Potent anti-inflammatory activity of sesquiterpene lactones from Neurolaena lobata (L.) R. Br. ex Cass., a Q'eqchi' Maya traditional medicine

Isolation, Structure Determination of Sesquiterpenes from Neurolaena lobata and Their Antiproliferative, Cell Cycle Arrest-Inducing and Anti-Invasive Properties against Human Cervical Tumor Cells

Seven new germacranolides (1–3, 5–8), among them a heterodimer (7), and known germacranolide (4), eudesmane (9) and isodaucane (10) sesquiterpenes were isolated from the aerial parts of Neurolaena lobata. Their structures were determined by using a combination of different spectroscopic methods, including HR-ESIMS and 1D and 2D NMR techniques supported by DFT-NMR calculations. The enantiomeric purity of the new compounds was investigated by chiral HPLC analysis, while their absolute configurations were determined by TDDFT-ECD and OR calculations. Due to the conformationally flexible macrocycles and difficulties in assigning the relative configuration, ¹³C and ¹H NMR chemical shift and ECD and OR calculations were performed on several stereoisomers of two derivatives. The isolated compounds (1–10) were shown to have noteworthy antiproliferative activities against three human cervical tumor cell line with different HPV status (HeLa, SiHa and C33A). Additionally, lobatolide C (6) exhibited substantial antiproliferative properties, antimigratory effect, and it induced cell cycle disturbance in SiHa cells.

Natural Sesquiterpene Lactones in the Prevention and Treatment of Inflammatory Disorders and cancer: A Systematic Study of this Emerging Therapeutic Approach based on Chemical and Pharmacological Aspect

Background and Introduction:

Sesquiterpene lactones are a class of secondary metabolite that contains sesquiterpenoids and lactone ring as pharmacophore moiety. A large group of bioactive secondary metabolites such as phytopharmaceuticals belong to this category. From the Asteraceae family-based medicinal plants, more than 5,000 sesquiterpene lactones have been reported so far. Sesquiterpene lactone-based pharmacophore moieties hold promise for broad-spectrum biological activities against cancer, inflammation, parasitic, bacterial, fungal, viral infection and other functional disorders. Moreover, these moiety based phytocompounds have been highlighted with a new dimension in the natural drug discovery program worldwide after the 2015 Medicine Nobel Prize achieved by the Artemisinin researchers.

Objective:

These bitter substances often contain an α, β-unsaturated-γ-lactone as a major structural backbone, which in recent studies has been explored to be associated with anti-tumor, cytotoxic, and anti-inflammatory action. Recently, the use of sesquiterpene lactones as phytomedicine has been increased. This study will review the prospect of sesquiterpene lactones against inflammation and cancer.

Methods:

Hence, we emphasized on the different features of this moiety by incorporating its structural diversity on biological activities to explore structure-activity relationships (SAR) against inflammation and cancer.

Results:

How the dual mode of action such as anti-inflammatory and anti-cancer has been exhibitedby these phytopharmaceuticals will be forecasted in this study. Furthermore, the correlation of anti-inflammatory and anti-cancer activity executed by the sesquiterpene lactones for fruitful phytotherapy will also be revealed in the present review in the milieu of pharmacophore activity relation and pharmacodynamics study as well.

Conclusion:

So, these metabolites are paramount in phytopharmacological aspects. The present discussion on the future prospect of this moiety based on the reported literature could be a guide for anti-inflammatory and anti-cancer drug discovery programs for the upcoming researchers.

Traditional Herbal Medicine in Mesoamerica: Toward Its Evidence Base for Improving Universal Health Coverage

The quality of health care in Mesoamerica is influenced by its rich cultural diversity and characterized by social inequalities. Especially indigenous and rural communities confront diverse barriers to accessing formal health services, leading to often conflicting plurimedical systems. Fostering integrative medicine is a fundamental pillar for achieving universal health coverage (UHC) for marginalized populations. Recent developments toward health sovereignty in the region are concerned with assessing the role of traditional medicines, and particularly herbal medicines, to foster accessible and culturally pertinent healthcare provision models. In Mesoamerica, as in most regions of the world, a wealth of information on traditional and complementary medicine has been recorded. Yet these data are often scattered, making it difficult for policy makers to regulate and integrate traditionally used botanical products into primary health care. This critical review is based on a quantitative analysis of 28 survey papers focusing on the traditional use of botanical drugs in Mesoamerica used for the compilation of the "Mesoamerican Medicinal Plant Database" (MAMPDB), which includes a total of 12,537 use-records for 2188 plant taxa. Our approach presents a fundamental step toward UHC by presenting a pharmacological and toxicological review of the cross-culturally salient plant taxa and associated botanical drugs used in traditional medicine in Mesoamerica. Especially for native herbal drugs, data about safety and effectiveness are limited. Commonly used cross-culturally salient botanical drugs, which are considered safe but for which data on effectiveness is lacking constitute ideal candidates for treatment outcome studies.

