Supporting gut health with medicinal cannabis in people with advanced cancer: potential benefits and challenges.

The side effects of cancer therapy continue to cause significant health and cost burden to the patient, their friends and family, and governments. A major barrier in the way in which these side effects are managed is the highly siloed mentality that results in a fragmented approach to symptom control. Increasingly, it is appreciated that many symptoms are manifestations of common underlying pathobiology, with changes in the gastrointestinal environment a key driver for many symptom sequelae. Breakdown of the mucosal barrier (mucositis) is a common and early side effect of many anti-cancer agents, known to contribute (in part) to a range of highly burdensome symptoms such as diarrhoea, nausea, vomiting, infection, malnutrition, fatigue, depression, and insomnia. Here, we outline a rationale for how, based on its already documented effects on the gastrointestinal microenvironment, medicinal cannabis could be used to control mucositis and prevent the constellation of symptoms with which it is associated. We will provide a brief update on the current state of evidence on medicinal cannabis in cancer care and outline the potential benefits (and challenges) of using medicinal cannabis during active cancer therapy.

Neuroprotective and Anti-Amyloid ß Effect and Main Chemical Profiles of White Tea: Comparison Against Green, Oolong and Black Tea.

White tea (WT) is one of six tea types originally derived from Fujian Province, China. White tea is known for its health-promoting properties. However, the neuroprotective and anti-aggregatory properties of WT against the hallmark toxic Alzheimer's protein, Aß have not been investigated. In this study, WT, green tea (GT), oolong tea (OT) and black tea (BT) were manufactured using tea leaves from the cultivar Camellia sinensis (Jin Guanyin). The protective effects of these tea extracts were then studied under oxidative stress conditions via t-bhp and H2O2 exposure, in addition to Aß treatment using a PC-12 cell model. Each tea type failed to rescue PC-12 cells from either t-bhp or H2O2-mediated toxicity, however each extract exerted significant protection against Aß-evoked neurotoxicity. Results of the Thioflavin T Kinetic (ThT) and TEM assay showed that Aß aggregate formation was inhibited by each tea type. Additionally, TEM also supported the different anti-aggregatory effect of WT by modifying Aß into an amorphous and punctate aggregate morphology. Higher accumulated precedent or potential neuroprotective compounds in WT, including ECG''3Me, 8-C-ascorbyl-EGCG, GABA and Gln, in addition to flavonol or flavone glycosides detected by using UPLC-QTOF-MS and UPLC-QqQ-MS, may contribute to a favourable anti-aggregative and neuroprotective effect of WT against Aß.

Acute colitis chronically alters immune infiltration mechanisms and sensory neuro-immune interactions.

OBJECTIVE: Little is understood regarding how disease progression alters immune and sensory nerve function in colitis. We investigated how acute colitis chronically alters immune recruitment and the impact this has on re-activated colitis. To understand the impact of disease progress on sensory systems we investigated the mechanisms underlying altered colonic neuro-immune interactions after acute colitis. DESIGN: Inflammation was compared in mouse models of health, acute tri-nitrobenzene sulphonic acid (TNBS) colitis, Remission and Reactivated colitis. Cytokine concentrations were compared by ELISA in-situ and in explanted colon tissue. Colonic infiltration by CD11b/F4-80 macrophage, CD4 THELPER (TH) and CD8 TCYTOTOXIC (TC) and α4ß7 expression on mesenteric lymph node (MLN) TH and TC was determined by flow cytometry. Cytokine and effector receptor mRNA expression was determined on colo-rectal afferent neurons and the mechanisms underlying cytokinergic effects on high-threshold colo-rectal afferent function were investigated using electrophysiology. RESULTS: Colonic damage, MPO activity, macrophage infiltration, IL-1ß and IL-6 concentrations were lower in Reactivated compared to Acute colitis. TH infiltration and α4ß7 expression on TH MLN was increased in Remission but not Acute colitis. IFN-γ concentrations, TH infiltration and α4ß7 expression on TH and TC MLN increased in Reactivated compared to Acute colitis. Reactivated explants secreted more IL-1ß and IL-6 than Acute explants. IL-6 and TNF-α inhibited colo-rectal afferent mechanosensitivity in Remission mice via a BKCa dependent mechanism. CONCLUSIONS: Acute colitis persistently alters immune responses and afferent nerve signalling pathways to successive episodes of colitis. These findings highlight the complexity of viscero-sensory neuro-immune interactions in painful remitting and relapsing diseases.

