Elsholtzia: A genus with antibacterial, antiviral, and anti-inflammatory advantages

Preparation of nanoemulsions from Elsholtzia kachinensis and Elsholtzia ciliata essential oils via ultrasonic homogenization and their antibacterial and anticancer activities

Plant essential oils can function as effective antibacterial and anticancer agents, but their low solubility and hydrophobic nature limit their practical applications. In this study, we report the preparation of nanoemulsions of Elsholtzia kachinensis and Elsholtzia ciliata via ultrasonic homogenization and the characterization of their antibacterial and anticancer activities for the first time. The product characteristics were evaluated based on turbidity, droplet size, polydispersion index, zeta potential and electrophoretic mobility. The activities were evaluated based on their ability to inhibit the growth of bacteria and HepG2 cancer cells. The Elsholtzia kachinensis and Elsholtzia ciliata nanoemulsions exhibited good stabilities, narrow size distributions with droplet sizes of 72.81 nm and 32.13 and zeta potentials of -27.8 mV and -11.2 mV, respectively. The Mulliken atomic charge analysis demonstrated that the E. kachinensis nanoemulsion had greater stability than the E. ciliata nanoemulsion. In vitro anti-bacterial studies using strains of Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, Bacillus subtilis and Staphylococcus epidermidis showed that both nanoemulsions exhibited higher growth inhibition efficiency than the respective essential oils. The inhibition efficiency of the Elsholtzia ciliata nanoemulsion against Bacillus subtilis and Staphylococcus epidermidis was 5 times higher than those of the corresponding essential oils. The HepG2 cell inhibition efficiency was about 80% for both nanoemulsions at a concentration of 500 μg mL-1, while the commercial essential oils inhibited only about 60% of HepG2 cells. Therefore, Elsholtzia kachinensis and Elsholtzia ciliata nanoemulsions can be potential candidates for modern biopharmaceuticals in the future.

Revisiting the backbone phylogeny and inferring the evolutionary trends in inflorescence of Elsholtzieae (Lamiaceae): new insights from orthologous nuclear genes

The angiosperm tribe of Elsholtzieae (Lamiaceae) is characterized by complex inflorescences and has notable medicinal and economic significance. Relationships within Elsholtzieae, including the monophyly of Elsholtzia and Keiskea, and relationships among Mosla, Keiskea and Perilla, remain uncertain, hindering insights into inflorescence evolution within the tribe. Using hybridization capture sequencing and deep genome skimming data analysis, we reconstruct a phylogeny of Elsholtzieae using 279 orthologous nuclear loci from 56 species. We evaluated uncertainty among relationships using concatenation, coalescent and network approaches. Using a time-calibrated phylogeny, we reconstructed ancestral inflorescence traits to elucidate the patterns in their evolution within the tribe. Our analyses consistently support the paraphyly of the genus Elsholtzia. Phylogenetic network analyses, confirmed by PhyloNetworks and SplitsTree, showed reticulation events among the major lineages of Elsholtzieae. The unstable polyphyly of Keiskea observed in ASTRAL (accurate species tree algorithm), ML (maximum likelihood) and MP (maximum parsimony) analyses may be related to introgression from Perilla and Mosla. Based on the analyses of phylogenetic trees within Elsholtzieae, the evolutionary trajectory of inflorescences demonstrates a pattern of diversification, with specialization as one aspect of this process. Elsholtzieae support the hypothesis that compressed inflorescences evolved from larger and more complex ancestral forms through successive compressions of the inflorescence axis. Additionally, certain lineages within the tribe display a trend towards simplified inflorescences, characterized by a reduction in the number of florets. This highlights both the specialization and the diversity in the evolution of inflorescence structures within the tribe.

