Localisation of Two Bioactive Labdane Diterpenoids in the Peltate Glandular Trichomes of Leonurus japonicus by Laser Microdissection Coupled with UPLC-MS/MS

Chain electrospray ionization mass spectrometry for ultra-low volume sample analysis

In this work, chain electrospray ionization (chain-ESI) was developed to efficiently ionize trace samples for mass spectrometry analysis. The primary ion source was found to have the ability to induce secondary electrospray ionization with an extraordinarily low sample consumption rate in the picoliters per minute (pLs/min). This allows low volume sample to generate substantial tandem mass spectrum (MS2) data for metabolite annotations. Notably, chain-ESI can effectively prevent the electro-redox reaction in the process of electrospray, so as to reflect the native state of the analytes. Furthermore, from a single Broussonetia papyrifera (B. papyrifera) trichome and a single A549 cancer cell, 1426 and 617 metabolites were detected respectively. All of those observations demonstrated that chain-ESI offers the advantages of direct, rapid analysis with extreme-low volumes and high coverage, enabling the measurement of bio-information in low volume samples.

Defensive furofuran lignans localized to the oil cells of Neocinnamomum delavayi and their metabolism by a specialist insect

Neocinnamomum delavayi (Lauraceae) leaves with abundant oil cells are seldom attacked by insects, but their chemical constituent and biological function remain obscure. Three furofuran lignans, including (+)-eudesmin (3), (+)-magnolin (4), and demethoxyaschantin (5), were identified to be the major specialized metabolites in the oil cells of N. delavayi leaves through laser microdissection coupled with NMR analysis. Compounds 3 and 4 exhibited obvious antifeedant activity against a generalist insect Spodoptera exigua, and their natural contents in the leaves could effectively defend against generalist insects. Intriguingly, three specific metabolites 9-11, the O-demethylation derivates of compounds 3-5, were identified from a native specialist insect Dindica polyphaenaria feeding with N. delavayi leaves, implying an adaptation mechanism of specialist insects to plant defensive compounds. The results revealed a chemical connection between plants and insects, which would contribute to our understanding of plant-insect interaction and insect management.

Micromorphology and Histology of the Secretory Apparatus of Diospyros villosa (L.) de Winter Leaves and Stem Bark

Diospyros villosa is a perennial species prominently acknowledged for its local medicinal applications. The native utilisation of this species in traditional medicine may be ascribed to the presence of secretory structures and their exudate (comprised of phytochemicals). However, the morphological nature and optical features of the secretory structures in D. villosa remain largely unclear. This study was directed to ascertain the occurrence and adaptive features of structures found within the leaves and stem bark of D. villosa using light and electron microscopy techniques. The current study notes the existence of trichomes, and other secretory structures were noted. SEM indicated the presence of non-glandular hirsute trichomes with bulky stalk on both leaves and stem surfaces. Transverse stem sections revealed the existence of crystal idioblasts. Moreover, the presence of the main phytochemical groups and their localisation within the foliage and stem bark was elucidated through various histochemical tests. The trichomal length and density were also assessed in leaves at different stages of development. The results indicated that the trichomal density at different stages of development of the D. villosa leaves and stem bark was not significantly different from one another, F_(3,39) = 1.183, p = 0.3297. The average length of the non-glandular trichomes in the emergent, young and mature leaves, as well as in the stem, was recorded to be 230 ± 30.6 µm, 246 ± 40.32 μm, 193 ± 27.55 µm and 164 ± 18.62 µm, respectively. The perimeter and circumference of the observed trichomes in the developmental stages of D. villosa leaf and the stem bark were not statistically different, F_(3,39) = 1.092, p = 0.3615. The results of histochemical tests showed the existence of phenols alkaloids, which are medicinally important and beneficial for treatment of diseases. The findings of this study, being reported for the first time may be considered in establishing microscopic and pharmacognostic measure for future identification and verification of natural herbal plant. Trichomal micromorphology and histological evaluations could be utilised as a tool for appropriate description for the assessment of this species.

Immunomodulatory and antitumour bioactive labdane diterpenoids from Leonurus japonicus

OBJECTIVES

Two labdane diterpenoids, leojapone B and heteronone B, were isolated from Leonurus japonicus Houtt., and their biological activity were evaluated in this study.

METHODS

Human and mouse cancer cells, human peripheral blood mononuclear cells (PBMCs) and mouse macrophages (RAW264.7 cells) were used to evaluate the activity of leojapone B and heteronone B, while the in vivo effects of leojapone B were further examined in Lewis Lung Cancer tumour-bearing mice.

KEY FINDINGS

In vitro studies showed that leojapone B selectively inhibited the proliferation of lung cancer cells, and both leojapone B and heteronone B inhibited the production of pro-inflammatory cytokines in activated PBMCs. In tumour-bearing mice model, lung tumours were reduced in size in mice treated with intraperitoneal injections of leojapone B at 20 and 30 mg/kg for 14 days. The population ratio of CD4⁺ /CD8⁺ T cells in mouse spleens was found to be increased, while regulatory T cells were decreased after leojapone B treatment.

