E-selectin and interleukin-8 in HUVECtert and THP-1 cells. LPS-induced elevation of mRNA encoding for E-selectin and interleukin-8 was also suppressed. Furthermore, the extract inhibited the development of acute inflammation in rats.

CONCLUSIONS

Sesquiterpene lactones from N. lobata interfered with the induction of inflammatory cell adhesion molecules and chemokines in cells stimulated with bacterial products and cytokines. Structure-activity analysis revealed the importance of the double bond at C-4-C-5 and C-2-C-3 and the acetyl group at C-9 for the anti-inflammatory activity. The effect was confirmed in vivo, which raises further interest in the therapeutic potential of the compounds for the treatment of inflammatory diseases.

Phytochemical and biological studies of Stachys species in relation to chemotaxonomy: a review

The genus Stachys is comprised of about 300 species spread throughout the world, hence representing one of the largest genera of the Lamiaceae. Several Stachys species have been exploited in traditional medicine as astringent, wound-healing, anti-diarrhoeal, anti-nephritic and anti-inflammatory agents. Moreover, antimicrobial, antioxidant and cytotoxic activities of some Stachys species are documented. Iridoids, flavonoids, phenolic acids and diterpenoids are reported as secondary metabolites of different species of this genus. The aim of the present review is to summarize and to highlight the recent advances in current knowledge on Stachys species and to compile reports of chemical constituents isolated from the genus Stachys over the past decades, together with their structural features, biological activities, and structure-activity relationships. Diversity of chemical constituents is discussed in relationship with current Stachys infrageneric taxonomy, classification and relationships with systematically close genera.

Harpagoside: from Kalahari Desert to pharmacy shelf

Harpagoside is an iridoid glycoside that was first isolated from Harpagophytum procumbens (devil's claw, Pedaliaceae), a medicinal plant in which it is the major constituent of the iridoid pool. Both the pure compound and devil's claw extracts have potent anti-rheumatic, anti-inflammatory and analgesic effects. According to the European Pharmacopoeia commercial devil's claw products should contain at least 1.2% harpagoside. However, the compound has also been isolated from several other plant species and in vitro plant culture systems. Recent advances in knowledge of harpagoside distribution, biosynthesis/accumulation and pharmacology are summarized in this review. We also discuss the possible synergism and/or antagonism between major constituents in harpagoside-containing phytopharmaceutical products. Finally, future perspectives for its potential application are highlighted.

Phytochemical analysis, biological evaluation and micromorphological study of Stachys alopecuros (L.) Benth. subsp. divulsa (Ten.) Grande endemic to central Apennines, Italy

Stachys alopecuros subsp. divulsa (Lamiaceae), a perennial herb endemic to central Italy growing on mountain pastures, was investigated for the first time for the content of secondary metabolites, for the micromorphology and histochemistry of glandular trichomes, and for the biological activity of the volatile oil, namely cytotoxic, antioxidant and antimicrobial. The plant showed the molecular pattern of iridoids, among which a new iridoid diglycoside (4'-O-β-D-galactopyranosyl-teuhircoside) was detected, together with a sterol glucoside and a phenylethanoid glycoside. The essential oil from the flowering aerial parts was characterized by a high proportion of sesquiterpene hydrocarbons (65.1%), with (E)-caryophyllene (33.2%) as the most abundant, while other main components were germacrene D (7.6%), α-humulene (6.4%) and the oxygenated cis-sesquisabinene hydrate (10.2%). Taken together, polar and apolar chemical profiles support the classification of the species within the section Betonica of the genus Stachys. Micromorphological study revealed three types of glandular hairs secreting different classes of compounds, with type A peltate hairs producing the bulk of the essential oil. MTT assay revealed the potential of the volatile oil in inhibiting A375, HCT116 and MDA-MB 231 tumor cells (IC₅₀ values below 20 μg/ml).

Evaluation of Verbascum species and harpagoside in models of acute and chronic inflammation

Verbascum species are widely used in folk medicine because of their broad range of biological activities. Harpagoside, an iridoid glycoside isolated from some Verbascum plants is known for its anti-inflammatory properties. In the present study, the effect of five extracts of Verbascum species and harpagosides were evaluated in mouse models of acute and chronic inflammation. The results demonstrate that Verbascum phoeniceum extract strongly inhibits COX-1 (60.2% inhibition vs PMA-stimulated cells) and COX-2 (44.8% inhibition) expression stimulated peritoneal macrophages resulting in reduced paw swelling in carrageenan-induced oedema (55.5% inhibition vs PBS-treated mice). Harpagoside ameliorated the development of zymosaninduced arthritis and reduced pathological changes in joints as shown by the decreased histological score for cell infiltration in synovial cavity (3.5±0.2 in vs 2.0±0.16), cartilage loss (2.5±0.3 vs 1.8±0.5) and bone resorption (2.4±0.2 vs 1.8±0.4). Molecular docking simulations of harpagoside suggest that it may function with increased specific affinity towards COX-1 than COX-2. The potential of harpagoside to be applied as an effective agent for treating joint-related disorders is discussed.