New Bisabolane-Type Sesquiterpenoids from Curcuma longa and Their Anti-Atherosclerotic Activity.

To explore the sesquiterpenoids in Curcuma longa L. and their activity related to anti-atherosclerosis. The chemical compounds of the rhizomes of C. longa were separated and purified by multiple chromatography techniques. Their structures were established by a variety of spectroscopic experiments. The absolute configurations were determined by comparing experimental and calculated NMR chemical shifts and electronic circular dichroism (ECD) spectra. Their anti-inflammatory effects and inhibitory activity against macrophage-derived foam cell formation were evaluated by lipopolysaccharide (LPS) and oxidized low-density lipoprotein (ox-LDL)-injured RAW264.7 macrophages, respectively. This study resulted in the isolation of 10 bisabolane-type sesquiterpenoids (1-10) from C. longa, including two pairs of new epimers (curbisabolanones A-D, 1-4). Compound 4 significantly inhibited LPS-induced nitric oxide (NO), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and prostaglandin E2 (PGE2) production in RAW264.7 cells. Furthermore, compound 4 showed inhibitory activity against macrophage-derived foam cell formation, which was represented by markedly reducing ox-LDL-induced intracellular lipid accumulation as well as total cholesterol (TC), free cholesterol (FC), and cholesterol ester (CE) contents in RAW264.7 cells. These findings suggest that bisabolane-type sesquiterpenoids, one of the main types of components in C. longa, have the potential to alleviate the atherosclerosis process by preventing inflammation and inhibiting macrophage foaming.

Cyclodextrin Conjugated α-Bisabolol Suppresses FAK Phosphorylation and Induces Apoptosis in Pancreatic Cancer.

BACKGROUND/AIM: α-Bisabolol is an essential oil component extracted from plants, such as chamomile. We have previously reported that α-bisabolol suppressed proliferation, invasion, and motility of pancreas cancer. Cyclodextrin improved the solubility of α-bisabolol, therefore it enabled to administer intravenously. The aim of this study was to clarify the effect of cyclodextrin conjugated α-bisabolol (CD-BSB) and the signals pathways associated with α-bisabolol for pancreatic cancer. MATERIALS AND METHODS: Human pancreatic cancer cell lines were treated with or without CD-BSB. Cytomorphology and apoptosis were assessed in these treated groups. In addition, several phosphorylated proteins were analyzed to clarify the signal pathway concerning CD-BSB. In subcutaneous xenograft model, tumor volume and Ki-67 expression were evaluated among Control (untreated), CD-BSB, or Gemcitabine (GEM). RESULTS: CD-BSB significantly changed cytomorphology and induced apoptosis in pancreatic cancer cells. CD-BSB suppressed phosphorylation of focal adhesion kinase (FAK). In addition, pFAK 397 was inhibited by CD-BSB in a concentration-dependent manner in cancer cells. In the subcutaneous xenograft models, the tumor volume in the CD-BSB groups was lower than Control groups. Ki67-positive cells in CD-BSB treated group were lower than the GEM-treated groups. CONCLUSION: We clarified the efficiency of CD-BSB in xenograft tumor using intravenous administration. α-Bisabolol suppresses phosphorylation of FAK 397 and impairs cytoskeletal polymerization in a pancreatic cancer cell line. Further investigations are required to reveal the precise mechanisms of the antitumor effects of solubilized α-bisabolol to facilitate its clinical application. Our data indicate that solubilized α-bisabolol has therapeutic potential and could improve the prognosis of cancer patients.

Bisabolane-type sesquiterpenoids with potential anti-inflammatory and anti-HIV activities from the stems and leaves of Morinda citrifolia.

The phytochemical study on the stems and leaves of Morinda citrifolia L. resulted in the isolation of a new naturally occurring bisabolane-type sesquiterpenoid, morincitrinoid A (1), together with five known analogues (2-6). The chemical structure of 1 was elucidated by comprehensive spectral analyses. The known compounds 2-6 were identified by comparing their spectral data with those reported in the literature, which were isolated from M. citrifolia for the first time. In addition, the anti-inflammatory and anti-HIV activities of compounds 1-6 were evaluated in vitro. Compounds 1-6 displayed significant inhibitory activities on NO (nitric oxide) production induced by lipopolysaccharide in mouse macrophage RAW 264.7 cells with IC50 values ranging from 0.98 ± 0.07 to 6.32 ± 0.11 µM, which was comparable to hydrocortisone. Meanwhile, compounds 1-6 showed remarkable anti-HIV-1 reverse transcriptase (RT) effects with the EC50 values ranging from 0.16 to 6.29 µM.

