Potential analgesic effect of a novel cannabidiol nanocrystals powder for the treatment of neuropathic pain.

BACKGROUND: The current analgesics often prevent patients from getting effective treatment due to their adverse effects. Cannabidiol (CBD) is well tolerated, has few side effects and has been extensively investigated in analgesia. However, its oral bioavailability is extremely low. In order to solve this problem, we developed the cannabidiol nanocrystals (CBD-NC) in the earlier stage. METHODS: In this study, we evaluated the nociceptive behaviours associated with neuropathic pain (NP) induced by the spared nerve injury (SNI) model. Assessment of pain threshold was evaluated by paw withdraw threshold (PWT) and paw withdrawal latency (PWL). The improving effect on the motor dysfunction was determined by rota-rod testing. To assess the neuroprotective effect, nerve demyelination and expression of peripheral myelin protein PMP22 were measured with myelin sheath staining and western blotting. Protein expressions in microglia of spinal cord were tested by western blot to explore the underlying mechanism. RESULTS: Compared with the CBD oil solution, CBD-NC significantly reduced mechanical allodynia and thermal hyperalgesia in rats. CBD-NC could improve motor dysfunction induced by SNI in rats, significantly reverse the demyelination and increase the expression of the marker protein of peripheral myelin. Underlying spinal analgesic mechanism of microglia and related factors were preliminarily confirmed. CONCLUSIONS: CBD-NC administration is an effective treatment for NP associated with SNI, and the analgesic effect of CBD-NC was significantly better than that of CBD oil sol. By contrast, CBD-NC has a fast-acting and long-term effect in the treatment of NP. Our study further supports the potential therapeutic effect of CBD-NC on NP. SIGNIFICANCE: The absolute bioavailability of the CBD-NC intramuscular injection formulation can reach 203.31%, which can solve the problem of low oral bioavailability. This research evaluated the therapeutic effect of CBD-NC on NP associated with the SNI model for the first time. All available date showed that whatever the analgesic or neuroprotective effect of CBD-NC, it was significantly better than that of CBD oil sol., which was consistent with the results of the pharmacokinetic. This research supports the initiation of more trials testing the efficacy of CBD-NC for treating NP.

Pharmacokinetics and Oral Bioavailability of Panax Notoginseng Saponins Administered to Rats Using a Validated UPLC-MS/MS Method.

Panax notoginseng saponins (PNS) are the most important bioactive components of P. Notoginseng. In this paper, an evaluation of the pharmacokinetics and oral absolute bioavailability of PNS was carried out following intravenous and oral administration of PNS to Sprague-Dawley rats. The plasma concentration of 28 PNS was determined using a validated UPLC-MS/MS system. The results demonstrated that Rb1(32.8%), Rg1(41.4%), R1(9.4%), Re(4.5%), and Rd(3.5%) are the five main ingredients of PNS for administration. After oral administration, it was found that the area under the curve (AUC0-72 h) for these five major saponins was significantly different. AUC0-72 h of Rb1 and Rd accounted for about 60% of all PNS exposure, while AUC0-72 h of Rg1 and R1 only accounted for 0.7%, and Re was undetectable in plasma. Also, PPD, PPT, and CK were detected as the major PNS metabolites in vivo. Furthermore, it was shown that the total oral bioavailability of PNS was only 1.2%.

Atypical Angucyclinones with Ring Expansion and Cleavage from a Marine Streptomyces sp.

A unique ring C-expanded angucyclinone, oxemycin A (1), and seven new ring-cleavage derivatives (2-5 and 9-11) were isolated from the marine actinomycete Streptomyces pratensis KCB-132, together with eight known analogues (6-8 and 12-16). Their structures were elucidated by spectroscopic analyses, single-crystal X-ray diffractions, and NMR and ECD calculations. Among these atypical angucyclinones, compound 1 represented the first seven-membered ketoester in the angucyclinone family, which sheds light on the origin of fragmented angucyclinones with C-ring cleavage at C-12/C-12a in the Baeyer-Villiger hypothesis, such as 2-4, while the related "nonoxidized" analogues 5-8 seem to originate from a diverse pathway within the Grob fragmentation hypothesis. Additionally, we have succeeded in the challenging separation of elmenols E and F (12) into their four stereoisomers, which remained stable in aprotic solvents but rapidly racemized under protic conditions. Furthermore, the absolute configurations of LS1924 and its isomers (14 and 15) were assigned by ECD calculations for the first time. Surprisingly, these two bicyclic acetals are susceptible to hydrolysis in solution, resulting in fragmented derivatives 17 and 18 with C-ring cleavage between C-6a and C-7. Compared with ring C-modified angucyclinones, ring A-cleaved 11 was more active to multiple resistant "ESKAPE" pathogens with MIC values ranging from 4.7 to 37.5 µg/mL.