Structure-activity relationships for flavone interactions with amyloid ß reveal a novel anti-aggregatory and neuroprotective effect of 2',3',4'-trihydroxyflavone (2-D08).

Naturally-occurring flavonoids have well documented anti-aggregatory and neuroprotective properties against the hallmark toxic protein in Alzheimer's disease, amyloid ß (Aß). However the extensive diversity of flavonoids has limited the insight into the precise structure-activity relationships that confer such bioactive properties against the Aß protein. In the present study we have characterised the Aß binding properties, anti-aggregatory and neuroprotective effects of a discreet set of flavones, including the recently described novel protein sumoylation inhibitor 2',3',4'-trihydroxyflavone (2-D08). Quercetin, transilitin, jaceosidin, nobiletin and 2-D08 were incubated with human Aß1-42 for 48h in vitro and effects on Aß fibrillisation kinetics and morphology measured using Thioflavin T (ThT) and electron microscopy respectively, in addition to effects on neuronal PC12 cell viability. Of the flavones studied, only quercetin, transilitin and 2-D08 significantly inhibited Aß1-42 aggregation and toxicity in PC12 cells. Of those, 2-D08 was the most effective inhibitor. The strong anti-amyloid activity of 2-D08 indicates that extensive hydroxylation in the B ring is the most important determinant of activity against ß amyloid within the flavone scaffold. The lack of efficacy of jaceosidin and nobiletin indicate that extension of B ring hydroxylation with methoxyl groups result in an incremental loss of anti-fibrillar and neuroprotective activity, highlighting the constraint to vicinal hydroxyl groups in the B ring for effective inhibition of aggregation. These findings reveal further structural insights into anti-amyloid bioactivity of flavonoids in addition to a novel and efficacious anti-aggregatory and neuroprotective effect of the semi-synthetic flavone and sumoylation inhibitor 2',3',4'-trihydroxyflavone (2-D08). Such modified flavones may facilitate drug development targeting multiple pathways in neurodegenerative disease.

Chemotherapy-induced gut toxicity and pain: involvement of TLRs.

PURPOSE: Chemotherapy-induced gut toxicity is associated with significant pain, and pain influences gut function. Toll-like receptors (TLRs) that regulate gut homeostasis are activated by tissue damage and microbes, and their altered expression following chemotherapy may change cellular responses. This study examined the interaction between chemotherapy-induced gut toxicity and pain and related these to gut TLR and glial fibrillary acidic protein (GFAP) expression. METHODS: Female tumor bearing Dark Agouti rats received irinotecan (175 mg/kg, n = 34) or vehicle (n = 5) and were assessed over 120 h for gut toxicity (diarrhea, weight loss), pain (facial), and GFAP, TLR2, 4, 5, and 9 gut expression. RESULTS: Irinotecan caused diarrhea (72 % of animals grade ≥ 1), weight loss (11.1 ± 6.6 %, P < 0.0001), and pain (5 (0-5), P < 0.0001) all peaking at 72 h. Higher pain scores were observed in rats with diarrhea versus those without: median (range) of 2.0 (0-5) versus 0 (0-5), P = 0.01. Irinotecan also caused a decrease in TLR4 and 5, and an increase in GFAP expression in jejuna crypt at 96 and 120 h (all P < 0.05); with lower TLR4 expression associated with lower pain (P = 0.012). CONCLUSIONS: The association between gut toxicity and pain suggests these toxicities are linked, possibly via TLR-mediated inflammatory pathways. Further, as TLR4 and 5 expression was absent during recovery in the jejuna and GFAP expression was increased in the jejuna, this implies expression of these may be critical in the healing phase following chemotherapy. Detailed studies of gut TLRs and GFAP are now warranted.

Cannabinoid effects on ß amyloid fibril and aggregate formation, neuronal and microglial-activated neurotoxicity in vitro.