Biotransformation of (-)-α-Bisabolol by Absidia coerulea.

(-)-α-Bisabolol, a bioactive monocyclic sesquiterpene alcohol, has been used in pharmaceutical and cosmetic products with anti-inflammatory, antibacterial and skin-caring properties. However, the poor water solubility of (-)-α-bisabolol limits its pharmaceutical applications. It has been recognized that microbial transformation is a very useful approach to generate more polar metabolites. Fifteen microorganisms were screened for their ability to metabolize (-)-α-bisabolol in order to obtain its more polar derivatives, and the filamentous fungus Absidia coerulea was selected for scale-up fermentation. Seven new and four known metabolites were obtained from biotransformation of (-)-α-bisabolol (1), and all the metabolites exhibited higher aqueous solubility than that of the parent compound 1. The structures of newly formed metabolites were established as (1R,5R,7S)- and (1R,5S,7S)-5-hydroxy-α-bisabolol (2 and 3), (1R,5R,7S,10S)-5-hydroxybisabolol oxide B (4), (1R,7S,10S)-1-hydroxybisabolol oxide B (5), 12-hydroxy-α-bisabolol (7), (1S,3R,4S,7S)- and (1S,3S,4S,7S)-3,4-dihydroxy-α-bisabolol (8 and 10) on the basis of spectroscopic analyses. These compounds could also be used as reference standards for the detection and identification of the metabolic products of 1 in the mammalian system.

In Vitro Anti-Inflammatory Activity of Essential Oil and ß-Bisabolol Derived from Cotton Gin Trash.

Natural α-bisabolol has been widely used in cosmetics and is sourced mainly from the stems of Candeia trees that have become endangered due to over exploitation. The in vitro anti-inflammatory activity of cotton gin trash (CGT) essential oil and the major terpenoid (ß-bisabolol) purified from the oil were investigated against lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages as well as the 3t3 and HS27 fibroblast cell lines. Nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), and interleukin 8 (IL-8) were measured using Greiss reagent, enzyme-linked immunosorbent assay (ELISA), and cytokine bead array (CBA)-flow cytometry. Non-toxic concentrations of CGT oil and ß-bisabolol (1.6-50.0 µg/mL) significantly inhibited the production of the inflammatory mediators in a dose-dependent manner. Maximal inhibition by ß-bisabolol was 55.5% for NO, 62.3% for PGE2, and 45.3% for TNF-α production in RAW cells. ß-Bisabolol induced a level of inhibition similar to an equal concentration of α-bisabolol (50.0 µg/mL), a known anti-inflammatory agent. These results suggest ß-bisabolol exerts similar in vitro effects to known topical anti-inflammatory agents and could therefore be exploited for cosmetic and therapeutic uses. This is the first study to report the in vitro anti-inflammatory activity of ß-bisabolol in CGT essential oil.

(-)-α-Bisabolol as a protective agent against epithelial renal cytotoxicity induced by amphotericin B.

INTRODUCTION: Amphotericin B (AmB), used for systemic fungal infections, has a limited clinical application because of its high nephrotoxicity. Natural antioxidant and anti-inflammatory substances have been widely studied for protection against drug-induced nephrotoxicity. α-Bisabolol (BIS) has demonstrated a nephroprotective effect on both in vitro and in vivo models. AIMS: The aim of this work was to evaluate the effect of BIS against AmB-induced nephrotoxicity in vitro. MATERIAL AND METHODS: LLC-MK2 cells were pre- and post-treated with non-toxic BIS concentrations and/or AmB IC50 (13.97 µM). Cell viability was assessed by MTT [(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide)] assay. Flow cytometry analyses were used to assess cell death mechanism, production of reactive oxidative stress (ROS) and mitochondrial transmembrane potential. Kidney Injury Molecule-1 (KIM-1) levels were measured via ELISA. KEY FINDINGS: The present work showed that BIS pretreatment (125; 62.5 and 31.25 µM) increased cell viability when compared to the group treated only with AmB IC50. AmB treatment induced both necrosis (7-AAD-labeled cells) and late apoptosis (AnxV-labeled). BIS was able to prevent the occurrence of these events. These effects were associated with a decrease of ROS accumulation, improving transmembrane mitochondrial potential and protecting against tubular cell damage, highlighted by the inhibition of KIM-1 release after BIS treatment. SIGNIFICANCE: BIS presented a potential effect on model of renal cytotoxicity induced by AmB, bringing perspectives for the research of new nephroprotective agents.

