Neuropathic pain is a chronic pain condition persisting past the presence of any noxious stimulus or inflammation. Zerumbone, of the Zingiber zerumbet ginger plant, has exhibited anti-allodynic and antihyperalgesic effects in a neuropathic pain animal model, amongst other pharmacological properties. This study was conducted to further elucidate the mechanisms underlying zerumbone's antineuropathic actions. Research on therapeutic agents involving cannabinoid (CB) and peroxisome proliferator-activated receptors (PPARs) is rising. These receptor systems have shown importance in causing a synergistic effect in suppressing nociceptive processing. Behavioural responses were assessed using the von Frey filament test (mechanical allodynia) and Hargreaves plantar test (thermal hyperalgesia), in chronic constriction injury (CCI) neuropathic pain mice. Antagonists SR141716 (CB1 receptor), SR144528 (CB2 receptor), GW6471 (PPARα receptor) and GW9662 (PPARγ receptor) were pre-administered before the zerumbone treatment. Our findings indicated the involvement of CB1, PPARα and PPARγ in zerumbone's action against mechanical allodynia, whereas only CB1 and PPARα were involved against thermal hyperalgesia. Molecular docking studies also suggest that zerumbone has a comparable and favourable binding affinity against the respective agonist on the CB and PPAR receptors studied. This finding will contribute to advance our knowledge on zerumbone and its significance in treating neuropathic pain.
Interleukin-6 is one of the factors affecting sensitivity to cytotoxic agents. Therefore, the current study was designed to investigate the role of IL-6 and IL6 receptors in the cytotoxic effects of zerumbone in ovarian and cervical cancer cell lines (Caov-3 and HeLa, respectively). Exposure of both cancer cells to zerumbone or cisplatin demonstrated growth inhibition at a dose-dependent manner as determined by the MTT (3-[4,5-dimethylthiazol-2-yl]-2,Sdiphenyltetrazolium bromide) reduction assay. Both laser scanning confocal microscopy and TUNEL assay showed typical apoptotic features in treated cells. The studies conducted seems to suggest that zerumbone induces cell death by stimulating apoptosis better than cisplatin, based on the significantly higher percentage of apoptotic cells in zerumbone's treated cancer cells as compared to cisplatin. In addition, zerumbone and cisplatin arrest cancer cells at G2/M phase as analyzed by flow cytometry. Our results indicated that zerumbone significantly decreased the levels of IL-6 secreted by both cancer cells. In contrast, HeLa and Caov-3 cells were still sensitive to cisplatin and zerumbone, even in the presence of exogenous IL-6. However, membrane-bound IL-6 receptor is still intact after zerumbone treatment as demonstrated using an immune-fluorescence technique. This study concludes that the compound, zerumbone inhibits both cancer cell growth through the induction of apoptosis, arrests cell cycle at G2/M phase and inhibits the secretion levels of IL-6 in both cancer cells. Therefore, zerumbone is a potential candidate as a useful chemotherapeutic agent in treating both cervical and ovarian cancers in future.
In this study, the immunomodulatory effects of zerumbone isolated from Zingiber zerumbet were investigated by evaluating the effects of this compound towards the lymphocytes proliferation (mice thymocytes, mice splenocytes and human human peripheral blood mononuclear cells, PBMC), cell cycle progression and cytokine (interleukin 2 and 12) induction. Lymphocyte proliferation assay showed that zerumbone was able to activate mice thymocytes, splenocytes and PBMC at dosage dependent pattern where the best concentration was 7.5 microg/ml. Flow cytometry analysis showed the highest population of PBMC entered into G2/M phase after treatment for 72 h with 7.5 microg/ml zerumbone. The production of human interleukin-2 and human interleukin-12 cytokines in culture supernatant from zerumbone activated lymphocytes was prominently upregulated at 24 hour and decreased from 48 h to 72 h. The above results indicate that zerumbone can be used as immunomodulatory agent which can react toward the immune cell cytokine production in dosage dependent pattern.
