Chromatographic analysis, anti-proliferative and radical scavenging activity of Pinus wallichina essential oil growing in high altitude areas of Kashmir, India

Comparative Study of Essential Oils from Tunisian Pinus Halepensis Mill. by Hydrodistillation and Microwave-Assisted Processes: Chemical Composition and Antioxidant and Cytotoxic Potential against Prostate and Cervical Cancer Cells

Pinus halepensis Mill. is a Mediterranean aromatic plant largely used, in addition to its nutritional value, in traditional medicine as antiseptic, antifungal, antituberculotic, and antirheumatic. Thus, the objective of this work was to appraise the antioxidant and cytotoxic activity of the essential oil (EO) of P. halepensis from Tunisia on cancer cell cultures, along with chemical composition evaluation by GC-MS. To attain the best yield and also highest quality in extraction of the EOs, conventional hydrodistillation (HD) and novel microwave-assisted extraction (MAE) methods have been performed and compared. The antioxidant activity was evaluated through the inhibition of 2,2-diphenyl-1-picrylhydrazyl (DPPH)• radicals. The cytotoxic activity in prostate cancer cells (LNCaP and PC3) and cervical cancer cells (HeLa) of EO was evaluated by the MTT assay and effect on the cell cycle by flow cytometry analysis. A total of 38 and 37 components were identified from HD (HD-EO)- and MAE (MAE-EO)-extracted EOs, respectively, which were dominated by hydrocarbon compounds (HD-EO = 86.65%; MAE-EO = 77.36%), especially monoterpenes (HD-EO = 32.11%; MAE-EO = 21.55%) and sesquiterpenes (HD-EO = 44.29%; MAE-EO = 61.32%). Both extracted EOs showed significant antioxidant activity, as shown by the inhibition of DPPH• radicals [IC50 (HD-EO) = 4102.30 ± 159.73 μg mL-1 and IC50 (MAE-EO) = 3430.13 ± 78.46 μg mL-1]. Also, the EOs exhibited substantial (p < 0.001) antiproliferative activities with G0-G1 arrest on PC3, LNCaP, and HeLa cells by yielding very low IC50 values more conspicuous in MAE-EO with respective IC50 values of 25.70 ± 6.58, 14.97 ± 3.21, and 14.55 ± 2.30 μg mL-1. This finding points out for the first time that the EO of P. halepensis Mill. from Tunisia can be an effective natural antitumor agent with more pronounced activity when extracted with the MAE method that, after further in vivo studies, can be harnessed as a putative phytopharmaceutical for prostate and cervical cancer treatment.

Tumor-derived OBP2A promotes prostate cancer castration resistance

Androgen deprivation therapy (ADT) is a systemic therapy for advanced prostate cancer (PCa); although most patients initially respond to ADT, almost all cancers eventually develop castration-resistant PCa (CRPC). Currently, most research focuses on castration-resistant tumors, and the role of tumors in remission is almost completely ignored. Here, we report that odorant-binding protein (OBP2A) released from tumors in remission during ADT catches survival factors, such as CXCL15/IL8, to promote PCa cell androgen-independent growth and enhance the infiltration of myeloid-derived suppressor cells (MDSCs) into tumor microenvironment, leading to the emergence of castration resistance. OBP2A knockdown significantly inhibits CRPC and metastatic CRPC development and improves therapeutic efficacy of CTLA-4/PD-1 antibodies. Treatment with OBP2A-binding ligand α-pinene interrupts the function of OBP2A and suppresses CRPC development. Furthermore, α-pinene-conjugated doxorubicin/docetaxel can be specifically delivered to tumors, resulting in improved anticancer efficacy. Thus, our studies establish a novel concept for the emergence of PCa castration resistance and provide new therapeutic strategies for advanced PCa.