Cannabinoid (CB) ligands have demonstrated neuroprotective properties. In this study we compared the effects of a diverse set of CB ligands against ß amyloid-mediated neuronal toxicity and activated microglial-conditioned media-based neurotoxicity in vitro, and compared this with a capacity to directly alter ß amyloid (Aß) fibril or aggregate formation. Neuroblastoma (SH-SY5Y) cells were exposed to Aß1-42 directly or microglial (BV-2 cells) conditioned media activated with lipopolysaccharide (LPS) in the presence of the CB1 receptor-selective agonist ACEA, CB2 receptor-selective agonist JWH-015, phytocannabinoids Δ(9)-THC and cannabidiol (CBD), the endocannabinoids 2-arachidonoyl glycerol (2-AG) and anandamide or putative GPR18/GPR55 ligands O-1602 and abnormal-cannabidiol (Abn-CBD). TNF-α and nitrite production was measured in BV-2 cells to compare activation via LPS or albumin with Aß1-42. Aß1-42 evoked a concentration-dependent loss of cell viability in SH-SY5Y cells but negligible TNF-α and nitrite production in BV-2 cells compared to albumin or LPS. Both albumin and LPS-activated BV-2 conditioned media significantly reduced neuronal cell viability but were directly innocuous to SH-SY5Y cells. Of those CB ligands tested, only 2-AG and CBD were directly protective against Aß-evoked SH-SY5Y cell viability, whereas JWH-015, THC, CBD, Abn-CBD and O-1602 all protected SH-SY5Y cells from BV-2 conditioned media activated via LPS. While CB ligands variably altered the morphology of Aß fibrils and aggregates, there was no clear correlation between effects on Aß morphology and neuroprotective actions. These findings indicate a neuroprotective action of CB ligands via actions at microglial and neuronal cells.

Characterizing cannabis-prevalent terpenes for neuroprotection reveal a role for α and ß-pinenes in mitigating amyloid ß-evoked neurotoxicity and aggregation in vitro.

BACKGROUND: Cannabis sativa L. (C. sativa) can efficiently synthesize of over 200 terpenes, including monoterpenes, sesquiterpenes and triterpenes that may contribute to the known biological activities of phytocannabinoids of relevance for the burgeoning access to medicinal cannabis formulations globally; however, to date have been uncharacterized. We assessed twelve predominant terpenes in C. sativa for neuroprotective and anti-aggregative properties in semi-differentiated PC12 neuronal cell line that is robust and validated as a cell model responsive to amyloid ß (Aß1-42) protein exposure and oxidative stress. METHODS: Cell viability was assessed biochemically using the MTT assay in the presence of myrcene, ß-caryophyllene, terpinolene, limonene, linalool, humulene, α-pinene, nerolidol, ß-pinene, terpineol, citronellol and friedelin (1-200 µM) for 24 hr. Sub-toxic threshold test concentrations of each terpene were then applied to cells, alone or with concomitant incubation with the lipid peroxidant tert-butyl hyrdroperoxide (t-BHP; 0-250 µM) or amyloid ß (Aß1-42; 0-1 µM) to assess neuroprotective effects. Direct effects of each terpene on Aß fibril formation and aggregation were also evaluated using the Thioflavin T (ThT) fluorometric kinetic assay and transmission electron microscopy (TEM) to visualize fibril and aggregate morphology. RESULTS: Terpenes were intrinsically benign to PC12 cells up to 50 µM, with higher concentrations of ß-caryophyllene, humulene and nerolidol inducing some loss of PC12 cell viability. No significant protective effects of terpenes were observed following t-BHP (0-200 µM) administration, with some enhanced toxicity instead demonstrated from both ß-caryophyllene and humulene treatment (each at 50 µM). α-pinene and ß-pinene demonstrated a significant neuroprotective effect against amyloid ß exposure. α-pinene, ß-pinene, terpineol, terpinolene and friedelin were associated with a variable inhibition of Aß1-42 fibril and aggregate density. CONCLUSIONS: The outcomes of this study underline a neuroprotective role of α-pinene and ß-pinene against Aß-mediated neurotoxicity associated with an inhibition of Aß1-42 fibrilization and density. This demonstrates the bioactive potential of selected terpenes for consideration in the development of medicinal cannabis formulations targeting neurodegenerative diseases.

Selected phytocannabinoids inhibit SN-38- and cytokine-evoked increases in epithelial permeability and improve intestinal barrier function in vitro.