Dolabellane Diterpenes and Elemane Alkaloids from the Soft Coral Clavularia inflata Collected in the South China Sea.

Five new dolabellane diterpenes, clavularinlides A-E (1-5), and four new racemic elemane alkaloids, clavulacylides A-D (7-10), together with one known compound (6), were isolated from the soft coral Clavularia inflata collected in the South China Sea. Their structures were elucidated by 1D and 2D NMR, HRESIMS, calculated ECD, and DP4+ probability analyses. Compounds 1-7 showed anti-inflammatory activity in the zebrafish assay.

Antifungal mono- and dimeric nitrogenous bisabolene derivatives from a sponge in the order Bubarida from Futuna Islands.

An abundant sponge of the order Bubarida was selected for further chemical investigation following biological and chemical screening of sponges collected from Futuna Islands in the Indo-Pacific. Ten new nitrogenous bisabolene derivatives were isolated and identified: the monomeric theonellin formamide analogues named bubaridins A-F (1-6) with unusual oxidised linear chains, and the first isocyanide/formamide dimeric and cyclised bisabolenes 7-9. The structure elucidation of these nitrogenous bisabolenes involved HRESIMS, NMR, and ECD analyses, and the chiral compounds were found to be racemates. A biosynthetic hypothesis for the production of these metabolites is proposed and some chemotaxonomic considerations are discussed. Furthermore, the antimicrobial and antitumoral activity were evalutated and the trans-dimer theonellin isocyanide (7) was shown to exhibit potent and selective antifungal activity.

Role of Caryophyllane Sesquiterpenes in the Entourage Effect of Felina 32 Hemp Inflorescence Phytocomplex in Triple Negative MDA-MB-468 Breast Cancer Cells.

Cannabis sativa L. crops have been traditionally exploited as sources of fibers, nutrients, and bioactive phytochemicals of medical interest. In the present study, two terpene-rich organic extracts, namely FOJ and FOS, obtained from Felina 32 hemp inflorescences collected in June and September, respectively, have been studied for their in vitro anticancer properties. Particularly, their cytotoxicity was evaluated in different cancer cell lines, and the possible entourage effect between nonintoxicating phytocannabinoids (cannabidiol and cannabichromene) and caryophyllane sesquiterpenes (ß-caryophyllene, ß-caryophyllene oxide and α-humulene), as identified at GC/MS analysis, was characterized. Modulation of cannabinoid CB1 and CB2 receptors was studied as a mechanistic hypothesis. Results highlighted marked cytotoxic effects of FOJ, FOS, and pure compounds in triple negative breast cancer MDA-MB-468 cells, likely mediated by a CB2 receptor activation. Cannabidiol was the main cytotoxic constituent, although low levels of caryophyllane sesquiterpenes and cannabichromene induced potentiating effects; the presence in the extracts of unknown antagonistic compounds has been highlighted too. These results suggest an interest in Felina 32 hemp inflorescences as a source of bioactive phytocomplexes with anticancer properties and strengthen the importance of considering the possible involvement of minor terpenes, such as caryophyllane sesquiterpenes, in the entourage effect of hemp-based extracts.

Antimicrobial and cytotoxic phenolic bisabolane sesquiterpenoids from the fungus Aspergillus flavipes 297.