Curcuma purpurascens Bl., belonging to the Zingiberaceae family, is known as temu tis in Yogyakarta, Indonesia. In this study, the hydrodistilled dried ground rhizome oil was investigated for its chemical content and antiproliferative activity against selected human carcinoma cell lines (MCF7, Ca Ski, A549, HT29, and HCT116) and a normal human lung fibroblast cell line (MRC5). Results from GC-MS and GC-FID analysis of the rhizome oil of temu tis showed turmerone as the major component, followed by germacrone, ar-turmerone, germacrene-B, and curlone. The rhizome oil of temu tis exhibited strong cytotoxicity against HT29 cells (IC50 value of 4.9 ± 0.4 μg/mL), weak cytotoxicity against A549, Ca Ski, and HCT116 cells (with IC50 values of 46.3 ± 0.7, 32.5 ± 1.1, and 35.0 ± 0.3 μg/mL, resp.), and no inhibitory effect against MCF7 cells. It exhibited mild cytotoxicity against a noncancerous human lung fibroblast cell line (MRC5), with an IC50 value of 25.2 ± 2.7 μg/mL. This is the first report on the chemical composition of this rhizome's oil and its selective antiproliferative effect on HT29. The obtained data provided a basis for further investigation of the mode of cell death.
Treatment of drug resistant protozoa, bacteria, and viruses requires new drugs with alternative chemotypes. Such compounds could be found from Southeast Asian medicinal plants. The present study examines the cytotoxic, antileishmanial, and antiplasmodial effects of 11 ethnopharmacologically important plant species in Malaysia. Chloroform extracts were tested for their toxicity against MRC-5 cells and Leishmania donovani by MTT, and chloroquine-resistant Plasmodium falciparum K1 strain by Histidine-Rich Protein II ELISA assays. None of the extract tested was cytotoxic to MRC-5 cells. Extracts of Uvaria grandiflora, Chilocarpus costatus, Tabernaemontana peduncularis, and Leuconotis eugenifolius had good activities against L. donovani with IC50
Centratherum anthelminticum (L.) seeds (CA) is a well known medicinal herb in Indian sub-continent. We recently reported anti-oxidant property of chloroform fraction of Centratherum anthelminticum (L.) seeds (CACF) by inhibiting tumor necrosis factor-α (TNF-α)-induced growth of human breast cancer cells. However, the active compounds in CACF have not been investigated previously.
This study investigated the antinociceptive effects of zerumbone in chemical behavioural models of nociception in mice. Zerumbone given through intraperitoneal route (i.p.) produced dose-related antinociception when assessed on acetic acid-induced abdominal writhing test in mice. In addition, the i.p. administration of zerumbone exhibited significant inhibition of the neurogenic pain induced by intraplantar (i.pl.) injection of capsaicin and bradykinin. Likewise, zerumbone given by i.p. route reduced the nociception produced by i.pl. injection of glutamate and phorbol myristate acetate (PMA). The antinociception caused by zerumbone in the acetic acid test was significantly attenuated by i.p. pre-treatment of mice with l-arginine (nitric oxide precursor) and glibenclamide (ATP-sensitive K(+) channel inhibitor). However, the antinociception of zerumbone was enhanced by methylene blue (non-specific gyanylyl cyclase inhibitor). Together, these results indicate that zerumbone produces pronounced antinociception against chemical models of nociception in mice. It also strongly suggests that the l-arginine-nitric oxide-cGMP-PKC-K(+) ATP channel pathways, the TRPV1 and kinin B2 receptors play an important role in the zerumbone-induced antinociception.