Sesquiterpene lactones from Polydora serratuloides and their quorum sensing inhibitory activity

The leaves of Polydora serratuloides, with the synonym Vernonia perrottetii are widely used as purgative agents for gastrointestinal problems, and other members of Vernonieae have been used in African traditional medicine for decades. A new sesquiterpene lactone of the keto-hirsutinolide type, 13-acetoxy-1(4β),5(6)β-diepoxy-8α-(senecioyloxy)-3-oxo-1,7(11)-germacradiene-12,6-olide 1, was isolated from the hexane extract of its leaves, in addition to the known 13-acetoxy-1,4β-epoxy-8α-(senecioyloxy)-3-oxo-1,5,7(11)-germacratriene-12,6-olide 2. Three common flavonoids (apigenin 3, luteolin 4 and velutin 5) were also isolated. The antibacterial and quorum sensing inhibitory activities of compounds 1 and 2 and crudes extracts showed limited activity on Bacillus subtilis and Staphylococcus aureus, with no activity on Gram negative bacteria. However, quorum sensing (QSI) experiments indicated that 1 and 2, and the four crude extracts had interesting inhibitory activity on the biosensor organism, Chromobacterium violaceum ATCC 12472 in the range of 0.33-5.25 mg mL^-1, with compound 1 being the most effective at 0.33 mg mL^-1.

Medicinal plants used in the traditional management of diabetes and its sequelae in Central America: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Globally 387 million people currently have diabetes and it is projected that this condition will be the 7th leading cause of death worldwide by 2030. As of 2012, its total prevalence in Central America (8.5%) was greater than the prevalence in most Latin American countries and the population of this region widely use herbal medicine. The aim of this study is to review the medicinal plants used to treat diabetes and its sequelae in seven Central American countries: Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua and Panama.

MATERIALS AND METHODS

We conducted a literature review and extracted from primary sources the plant use reports in traditional remedies that matched one of the following disease categories: diabetes mellitus, kidney disease, urinary problems, skin diseases and infections, cardiovascular disease, sexual dysfunctions, visual loss, and nerve damage. Use reports were entered in a database and data were analysed in terms of the highest number of use reports for diabetes management and for the different sequelae. We also examined the scientific evidence that might support the local uses of the most reported species.

RESULTS

Out of 535 identified species used to manage diabetes and its sequelae, 104 species are used to manage diabetes and we found in vitro and in vivo preclinical experimental evidence of hypoglycaemic effect for 16 of the 20 species reported by at least two sources. However, only seven of these species are reported in more than 3 studies: Momordica charantia L., Neurolaena lobata (L.) R. Br. ex Cass., Tecoma stans (L.) Juss. ex Kunth, Persea americana Mill., Psidium guajava L., Anacardium occidentale L. and Hamelia patens Jacq. Several of the species that are used to manage diabetes in Central America are also used to treat conditions that may arise as its consequence such as kidney disease, urinary problems and skin conditions.

CONCLUSION

This review provides an overview of the medicinal plants used to manage diabetes and its sequelae in Central America and of the current scientific knowledge that might explain their traditional use. In Central America a large number of medicinal plants are used to treat this condition and its sequelae, although relatively few species are widely used across the region. For the species used to manage diabetes, there is variation in the availability and quality of pharmacological, chemical and clinical studies to explain traditional use.

Ethnomedical research and review of Q'eqchi Maya women's reproductive health in the Lake Izabal region of Guatemala: Past, present and future prospects

ETHNOPHARMACOLOGICAL RELEVANCE

In Central America, most Maya women use ethnomedicines for all aspects of their reproductive cycle including menstruation, pregnancy and menopause. However, very few of these plants have been documented, collected and tested in appropriate pharmacological assays to determine possible safety and efficacy. The aim of this work was to provide an overview of information on the ethnomedical uses, ethnopharmacology, chemistry and pharmacological research for medicinal plants used for women's reproductive health in Guatemala, with a special emphasis on the Q'eqchi Maya of the Lake Izabal region, to demonstrate therapeutic potential and support future research in the field.

MATERIALS AND METHODS

Reviews of the ethnobotanical, ethnomedical and ethnopharmacological literature were performed for 30 plants collected in the Lake Izabal region of Guatemala and used by the Q'eqchi Maya for treatment of reproductive health issues were performed up to and including July 2015 using multiple databases, library searches for abstracts, books, dissertations, and websites.