Phenolic bisabolane-type sesquiterpenoids (PBS) represent a rare class of natural products with diverse biological activities. In this study, chemical investigations of the fungus Aspergillus flavipes 297 resulted in the isolation and identification of seven PBS, including a pair of new enantiomers (+)-1a and (-)-1b, a new derivative 2, and five previously reported ones 3-7. The chemical structures of the isolated PBS were determined by extensive NMR and HRESIMS spectroscopic analysis. The absolute configurations of the separated enantiomers (+)-1a and (-)-1b were solved by comparison of the experimental ECD spectra with those of the TDDFT-ECD calculated spectra. The new compounds 1 and 2 represent rare cases of PBS bearing a methylsulfinyl group, which was distinct from the commonly-observed PBS structurally. All the isolated compounds 1-7 were evaluated their antimicrobial and cytotoxic activities. As a result, the tested compounds showed selective antimicrobial activity against several pathogenic bacteria and fungi with the MIC (minimum inhibiting concentrations) values ranging from 2 to 64 µg/mL. Moreover, enantiomers (+)-1a and (-)-1b, together with compound 2, exhibited promising cytotoxicity against MKN-45 and HepG2 cell lines, respectively, indicating that the methylsulfinyl substituent enhanced cytotoxicity to a certain degree.

Bisabolane, cadinane, and cyclonerane sesquiterpenes from an algicolous strain of Trichoderma asperelloides.

Ten new bisabolane derivatives, trichobisabolins Q-Z (1-10), one new cadinane derivative, cadin-4-en-11-ol (11), and three new cyclonerane derivatives, cycloner-3-en-7,11-diol (12), isoepicyclonerodiol oxide (13), and norepicyclonerodiol oxide (14), were isolated from the endophytic fungal strain RR-dl-6-11 of Trichoderma asperelloides that was obtained from a marine alga. Their structures along with relative configurations were established mainly by NMR and IR as well as MS techniques, and the absolute configurations of 10 and 11 were assigned by ECD and X-ray diffraction data, respectively. Sesquiterpenes from the fungus T. asperelloides are reported for the first time. It is interesting that half of the bisabolane derivatives are demethylated. Compound 12 represents the first the occurrence of cyclopentenyl-bearing cycloneranes, and 14 seems a cyclopentyl-degrading cyclonerane derivative. Several isolates feature potent inhibition of marine phytoplankton species.

New bisabolane-type phenolic sesquiterpenoids from the marine sponge Plakortis simplex.

Six new bisabolane-type phenolic sesquiterpenoids, including plakordiols A-D (1-4), (7R, 10R)-hydroxycurcudiol (5) and (7R, 10S)-hydroxycurcudiol (6) were isolated from the marine sponge Plakortis simplex collected from the South China Sea. Their structures were determined based on extensive analysis of spectroscopic data. Their configurations were assigned by coupling constant analysis, NOESY correlations, and the modified Mosher's method. Furthermore, their cytotoxic and antibacterial activities were evaluated.

Bisabolane-type sesquiterpenoids from Curcuma longa L. exert anti-influenza and anti-inflammatory activities through NF-κB/MAPK and RIG-1/STAT1/2 signaling pathways.

Influenza is a viral respiratory illness that causes seasonal epidemics and occasional pandemics. Disease severity may be contributed by influenza virus-induced cytokine dysregulation. The study was designed to investigate the isolation and identification of bisabolane-type sesquiterpenoids from Curcuma longa L., their antiviral and anti-inflammatory activities against H1N1 and their potential role in regulating host immune response in vitro. A pair of new bisabolane-type sesquiterpenoids, (6S,7S)-3-hydroxy-3-hydroxymethylbisabola-1,10-diene-9-one (18) together with seventeen known analogs (1-17), was isolated and elucidated from Curcuma longa L. Compounds 2, 11 and 14 could significantly inhibit A/PR/8/34 (H1N1) replication in MDCK cells, and compound 2 could significantly inhibit A/PR/8/34 (H1N1) replication in A549 cells. Compounds 4, 8, 9, 13 and 17 could markedly reduce pro-inflammatory cytokine (TNF-α, IL-6, IL-8 and IP-10) production at the mRNA and protein levels in A549 cells. Compound 4 regulated the levels of steroid biosynthesis, oxidative phosphorylation and protein processing in the endoplasmic reticulum, thereby inhibiting immune responses by proteomics analysis. Furthermore, compound 4 could inhibit the expression of p-NF-κB p65, NF-κB p65, IκBα, p-p38 MAPK, p-IκBα, RIG-1, STAT-1/2 and p-STAT-1/2 in the signaling pathways. These findings indicate that bisabolane-type sesquiterpenoids of C. longa could inhibit the expression of inflammatory cytokines induced by the virus and regulate the activity of NF-κB/MAPK and RIG-1/STAT-1/2 signaling pathways in vitro.