Irinotecan use is linked to the development of gastrointestinal toxicity and inflammation, or gastrointestinal mucositis. Selected phytocannabinoids have been ascribed anti-inflammatory effects in models of gastrointestinal inflammation, associated with maintaining epithelial barrier function. We characterised the mucoprotective capacity of the phytocannabinoids: cannabidiol, cannabigerol, cannabichromene and cannabidivarin in a cell-based model of intestinal epithelial stress occurring in mucositis. Transepithelial electrical resistance (TEER) was measured to determine changes in epithelial permeability in the presence of SN-38 (5 µM) or the pro-inflammatory cytokines TNFα and IL-1ß (each at 100 ng/mL), alone or with concomitant treatment with each of the phytocannabinoids (1 µM). The DCFDA assay was used to determine the ROS-scavenging ability of each phytocannabinoid following treatment with the lipid peroxidant tbhp (200 µM). Each phytocannabinoid provided significant protection against cytokine-evoked increases in epithelial permeability. Cannabidiol, cannabidivarin and cannabigerol were also able to significantly inhibit SN-38-evoked increases in permeability. None of the tested phytocannabinoids inhibited tbhp-induced ROS generation. These results highlight a novel role for cannabidiol, cannabidivarin and cannabigerol as inhibitors of SN-38-evoked increases in epithelial permeability and support the rationale for the further development of novel phytocannabinoids as supportive therapeutics in the management of irinotecan-associated mucositis.

Sesquiterpene-evoked phytochemical toxicity in PC12 neuronal cells reveals a variable degree of oxidative stress and alpha-tocopherol and glutathione-dependent protection.

Phytochemicals are often promoted generally as antioxidants and demonstrate variable levels of reactive oxygen species (ROS) sequestration in vitro, which attributes to their neuroprotective bioactivity. Sesquiterpenes from cannabis and essential oils may demonstrate bifunctional properties towards cellular oxidative stress, possessing pro-oxidant activities by generating ROS or scavenging ROS directly. Sesquiterpenes can also oxidize forming sesquiterpene oxides, however the relative contribution they make to the bioactivity or cytotoxicity of complex botanical extracts more generally is unclear, while selected cannabis-prevalent terpenes such as ß-caryophyllene may also activate cannabinoid receptors as part of their biological activity. In the present study, we investigated selected sesquiterpenes ß-caryophyllene and humulene and their oxidized forms (ß-caryophyllene oxide and zerumbone, respectively) against established antioxidants (ascorbic acid, α-tocopherol, and glutathione) and in the presence of cannabinoid receptor 1 and cannabinoid receptor 2 antagonists, to gain a better understanding of the molecular and cellular mechanisms of neuroprotection versus neurotoxicity in semi-differentiated rat neuronal phaeochromocytoma (PC12) cells. Our results demonstrate that the sesquiterpenes ß-caryophyllene, humulene and zerumbone possess concentration-dependent neurotoxic effects in PC12 cells. Both ß-caryophyllene- and humulene-evoked toxicity was unaffected by CB1 or CB2 receptor antagonism, demonstrating this occurred independently of cannabinoid receptors. Both glutathione and α-tocopherol were variably able to alleviate the concentration-dependent loss of PC12 cell viability from exposure to ß-caryophyllene, humulene and zerumbone. During 4-hour exposure to sesquiterpenes only modest increases in ROS levels were noted in PC12 cells, with glutathione co-incubation significantly inhibiting intracellular ROS production. However, significant increases in ROS levels in PC12 cells were demonstrated during 24-hour incubation with either antioxidants or sesquiterpenes individually, and with additive toxicity exhibited in combination. Overall, the results highlight a concentration-dependent profile of sesquiterpene neurotoxicity independent of cannabinoid receptors and dissociated from the formation of reactive oxygen species as a marker or correlate to the loss of cell viability.

The structurally diverse phytocannabinoids cannabichromene, cannabigerol and cannabinol significantly inhibit amyloid ß-evoked neurotoxicity and changes in cell morphology in PC12 cells.

BACKGROUND: Phytocannabinoids (pCBs) have been shown to inhibit the aggregation and neurotoxicity of the neurotoxic Alzheimer's disease protein beta amyloid (Aß). We characterized the capacity of six pCBs-cannabichromene (CBC), cannabigerol (CBG), cannabinol (CBN), cannabidivarin (CBDV), cannabidiol (CBD) and Δ9 -tetrahydrocannabinol (Δ9 -THC)-to disrupt Aß aggregation and protect against Aß-evoked neurotoxicity in PC12 cells. METHODS: Neuroprotection against lipid peroxidation and Aß-induced cytotoxicity was assessed using the MTT assay. Transmission electron microscopy was used to visualize pCB effects on Aß aggregation and fluorescence microscopy, with morphometrics and principal component analysis to assess PC12 cell morphology. RESULTS: CBD inhibited lipid peroxidation with no significant effect on Aß toxicity, whilst CBN, CBDV and CBG provided neuroprotection. CBC, CBG and CBN inhibited Aß1-42 -induced neurotoxicity in PC12 cells, as did Δ9 -THC, CBD and CBDV. CBC, CBN and CBDV inhibited Aß aggregation, whilst Δ9 -THC reduced aggregate density. Aß1-42 induced morphological changes in PC12 cells, including a reduction in neuritic projections and rounded cell morphology. CBC and CBG inhibited this effect, whilst Δ9 -THC, CBD and CBDV did not alter Aß1-42 effects on cell morphology. CONCLUSIONS: These findings highlight the neuroprotective activity of CBC, CBG and CBN as novel pCBs associated with variable effects on Aß-evoked neurite damage and inhibition of amyloid ß aggregation.