Design, synthesis, and biological evaluation of triazole-pyrimidine-methylbenzonitrile derivatives as dual A2A/A2B adenosine receptor antagonists.

A series of novel dual A2A/A2B AR antagonists based on the triazole-pyrimidine-methylbenzonitrile core were designed and synthesised. The A2A AR antagonist cAMP functional assay results were encouraging for most target compounds containing quinoline or its open-ring bioisosteres. In addition, compound 7i displayed better inhibitory activity on A2B AR (IC50 14.12 nM) and higher potency in IL-2 production than AB928. Moreover, molecular docking studies were carried out to explain the rationality of molecular design and the activity of compound 7i. Further studies on 7f and 7i revealed good liver microsomes stabilities and acceptable in vivo PK profiles. This study provides insight into the future development of dual A2A/A2B AR antagonists for cancer immunotherapy.

Enhanced Intramuscular Bioavailability of Cannabidiol Using Nanocrystals: Formulation, In Vitro Appraisal, and Pharmacokinetics.

Cannabidiol (CBD) has poor water solubility and is subjected to extensive first-pass metabolism. These absorption obstacles are responsible for low and variable oral bioavailability of CBD. This study endeavored to improve CBD bioavailability by intramuscular (IM) injection of CBD nanocrystals (CBD-NC). The nanocrystals were prepared by antisolvent precipitation method and were characterized in terms of the particle size, polydispersity index (PDI), zeta potential, morphology, and crystalline status. CBD-NC displayed a particle size of 141.7±1.5 nm, a PDI of 0.18±0.01, and a zeta potential of -25.73 mV. CBD-NC freeze-dried powder using bovine serum albumin (BSA) as cryoprotectant had good redispersibility, and the average particle size was 139.1±1.4 nm after reconstitution. Moreover, these freeze-dried powders were characterized for drug loading and pH and were evaluated for in vitro dissolution and in vivo studies in a rat model. The in vivo results showed that AUC0-24 h and Cmax of CBD by IM injection of CBD nanocrystals increased significantly compared with that of oral (P.O) administration of CBD nanocrystals and CBD oil solution. This underlines the nano-sized CBD could be suggested as a practical and simple nanosystem for IM delivery with improved bioavailability. More importantly, these results pave the way for future development of CBD-NC retentive dosage forms. Graphical abstract.

Strepyrazinone, a tricyclic diketopiperazine derivative with cytotoxicity from a marine-derived actinobacterium.

Strepyrazinone (1), a tricyclic diketopiperazine derivative with a carbon skeleton unprecedented in natural products, was isolated from the marine-derived Streptomyces sp. B223. Its structure was elucidated by spectroscopic analyses and electronic circular dichroism calculation. Compound 1 showed cytotoxic activity against HCT-116 cancer cell lines with an IC50 value of 0.34 µM.

Antibacterial and Cytotoxic Bridged and Ring Cleavage Angucyclinones From a Marine Streptomyces sp.

Chemical investigation of a marine-derived Streptomyces sp. KCB-132, cultivated in liquid ISP2 medium, had led to the discovery of three C-ring cleavage angucyclinone N-heterocycles, pratensilins A-C, with a novel spiro indolinone-naphthofuran skeleton. Addition of 50 µM LaCl3 to the same medium and subsequent chemical analysis of this strain returned a new member of this rare class, pratensilin D (1), along with two new angucyclinone derivatives, featuring ether-bridged (2) and A-ring cleavage (3) structural properties. Their structures and absolute configurations were assigned by spectroscopic analysis, single-crystal X-ray diffractions, and equivalent circulating density (ECD) calculations. (+)- and (-)-1, a pair of enantiomeric nitrogen-containing angucyclinones, exhibited different strengths of antibacterial and cytotoxic activities.

Intensity modulated radiotherapy in combination with endocrinotherapy in the treatment of middle and advanced Prostatic Cancer.

OBJECTIVE: To evaluate the clinical efficacy of intensity modulated radiation therapy and endocrinotherapy for middle and advanced prostate cancer. METHODS: Total 104 elderly patients with middle and advanced prostate cancer who were admitted to our hospital from November 2014 to August 2015 were selected using random number table method. They were divided into intensity-modulated radiotherapy combined with endocrinotherapy group (observation group) and conventional radiotherapy combined with endocrinotherapy group (control group), 52 each. The serum levels of prostate specific antigen (PSA) and free prostate antigen (f PSA) were measured three months after treatment. The short-term efficacy and toxic and side effects of the patients were observed, and the survival rate was recorded through three-year follow up. RESULTS: The clinical effective rate of the observation group was 92.68%, and that of the control group was 70.73%; there was a significant difference between the two groups (P<0.05). The serum PSA and f PSA levels of the two groups were similar before treatment, but there was no significant difference (P>0.05). The serum PSA and f PSA levels after treatment were significantly lower than before treatment. The incidence of adverse reactions in the observation group was lower than that in the control group (P<0.05). The one-year and three-year survival rates of the two groups were significantly different (90.0 vs. 80.0%, 60.0 vs. 43.3%, P>0.05). CONCLUSION: Intensity modulated radiotherapy combined with endocrinotherapy was safe and well tolerated in the treatment of middle and advanced prostate cancer. It can improve the short-term efficacy and effectively reduce the serum oncological index concentration of patients. It can be promoted in clinics.