Cytotoxicity Effect of Constituents of Pinus taiwanensis Hayata Twigs on B16-F10 Melanoma Cells

Pinus taiwanensis Hayata (Pinaceae) is an endemic plant in Taiwan. According to the Chinese Materia Medica Grand Dictionary, the Pinus species is mainly used to relieve pain, and eliminate pus and toxicity. In this study, nineteen compounds were isolated from the ethyl acetate layer of the ethanolic extract of P. taiwanensis Hayata twigs using bioassay-guided fractionation, and their anti-melanoma effects were investigated through a B16-F10 mouse melanoma cell model. The structures of the purified compounds were identified by 2D-NMR, MS, and IR, including 1 triterpenoid, 9 diterpenoids, 2 lignans, 4 phenolics, 1 phenylpropanoid, 1 flavonoid, and 1 steroid. Among them, compound 3 was found to be a new diterpene. Some of the compounds (2, 5, 6, 17, 18) showed moderate cytotoxicity effects. On the other hand, the anti-melanoma effect was no better than that from the original ethyl acetate layer. We presumed it resulted from the synergistic effect, although further experimentation needs to be performed.

Pinus kesiya Royle ex Gordon induces apoptotic cell death in hepatocellular carcinoma HepG2 cell via intrinsic pathway by PARP and Topoisomerase I suppression

Pinus kesiya Royle ex Gordon (PK), widely found in Southeast Asia, has been traditionally used for the treatment of several illnesses. Our previous studies showed that PK was highly cytotoxicity against liver cancer cells. The detailed mechanism of anticancer action of 50% hydro-ethanolic extract of PK's twig was, therefore, investigated in hepatocellular carcinoma HepG2 cells. Cytotoxicity of PK was determined by using NR assay, followed by determination of the mode of cell death by flow cytometry. The apoptosis-inducing effect was determined based on caspases activity, mitochondria membrane potential change, and expression of proteins related to apoptosis by western blot. The biomolecular alteration in the PK-treated HepG2 cells was investigated by FTIR microspectroscopy. Inhibition of topoisomerase I enzyme was determined by using DNA relaxation assay. Results showed that PK displayed high selective cytotoxicity and induced apoptosis against HepG2. FTIR microspectroscopy indicated that PK altered major biomolecules in HepG2 different from melphalan (a positive control), indicating a different mechanism of anticancer action. PK induced apoptotic cell death through the intrinsic pathway by increasing caspases 9 and 3/7 activity, increasing Bax, and decreasing Bcl-2 expression leading to mitochondrial membrane potential changes. PK also inhibited Top I and PARP activity that triggered an intrinsic apoptotic pathway. The phytochemical test presented terpenoids (i.e., α-pinene confirmed by GC-MS), alkaloids, steroids, xanthone, reducing sugar, and saponin. α-Pinene exhibited low cytotoxicity against HepG2, therefore, several terpene derivatives may work synergistically for inducing apoptosis. Our data demonstrated that PK has the potential for further study with chemotherapeutic purposes.

Antioxidant Potential of Pine Needles: A Systematic Study on the Essential Oils and Extracts of 46 Species of the Genus Pinus

The antioxidant activity of the essential oils, as well as of the organic and hydroethanolic extracts, of the fresh needles of 54 pine taxa was evaluated using the peroxy-oxalate and luminol chemiluminescence assays. Among all evaluated essential oils, P. canariensis and P. attenuata displayed the highest levels of activity. P. contorta var. murrayana, followed by P. nigra var. caramanica, exhibited the highest antioxidant capacity among the organic extracts, while the most active hydroethanolic extract was that of P. nigra subsp. nigra. Based on the overall levels of activity, the latter taxon was selected for phytochemical analysis targeting the isolation of the bioactive constituents. As such, the organic extract of P. nigra subsp. nigra was subjected to chromatographic separations to yield 11 secondary metabolites (1-11) that were evaluated for their antioxidant activity. Nonetheless, the isolated compounds were found to be less active than the crude extract, thus suggesting the potential role of synergism.