CONCLUSIONS

The inhibitory effects of leojapone B in mouse lung tumours were demonstrated for the first time in this study. The immunomodulatory activity of heteronone B were also demonstrated. Our findings indicated that both leojapone B and heteronone B may act as active components in L. japonicus.

Diterpenoids and Flavonoids from the Twigs of Cephalotaxus fortunei var. alpina

Three new diterpenoids (a cephalotane, an abietane and a 9(10→20)-abeo-abietane) and one new flavonoid, together with 11 known compounds, were isolated from the twigs of Cephalotaxus fortunei var. alpina. The new compounds were identified by comprehensive spectroscopic (including 1D and 2D-NMR and HR-ESI-MS) analysis. Anti-inflammatory, immunosuppressive and cytotoxic activities of three new compounds were evaluated. 3β,20-epoxyabieta-8,11,13-triene-3α,12-diol showed weak cytotoxicity against tumor cell lines NCI-H1975, HepG2, MCF-7, while fortalpinoid R and 3-acetonyl-3,5,7,4'-tetrahydroxy-2-methoxyflavanone were not active at 80 μM. None of these compounds showed anti-inflammatory and immunosuppressive activities.

Traditional Chinese patent medicine Zhixiong Capsule (ZXC) alleviated formed atherosclerotic plaque in rat thoracic artery and the mechanism investigation including blood-dissolved-component-based network pharmacology analysis and biochemical validation

ETHNOPHARMACOLOGICAL RELEVANCE

Chinese patent medicine Zhixiong Capsule (ZXC) is the equal mixture of the extract of leech, Ligusticum chuanxiong Hort., Salvia miltiorrhiza Bunge, Leonurus japonicus Houtt., and Pueraria lobate (Willd.) Ohwi, which have been long used against inflammation, hyperlipidemia or blood stasis. In our previous study, ZXC showed good efficacy in preventing atherosclerosis (AS) plaque formation in rabbits.

AIM OF THE STUDY

In actual clinic practice, patients are more likely to receive treatments after AS plaque formation. Therefore, the efficacy of ZXC on formed AS plaques and the underlying mechanisms were further investigated in this study.

MATERIALS AND METHODS

Simvastatin (positive control) and ZXC (420 mg/kg and 840 mg/kg) were administrated to rats which first received long-term high fat diet administration (12 weeks). The blood lipid profiles of rats were monitored during the whole experiment, and the thoracic arteries were collected at the end of experiment for AS assessment (18th week). The blood-dissolved ZXC components were determined using an UPLC-QTOF-MS method, and the attained components were then used for network pharmacology analysis to predict the key ZXC components and targets. At last, the predicted targets were validated by ELISA and western blot methods.

RESULTS

ZXC administration showed good blood lipid-lowering effect by significantly reduced LDL-C and TC levels in rats while significantly increased HDL-C level. Compared with model group, simvastatin, low- and high-dose of ZXC administration decreased the ratio of intimal area and medial area by 81.1%, 71.1% and 71.4%, respectively (p < 0.01), and significantly alleviated collagen deposition and mineralization in rat arteries. It was found by network pharmacology analysis that leech and four components (namely daidzein, 4-methylenemiltirone, isorhamnetin and 2-isopropyl-8-methylphenanthrene-3,4-dione) are vital components for the anti-AS efficacy of ZXC. Combing the results from biochemical validation, IL-4, IL-13, MAPK1, MAPK14, JUN and P53 were confirmed as key targets of ZXC.

CONCLUSION

It could be concluded that ZXC has value as an anti-AS agent in clinical treatment against formed AS plaque at the current application dosage.

Non-volatile natural products in plant glandular trichomes: chemistry, biological activities and biosynthesis

The investigation methods, chemistry, bioactivities, and biosynthesis of non-volatile natural products involving 489 compounds in plant glandular trichomes are reviewed.

Agrobiotechnology Goes Wild: Ancient Local Varieties as Sources of Bioactives

The identification and use of species that have best adapted to their growth territory is of paramount importance to preserve biodiversity while promoting sustainable agricultural practices. Parameters including resistance to natural conditions (biotic and abiotic risk factors), biomass and fruit productivity, and phytochemical content with nutraceutical potential, could be used as quantitative markers of the adaptability of plants to wild environments characterized by minimal human impact. Ancient varieties, which are plant varieties growing in regional territories and not destined for market distribution, are a source of unique genetic characters derived from many years of adaptation to the original territory. These plants are often more resistant to biotic and abiotic stresses. In addition, these varieties have a high phytochemical (also known as bioactives) content considered health-beneficial. Notably, the content of these compounds is often lower in commercial cultivars. The use of selected territorial varieties according to the cultivation area represents an opportunity in the agricultural sector in terms of biodiversity preservation, environmental sustainability, and valorization of the final products. Our survey highlights the nutraceutical potential of ancient local varieties and stresses the importance of holistic studies (-omics) to investigate their physiology and secondary metabolism.