Glochidion littorale Leaf Extract Exhibits Neuroprotective Effects in Caenorhabditis elegans via DAF-16 Activation.

A number of plants used in folk medicine in Thailand and Eastern Asia are attracting interest due to the high bioactivities of their extracts. The aim of this study was to screen the edible leaf extracts of 20 plants found in Thailand and investigate the potential neuroprotective effects of the most bioactive sample. The total phenol and flavonoid content and 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity were determined for all 20 leaf extracts. Based on these assays, Glochidion littorale leaf extract (GLE), which showed a high value in all tested parameters, was used in further experiments to evaluate its effects on neurodegeneration in Caenorhabditis elegans. GLE treatment ameliorated H2O2-induced oxidative stress by attenuating the accumulation of reactive oxygen species and protected the worms against 1-methyl-4-phenylpyridinium-induced neurodegeneration. The neuroprotective effects observed may be associated with the activation of the transcription factor DAF-16. The characterization of this extract by LC-MS identified several phenolic compounds, including myricetin, coumestrin, chlorogenic acid, and hesperidin, which may play a key role in neuroprotection. This study reports the novel neuroprotective activity of GLE, which may be used to develop treatments for neurodegenerative diseases such as Parkinson's syndrome.

Levodopa-Reduced Mucuna pruriens Seed Extract Shows Neuroprotective Effects against Parkinson's Disease in Murine Microglia and Human Neuroblastoma Cells, Caenorhabditis elegans, and Drosophila melanogaster.

Mucuna pruriens (Mucuna) has been prescribed in Ayurveda for various brain ailments including 'kampavata' (tremors) or Parkinson's disease (PD). While Mucuna is a well-known natural source of levodopa (L-dopa), published studies suggest that other bioactive compounds may also be responsible for its anti-PD effects. To investigate this hypothesis, an L-dopa reduced (<0.1%) M. pruriens seeds extract (MPE) was prepared and evaluated for its anti-PD effects in cellular (murine BV-2 microglia and human SH-SY5Y neuroblastoma cells), Caenorhabditis elegans, and Drosophila melanogaster models. In BV-2 cells, MPE (12.5⁻50 µg/mL) reduced hydrogen peroxide-induced cytotoxicity (15.7-18.6%), decreased reactive oxygen species production (29.1-61.6%), and lowered lipopolysaccharide (LPS)-induced nitric oxide species release by 8.9⁻60%. MPE (12.5-50 µg/mL) mitigated SH-SY5Y cell apoptosis by 6.9-40.0% in a non-contact co-culture assay with cell-free supernatants from LPS-treated BV-2 cells. MPE (12.5-50 µg/mL) reduced 6-hydroxydopamine (6-OHDA)-induced cell death of SH-SY5Y cells by 11.85⁻38.5%. Furthermore, MPE (12.5-50 µg/mL) increased median (25%) and maximum survival (47.8%) of C. elegans exposed to the dopaminergic neurotoxin, methyl-4-phenylpyridinium. MPE (40 µg/mL) ameliorated dopaminergic neurotoxin (6-OHDA and rotenone) induced precipitation of innate negative geotaxis behavior of D. melanogaster by 35.3 and 32.8%, respectively. Therefore, MPE contains bioactive compounds, beyond L-dopa, which may impart neuroprotective effects against PD.

Pomegranate's Neuroprotective Effects against Alzheimer's Disease Are Mediated by Urolithins, Its Ellagitannin-Gut Microbial Derived Metabolites.