Harnessing the Phytochemistry Through Pesticidal Potential of Diverse Elsholtzia Species: A Path to Sustainable Agriculture

This study investigates the phytochemical profiles and pesticidal activities of various Elsholtzia species, including E. ciliata, E. flava, E. fruticosa, and E. eriostachya, to discover their bioactive potential for sustainable pest management. Through comparative phytochemical analysis using GC-MS technique, key compounds in the essential oils were identified. The major components were thymoquinone (44.97 %) in E. ciliata, shisofuran (28.66 %) in E. flava, perillene (50.88 %) in E. fruticosa, and pinocarvone (42.41 %) in E. eriostachya. Despite variability in chemical composition, all species primarily contained oxygenated monoterpenes. The bioactivity of the oils was evaluated for their nematicidal and herbicidal bioassays. E. ciliata showed the highest egg hatching inhibition and juvenile mortality of M. incognita, while E. flava exhibited the lowest activity. For herbicidal activity, E. eriostachya achieved 96.70 % seed germination inhibition, 100 % root growth inhibition, and 95.56 % shoot growth inhibition. E. flava showed the lowest inhibition in germination, root length, and shoot length at 66.70 %, 81.56 %, and 85.28 %, respectively. The findings revealed significant variations in phytochemical composition and pesticidal efficacy, emphasizing the importance of species selection for pest management. This research highlights the bioactive potential of Elsholtzia species in sustainable pest management strategies.

Inhibitory Activity of Glycosides from Elsholtzia ciliata against Soluble Epoxide Hydrolase and Cytokines in RAW264.7 Cells

Soluble epoxide hydrolase (sEH) and pro-inflammatory cytokines are associated with the development of inhibitors for cardiovascular and inflammatory diseases. Here, we report on four natural sEH inhibitors isolated from the aerial parts of Elsholtzia ciliata (Thunb.) Hyl.. The four compounds, 1-4, were identified as luteolin-7-O-glucoside (1), yuanhuanin (2), apigenin-7-O-glucoside (3), and butein-4'-O-glucoside (4). Among them, compounds 2 and 4 are reported for the first time from this plant. In vitro and in silico, they showed inhibitory activity towards sEH at micromole concentrations. Moreover, they suppressed pro-inflammatory cytokines in polyinosinic:polycytidylic acid (poly(I:C))-stimulated RAW264.7 cells. Notably, 4 significantly downregulated the sEH catalytic reaction, NO and PGE2 production, and the expression levels of iNOS, COX-2, IL-6 mRNA, and sEH mRNA. Therefore, butein-4'-O-glucoside (4) is a potential sEH inhibitor that may be suitable for treating inflammation and cardiovascular diseases caused by infection.

Rapid characterization of non-volatile phenolic compounds reveals the reliable chemical markers for authentication of traditional Chinese medicine Xiang-ru among confusing Elsholtzia species

The aerial parts of Mosla chinensis Maxim. and Mosla chinensis cv. 'Jiangxiangru' (MCJ) are widely utilized in traditional Chinese medicine (TCM), known collectively as Xiang-ru. However, due to clinical effectiveness concerns and frequent misidentification, the original plants have increasingly been substituted by various species within the genera Elsholtzia and Mosla. The challenge in distinguishing between these genera arises from their similar morphological and metabolic profiles. To address this issue, our study introduced a rapid method for metabolic characterization, employing high-resolution mass spectrometry-based metabolomics. Through detailed biosynthetic and chemometric analyses, we pinpointed five phenolic compounds-salviaflaside, cynaroside, scutellarein-7-O-D-glucoside, rutin, and vicenin-2-among 203 identified compounds, as reliable chemical markers for distinguishing Xiang-ru from closely related Elsholtzia species. This methodology holds promise for broad application in the analysis of plant aerial parts, especially in verifying the authenticity of aromatic traditional medicinal plants. Our findings underscore the importance of non-volatile compounds as dependable chemical markers in the authentication process of aromatic traditional medicinal plants.