Medicinal cannabis extracts are neuroprotective against Aß1-42-mediated toxicity in vitro.

BACKGROUND: Phytocannabinoids inhibit the aggregation and neurotoxicity of the neurotoxic Alzheimer's disease protein ß amyloid (Aß). We characterised the capacity of five proprietary medical cannabis extracts, heated and non-heated, with varying ratios of cannabidiol and Δ9-tetrahydrocannabinol and their parent carboxylated compounds to protect against lipid peroxidation and Aß-evoked neurotoxicity in PC12 cells. METHODS: Neuroprotection against lipid peroxidation and Aß1-42-induced cytotoxicity was assessed using the thiazolyl blue tetrazolium bromide (MTT) assay. Transmission electron microscopy was used to visualise phytocannabinoid effects on Aß1-42 aggregation and fluorescence microscopy. RESULTS: Tetrahydrocannabinol (THC)/tetrahydrocannabinolic acid (THCA)-predominant cannabis extracts demonstrated the most significant overall neuroprotection against Aß1-42-induced loss of PC12 cell viability. These protective effects were still significant after heating of extracts, while none of the extracts provided significant neuroprotection to lipid peroxidation via tbhp exposure. Modest inhibition of Aß1-42 aggregation was demonstrated only with the non-heated BC-401 cannabis extract, but overall, there was no clear correlation between effects on fibrils and conferral of neuroprotection. CONCLUSIONS: These findings highlight the variable neuroprotective activity of cannabis extracts containing major phytocannabinoids THC/THCA and cannabidiol (CBD)/cannabidiolic acid (CBDA) on Aß-evoked neurotoxicity and inhibition of amyloid ß aggregation. This may inform the future use of medicinal cannabis formulations in the treatment of Alzheimer's disease and dementia.

Black Goji Berry (Lycium ruthenicum) Juice Fermented with Lactobacillus rhamnosus GG Enhances Inhibitory Activity against Dipeptidyl Peptidase-IV and Key Steps of Lipid Digestion and Absorption.

With the global increase in hyperglycemia and hyperlipidemia, there is an urgent need to explore dietary interventions targeting the inhibition of dipeptidyl peptidase-IV (DPP-IV) and lipid digestion and absorption. This study investigated how Lactobacillus rhamnosus GG (LGG) affects various aspects of black goji berry (BGB) (Lycium ruthenicum Murr.) juice, including changes in physicochemical and functional properties, as well as microbiological and sensory attributes. Throughout the fermentation process with 2.5-10% (w/v) BGB, significantly improved probiotic viability, lactic acid production, and decreased sugar content. While total flavonoids increase, anthocyanins decrease, with no discernible change in antioxidant activities. Metabolite profiling reveals elevated phenolic compounds post-fermentation. Regarding the inhibition of lipid digestion and absorption, fermented BGB exhibits improved bile acid binding, and disrupted cholesterol micellization by approximately threefold compared to non-fermented BGB, while also increasing pancreatic lipase inhibitory activity. Furthermore, a decrease in cholesterol uptake was observed in Caco-2 cells treated with fermented BGB (0.5 mg/mL), with a maximum reduction of 16.94%. Fermented BGB also shows more potent DPP-IV inhibition. Sensory attributes are significantly improved in fermented BGB samples. These findings highlight the potential of BGB as a bioactive resource and a promising non-dairy carrier for LGG, enhancing its anti-hyperglycemic and anti-hyperlipidemic properties.

Prostaglandin ethanolamides attenuate damage in a human explant colitis model.