Review on essential oils, chemical composition, extraction, and utilization of some conifers in Northwestern Himalayas

Essential oils (EOs) are regarded as alternative therapeutic agents for many diseases. In phytotherapy research areas, it is now well reported that conifers are the rich source of EOs. This review aims to update information on the biological sources and the best extraction processes of the significant constituents along with the traditional and therapeutic properties of the EOs from selected conifers of Himachal Pradesh, Northwestern Himalaya. In the present review, ten conifer species of high values have been selected. Results from several studies suggest that the conifers contain monoterpenes, sesquiterpenes, diterpenes, ketones, alcohols, and esters, which are used in medicines, food products, and cosmetics as well as other commercial and industrial products. Traditionally, the EOs from the conifers have been reported to be used against fever, cough, bronchitis, skin diseases, gastrointestinal disorders, and asthma. The pharmacological studies suggest that these EOs can be used as antirheumatic, antiseptic, antispasmodic, anticancer, anti-inflammatory, antitoxic, aphrodisiac, and astringent agents. It is, therefore, concluded that the EOs from the conifers might be one of the promising tools for the treatment of various diseases. Extensive research is required to ascertain the efficacy of the EOs from unstudied conifers.

Ethnobotany and Pharmacology of Pinus Species Growing Naturally in Indian Himalayas: A Plant Review

Pinus species are amongst the most commonly used medicinal plants in Indian Northwestern Himalayas. Nearly all parts of the plant especially needles are believed to possess medicinal and clinical values in traditional systems of medicine such as Ayurvedic, Unani or Homeopathic. They are used to heal numerous diseases, including afflictions of the skin, eyes, throats and ears. Various parts of the plant including needles are rich in biologically active compounds, such as thunbergol, 3-carene, cembrene, α-pinene, quercetin, xanthone, etc. The scientific data available for the biological potential of this plant and its constituents have been found to be scanty and also does not satisfy the basis of their age-old folklore and local uses. This review focuses on a detailed analysis of ethnopharmacognosical studies on the needles of different Pinus species growing naturally in northwestern region of Indian Himalayas including investigations and findings that have come up with a concrete view of the abilities of plant components for example phenolics, flavonoids, tannins and other constituents to treat oxidative, inflammatory and microbial responses. Careful evaluation of the data presented may be helpful for the researchers to discover and evaluate the specific chemical entities responsible for the traditional medicinal uses of P. roxburghii, P.wallichiana, P. merkusii, P.kesiya and P.thunbergii.

Daucosterol Inhibits the Proliferation, Migration, and Invasion of Hepatocellular Carcinoma Cells via Wnt/β-Catenin Signaling

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide. The purpose of this study was to determine the effects of daucosterol on HCC by investigating Wnt/β-catenin signaling. In this study, HepG2 and SMMC-7721 cells were treated with varying concentrations of daucosterol, and the corresponding inhibitory effects on HCC cells were examined via CCK-8 assays. Cell migration and invasion abilities were detected via transwell assays. β-Catenin and phospho (p)-β-catenin levels were analyzed via western blotting. Our results showed that daucosterol reduced the proliferation, migration, and invasion capacities of HCC cells in a concentration-dependent manner. In addition, daucosterol reduced the levels of β-catenin and p-β-catenin in HepG2 and SMMC-7721 cells. Furthermore, the Wnt signaling pathway inhibitor SB-216763 was used to treat HepG2 and SMMC-7721 cells with daucosterol. Our results showed that co-treatment with daucosterol and SB-216763 abolished the effects of daucosterol on cell inhibition ratios, cell migration, and cell invasion. These findings indicated that daucosterol inhibited cell migration and invasion in HCC cells via the Wnt/β-catenin signaling pathway. Therefore, our study highlights the use of daucosterol as a promising therapeutic strategy for HCC treatment.

General Toxicity and Antifungal Activity of a New Dental Gel with Essential Oil from Abies Sibirica L

Background

The aim of this study was to analyze the antifungal activity and the general toxicity of a new dental gel containing essential oil from the tree Abies sibirica L., which grows in the Republic of Kazakhstan.

Material/Methods

The essential oil from Abies sibirica L. was obtained by microwave heating method using the STARTE Microwave Extraction System. Adjutants used to prepare the oil were carbomer 974P, glycerin, polysorbate 80, xylitol, triethanolamine, and purified water, all allowed for medical usage. The antifungal activity of the essential oil was assessed by monitoring the optical density of Candida albicans in a microplate reader. The safety was determined by analyzing the acute and subacute toxicity.