RESULTS AND CONCLUSIONS

Review of the published research confirms that many of the plants used by Q'eqchi Maya women for the management of reproductive health issues have pharmacological activities, including analgesic, anti-inflammatory, estrogenic, progestagenic and/or serotonergic effects, that support the use of these plants and provide plausible mechanisms of action for their traditional uses. Furthermore, a new serotonin agonist, 9, 10-methylenedioxy-5, 6-Z-fadyenolide was isolated, thereby demonstrating an untapped potential for drug discovery. However, to date much of the pharmacological assays have been in vitro only, and few in vivo studies have been performed. Considering the large percentage of the Maya population in Guatemala that use traditional medicines, there remains a significant lack of pharmacological and toxicological data for these plants. Future research should focus on the safety and efficacy of medicinal plants using in vivo preclinical studies and clinical trials, as well as chemical analysis. Since medicinal plants from the Piperaceae are most commonly used as traditional medicines by the Q'eqchi Maya women, and new bioactive compounds have been identified from Piper species, investigations of commonly used plants from this family would be an appropriate place to start. Data generated from such studies would contribute to Guatemala's national effort to promote a complementary relationship between traditional Maya medicine and public health services.

An ethnobotanical survey of medicinal plants in Trinidad

BACKGROUND

An ethnobotanical survey was conducted on the Caribbean island of Trinidad to identify medicinal plants commonly used in traditional medicine to treat a variety of medical conditions.

METHODS

A pilot survey was conducted to identify the top ten most common ailments where medicinal plants were used. The results of the foregoing study guided a wider national survey conducted between October 2007 and July 2008. A total of 450 households from 50 rural communities were interviewed using the TRAMIL (Traditional Medicine in the Islands) questionnaire for data collection. Details of plants, part(s) used, and remedy formulations were elicited from informants and voucher specimens collected for identification at the National Herbarium of Trinidad and Tobago. The TRAMIL methodology set a limit of a plant with 20 % or more citations for any particular ailment as having significant or popular use.

RESULTS

At the end of the survey 917 single plant remedies were identified. The majority of species were from the following families; Asteraceae, Lamiaceae, Leguminosae, Verbenaceae and Poaceae. Applying the TRAMIL 20 % citation of a plant for popular use as significant, Leonotis nepetifolia (for cough/common cold), Gomphrena globosa (for "stoppage-of-water"), Curcuma longa and Senna occidentalis (for "afterbirth"), Cymbopogon citratus and Neurolaena lobata (for fever), and Citrus limon (for kidney stones) qualified in our study. Those not reaching the TRAMIL 20 % significant (popular) use were Stachytarpheta jamaicensis (L.) Vahl, Senna alata (L.) Roxb.and Momordica charantia L. which were widely used as "'cooling/cleanser'" in our survey.

CONCLUSIONS

Our survey showed significant retention of traditional knowledge of medicinal plants in rural Trinidad. More interestingly, a large remnant of medico-cultural concepts such as "cooling/cleanser", "afterbirth", "stoppage-of-water" and "womb infection" persist in the rural population. Although the scientific literature show that some of the cited plants possessed antimicrobial, anti-inflammatory and related pharmacological activities in laboratory studies, these results must be taken with caution until clinical trials are conducted to establish safety and efficacy.

Design, synthesis and biological evaluation of novel sesquiterpene mustards as potential anticancer agents

Several novel series of sesquiterpene mustards (SMs) bearing nitrogen mustard and glutathione (GSH)-reactive α-methylene-γ-butyrolactone groups were successfully prepared for the first time and showed excellent antiproliferative activities in vitro. Among them, compounds 2e and 2g displayed the highest antiproliferative properties with IC50 values ranging from 2.5 to 8.7 μM. The selectivity of these two compounds was evaluated by SRB method against human cancer and normal hepatic cells (HepG2 and L02). The induction of apoptosis and effects on the cell cycle distribution with compounds 2e and 2g were investigated by Hoechst 33,258 staining and flow cytometry, which exhibited that they could induce selective cell apoptosis and cell cycle arrest in HepG2 and L02 cells. In addition, further investigation showed that compounds 2e and 2g could obviously inhibit the proliferation of HepG2 cells by inducing significant DNA cross-linking and depleting GSH in cell media. The good cytotoxicity and selectivity of compounds 2e and 2g pointed them as promising leads for anticancer drug design.