Endocannabinoids are protective in animal colitis models. As endocannabinoids also form novel prostaglandin ethanolamides (prostamides) via COX-2, we investigated the effects of prostamides and other COX-2 mediators on tissue damage in an ex vivo human mucosal explant colitis model. Healthy human colonic mucosae were incubated with pro-inflammatory cytokines TNF-α and IL-1ß to elicit colitis-like tissue damage. The PGF-ethanolamide analogue, bimatoprost decreased colitis scores which were reversed by a prostamide-specific antagonist AGN 211334, but not the FP receptor antagonist AL-8810. PGF-ethanolamide and PGE-ethanolamide also reduced cytokine-evoked epithelial damage. Anandamide was protective in the explant colitis model; however COX-2 inhibition did not alter its effects, associated with a lack of COX-2 induction in explant mucosal tissue. These findings support an anti-inflammatory role for prostamides and endocannabinoids in the human colon.

Cannabis terpenes display variable protective and anti-aggregatory actions against neurotoxic ß amyloid in vitro: highlighting the protective bioactivity of α-bisabolol in motorneuronal-like NSC-34 cells.

BACKGROUND: Terpenes form a diverse class of naturally occurring chemicals ascribed various biological activities. Cannabis contains over 400 different terpenes of varying chemical complexity which may add to the known biological activities of phytocannabinoids of relevance to the increasing use of medical cannabis; however, to date have been incompletely characterized. We assessed three terpenes predominant in cannabis: α-bisabolol, myrcene and ß-caryophyllene for neuroprotective and anti-aggregative properties in both undifferentiated and differentiated NSC-34 motorneuronal-like cells as a sensitive model for neurotoxicity to oxidative stress and amyloid ß (Aß1-42) protein exposure. METHODS: Cell viability was assessed biochemically using the MTT assay in the presence of either α-bisabolol, myrcene and ß-caryophyllene (1-1000 µM) for 48 hr. Sub-toxic threshold test concentrations of each terpene were then applied to cells, alone or with concomitant incubation with the lipid peroxidant tert-butyl hyrdroperoxide (t-BHP) or amyloid ß (Aß1-42; 0-1 µM) to assess neuroprotective effects. Direct effects of each terpene on Aß fibril formation and aggregation were also evaluated using the Thioflavin T (ThT) fluorometric kinetic assay, circular dichroism and transmission electron microscopy (TEM) to visualise fibril and aggregate morphology. RESULTS: Terpenes were intrinsically benign to NSC-34 cells up to 100 µM. No significant antioxidant effects were observed following t-BHP administration with myrcene and ß-caryophyllene, however α-bisabolol provided a modest but significant increase in cell viability in undifferentiated cells. α-bisabolol also demonstrated a significant neuroprotective effect against amyloid ß exposure, with ß-caryophyllene also providing a lesser, but significant increase in cell viability. Protective effects of terpenes were more pronounced in undifferentiated versus differentiated cells, attributable more so to an attenuated loss of cell viability in response to Aß1-42 following NSC-34 cell differentiation. Neuroprotection was associated with a direct inhibition of Aß1-42 fibril and aggregate density, evidenced by both attenuated ThT fluorescence kinetics and both spectral and microscopic evidence of altered and diminished density of Aß aggregates. While myrcene and ß-caryophyllene also elicited reductions in ThT fluorescence and alterations in Aß aggregation, these were less well associated with neuroprotective capacity. CONCLUSIONS: These findings highlight a neuroprotective role of α-bisabolol against Aß-mediated neurotoxicity associated with an inhibition of Aß fibrillization and modest antioxidant effect against lipid peroxidation, while ß-caryophyllene also provided a small but significant measure of protection to Aß-mediated neurotoxicity. Anti-aggregatory effects were not directly correlated with neuroprotective efficacy. This demonstrates that bioactivity of selected terpenes should be a consideration in the emergent use of medicinal cannabis formulations for the treatment of neurodegenerative diseases.

Evaluating Cannabis sativa L.'s neuroprotection potential: From bench to bedside.