Antibacterial Ingredients and Modes of the Methanol-Phase Extract from the Fruit of Amomum villosum Lour

Epidemics of infectious diseases threaten human health and society stability. Pharmacophagous plants are rich in bioactive compounds that constitute a safe drug library for antimicrobial agents. In this study, we have deciphered for the first time antibacterial ingredients and modes of the methanol-phase extract (MPE) from the fruit of Amomum villosum Lour. The results have revealed that the antibacterial rate of the MPE was 63.64%, targeting 22 species of common pathogenic bacteria. The MPE was further purified by high performance liquid chromatography (Prep-HPLC), and three different constituents (Fractions 1-3) were obtained. Of these, the Fraction 2 treatment significantly increased the cell membrane fluidity and permeability, reduced the cell surface hydrophobicity, and damaged the integrity of the cell structure, leading to the leakage of cellular macromolecules of Gram-positive and Gram-negative pathogens (p < 0.05). Eighty-nine compounds in Fraction 2 were identified by ultra HPLC-mass spectrometry (UHPLC-MS) analysis, among which 4-hydroxyphenylacetylglutamic acid accounted for the highest 30.89%, followed by lubiprostone (11.86%), miltirone (10.68%), and oleic acid (10.58%). Comparative transcriptomics analysis revealed significantly altered metabolic pathways in the representative pathogens treated by Fraction 2 (p < 0.05), indicating multiple antibacterial modes. Overall, this study first demonstrates the antibacterial activity of the MPE from the fruit of A. villosum Lour., and should be useful for its application in the medicinal and food preservative industries against common pathogens.

Acute and Sub-Chronic Intraperitoneal Toxicity Studies of the Elsholtzia ciliata Herbal Extract in Balb/c Mice

Elsholtzia ciliata essential oil (E. ciliata) has been reported to have an impact on the cardiovascular system. However, its toxicity remains unknown. Therefore, the objective of this investigation was to evaluate the toxicological aspects of the E. ciliata extract. Male Balb/c mice were subjected to either acute (a single dose administered for 24 h) or sub-chronic (daily dose for 60 days) intraperitoneal injections of the E. ciliata extract. The mice were assessed for blood hematological/biochemical profiles, mitochondrial functions, and histopathological changes. Additionally, in vitro cytotoxicity assessments of the E. ciliata extract were performed on immobilized primate kidney cells (MARC-145, Vero) and rat liver cells (WBF344) to evaluate cell viability. The control groups received an equivalent volume of olive oil or saline. Our results demonstrated no significant detrimental effects on hematological and biochemical parameters, mitochondrial functions, cellular cytotoxicity, or pathological alterations in vital organs following the intraperitoneal administration of the E. ciliata extract over the 60-day sub-chronic toxicity study. In general, E. ciliata displayed no indications of toxicity, suggesting that the E. ciliata extract is a safe natural product with a well-defined therapeutic and protective index (found to be 90 and 54, respectively) in Balb/c mice.

Evaluation of the antibacterial activity of Elsholtzia ciliate essential oil against halitosis-related Fusobacterium nucleatum and Porphyromonas gingivalis

The broad-spectrum antimicrobial activity of Elsholtzia ciliate essential oil (ECO) has been previously reported, but its effectiveness against halitosis-causing bacteria such as Fusobacterium nucleatum and Porphyromonas gingivalis is not well understood. In this study, we investigated the bacteriostatic activity of ECO against planktonic cells and biofilms of F. nucleatum and P. gingivalis, as well as its ability to inhibit bacterial metabolism and production of volatile sulfur compounds (VSCs) at sub-lethal concentrations. Our findings revealed that ECO exhibited comparable activities to chlorhexidine against these oral bacteria. Treatment with ECO significantly reduced the production of VSCs, including hydrogen sulfide, dimethyl disulfide, and methanethiol, which are major contributors to bad breath. As the major chemical components of ECO, carvacrol, p-cymene, and phellandrene, were demonstrated in vitro inhibitory effects on F. nucleatum and P. gingivalis, and their combined use showed synergistic and additive effects, suggesting that the overall activity of ECO is derived from the cumulative or synergistic effect of multiple active components. ECO was found to have a destructive effect on the bacterial cell membrane by examining the cell morphology and permeability. Furthermore, the application of ECO induced significant changes in the bacterial composition of saliva-derived biofilm, resulting in the elimination of bacterial species that contribute to halitosis, including Fusobacterium, Porphyromonas, and Prevotella. These results provide experimental evidence for the potential clinical applications of ECOs in the prevention and treatment of halitosis.

