Bee propolis, especially Euro-Asian poplar propolis, is among the most well-known natural products traditionally used to treat pharyngitis and minor wounds. The aim of this research was to investigate the pharmacological properties responsible for poplar propolis effectiveness using, for the first time, different in vitro approaches applied to a chemically characterized sample. The anti-inflammatory activity was compared with flurbiprofen by determining pro-inflammatory cytokines released by lipopolysaccharide-stimulated human peripheral blood mononuclear cells (PBMC). The antibacterial activity against Gram+ and Gram- bacteria was assessed, as well as antiviral effects on H1N1 influenza a virus. Poplar propolis (5 and 25 µg/mL) exerted a concentration-dependent anti-inflammatory activity. In this range of concentrations, propolis effect was not inferior to flurbiprofen on cytokines released by lipopolysaccharide (LPS)-stimulated human PBMC. Poplar propolis was found to upregulate IL-6 and IL-1β in non-stimulated PBMC. S. aureus, S. pyogenes, and S. pneumoniae were the most susceptible bacterial strains with inhibitory concentrations ranging from 156 to 625 µg/mL. A direct anti-influenza activity was not clearly seen. Effective anti-inflammatory concentrations of propolis were significantly lower than the antibacterial and antiviral ones and results suggested that the anti-inflammatory activity was the most important feature of poplar propolis linked to its rationale use in medicine.

Ylang-ylang essential oil (YEO), obtained from the flowers of the tropical tree Cananga odorata (Lam.) Hook. f. & Thomson (family Annonaceae), has been largely used in the traditional medicine with many uses, including anxiety and altered neuronal states. Neuropathic pain is a chronic pain condition with a high incidence of comorbidities, such as anxiety, depression, and other mood disorders, that drastically affect the patient's quality of life. The currently available drugs used for the management of neuropathic pain are inadequate due to poor efficacy and tolerability, highlighting the medicinal need of a better pharmacotherapy. Several clinical studies have reported that massage or inhalation with selected essentials oils reduces symptoms associated to pain and anxiety. The aim of this study was to investigate the analgesic properties of YEO and its efficacy in reducing neuropathy-associated mood alterations. The analgesic properties were tested in the spared nerve injury (SNI) model using male mice. Anxiolytic, antidepressant, and locomotor properties were also evaluated using behavioural tests. Finally, the YEO mechanism of action was investigated in the spinal cord and hippocampus of neuropathic mice. Oral administration of YEO (30 mg/kg) reduced SNI-induced neuropathic pain and ameliorates pain-related anxiety symptoms that appeared 28 days after surgery. YEO reduced the expression of MAPKs, NOS2, p-p65, markers of neuroinflammation, and promoted normalizing effect on neurotrophin levels (BDNF). YEO induced neuropathic pain relief and ameliorated pain-associated anxiety, representing an interesting candidate for the management of neuropathic pain conditions and pain-related comorbidities.

Cannabis sativa L. is increasingly emerging for its protective role in modulating neuroinflammation, a complex process orchestrated among others by microglia, the resident immune cells of the central nervous system. Phytocannabinoids, especially cannabidiol (CBD), terpenes, and other constituents trigger several upstream and downstream microglial intracellular pathways. Here, we investigated the molecular mechanisms of a CBD‐ and terpenes‐enriched C. sativa extract (CSE) in an in vitro model of neuroinflammation. We evaluated the effect of CSE on the inflammatory response induced by exposure to lipopolysaccharide (LPS) in BV‐2 microglial cells, compared with CBD and β‐caryophyllene (CAR), CB2 receptors (CB2r) inverse and full agonist, respectively. The LPS‐induced upregulation of the pro‐inflammatory cytokines IL‐1β, IL‐6, and TNF‐α was significantly attenuated by CSE and only partially by CBD, whereas CAR was ineffective. In BV‐2 cells, these anti‐inflammatory effects exerted by CSE phytocomplex were only partially dependent on CB2r modulation and they were mediated by the regulation of enzymes responsible for the endocannabinoids metabolism, by the inhibition of reactive oxygen species release and the modulation of JNK/p38 cascade with consequent NF‐κB p65 nuclear translocation suppression. Our data suggest that C. sativa phytocomplex and its multitarget mechanism could represent a novel therapeutic strategy for neuroinflammatory‐related diseases.

Background and Purpose: Chronic pain is considered a key factor contributing to alcohol use disorder (AUD). The mechanisms responsible for chronic pain associated with chronic alcohol consumption are unknown. We evaluated the development of chronic pain in a mouse model of alcohol dependence and investigate the role of neuroinflammation.Experimental Approach: The chronic‐intermittent ethanol two‐bottle choice CIE‐2BC paradigm generates three groups: alcohol‐dependent with escalating alcohol intake, nondependent (moderate drinking) and alcohol‐naïve control male and female mice. We measured mechanical allodynia during withdrawal and after the last voluntary drinking. Immunoblotting was used to evaluate the protein levels of IBA‐1, CSFR, IL‐6, p38 and ERK2/1 in spinal cord tissue of dependent and non‐dependent animals.Key Results: We found significant escalation of drinking in the dependent group in male and female compared with the non‐dependent group. The dependent group developed mechanical allodynia during 72 h of withdrawal, which was completely reversed after voluntary drinking. We observed an increased pain hypersensitivity compared with the naïve in 50% of non‐dependent group. Increased IBA‐1 and CSFR expression was observed in spinal cord tissue of both hypersensitivity‐abstinence related and neuropathy‐alcohol mice, and increased IL‐6 expression and ERK1/2 activation in mice with hypersensitivity‐related to abstinence, but not in mice with alcohol‐evoked neuropathic pain.Conclusions and Implications: The CIE‐2BC model induces two distinct pain conditions specific to the type of ethanol exposure: abstinence‐related hypersensitivity in dependent mice and alcohol‐evoked neuropathic pain in about a half of the non‐dependent mice.

The worldwide incidence of neuropathic pain is around 7–8% and is associated with significant and disabling comorbidities (sleep disturbances, depression, anxiety). It is now known that cellular ageing of microglia contributes to neurodegenerative diseases, mood disorders, and, even if with less evidence, chronic pain. The aim of this work was to investigate in vitro and in vivo the senolytic activity of rosmarinic acid (RA) to be exploited for the management of NP symptoms. BV2 cells were stimulated with LPS 500 ng/mL for 24 h. Treatment with RA 1 µM improved cell viability and reduced IL-1ß release leading to an attenuation of neuroinflammation. We then moved on to test the efficacy of RA in reducing microglial senescence. In our model, BV2 cells were stimulated with LPS 500 ng/mL every 72 h for 4 h/day, over a period of 10 days. RA 1 µM reduced the expression of the β-galactosidase enzyme, reduced the release of senescence-associated secretory phenotype (SASP) factors, increased cell viability, and reduced the presence of nuclear foci of senescence (SAHF), well-known cellular senescence markers. In the Spared Nerve Injury (SNI) model, 28 days from surgery, repeated oral administration of RA 5 mg/kg reduced hyperalgesia and NP-associated symptoms, such as anxiety and depression. A reduction of senescence markers was detected on both hippocampal and spinal samples of SNI-treated mice. This study represents a starting point for investigating the role of microglial senescence as a possible pharmacological target in controlling symptoms related to the more advanced stages of peripheral neuropathy.