Role of the NO-cGMP-K+ channels pathway in the peripheral antinociception induced by α-bisabolol.

The aim of this study was to examine if the peripheral antinociception of α-bisabolol involves the participation of nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) synthesis followed by K+ channel opening in the formalin test. Wistar rats were injected in the dorsal surface of the right hind paw with formalin (1%). Rats received a subcutaneous injection into the dorsal surface of the paw of vehicles or increasing doses of α-bisabolol (100-300 µg/paw). To determine whether the peripheral antinociception induced by α-bisabolol was mediated by either the opioid receptors or the NO-cGMP-K+ channels pathway, the effect of pretreatment (10 min before formalin injection) with the appropriate vehicles, naloxone, naltrexone, NG-nitro-l-arginine methyl ester (L-NAME), 1H-[1,2,4]-oxadiazolo[4,2-a]quinoxalin-1-one (ODQ), glibenclamide, glipizide, apamin, charybdotoxin, tetraethylammonium, or 4-aminopyridine on the antinociceptive effects induced by local peripheral α-bisabolol (300 µg/paw) were assessed. α-Bisabolol produced antinociception during both phases of the formalin test. α-Bisabolol antinociception was blocked by L-NAME, ODQ, and all the K+ channels blockers. The peripheral antinociceptive effect produced by α-bisabolol was not blocked by the opioid receptor inhibitors. α-Bisabolol was able to active the NO-cGMP-K+ channels pathway to produce its antinoceptive effect. The participation of opioid receptors in the peripheral local antinociception induced by α-bisabolol is excluded.

Anti-Tumor Drug Discovery Based on Natural Product ß-Elemene: Anti-Tumor Mechanisms and Structural Modification.

Natural products are important sources for drug discovery, especially anti-tumor drugs. ß-Elemene, the prominent active ingredient extract from the rhizome of Curcuma wenyujin, is a representative natural product with broad anti-tumor activities. The main molecular mechanism of ß-elemene is to inhibit tumor growth and proliferation, induce apoptosis, inhibit tumor cell invasion and metastasis, enhance the sensitivity of chemoradiotherapy, regulate the immune system, and reverse multidrug resistance (MDR). Elemene oral emulsion and elemene injection were approved by the China Food and Drug Administration (CFDA) for the treatment of various cancers and bone metastasis in 1994. However, the lipophilicity and low bioavailability limit its application. To discover better ß-elemene-derived anti-tumor drugs with satisfying drug-like properties, researchers have modified its structure under the premise of not damaging the basic scaffold structure. In this review, we comprehensively discuss and summarize the potential anti-tumor mechanisms and the progress of structural modifications of ß-elemene.

Anti-inflammatory and anti-apoptotic effect of zingiberene on isoproterenol-induced myocardial infarction in experimental animals.

This study aimed to investigate the antihyperlipidemic and anti-inflammatory effect of zingiberene (ZBN) on isoproterenol-(ISO) induced myocardial infarction in rats. ZBN (10 mg/kg b.wt.) was orally administered to rats for 21 days and ISO (85 mg/kg b.wt.) was subcutaneously injected into the rats at 24 h intervals for the last 2 consecutive days. We observed increased serum creatine kinase, creatine kinase-MB, cardiac troponin T, and I levels in ISO-treated MI rats. Conversely, ZBN oral administration significantly prevented in cardiac marker enzyme activities in ISO-mediated rats. We also noticed that ZBN oral administration prevented ISO-induced expression of lipid peroxidative markers, total cholesterol, triglycerides, phospholipids, free fatty acids, very-low-density lipoprotein cholesterol (VLDL-C), low-density lipoprotein cholesterol (LDL-C) to the normal basal level. Furthermore, ZBN restored ISO-mediated antioxidant status, increased level of high-density lipoprotein cholesterol (HDL-C), and tissue phospholipids to the near-normal levels. Besides, ZBN pre-treatment significantly reduced the level of inflammatory markers (TNF-α, IL-6, NF-κB, and IL-1ß) in ISO-induced MI in rats. We noticed that ZBN pretreatment inhibited the pro-apoptotic proteins Bax and cytochrome c and increased the Bcl-2 expression in ISO induced rats. The gene expression profiling by qRT-PCR array illustrates that ZBN treatment prevents the ISO mediated activation of cardiac markers, inflammatory, and fibrosis-related genes in the heart tissue. Taken together, pre-treatment with ZBN attenuated ISO-induced MI resolved exhibits the anti-inflammatory and antiapoptotic effect.