Results

The essential oil obtained by the microwave heating method revealed a higher antifungal activity in comparison with the essential oil obtained by the steam distillation method. No obvious changes were detected in guinea pigs following cutaneous application of the gel. Enteral administration of the essential oil caused minimal functional and histological changes in mice after 4 weeks. The new harmless dental gel containing pine oil from Abies sibirica L. was provided for the purposes of this particular clinical research.

Conclusions

The high antifungal activity of the gel is the basis for more in-depth studies on its safety and pharmacological activity.

Daucosterol inhibits cancer cell proliferation by inducing autophagy through reactive oxygen species-dependent manner

AIMS

This study aims to evaluate the anti-cancer effect of daucosterol and explore its possible mechanism.

MAIN METHODS

MTT and colony formation assay were performed to determine the effect of daucosterol on cancer cell proliferation in vitro. H22 allograft model was used for the assessment of its anti-cancer activity in vivo. Intracellular generation of reactive oxygen species (ROS) was measured using DCFH-DA probe with flow cytometry system and a laser scanning confocal microscope. LC3 (microtubule-associated protein 1 light chain 3)-II conversion was monitored with immunofluorescence and immunoblotting to demonstrate daucosterol-induced autophagy.

KEY FINDINGS

We found that daucosterol inhibits the proliferation of human breast cancer cell line MCF-7 and gastric cancer cell lines MGC803, BGC823 and AGS in a dose-dependent manner. Furthermore, daucosterol inhibits murine hepatoma H22 cell growth in ICR mice. Daucosterol treatment induces intracellular ROS generation and autophagy, but not apoptotic cell death. Treatment with ROS scavenger GSH (reduced glutathione), NAC (N-acetyl-l-cysteine) or autophagy inhibitor 3-Methyladenine (3-MA) counteracted daucosterol-induced autophagy and growth inhibition in BGC823 and MCF-7 cancer cells.

SIGNIFICANCE

Daucosterol inhibits cancer cell proliferation by inducing autophagy through ROS-dependent manner and could be potentially developed as an anti-cancer agent.

Diversity, molecular phylogeny, and bioactive potential of fungal endophytes associated with the Himalayan blue pine (Pinus wallichiana)

In this study, we investigated the diversity of fungal endophytes associated with Pinus wallichiana from the Western Himalayas, with emphasis on comparison of endophytic communities harbored by the stem and needle tissues of the host and their antimicrobial potential. A total number of 130 isolates, comprising of 38 different genera, were recovered from 210 fragments of the plant. Among the isolated fungi, only a single isolate, Tritirachium oryzae, belonged to the Phylum Basidiomycota whereas the rest belonged to Ascomycota. Dothideomycetes was the dominant class with the highest isolation frequency of 49.2 %. The most frequent colonizers of the host were Alternaria spp., Pestalotiopsis spp., Preussia spp., and Sclerostagonospora spp. The diversity and species richness were higher in needle tissues than in the stems. Antimicrobial activities were displayed by extracts from a total number of 22 endophytes against one or more pathogens. Endophytes designated as P1N13 (Coniothyrium carteri), P2N8 (Thielavia subthermophila), P4S6b (Truncatella betulae), P7N10 (Cochliobolus australiensis), and P8S4 (Tritirachium oryzae) were highly active against Candida albicans. Broad spectrum antimicrobial activities were obtained with the extracts of P8-S4 (Tritirachium oryzae) and P5-N26 (Coniochaeta gigantospora) that were potentially active against the Gram-positive and Gram-negative bacteria as well as the fungal pathogen, Candida albicans. The most prominent antagonistic activity against fungal pathogens was shown by P8-S4 (Tritirachium oryzae), P5-N31a (Truncatella spadicea), and P5-N20 (Fusarium larvarum). Our findings indicate that Pinus wallichiana harbors a rich endophytic fungal community with potential antimicrobial activities. Further studies are needed to understand the ecology and evolutionary context of the associations between the Himalayan pine and its endophytes.