Dysregulation of p27(Kip1) due to proteolysis that involves the ubiquitin ligase (SCF) complex with S-phase kinase-associated protein 2 (Skp2) as the substrate-recognition component (SCF(Skp2)) frequently results in tumorigenesis. In this report, we developed a high-throughput screening system to identify small-molecule inhibitors of p27(Kip1) degradation. This system was established by tagging Skp2 with fluorescent monomeric Azami Green (mAG) and CDK subunit 1 (Cks1) (mAGSkp2-Cks1) to bind to p27(Kip1) phosphopeptides. We identified two compounds that inhibited the interaction between mAGSkp2-Cks1 and p27(Kip1): linichlorin A and gentian violet. Further studies have shown that the compounds inhibit the ubiquitination of p27(Kip1) in vitro as well as p27(Kip1) degradation in HeLa cells. Notably, both compounds exhibited preferential antiproliferative activity against HeLa and tsFT210 cells compared with NIH3T3 cells and delayed the G1 phase progression in tsFT210 cells. Our approach indicates a potential strategy for restoring p27(Kip1) levels in human cancers.
Zerumbone (ZER), isolated mainly from the Zingiber zerumbet (Z. zerumbet) rhizomes was found to be effective against numerous inflammatory and immune disorders, however, the molecular and biochemical mechanisms underlying its anti-inflammatory and immunosuppressive properties have not been well studied. This study was carried out to examine the profound effects of ZER on inflammatory mediated MyD88-dependent NF-κB/MAPK/PI3K-Akt signaling pathways in LPS-stimulated U937 human macrophages. ZER significantly suppressed the up-regulation pro-inflammatory mediators, TNF-α, IL-1β, PGE2, and COX-2 protein in LPS-induced human macrophages. Moreover, ZER significantly downregulated the phosphorylation of NF-κB (p65), IκBα, and IKKα/β as well as restored the degradation of IκBα. ZER correspondingly showed remarkable attenuation of the expression of Akt, JNK, ERK, and p38 MAPKs phosphorylation in a concentration-dependent manner. ZER also diminished the expression of upstream signaling molecules TLR4 and MyD88, which are prerequisite for the NF-κB, MAPK and PI3K-Akt activation. Additionally, quantification of relative gene expression of TNF-α, IL-1β, and COX-2 indicated that, at a higher dose (50μM), ZER significantly downregulated the elevated mRNA transcription levels of the stated pro-inflammatory markers in LPS-stimulated U937 macrophages. The strong suppressive effects of ZER on the activation of inflammatory markers in the macrophages via MyD88-dependent NF-κB/MAPK/PI3K-Akt signaling pathways suggest that ZER can be a preventive and potent therapeutic candidate for the management of various inflammatory-mediated immune disorders.
The co-use of conventional drug and herbal medicines may lead to herb-drug interaction via modulation of drug-metabolizing enzymes (DMEs) by herbal constituents. UDP-glucuronosyltransferases (UGTs) catalyzing glucuronidation are the major metabolic enzymes of Phase II DMEs. The in vitro inhibitory effect of several herbal constituents on one of the most important UGT isoforms, UGT2B7, in human liver microsomes (HLM) and rat liver microsomes (RLM) was investigated. Zidovudine (ZDV) was used as the probe substrate to determine UGT2B7 activity. The intrinsic clearance (Vmax/Km) of ZDV in HLM is 1.65 µL/mg/min which is ten times greater than in RLM, which is 0.16 µL/mg/min. Andrographolide, kaempferol-3-rutinoside, mitragynine and zerumbone inhibited ZDV glucuronidation in HLM with IC50 values of 6.18 ± 1.27, 18.56 ± 8.62, 8.11 ± 4.48 and 4.57 ± 0.23 µM, respectively, hence, herb-drug interactions are possible if andrographolide, kaempferol-3-rutinoside, mitragynine and zerumbone are taken together with drugs that are highly metabolized by UGT2B7. Meanwhile, only mitragynine and zerumbone inhibited ZDV glucuronidation in RLM with IC50 values of 51.20 ± 5.95 μM and 8.14 ± 2.12 µM, respectively, indicating a difference between the human and rat microsomal model so caution must be exercised when extrapolating inhibitory metabolic data from rats to humans.