Pomegranate shows neuroprotective effects against Alzheimer's disease (AD) in several reported animal studies. However, whether its constituent ellagitannins and/or their physiologically relevant gut microbiota-derived metabolites, namely, urolithins (6H-dibenzo[b,d]pyran-6-one derivatives), are the responsible bioactive constituents is unknown. Therefore, from a pomegranate extract (PE), previously reported by our group to have anti-AD effects in vivo, 21 constituents, which were primarily ellagitannins, were isolated and identified (by HPLC, NMR, and HRESIMS). In silico computational studies, used to predict blood-brain barrier permeability, revealed that none of the PE constituents, but the urolithins, fulfilled criteria required for penetration. Urolithins prevented ß-amyloid fibrillation in vitro and methyl-urolithin B (3-methoxy-6H-dibenzo[b,d]pyran-6-one), but not PE or its predominant ellagitannins, had a protective effect in Caenorhabditis elegans post induction of amyloid ß(1-42) induced neurotoxicity and paralysis. Therefore, urolithins are the possible brain absorbable compounds which contribute to pomegranate's anti-AD effects warranting further in vivo studies on these compounds.

Evaluation of clonal herbs of Lamiaceae species for management of diabetes and hypertension.

In the current study, we screened 7 clonal lines from single seed phenotypes of Lamiaceae family for the inhibition of alpha-amylase, alpha-glucosidase and angiotensin converting enzyme (ACE) inhibitory activity. Water extracts of oregano had the highest alpha-glucosidase inhibition activity (93.7%), followed by chocolate mint (85.9%) and lemon balm (83.9%). Sage (78.4 %), and three different clonal lines of rosemary: rosemary LA (71.4%), rosemary 6 (68.4%) and rosemary K-2 (67.8%) also showed significant alpha-glucosidase inhibitory activity. The alpha-glucosidase inhibitory activity of the extracts was compared to selected specific phenolics detected in the extracts using HPLC. Catechin had the highest alpha-glucosidase inhibitiory activity (99.6 %) followed by caffeic acid (91.3 %), rosmarinic acid (85.1%) and resveratrol (71.1 %). Catechol (64.4%), protocatechuic acid (55.7%) and quercetin (36.9%) also exhibited significant alpha-glucosidase inhibitory activity. Results suggested that alpha-glucosidase inhibitory activity of the clonal extracts correlated to the phenolic content, antioxidant activity and phenolic profile of the extracts. The clonal extracts of the herbs and standard phenolics tested in this study did not have any effect on the alpha-amylase activity. We also investigated the ability of the clonal extracts to inhibit rabbit lung angiotensin I-converting enzyme (ACE). The water extracts of rosemary, rosemary LA had the highest ACE inhibitory activity (90.5%), followed by lemon balm (81.9%) and oregano (37.4 %). Lower levels of ACE inhibition were observed with ethanol extracts of oregano (18.5 %) and lemon balm (0.5 %). Among the standard phenolics only resveratrol (24.1 %), hydroxybenzoic acid (19.3 %) and coumaric acid (2.3 %) had ACE inhibitory activity.

Enhancing health benefits of berries through phenolic antioxidant enrichment: focus on cranberry.

Emerging epidemiological evidence is increasingly pointing to the beneficial effects of fruits and vegetables in managing chronic and infectious diseases. These beneficial effects are now suggested to be due to the constituent phenolic phytochemicals having antioxidant activity. Cranberry like other fruits is also rich in phenolic phytochemicals such as phenolic acids, flavonoids and ellagic acid. Consumption of cranberry has been historically been linked to lower incidences of urinary tract infections and has now been shown to have a capacity to inhibit peptic ulcer-associated bacterium, Helicobacter pylori. Isolated compounds from cranberry have also been shown to reduce the risk of cardiovascular diseases. Recent evidence suggests the ability of phytochemical components in whole foods in being more effective in protectively supporting human health than compared to isolated individual phenolic phytochemicals. This implies that the profile of phenolic phytochemicals determines the functionality of the whole food as a result of synergistic interaction of constituent phenolic phytochemicals. Solid state bioprocessing using food grade fungi common in Asian food cultures as well as cranberry phenolic synergies through the addition of functional biphenyls such as ellagic acid and rosmarinic acid along with processed fruit extracts have helped to advance these concepts. These strategies could be further explored to enrich cranberry and cranberry products with functional phytochemicals and further improve their functionality for enhancing health benefits.