Lobatin B inhibits NPM/ALK and NF-κB attenuating anaplastic-large-cell-lymphomagenesis and lymphendothelial tumour intravasation

An apolar extract of the traditional medicinal plant Neurolaena lobata inhibited the expression of the NPM/ALK chimera, which is causal for the majority of anaplastic large cell lymphomas (ALCLs). Therefore, an active principle of the extract, the furanoheliangolide sesquiterpene lactone lobatin B, was isolated and tested regarding the inhibition of ALCL expansion and tumour cell intravasation through the lymphendothelium. ALCL cell lines, HL-60 cells and PBMCs were treated with plant compounds and the ALK inhibitor TAE-684 to measure mitochondrial activity, proliferation and cell cycle progression and to correlate the results with protein- and mRNA-expression of selected gene products. Several endpoints indicative for cell death were analysed after lobatin B treatment. Tumour cell intravasation through lymphendothelial monolayers was measured and potential causal mechanisms were investigated analysing NF-κB- and cytochrome P450 activity, and 12(S)-HETE production. Lobatin B inhibited the expression of NPM/ALK, JunB and PDGF-Rβ, and attenuated proliferation of ALCL cells by arresting them in late M phase. Mitochondrial activity remained largely unaffected upon lobatin B treatment. Nevertheless, caspase 3 became activated in ALCL cells. Also HL-60 cell proliferation was attenuated whereas PBMCs of healthy donors were not affected by lobatin B. Additionally, tumour cell intravasation, which partly depends on NF-κB, was significantly suppressed by lobatin B most likely due to its NF-κB-inhibitory property. Lobatin B, which was isolated from a plant used in ethnomedicine, targets malignant cells by at least two properties: I) inhibition of NPM/ALK, thereby providing high specificity in combating this most prevalent fusion protein occurring in ALCL; II) inhibition of NF-κB, thereby not affecting normal cells with low constitutive NF-κB activity. This property also inhibits tumour cell intravasation into the lymphatic system and may provide an option to manage this early step of metastatic progression.

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.

Sesquiterpenes from Neurolaena lobata and their antiproliferative and anti-inflammatory activities

Five new sesquiterpenes, neurolobatin A (1), neurolobatin B (2), 5β-hydroxy-8β-isovaleroyloxy-9α-hydroxycalyculatolide (3), 3-epi-desacetylisovaleroylheliangine (4), and 3β-acetoxy-8β-isovaleroyloxyreynosin (5), were isolated from the aerial parts of Neurolaena lobata. The structures were established by means of a combined spectroscopic data analysis, including ESIMS, APCI-MS, and 1D- and 2D-NMR techniques. Neurolobatin A (1) and B (2) are unusual isomeric seco-germacranolide sesquiterpenes with a bicyclic acetal moiety, compounds 3 and 4 are unsaturated epoxy-germacranolide esters, and compound 5 is the first eudesmanolide isolated from the genus Neurolaena. The isolated compounds (1-5) were shown to have noteworthy antiproliferative activities against human tumor cell lines (A2780, A431, HeLa, and MCF7). The anti-inflammatory effects of 1-5, evaluated in vitro using LPS- and TNF-α-induced IL-8 expression inhibitory assays, revealed that all these compounds strongly down-regulated the LPS-induced production of IL-8 protein, with neurolobatin B (2) and 3-epi-desacetylisovaleroylheliangine (4) being the most effective.

A perspective on natural products research and ethnopharmacology in Mexico: the eagle and the serpent on the prickly pear cactus

Mexico's extraordinarily rich cultural and floristic diversity has fascinated explorers and researchers ever since the "New World" was discovered for and by Europeans. For many decades, natural product research has been a very active field of research in Mexico, and there also are some ongoing ethnopharmacological research efforts. This review provides an overview and critical appraisal on some key developments in these fields and examples of medicinal plants used by indigenous communities that have become of great local importance in Mexican popular medicine. In this review, the focus is on plants with effects on the CNS, diabetes, metabolic syndrome, inflammatory processes, and gastrointestinal disorders. While some of the major food plants consumed worldwide originate from southern North America, only very few medicinal plants have become of major global importance. Opuntia species are now used increasingly to manage diabetes and metabolic syndrome and represent an example of a novel medicinal product/supplement. Undoubtedly, narcotic and mind-altering drugs both have received the widest scientific interest and have attracted considerable popular attention. The history of use of the indigenous Mexican Materia Medica in the context of research on local and popular resources specifically with regard to the diverse challenges in the context of studying the world's biodiversity and the development of comparative and semiquantitative ethnobotanical research methods is discussed herein. Natural product and ethnopharmacological research in Mexico seems to have been influenced by the political and societal developments originating from the Convention on Biological Diversity (CBD) and subsequent conventions, which have not yet had the desired effect of giving value to these local resources, as they might deserve. Their equitable and sustainable implementation remains a challenge. Natural product research and ethnopharmacology will play a key role in developing an adequate evidence base for such products derived from local and traditional knowledge in Mexico.