BACKGROUND: Neurodegenerative diseases and dementia pose a global health challenge in an aging population, exemplified by the increasing incidence and prevalence of its most common form, Alzheimer's disease. Although several approved treatments exist for Alzheimer's disease, they only afford transient symptomatic improvements and are not considered disease-modifying. The psychoactive properties of Cannabis sativa L. have been recognized for thousands of years and now with burgeoning access to medicinal formulations globally, research has turned to re-evaluate cannabis and its myriad phytochemicals as a potential treatment and adjunctive agent for neurodegenerative diseases. PURPOSE: This review evaluated the neuroprotective potential of C. sativa's active constituents for potential therapeutic use in dementia and Alzheimer's disease, based on published studies demonstrating efficacy in experimental preclinical settings associated with neurodegeneration. STUDY DESIGN: Relevant information on the neuroprotective potential of the C. sativa's phytoconstituents in preclinical studies (in vitro, in vivo) were included. The collated information on C. sativa's component bioactivity was organized for therapeutic applications against neurodegenerative diseases. METHODS: The therapeutic use of C. sativa related to Alzheimer's disease relative to known phytocannabinoids and other phytochemical constituents were derived from online databases, including PubMed, Elsevier, The Plant List (TPL, www.theplantlist.org), Science Direct, as well as relevant information on the known pharmacological actions of the listed phytochemicals. RESULTS: Numerous C. sativa -prevalent phytochemicals were evidenced in the body of literature as having efficacy in the treatment of neurodegenerative conditions exemplified by Alzheimer's disease. Several phytocannabinoids, terpenes and select flavonoids demonstrated neuroprotection through a myriad of cellular and molecular pathways, including cannabinoid receptor-mediated, antioxidant and direct anti-aggregatory actions against the pathological toxic hallmark protein in Alzheimer's disease, amyloid ß. CONCLUSIONS: These findings provide strong evidence for a role of cannabis constituents, individually or in combination, as potential neuroprotectants timely to the emergent use of medicinal cannabis as a novel treatment for neurodegenerative diseases. Future randomized and controlled clinical studies are required to substantiate the bioactivities of phytocannabinoids and terpenes and their likely synergies.

The semi-synthetic flavonoid 2',3',4'-trihydroxyflavone (2-D08) inhibits both SN-38- and cytokine-evoked increases in epithelial barrier permeability in an in vitro intestinal mucositis model.

The chemotherapeutic drug irinotecan and its active metabolite SN-38 have been linked to the development of off-target gastrointestinal toxicity and inflammation, termed gastrointestinal mucositis (GIM). Flavonoids possess antioxidant and anti-inflammatory effects in models of gastrointestinal inflammation; however, few studies have investigated their potential in ameliorating chemotherapy-induced GIM. Here, we characterised the intestinal epithelial barrier-protective and antioxidant capacity of the novel flavonoids 2',3',4'-trihydroxyflavone (2-D08) and transilitin in comparison with flavones myricetin and quercetin in vitro via viability and permeability assessments in Caco-2 epithelial monolayers exposed to 7-ethyl-10-hydroxycamptothecin (SN-38). Transilitin, 2-D08 and myricetin maintained barrier function in the presence of SN-38, with 2-D08 proving most effective. 2-D08 was the most effective inhibitor of cytokine-evoked increases in epithelial permeability, with myricetin providing modest protection; quercetin afforded no significant protection against either SN-38 or cytokine-evoked reductions in barrier integrity. Each flavonoid significantly reduced tert-butyl hydroperoxide (tbhp)-induced reactive oxygen species (ROS) generation, although 2-D08 was comparatively less effective. These results highlight a novel role for 2-D08 as an inhibitor of both SN-38 and cytokine-evoked increases in epithelial permeability, with lesser barrier protective roles ascribed to transilitin and myricetin and not correlated with antioxidant capacity. Such novel flavonoids as 2-D08 may have active or adjunctive roles in ameliorating chemotherapy and inflammation-evoked changes in intestinal barrier function.

Phytocannabinoids: General Aspects and Pharmacological Potential in Neurodegenerative Diseases.

In the last few years research into Cannabis and its constituent phytocannabinoids has burgeoned, particularly in the potential application of novel cannabis phytochemicals for the treatment of diverse illnesses related to neurodegeneration and dementia, including Alzheimer's (AD), Parkinson's (PD) and Huntington's disease (HD). To date, these neurological diseases have mostly relied on symptomatological management. However, with an aging population globally, the search for more efficient and disease-modifying treatments that could delay or mitigate disease progression is imperative. In this context, this review aims to present state of the art in the research with cannabinoids and novel cannabinoid-based drug candidates that have been emerged as novel promising alternatives for drug development and innovation in the therapeutics of a number of diseases, especially those related to CNS-disturbance and impairment.

P53 activation suppresses irinotecan metabolite SN-38-induced cell damage in non-malignant but not malignant epithelial colonic cells.