The anti-leukemic activity of a luteolin-apigenin enriched fraction from an edible and ethnomedicinal plant, Elsholtzia stachyodes, is exerted through an ER stress/autophagy/cell cycle arrest/ apoptotic cell death signaling axis

BACKGROUND

Elsholtzia is a genus in the family Lamiaceae, and some species in this genus are commonly used for food and in ethnomedicinal formulations by some ethnic groups of China and Thailand. Despite their apparent utility, few studies have been conducted to evaluate their potential as sources of medicinally active agents.

PURPOSE

We aimed to investigate the cytotoxicity of ethanolic extracts from three selected edible plant species of the genus Elsholtzia and the most promising extract was further characterized for the bioactive constituents and signaling mechanisms associated with the anti-leukemic activity.

MATERIALS AND METHODS

Ethanolic extracts were screened for cytotoxicity using flow cytometry. HPLC and LC-MS were used to analyze the chemical constituents of the most potent fraction from E. stachyodes. The relevant mechanism of action was assessed by western blot and multispectral imaging flow cytometry (MIFC).

RESULTS

The most potent anti-leukemic activity was observed with the ethanolic extract from E. stachyodes. Luteolin and apigenin were characterized as the major constituents in the fraction from E. stachyodes. Mechanistically, the luteolin-apigenin enriched fraction (LAEF) induced the UPR, increased autophagic flux, induced cell cycle arrest and apoptotic cell death. LAEF showed significantly less cytotoxicity towards peripheral blood mononuclear cells (PBMCs) as compared to leukemia cell lines.

CONCLUSION

This study is the first to report E. stachyodes as a new source of luteolin and apigenin which are capable of triggering leukemic cell death. This could lead to a novel strategy against leukemia using ethnomedicinal plant extracts as an alternative or supplemental anti-cancer agent.

The complete chloroplast genome of Elsholtzia fruticosa (D. Don) Rehd. (Labiatae), an ornamental plant with high medicinal value

Elsholtzia fruticosa is an ornamental plant with high medicinal value. In this study, we sequenced and analyzed the complete chloroplast (cp) genome of the species. The complete cp sequence is 151,550 bp, including the large single-copy (LSC) region of 82,778 bp, the small single-copy (SSC) region of 17,492 bp, and a pair of invert repeats (IRs) regions of 25,640 bp. It encodes 132 unique genes in total, including 87 protein-coding genes, 37 transfer RNA genes (tRNAs), and eight ribosomal RNA genes (rRNAs). The comparative analysis of complete cp genomes showed that the genomic structure and gene order of E. fruticosa cps were conserved. The sequences of rps15, rps19, ycf1, ycf3, ycf15, psbL, psaI, trnG-UCC, trnS-GCU, trnR-UCU, trnL-UAG, trnP-UG, and trnL-UAA serve as hotspots for developing the DNA barcoding of Elsholtzia species. There are 49 SSR loci in the cp genome of E. fruticosa, among which the repeat numbers of mononucleotide, dinucleotide, trinucleotide, tetranucleotide, and pentanucleotides SSR are 37, 9, 3, 0, and 0, respectively. A total of 50 repeats were detected, including 15 forward repeats, seven reverse repeats, 26 palindromic repeats, and two complementary repeats. Phylogenetic analysis based on the complete cp genome and protein-coding DNA sequences of 26 plants indicates that E. fruticosa has a dose relationship with E. splendens and E. byeonsanensis.