N-methyl-D-aspartate receptor and L-type voltage-gated Ca2+ channel activation mediate proline-rich tyrosine kinase 2 phosphorylation during cerebral ischemia in rats.

Cerebral ischemia induces rapid efflux of glutamate into the extracellular space contributing to excessive activation of glutamate receptors in postsynaptic cells, particularly N-methyl-D-aspartate (NMDA) receptors, which triggers the neuron lesion through calcium overload. Our studies indicated that cerebral ischemia stimulated the rapid activation of nonreceptor tyrosine kinases proline-rich tyrosine kinase 2 (Pyk2) and Src and the binding to Pyk2 activated the latter. Pyk2 activation significantly depends on the increase of the intracellular calcium level; blockage of both calcium ion channel NMDA receptors and L-type voltage-gated Ca2+ channel (L-VGCC), respectively, could effectively inhibit phosphorylation of Pyk2 in early ischemia episodes. Moreover, pretreatment with the protein kinase C inhibitor (chelerythrine chloride) reduced the ischemia-induced activation of Pyk2. Noticeably, CaMKII, a family of calcium/calmodulin-dependent kinases, also may be involved in the regulation of Pyk2 activity because its inhibitor KN62 attenuated Pyk2 phosphorylation during ischemia. Together with previous studies, these results indicate that calcium influx elicited by active NMDA receptors and L-VGCC triggers the Pyk2-Src signaling pathway mediated by PKC, which aggravates cerebral ischemia lesions through up-regulating the function of NMDA receptors after the onset of ischemia, and also could be regulated partly by CaM-dependent kinases like CaMKII.

NMDA receptor-mediated immediate Ser831 phosphorylation of GluR1 through CaMKIIalpha in rat hippocampus during early global ischemia.

The phosphorylation of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptors subunit GluR1 at Ser831 has been implicated in the regulation of AMPA receptors channel. In this paper, Ser831 phosphorylation of GluR1 in rat hippocampus was investigated, which significantly increased during early global ischemia. To further illustrate the underlying mechanisms, calcium/calmodulin-dependent kinase IIalpha (CaMKIIalpha) inhibitor 1-[N,O-bis-(5-isoquinolinesulfonyl)-N-methyl-L-tyrosyl]-4-phenylpiperazine (KN62), CaM antagonist trifluoperazine (TFP), N-methyl-D-aspartate (NMDA) receptor antagonist dextromethorphan (DEX), AMPA receptor antagonist 6,7-dinitro-quinoxaline-2,3-(1H,4H)-dione (DNQX) and L-type voltage-gated Ca2+ channel (L-VGCC) blocker nifedipine (NIF), were respectively administrated to the rats 20 min prior to ischemia. The results showed that KN62, TFP and DEX significantly attenuated Ser831 phosphorylation of GluR1, while DNQX and NIF had no obvious effects. Consequently, the studies suggest that early global ischemia induced Ser831 phosphorylation of GluR1 may be closely associated with CaMKIIalpha and the NMDA receptor, while the immediate Ser831 phosphorylation of GluR1 may have been involved in pathogenic events after early global ischemia.

Delayed activation and regulation of MKK7 in hippocampal CA1 region following global cerebral ischemia in rats.

c-Jun N-terminal protein kinase (JNK) activation and subsequent c-Jun phosphorylation which stimulates its transcriptional activity have been well studied in cerebral ischemia. To determine whether mitogen-activated protein kinase kinase 7 (MKK7) play a role in JNK activation in response to the stress of global cerebral ischemia, we tested the activation of such a kinase by using phospho-Ser and phospho-Thr antibodies. Immunoprecipitation and Western blot analysis revealed that MKK7 was expressed at similar levels in all conditions, whereas phospho-MKK7 was highly augmented from 1 to 5 days and reached its peak at 3 days after 15 min of ischemia. Consistent with the active phase, the interaction of MLK3, ASK1 and phospho-JNK with MKK7 was increased compared with sham control, as shown by coimmunoprecipitation experiments. Moreover, MKK7 activation was markedly reduced by pretreatment of the free radical scavenging thiol antioxidant N-acetylcysteine (NAC). Together with previous studies, the late activation of MKK7 in hippocampal CA1 region may contribute to delayed cell death, and the protective effects of antioxidant against ischemia-induced injury may be partially mediated by the down-regulation of JNK signal pathway.