Zerumbone exhibited various biological properties including in vitro immunosuppressive effects. However, its modulatory activity on the immune responses in experimental animal model is largely unknown. This investigation was conducted to explore the effects of daily treatment of zerumbone (25, 50, and 100 mg/kg) isolated from Zingiber zerumbet rhizomes for 14 days on various cellular and humoral immune responses in Balb/C mice. For measurement of adaptive immunity, sheep red blood cells (sRBC) were used to immunize the mice on day 0 and orally fed with similar doses of zerumbone for 14 days. The effects of zerumbone on phagocytosis, nitric oxide (NO) release, myeloperoxidase (MPO) activity, proliferation of T and B cells, lymphocyte phenotyping, cytokines release in serum by activated T cells, delayed type hypersensitivity (DTH) and immunoglobulins production (IgG and IgM) were investigated. Zerumbone downregulated the engulfment of E. coli by peritoneal macrophages and the release of NO and MPO in a concentration-dependent manner. Zerumbone showed significant and concentration-dependent suppression of T and B lymphocytes proliferation and inhibition of the Th1 and Th2 cytokines release. At higher concentrations of zerumbone, the % expression of CD4+ and CD8+ in splenocytes was significantly inhibited. Zerumbone also concentration-dependently demonstrated strong suppression on sRBC-triggered swelling of mice paw in DTH. Substantial suppression of anti-sRBC immunoglobulins antibody titer was noted in immunized and zerumbone-treated mice in a concentration-dependent manner. The potent suppressive effects of zerumbone on the immune responses suggest that zerumbone can be a potential candidate for development of immunosuppressive agent.
COVID-19, caused by the SARS-CoV-2 outbreak, has resulted in a massive global health crisis. Bioactive molecules extracted or synthesized using starting material obtained from marine species, including griffithsin, plitidepsin and fingolimod are in clinical trials to evaluate their anti-SARS-CoV-2 and anti-HIV efficacies. The current review highlights the anti-SARS-CoV-2 potential of marine-derived phytochemicals explored using in silico, in vitro and in vivo models. The current literature suggests that these molecules have the potential to bind with various key drug targets of SARS-CoV-2. In addition, many of these agents have anti-inflammatory and immunomodulatory potentials and thus could play a role in the attenuation of COVID-19 complications. Overall, these agents may play a role in the management of COVID-19, but further preclinical and clinical studies are still required to establish their role in the mitigation of the current viral pandemic.
In this study the novel caryophyllene type sesquiterpene lactone (aspfalcolide) has been isolated from the leaves of Asparagus falcatus (Linn.) and characterized by IR, 1D NMR, 2D NMR, EI-MS, HR-ESI-MS and X-ray single crystal diffraction analysis. The aspfalcolide crystallizes in the orthorhombic space group P2(1)2(1)2(1) with a = 6.37360(10), b = 7.6890(2), c = 27.3281(6) Å, α = β = γ = 90(°) and Z = 4. One intermolecular O-H⋯O hydrogen bond enforces these natural molecules to form infinite chains through the crystal. Aspfalcolide was screened for its anti-angiogenic activity in human umbilical vein endothelial cells (HUVECs) and the result showed the remarkable inhibitory effect of aspfalcolide on the proliferation (IC(50) 1.82 μM), migration and tube formation of HUVECs.
Isoprenoids are a large, diverse group of secondary metabolites which has recently raised a renewed research interest due to genetic engineering advances, allowing specific isoprenoids to be produced and characterized in heterologous hosts. Many researches on metabolic engineering of heterologous hosts for increased isoprenoid production are focussed on Escherichia coli and yeasts. E. coli, as most prokaryotes, use the 2-C-methyl-d-erythritol-4-phosphate (MEP) pathway for isoprenoid production. Yeasts on the other hand, use the mevalonate pathway which is commonly found in eukaryotes. However, Lactococcus lactis is an attractive alternative host for heterologous isoprenoid production. Apart from being food-grade, this Gram-positive prokaryote uses the mevalonate pathway for isoprenoid production instead of the MEP pathway. Previous studies have shown that L. lactis is able to produce sesquiterpenes through heterologous expression of plant sesquiterpene synthases. In this work, we analysed the gene expression of the lactococcal mevalonate pathway through RT-qPCR to successfully engineer L. lactis as an efficient host for isoprenoid production. We then overexpressed the mvk gene singly or co-expressed with the mvaA gene as an attempt to increase β-sesquiphellandrene production in L. lactis. It was observed that co-expression of mvk with mvaA doubled the amount of β-sesquiphellandrene produced.