Nutlin-3a is a p53 activator and potential cyclotherapy approach that may also mitigate side effects of chemotherapeutic drugs in the treatment of colorectal cancer. We investigated cell proliferation in a panel of colorectal cancer (CRC) cell lines with wild-type or mutant p53, as well as a non-tumorigenic fetal intestinal cell line following Nutlin-3a treatment (10 µM). We then assessed apoptosis at 24 and 48 h following administration of the active irinotecan metabolite, SN-38 (0.001 µM - 1 µM), alone or following pre-treatment with Nutlin-3a (10 µM). Nutlin-3a treatment (10 µM) significantly reduced proliferation in wild-type p53 expressing cell lines (FHS 74 and HCT116+/+) at 72 and 96 h, but was without effect in cell lines with mutated or deleted p53 (Caco-2, SW480, and HCT 116-/-). SN-38 treatment induced significant apoptosis in all cell lines after 48 h. Nutlin-3a unexpectedly increased cell death in the p53 wild-type CRC cell line, HCT116+/+, while Nutlin-3a pre-treatment provided protection from SN-38 in the p53 wild-type normal cell line, FHs 74. These results demonstrate Nutlin-3a's selective growth-arresting efficacy in p53 wild-type non-malignant intestinal cell lines, enabling the selective targeting of malignant cells with chemotherapy drugs. These studies highlight the potential of Nutlin-3a to minimise intestinal mucosal damage following chemotherapy.

Polyphenol Honokiol and Flavone 2',3',4'-Trihydroxyflavone Differentially Interact with α-Synuclein at Distinct Phases of Aggregation.

The association between protein aggregation and neurodegenerative diseases such as Parkinson's disease continues to be well interrogated but poorly elucidated at a mechanistic level. Nevertheless, the formation of amyloid fibrils from the destabilization and misfolding of native proteins is a molecular hallmark of disease. Consequently, there is ongoing demand for the identification and development of small molecules which prevent fibril formation. This study comprehensively assesses the inhibitory properties of two small molecules, the lignan polyphenol honokiol and the flavonoid 2',3',4'-trihydroxyflavone, in preventing α-synuclein fibrilization. The data shows that honokiol does not prevent α-synuclein fibril elongation, while 2',3',4'-trihydroxyflavone is effective at inhibiting fibril elongation and induces oligomer formation (for both wild-type α-synuclein and the disease-associated A53T mutation). Moreover, the exposed hydrophobicity of α-synuclein fibrils is reduced in the presence of 2',3',4'-trihydroxyflavone, whereas the addition of honokiol did not reduce the hydrophobicity of fibrils. In addition, ion mobility-mass spectrometry revealed that the conformation of α-synuclein wild-type and A53T monomers after disassembly is restored to a nonaggregation-prone state upon 2',3',4'-trihydroxyflavone treatment. Collectively, this study shows that the mechanisms by which these polyphenols and flavonoids prevent fibril formation are distinct by their interactions at various phases of the fibril-forming pathway. Furthermore, this study highlights how thorough biophysical interrogation of the interaction is required for understanding the ability of inhibitors to prevent protein aggregation associated with disease.

Ecklonia radiata extract containing eckol protects neuronal cells against Aß1-42 evoked toxicity and reduces aggregate density.

Brown seaweed (Phaeophyceae) polyphenolics such as phlorotannins are ascribed various biological activities, including neuroprotection. Of these seaweeds, Ecklonia radiata (E. radiata) is found abundantly along South Australian coastal regions; however it has not been explored for various biological activities relative to any component phlorotannins previously ascribed neuroprotective capacity. In the present study, we evaluated neuroprotective activity against the neurotoxic amyloid ß protein (Aß1-42) of an ethanol extract of E. radiata compared with various additional solvent-solubilised fractions in a neuronal PC-12 cell line. The ethyl acetate fraction comprising 62% phlorotannins demonstrated the most efficacious neuroprotective activity, inhibiting neurotoxicity at all Aß1-42 concentrations. In addition, this fraction demonstrated a significant reduction in Aß aggregate density, but did not alter overall aggregate morphology. Centrifugal partitioning chromatography was used to isolate the major component, eckol, in high yield and liquid chromatography-mass spectrometry was used to characterize the major components of the ethyl acetate fraction. Our results demonstrate that the prevalence of eckol-type phlorotannins are associated with neuroprotective bioactivity of E. radiata, suggestive of potential nutraceutical and biopharmaceutical uses of this brown seaweed phlorotannin in dementia.