Phenolic bisabolane and cuparene sesquiterpenoids with anti-inflammatory activities from the deep-sea-derived Aspergillus sydowii MCCC 3A00324 fungus.

Seventeen undescribed sesquiterpenoids including 14 phenolic bisabolanes, namely asperbisabolanes A-N (1-14), and 3 cuparenes (aspercuparenes A-C, 15-17), together with 10 known bisabolane analogues (18-27) were isolated from the EtOAc extract of fermented cultures of the deep sea sediment-derived fungus Aspergillus sydowii MCCC 3A00324. The new structures were established on the basis of extensive NMR and HRESIMS spectroscopic data analyses, while their absolute configurations were assigned by comparison of the experimental ECD spectra with those of the TDDFT-ECD calculated spectra or reported data in literature. Asperbisabolanes A (1) and B (2) are the first examples of bisabolane sesquiterpenoids featuring a 6/6/6 tricyclic nucleus. Compound 3 possessed a novel seco-bisabolane skeleton with a rare dioxolane ring moiety, while asperbisabolane K (11) represents the first case of bisabolanes bearing a rare methylsulfonyl group. All the isolated compounds (1-27) were evaluated their activities against NO secretion in LPS-activated BV-2 microglia cells. As a result, 6, 12, 16, and 25-27 exhibited the inhibition rate over 45% at a concentration of 10 µM. Moreover, 12 exerted the anti-inflammatory activity by inhibiting the NF-κB-activated pathway in dose-dependent manner.

Zingiberene targets the miR-16/cyclin-B1 axis to regulate the growth, migration and invasion of human liver cancer cells.

PURPOSE: Liver cancer or hepatocellular carcinoma (HCC) is considered as one of the most frequent malignancies with significantly high morbidity and mortality across the globe. MicroRNAs (miRs) are regarded as important regulators of liver cancer formation and its development. However, the full biochemical mechanism of their role is still very less understood. The main objective of the current research work was to examine the role of miR-16/cyclin-B1 axis in liver cancer regulation and how this pathway along with liver cancer migration and invasion are targeted by zingiberene molecule. METHODS: Quantitative reverse transcriptase polymerase chain reaction was used to evaluate miR-16 expression in HCC cell lines. Western blotting was performed to evaluate the expression of the miR-16 target genes. Effects on cell migration and invasion were evaluated by in vitro wound healing assay and transwell Matrigel assay, respectively. Effects of zingiberene on HCC cell viability were evaluated by MTT assay. RESULTS: Zingiberene treatment led to downregulation of miR-16 in HepG2 human hepatocellular carcinoma cells, accompanied by induction of G0/G1 cell cycle arrest targeting cyclin B1 as direct target. These effects were also accompanied by inhibition of cell migration and invasion, indicating that miR-16 can have a significant role as liver cancer suppressor after zingiberene treatment. Luciferase reporter assay confirmed that miR-16, which was one of HCC downregulated miRs, directly targeted Cyclin B1 in HCC cells. CONCLUSION: The current study indicates miR-16/cyclin B1 axis might have significant applications as a therapeutic target for patients with liver cancer.

α-Bisabolol, a Dietary Bioactive Phytochemical Attenuates Dopaminergic Neurodegeneration through Modulation of Oxidative Stress, Neuroinflammation and Apoptosis in Rotenone-Induced Rat Model of Parkinson's disease.

