Blackberry Leaf (Rubus fruticosus) and Arthritis / joint pain: evidence and sources

Vascular dementia (VaD) is characterized by progressive memory impairment, which is associated with microglia-mediated neuroinflammation. Polyphenol-rich natural plants, which possess anti-inflammatory activities, have attracted scientific interest worldwide. This study investigated whether Rubus fruticosus leaf extract (RFLE) can attenuate VaD. Sprague-Dawley rats were separated into five groups: SO, sham-operated and treated with vehicle; OP, operated and treated with vehicle; RFLE-L, operated and treated with low dose (30 mg/kg) of RFLE; RFLE-M, operated and treated with medium dose (60 mg/kg) of RFLE; and RFLE-H, operated and treated with high dose (90 mg/kg) of RFLE. Bilateral common carotid artery and hypotension were used as a modeling procedure, and the RFLE were intraorally administered for 5 days (preoperative 2 and postoperative 3 days). The rats then underwent memory tests including the novel object recognition, Y-maze, Barnes maze, and passive avoidance tests, and neuronal viability and neuroinflammation were quantified in their hippocampi. The results showed that the OP group exhibited VaD-associated memory deficits, neuronal death, and microglial activation in hippocampi, while the RFLE-treated groups showed significant attenuation in all above parameters. Next, using BV-2 microglial cells challenged with lipopolysaccharide (LPS), we evaluated the effects of RFLE in dynamics of proinflammatory mediators and the upstream signaling pathway. RFLE pretreatment significantly inhibited the LPS-induced release of nitric oxide, TNF-α, and IL-6 and upregulation of the MAPKs/NF-κB/iNOS pathway. Collectively, we suggest that RFLE can attenuate the histologic alterations and memory deficits accompanied by VaD, and these roles are, partly due to the attenuation of microglial activation.

A comprehensive characterization of the phytochemicals present in a blackberry fruit extract by HPLC-TOF-MS has been carried out. The main compounds in the extract were ursane-type terpenoids which, along with phenolic compounds, may be responsible for the bioactivity of the extract. In vitro antioxidant capacity was assessed through Folin-Ciocalteu (31.05 ± 4.9 mg GAE/g d.w.), FRAP (637.8 ± 3.2 μmol Fe 2+ /g d.w.), DPPH (IC 50 97.1 ± 2.4 μg d.w./mL) and TEAC (576.6 ± 8.3 μmol TE/g d.w.) assays. Furthermore, the extract exerted remarkable effects on in vitro cellular antioxidant activity in HUVEC cells at a concentration of 5 mg/mL. Antimicrobial activity of the extract was also tested. Most sensible microorganisms were Gram-positive bacteria, such as E. faecalis , B. cereus and Gram-negative E. coli (MBC of 12.5 mg/mL). IC 50 values against colon tumoral cells HT-29 (4.9 ± 0.2 mg/mL), T-84 (5.9 ± 0.3 mg/mL) and SW-837 (5.9 ± 0.2 mg/mL) were also obtained. Furthermore, blackberry extract demonstrated anti-inflammatory activity inhibiting the secretion of pro-inflammatory IL-8 cytokines in two cellular models (HT-29 and T-84) in a concentration-dependent manner. These results support that blackberry fruits are an interesting source of bioactive compounds that may be useful in the prevention and treatment of different diseases, mainly related to oxidative stress.

The polyphenolic profiles by HPLC-TOF-MS of strawberry 'San Andreas' and blackberry 'Black Satin' crude extracts (CE) were analyzed. Anthocyanin-enriched fractions (AEFs) and proanthocyanidin-enriched fractions (PEFs) were prepared, and all samples were probed for in vitro anti-inflammatory and wound healing effects in a LPS-stimulated RAW 264.7 macrophage model and in a skin fibroblast migration and proliferation assay, respectively. Blackberry samples exhibited higher ROS reduction than strawberry's (up to 50% ROS suppression). Berries CEs exhibited 20% inhibition in Cox-2 gene expression, while AEFs and PEFs were inactive at the same concentration. Strawberry AEF and PEF were more active against IL-1β and IL-6 gene expressions than the similar fractions from blackberry, where PEF was more active than AEF (75% suppression by strawberry PEF). Moreover, berry PEFs were the active polyphenol fraction against iNOS gene expression (50% and 65% gen suppression by strawberry and blackberry PEF, respectively), mirroring results of NO synthesis suppression. The cell migration potential of berry polyphenolics was associated with anthocyanins. AEFs showed fibroblast migration around 50% of that registered for the positive control. Results obtained in this work highlight the anti-inflammatory properties of berry polyphenolics, especially due to proanthocyanidins. Moreover, promising results were obtained about the effects of berry anthocyanins on wound healing.