Chemical compositions of Litsea umbellata and inhibition activities

Litsea umbellata (Lour.) Merr. is a plant commonly grown in Vietnam and some Asian countries. The plant is used in traditional medicines and exhibits significant biological activities. However, the sesquiterpenes’ extraction in the essential oil (EO) of L. umbellata harvested from the northern region of Vietnam has been limitedly known. Therefore, in the present study, the L. umbellata leaves and stem EOs were obtained by hydrodistillation method, then determined for the phytochemical profile by using gas chromatography–mass spectrometry system, and investigated the cytotoxicity activities against five cancer cell lines. Results have identified a total of 21 and 26 compounds in the EOs of L. umbellata leaves and stem, respectively, with the main sesquiterpene compounds being β-caryophyllene (16.87–11.04%), (+)-spathulenol (9.74–6.57%), β-caryophyllene oxide (26.12–18.34%), and (−)-spatulenol (11.08–8.8%). L. umbellata leaves exhibit significant anti-cancer activity with IC50 values ranging from 29.58 to 62.96 µg/ml. Otherwise, L. umbellata EOs also exhibited the good inhibition activities against DPPH free radical and three bacteria strains. The chemical constituents and cytotoxicity activity of L. umbellata EO stems have been reported for the first time and provided the future applications of this plant.

Effects of Litsea cubeba Essential Oil Incorporated into Denture Soft Lining Materials

The antimicrobial properties, cell cytotoxicity and surface hardness of soft lining materials (GC soft liner, Viscogel and Coe comfort) incorporated with various concentrations of Litsea cubeba essential oil (LCEO) were evaluated. The minimum inhibitory concentrations of LCEO against Candida albicans and Streptococcus mutans were 1.25% v/v and 10% v/v, respectively. However, when LCEO was incorporated into the three soft lining materials (GC soft liner, Viscogel and Coe comfort), 10% v/v and 30% v/v of LCEO could inhibit the growth of C. albicans and S. mutans, respectively. The extracts of soft lining materials with 10% and 30% v/v LCEO, 2% chlorhexidine, 30% v/v nystatin and no additive were used for cytotoxicity tests on a human gingival fibroblast cell line. There was no significant difference in cell viability in all groups with additives compared to the no additive group (p > 0.05). Surface hardness increased significantly between 2 h and 7 day incubation times in all groups, including the controls (p < 0.05). A higher LCEO concentration had a dose-dependent effect on the surface hardness of all soft lining materials (p < 0.05). However, the surface hardness of materials with additive remained in accordance with ISO 10139-1. LCEO could be used as a natural product against oral pathogens, without having a negative impact on soft lining materials.

Review On Documented Medicinal Plants Used For The Treatment Of Cancer

Background:

Cancer is a frightful disease and it is the second leading cause of death worldwide. Naturally derived compounds are gaining interest of research workers as they have less toxic side effects as compared to currently used treatments such as chemotherapy. Plants are the pool of chemical compounds which provides a promising future for research on cancer.

Objective:

This review paper provides updated information gathered on medicinal plants and isolated phytoconstituents used as anticancer agents and summarises the plant extracts and their isolated chemical constituents exhibiting anticancer potential on clinical trials.

Methods:

An extensive bibliographic investigation was carried out by analysing worldwide established scientific databases like SCOPUS, PUBMED, SCIELO, ScienceDirect, Springerlink, Web of Science, Wiley, SciFinder and Google Scholar etc. In next few decades, herbal medicine may become a new epoch of medical system.

Results:

Many researches are going on medicinal plants for the treatment of cancer but it is a time to increase further experimental studies on plant extracts and their chemical constituents to find out their mechanism of action at molecular level.

Conclusion:

The article may help many researchers to start off further experimentation that might lead to the drugs for the cancer treatment.