Anti-proliferative and apoptotic activities of constituents of chloroform extract of Juglans regia leaves

OBJECTIVES

To evaluate anti-proliferative as well as apoptotic activities of compounds identified in chloroform extract of Juglans regia leaves, on human breast and oral cancer cell lines (MCF-7 and BHY).

MATERIALS AND METHODS

Column chromatography, MTT assay, flowcytometry and western blotting have all been used in the study.

RESULTS

Bioassay-guided fractionation of chloroform extract of J. regia afforded isolation of 5-hydroxy-3,7,4'-trimethoxyflavone [1], lupeol [2], daucosterol [3], 4-hydroxy-α-tetralone [4], β-sitosterol [5], 5,7- dihydroxy-3,4'-dimethoxyflavone [6] and regiolone [7]. Structures of the compounds were established on the basis of spectroscopic analyses [Nuclear magnetic resonance (NMR) and mass]. All compounds inhibited proliferation of MCF-7 (human breast adenocarcinoma) and BHY (human oral squamous carcinoma) cells in a concentration-dependent manner. Compounds 6 and 7 had potent cytotoxic effects on both MCF-7 and BHY cells (IC50 21-51 μm), yet were not toxic to normal cells. MCF-7 growth inhibition was attributed to apoptosis; population of apoptotic cells increased from 1.12% in controls to 5.64 and 8.1% after 48-h treatment with compounds 6 and 7, indicating their potential at inducing early and late apoptosis. The caspase cascade was not activated, as indicated by only insignificant cleavage of caspase-3.

CONCLUSIONS

Our results suggest that compounds 6 and 7 can induce apoptosis in MCF-7 cells through the caspase-3 independent pathway.

Induction of apoptosis in human pancreatic MiaPaCa-2 cells through the loss of mitochondrial membrane potential (ΔΨm) by Gentiana kurroo root extract and LC-ESI-MS analysis of its principal constituents

The objective of the current study was to evaluate the methanolic root extract of Gentiana kurroo for antioxidant and antiproliferative activities as well as to study the effect of the extract on the induction of apoptosis in human pancreatic cancer cell line (MiaPaCa-2). The extract exerted significant antioxidant activity as verified by DPPH, hydroxyl radical, lipid peroxidation and protective oxidative DNA damage assays. The results were comparable to standard antioxidants like α-tocopherol, catechin and BHT used in such experiments. Antioxidant potential of G. kurroo may be attributed to the presence of high phenolic and flavonoid content (73±1.02 and 46±2.05 mg/g extract respectively). The anti-proliferative property of Gentiana kurroo root extract was determined by sulphorhodamine B (SRB) assay against Human colon cancer cell line (HCT-116), Lung carcinoma cell line (A-549), Pancreatic cancer cell line (MiaPaCa-2), Lung cancer cell line (HOP-62) and acute monocytic leukaemia cell line (THP-1). G. kurroo root extract inhibited cancer cell growth depending upon the cell line used and in a dose dependent manner. The extract induced potent apoptotic effects in MiaPaCa-2 cells. The population of apoptotic cells increased from 11.4% in case of control to 49.6% at 100 μg/ml of G. kurroo root extract. The extract also induced a remarkable decrease in mitochondrial membrane potential (ΔΨm) leading to apoptosis of cancer cells used. The main chemical constituents identified by the liquid chromatography-tandem mass spectrometry (LC-ESI-MSMS) were found to be iridoid glucosides (iridoids and secoiridoids), xanthones and flavonoids. Iridoid glucosides are the bitter principles of Gentiana species. Loganic acid, Sweroside, Swertiamarin, Gentiopicroside, Gentisin, Isogentisin, Gentioside, Norswertianolin, Swertianolin, 4″-O-β-D-glucosyl-6'-O-(4-O-β-D-glucosylcaffeoyl)-linearoside and Swertisin were the principal compounds present in the methanol root extract of G. kurroo.