Rotenone (ROT), a plant-derived pesticide is a well-known environmental neurotoxin associated with causation of Parkinson's disease (PD). ROT impairs mitochondrial dysfunction being mitochondrial complex-I (MC-1) inhibitor and perturbs antioxidant-oxidant balance that contributes to the onset and development of neuroinflammation and neurodegeneration in PD. Due to the scarcity of agents to prevent the disease or to cure or halt the progression of symptoms of PD, the focus is on exploring agents from naturally occurring dietary phytochemicals. Among numerous phytochemicals, α-Bisabolol (BSB), natural monocyclic sesquiterpene alcohol found in many ornamental flowers and edible plants garnered attention due to its potent pharmacological properties and therapeutic potential. Therefore, the present study investigated the neuroprotective effects of BSB in a rat model of ROT-induced dopaminergic neurodegeneration, a pathogenic feature of PD and underlying mechanism targeting oxidative stress, inflammation and apoptosis. BSB treatment significantly prevented ROT-induced loss of dopaminergic neurons and fibers in the substantia nigra and striatum respectively. BSB treatment also attenuated ROT-induced oxidative stress evidenced by inhibition of MDA formation and GSH depletion as well as improvement in antioxidant enzymes, SOD and catalase. BSB treatment also attenuated ROT-induced activation of the glial cells as well as the induction and release of proinflammatory cytokines (IL-1ß, IL-6 and TNF-α) and inflammatory mediators (iNOS and COX-2) in the striatum. In addition to countering oxidative stress and inflammation, BSB also attenuated apoptosis of dopaminergic neurons by attenuating downregulation of anti-apoptotic protein Bcl-2 and upregulation of pro-apoptotic proteins Bax, cleaved caspases-3 and 9. Further, BSB was observed to attenuate mitochondrial dysfunction by inhibiting mitochondrial lipid peroxidation, cytochrome-C release and reinstates the levels/activity of ATP and MC-I. The findings of the study demonstrate that BSB treatment salvaged dopaminergic neurons, attenuated microglia and astrocyte activation, induction of inflammatory mediators, proinflammatory cytokines and reduced the expression of pro-apoptotic markers. The in vitro study on ABTS radical revealed the antioxidant potential of BSB. The results of the present study are clearly suggestive of the neuroprotective effects of BSB through antioxidant, anti-inflammatory and anti-apoptotic properties in ROT-induced model of PD.

Acaricidal activity of (E)-cinnamaldehyde and α-bisabolol on populations of Rhipicephalus microplus (Acari: Ixodidae) with different resistance profiles.

This study aimed to investigate the acaricidal activity of (E)-cinnamaldehyde and α-bisabolol on populations of Rhipicephalus microplus with different resistance profiles. The adult immersion test (AIT) was used to characterize the susceptibility of tick populations (50 field populations) to synthetic acaricides: deltamethrin, amitraz, and chlorfenvinphos. The larval packet test (LPT) was used to determine the LC50 values for (E)-cinnamaldehyde (populations 1-25) and α-bisabolol (populations 26-50) at the concentrations of 0.31, 0.62, 1.25, 2.0, 2.5, 5.0 and 10.0 mg/mL. The susceptible strain Porto Alegre (POA) was used as a reference for calculating the resistance ratio (RR). In the AIT, deltamethrin did not show efficacy >95 % for any of the populations, whereas amitraz and chlorfenvinphos have presented efficacy >95 % for three (6 %) and 15 (30 %) populations, respectively. In the LPT, the LC50 values of (E)-cinnamaldehyde and α-bisabolol varied from 0.23 to 2.36 mg/mL and 1.57-3.01 mg/mL, respectively. The RR50 for (E)-cinnamaldehyde showed 20 (80 %) populations with values <1.0 and no population with values>1.5. As for α-bisabolol, only two (8%) populations have presented RR50 <1.0, whereas three (12 %) populations showed incipient resistance to this sesquiterpene (RR50 between 1.5 and 2.0). The results indicate that all studied tick populations showed low susceptibility to at least one of the commercial acaricides tested. In addition, comparison between the LC50 values of (E)-cinnamaldehyde and α-bisabolol for the field populations and the susceptible strain POA suggests that there is no cross-resistance of (E)-cinnamaldehyde and α-bisabolol for the tick populations evaluated, and that the differences in the LC50 values are due to population variations.