Transcriptomic Analysis of Drug-Resistance Acinetobacter baumannii under the Stress Condition Caused by Litsea cubeba L. Essential Oil via RNA Sequencing

Litsea cubeba L. essential oil(LCEO) can affect the growth of drug-resistance bacteria. However, research on stress response of drug-resistant A. baumannii under sub-lethal LCEO concentrations had been limited so far. Therefore, transcriptomic analysisof A. baumannii under 1/2 minimum inhibitory concentration (MIC, 0.54 mg/mL) of LCEO was performed. Results of transcriptomic analysis showed that 320/352 genes were significantly up/down-regulated, respectively, in LCEO-treated A. baumannii. Both up and down-regulated genes were significantly enriched in three GO terms (oxidation-reduction process; oxidoreductase activity; oxidoreductase activity, acting on the CH-CH group of donors), which indicated that the redox state of A. baumannii was significantly affected by LCEO. LCEO may also inhibit aerobic respiration, synthesis of ketone bodies and the metabolism of some amino acids while, meanwhile, promoting fatty acid degradation of A. baumannii according to Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment. The permeability and the stress of cell membrane of A. baumannii were significantly affected by LCEO. After crystal violet dyeing, the biofilm formation of A. baumannii was promoted/inhibited by extremely low/relatively high concentration of LCEO, respectively. LCEO and chloramphenicol have synergistic growth inhibitory effect against A. baumannii according to the Fractional Inhibitory Concentration Index (FICI) value = 0.375. Our results indicate that the growth of A. baumannii was inhibited by LCEO, and give insights into the stress response of A. baumannii under sub-lethal concentrations of LCEO. These results provided evidence that A. baumannii was inhibited by LCEO, and expanded knowledges of stress response of A. baumannii under sub-lethal concentration of LCEO.

An Overview on Total Valorization of Litsea cubeba as a New Woody Oil Plant Resource toward a Zero-Waste Biorefinery

With the increasing global demand for edible oils and the restriction of arable land minimum in China, woody oil plants have gradually become the optimal solution to cover the shortage of current edible oil supply and to further improve the self-sufficiency rate. However, due to the lack of knowledge and technique, problems like “how to make full use of these plant resources?” and “how to guide consumers with reasonable data?” limit the development of woody oilseed industry towards a sustainable circular economy. In this review, several emerging unique woody oil plants in China were introduced, among which Litsea cubeba as a new woody oil plant was highlighted as a reference case based on its current research progress. Unlike other woody oil plants, essential oil rather than oil from Litsea cubeba has always been the main product through the years due to its interesting biological activities. Most importantly, its major component, citral, could be the base for other synthesized perfume compounds with added value. Moreover, the sustainable biorefinery of large amounts of waste residual after Litsea cubeba essential oil processing is now technically feasible, which could inspire a total valorization pathway for other woody oil plants to make more competitive plant-based products with both economic, social, and ecological benefits.

Litsea cubeba essential oil: chemical profile, antioxidant activity, cytotoxicity, effect against Fusarium verticillioides and fumonisins production

The purpose of this study was to determine the chemical profile of Litsea cubeba essential oil, carry out an in vitro evaluation of its antioxidant potential and its cytotoxicity, as well as its antifungal and antimicotoxigenic activities against Fusarium verticillioides. Most of the compounds observed in the EO were neral (32.75%) and geranial (37.67%). The radical scavenging capacity of 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid was 104.4 and 56.4 mmol Trolox mg^-1, respectively, indicating good antioxidant activity. The EO studied by us revealed cytotoxic effect against HT-29 and HeLa cancer cells. The Minimum Inhibitory and Minimum Fungicidal Concentrations against F. verticillioides were both 125 µg mL^-1. Morphological investigation, performed by fluorescence microscopy and scanning electron microscopy, showed that hyphae and microconidia structures underwent changes after treatment with the EO. Analyses performed with the EO strongly reduced the mycelial development of F. verticillioides and the synthesis of fumonisins B₁ and B₂ in dose-dependence effect compared (P < 0.01) with the fungal control (10⁵ conidia mL^-1) and positive control (fludioxonil + metalaxyl-M). Thus, the results obtained in vitro suggest that L. cubeba EO has excellent antioxidant, fungicidal, and antimycotoxigenic effects.