Polygonum minus is an aromatic plant, which contains high abundance of terpenoids, especially the sesquiterpenes C15H24. Sesquiterpenes were believed to contribute to the many useful biological properties in plants. This study aimed to functionally characterize a full length sesquiterpene synthase gene from P. minus. P. minus sesquiterpene synthase (PmSTS) has a complete open reading frame (ORF) of 1689 base pairs encoding a 562 amino acid protein. Similar to other sesquiterpene synthases, PmSTS has two large domains: the N-terminal domain and the C-terminal metal-binding domain. It also consists of three conserved motifs: the DDXXD, NSE/DTE, and RXR. A three-dimensional protein model for PmSTS built clearly distinguished the two main domains, where conserved motifs were highlighted. We also constructed a phylogenetic tree, which showed that PmSTS belongs to the angiosperm sesquiterpene synthase subfamily Tps-a. To examine the function of PmSTS, we expressed this gene in Arabidopsis thaliana. Two transgenic lines, designated as OE3 and OE7, were further characterized, both molecularly and functionally. The transgenic plants demonstrated smaller basal rosette leaves, shorter and fewer flowering stems, and fewer seeds compared to wild type plants. Gas chromatography-mass spectrometry analysis of the transgenic plants showed that PmSTS was responsible for the production of β -sesquiphellandrene.
Isoprenoids are a large and diverse group of metabolites with interesting properties such as flavour, fragrance and therapeutic properties. They are produced via two pathways, the mevalonate pathway or the 2-C-methyl-D-erythritol-4-phosphate (MEP) pathway. While plants are the richest source of isoprenoids, they are not the most efficient producers. Escherichia coli and yeasts have been extensively studied as heterologous hosts for plant isoprenoids production. In the current study, we describe the usage of the food grade Lactococcus lactis as a potential heterologous host for the production of sesquiterpenes from a local herbaceous Malaysian plant, Persicaria minor (synonym Polygonum minus). A sesquiterpene synthase gene from P. minor was successfully cloned and expressed in L. lactis. The expressed protein was identified to be a β-sesquiphellandrene synthase as it was demonstrated to be functional in producing β-sesquiphellandrene at 85.4% of the total sesquiterpenes produced based on in vitro enzymatic assays. The recombinant L. lactis strain developed in this study was also capable of producing β-sesquiphellandrene in vivo without exogenous substrates supplementation. In addition, overexpression of the strain's endogenous 3-hydroxy-3-methylglutaryl coenzyme-A reductase (HMGR), an established rate-limiting enzyme in the eukaryotic mevalonate pathway, increased the production level of β-sesquiphellandrene by 1.25-1.60 fold. The highest amount achieved was 33 nM at 2 h post-induction.
Zerumbone (ZER), a potential anticancer compound, isolated from the fresh rhizomes of Zingiber zerumbet. In this investigation, the cytotoxic properties of ZER were evaluated, on cancer cells of human cervix (HeLa), breast and ovary, and normal cells of Chinese Hamster ovary, using MTT assay. Apoptogenic effects of ZER on HeLa were studied using fluorescence microscopy (AO/PI double staining), scanning and transmission electron microscopy (SEM and TEM), and colorimetric assay of the apoptosis promoter enzyme, caspase-3. The results of MTT assay showed that ZER has less effect on normal cells compared to cancer cells. The lowest IC(50) of ZER was observed on HeLa cells. Cytological observations showed nuclear and chromatin condensation, cell shrinkage, multinucleation, abnormalities of mitochondrial cristae, membrane blebbing, holes, cytoplasmic extrusions and formation of apoptotic bodies as confirmed collectively by double staining of AO/PI, SEM and TEM. Statistical analysis (two-tailed t-test) of differential counting of 200 cells under fluorescence microscope revealed significant difference in apoptotic cells populations between treated and untreated HeLa cells. In addition, ZER has increased the cellular level of caspase-3 on the treated HeLa cells. It could be concluded that ZER was able to produce distinctive morphological features of cell death that corresponds to apoptosis.