β-Cyclodextrin Inclusion Complex Containing Litsea cubeba Essential Oil: Preparation, Optimization, Physicochemical, and Antifungal Characterization

Litsea cubeba essential oil (LCEO), as naturally plant-derived products, possess good antimicrobial activities against many pathogens, but their high volatility and poor water solubility limit greatly the application in food industry. In this research, inclusion complex based on β-cyclodextrin (β-CD) and LCEO, was prepared by saturated aqueous solution method. An optimum condition using the response surface methodology (RSM) based on Box–Behnken design (BBD) was obtained with the inclusion time of 2 h and β-CD/LCEO ratio of 4.2 at 44 °C. Under the condition, the greatest yield of 71.71% with entrapment efficiency of 33.60% and loading capacity of 9.07% was achieved. In addition, the structure and characteristic of LCEO/β-CD inclusion complex (LCEO/βCD-IC) were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR), which indicated that LCEO/βCD-IC was successfully formed. The particle size of LCEO/βCD-IC was determined to be 17.852 μm. Thermal properties of LCEO/βCD-IC evaluated by thermogravimetric-differential scanning calorimetry (TG-DTA) illustrated better thermal stability of the aimed product compared with the physical mixture. Furthermore, the tests of antifungal activity showed that LCEO/βCD-IC was able to control the growth of Penicillium italicum, Penicillium digitatum, and Geotrichum citri-aurantii isolated from postharvest citrus. Our present study confirmed that LCEO/βCD-IC might be further applied as an alternative to chemical fungicides for protecting citrus fruit from postharvest disease.

Characterization of Endophytic Streptomyces griseorubens MPT42 and Assessment of Antimicrobial Synergistic Interactions of its Extract and Essential Oil from Host Plant Litsea cubeba

The present study aimed to evaluate the synergistic effects of the crude ethyl acetate extract (CEAE) from endophytic actinomycete MPT42 and essential oil (EO) of the same host plant Litsea cubeba. The isolate MPT42, exhibiting broad-spectrum antimicrobial activities and harboring all three antibiotic-related biosynthetic genes pks-I, pks-II, and nrps, was identified as Streptomycete griseorubens based on an analysis of the morphology, physiology, and 16S rDNA sequence. Minimum inhibitory concentrations (MICs) and the fractional inhibitory concentration index were used to estimate the synergistic effects of various combined ratios between CEAE or antibiotics (erythromycin, vancomycin) and EO toward 13 microbial strains including pathogens. L. cubeba fruit EO, showing the main chemical constituents of 36.0% citral, 29.6% carveol, and 20.5% limonene, revealed an active-low against tested microbes (MICs ≥ 600 μg/mL). The CEAE of S. griseorubens culture exhibited moderate–strong antimicrobial activities against microbes (MICs = 80–600 μg/mL). Analysis of the mechanism of action of EO on Escherichia coli ATCC 25922 found that bacterial cells were dead after 7 h of the EO treatment at 1 MIC (5.5 mg/mL), where 62% cells were permeabilized after 2 h and 3% of them were filament (length ≥ 6 μm). Combinations of CEAE, erythromycin, or vancomycin with EO led to significant synergistic antimicrobial effects against microbes with 4–16 fold reduction in MIC values when compared to their single use. Interestingly, the vancomycin–EO combinations exhibited a strong synergistic effect against five Gram-negative bacterial species. This could assume that the synergy was possibly due to increasing the cell membrane permeability by the EO acting on the bacterial cells, which allows the uptake and diffusion of antimicrobial substances inside the cell easily. These findings in the present study therefore propose a possible alternative to combat the emergence of multidrug-resistant microbes in veterinary and clinics.

Ethnopharmacological Properties and Medicinal Uses of Litsea cubeba

The genus Litsea is predominant in tropical and subtropical regions of India, China, Taiwan, and Japan. The plant possesses medicinal properties and has been traditionally used for curing various gastro-intestinal ailments (e.g., diarrhea, stomachache, indigestion, and gastroenteritis) along with diabetes, edema, cold, arthritis, asthma, and traumatic injury. Besides its medicinal properties, Litsea is known for its essential oil, which has protective action against several bacteria, possesses antioxidant and antiparasitic properties, exerts acute and genetic toxicity as well as cytotoxicity, and can even prevent several cancers. Here we summarize the ethnopharmacological properties, essentials oil, medicinal uses, and health benefits of an indigenous plant of northeast India, emphasizing the profound research to uplift the core and immense potential present in the conventional medicine of the country. This review is intended to provide insights into the gaps in our knowledge that need immediate focus on in-situ conservation strategies of Litsea due to its non-domesticated and dioecious nature, which may be the most viable approach and intense research for the long-term benefits of society and local peoples.