Recent in vitro and in vivo studies have demonstrated that zerumbone (ZER) possesses anticancer properties. The main objective of this study was to examine the effectiveness of the combination of ZER and cisplatin (CIS) to treat cervical intraepithelial neoplasia (CIN) in vivo. Microculture tetrazolium assay and immunohistochemistry of proliferating cellular nuclear antigen were used to study the antitumor effect of ZER. Prenatally exposed female BALB/c mice were used as a model. The progenies with CIN were injected peritoneally with isotonic sodium chloride solution (positive control), CIS, ZER, and a combination of both compounds. All treated and untreated mice were humanely killed, and serum and cervix were obtained for interleukin 6 analysis and histopathologic studies using hematoxylin and eosin staining, respectively. Zerumbone has revealed an antitumor effect on human cervical cancer cells and downregulates immunoexpression of proliferating cellular nuclear antigen (P < 0.05). In vivo study indicates that ZER at 16 mg/kg and CIS at 10 mg/kg have a regressing effect on CIN. The combination of ZER and CIS also showed similar effectiveness in regressing CIN. Our results indicate that the combination of ZER and CIS has modulated the serum level of interleukin 6 when compared with that in mice treated with isotonic sodium chloride solution (P < 0.05). The effectiveness of combining ZER and CIS could be further explored as a new therapeutic intervention of early precancerous stages of carcinogenesis before the invasive stage begins.
A series of 21 compounds isolated from Curcuma zedoaria was subjected to cytotoxicity test against MCF7; Ca Ski; PC3 and HT-29 cancer cell lines; and a normal HUVEC cell line. To rationalize the structure-activity relationships of the isolated compounds; a set of electronic; steric and hydrophobic descriptors were calculated using density functional theory (DFT) method. Statistical analyses were carried out using simple and multiple linear regressions (SLR; MLR); principal component analysis (PCA); and hierarchical cluster analysis (HCA). SLR analyses showed that the cytotoxicity of the isolated compounds against a given cell line depend on certain descriptors; and the corresponding correlation coefficients (R2) vary from 0%-55%. MLR results revealed that the best models can be achieved with a limited number of specific descriptors applicable for compounds having a similar basic skeleton. Based on PCA; HCA and MLR analyses; active compounds were classified into subgroups; which was in agreement with the cell based cytotoxicity assay.
Drug metabolism involving cytochrome P450 (CYP) enzymes is a key determinant of significant drug interactions. Deoxyelephantopin was evaluated for its effects on the expression of mRNAs encoding CYP1A2, CYP2D6 and CYP3A4, and protein expression and resultant enzymatic activity. The mRNA and protein expression of cytochrome isoforms were carried out using an optimized multiplex qRT-PCR assay and Western blot analysis, respectively. Human CYP3A4 protein expression was determined using an optimized hCYP3A4-HepG2 cell-based assay and the enzymatic activity was evaluated using P450-Glo™ CYP3A4 assay. The molecular interaction and possible inhibition of deoxyelephantopin of the CYP3A4 enzyme was determined in silico and further validated using substrate-specific CYP3A4 inhibition assays. Deoxyelephantopin produced no significant effect on the CYP1A2 and CYP2D6 mRNA and protein expression. However, it has a weak induction effect on CYP3A4 at the transcriptional level. In silico docking simulation showed that deoxyelephantopin has a weak interaction with CYP3A4 enzyme and it minimally affects the metabolism of CYP3A4 substrates. Deoxyelephantopin is not an in vitro CYP1A2 and CYP2D6 inducer. It is both a weak in vitro CYP3A4 inducer and inhibitor and is unlikely to elicit a clinically significant effect in human.