Papaya epicarp extract protects against aluminum-induced neurotoxicity

Neuroprotective role of hyperforin on aluminum maltolate-induced oxidative damage and apoptosis in PC12 cells and SH-SY5Y cells

Many reports demonstrated that aluminum maltolate (Almal) has potential toxicity to human and animal. Our study has demonstrated that Almal can induce oxidative damage and apoptosis in PC12 cells and SH-SY5Y Cells, two in vitro models of neuronal cells. Hyperforin (HF) is a well-known antioxidant, anti-inflammatory, anti-amyloid and anti-depressant compound extracted from Hypericum perforatum extract. Here, we investigated the neuroprotective effect of HF against Almal-induced neurotoxicity in cultured PC12 cells and SH-SY5Y cells, mainly caused by oxidative stress. In the present study, HF significantly inhibited the formation of reactive oxygen species (ROS), decreased the level of lipid peroxide and enhanced the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) compared with Almal group in PC12 cells and SH-SY5Y cells. Additionally, HF suppressed the reduction of the mitochondrial membrane potential (MMP), cytochrome c (Cyt-c) release, activation of caspase-3, and the down-regulation of Bcl-2 expression and up-regulation of Bax expression induced by Almal in PC12 cells and SH-SY5Y cells. In summary, HF protects PC12 cells and SH-SY5Y cells from damage induced by Almal through reducing oxidative stress and preventing of mitochondrial-mediated apoptosis.

Selenium added unripe carica papaya pulp extracts enhance wound repair through TGF-β1 and VEGF-a signalling pathway

BACKGROUND

Increased wound healing efficiency by Se(2+) added Carica papaya L. (Caricaceae) fruit extract was linked to increased antioxidant and anti-inflammatory responses during healing. We investigated the impact of Se(2+) or Zn(2+) added papaya water (WE) and phosphate-buffered saline (PE) extracts on cells recruitment and bio-molecular alterations on days 4 and 10 post wounding in an in vivo excision wound.

METHODS

Excision wounds were created on the dorsum of Sprague Dawley rats and treated topically twice/day with 20 μL of PE and WE (5 mg extract/mL), 0.5 μgSe(2+) added PE and WE (PES and WES), or 100 μMZn(2+) added PE and WE (PEZ and WEZ). Deionised water (negative) and Solcoseryl (positive) were applied on the control groups. Histochemical and biochemical assays were used to evaluate cellular and bio-molecular changes in the wound.

RESULTS

PES (PE + 0.5 μg Se(2+)) only increased significantly (p < 0.05) wound total protein content (95.14 ± 1.15 mg/g tissue vs positive control; 80.42 ± 0.86 mg/g tissue) on day 10 post wounding. PES increased significantly (p < 0.05) the number of fibroblasts/high power field (HPF) (75.60 ± 9.66) but decreased significantly (p < 0.05) the number of polymorphonuclear leukocytes/HPF (59.20 ± 12.64) in the wound compared to positive control (50.60 ± 12.58 fibroblasts/HPF, 101.00 ± 27.99 polymorphonuclear leukocytes/HPF) on day 4. Similar results were recorded for WES. PES demonstrated increased neovascularization, TGF-β1 and VEGFA expressions at day 4 and increased collagen at day 10.

CONCLUSION

Papaya extract improved wound repair by increasing fibroblasts recruitment and reducing polymorphonuclear leukocytes infiltration through early transient expressions of TGF-β1 and VEGFA at the wound area. The processes were amplified with Se(2+) addition.

Oxidative stress in patients with Alzheimer's disease: effect of extracts of fermented papaya powder

Brain tissue is particularly susceptible to oxidative stress (OS). Increased production of reactive oxygen species (ROS), reduced antioxidant systems, and decreased efficiency in repairing mechanisms have been linked to Alzheimer's disease (AD). Postmortem studies in AD patients' brains have shown oxidative damage markers (i.e., lipid peroxidation, protein oxidative damage, and glycoxidation). Fermented papaya (FPP, a product of Carica papaya Linn fermentation with yeast) is a nutraceutical supplement with favorable effects on immunological, hematological, inflammatory, and OS parameters in chronic/degenerative diseases. We studied 40 patients (age 78.2 ± 1.1 years), 28 AD patients, and 12 controls. Urinary 8-OHdG was measured to assess OS. Twenty AD patients were supplemented with FPP (Immunage, 4.5 grams/day) for 6 months, while controls did not receive any treatment. At baseline, 8-OHdG was significantly higher in patients with AD versus controls (13.7 ± 1.61 ng/mL versus 1.6 ± 0.12 ng/mL, P < 0.01). In AD patients FPP significantly decreased 8-OHdG (14.1 ± 1.7 ng/mL to 8.45 ± 1.1 ng/mL, P < 0.01), with no significant changes in controls. AD is associated with increased OS, and FPP may be helpful to counteract excessive ROS in AD patients.

Antioxidant potential properties of mushroom extract (Agaricus bisporus) against aluminum-induced neurotoxicity in rat brain

Aluminum (Al) is an environmental toxin that induces oxidative stress in neuronal cells. Mushroom cultivar extract (MCE) acted as a potent antioxidant agent and protects against cellular oxidative stress in human cultured neuronal cells. This study aimed to investigate the neuroprotective effect of MCE against Al-induced neurotoxicity in rat brain. Forty Sprague-Dawley rats were divided into 4 groups (10 rats per group), control group, MCE-fed group, Al-administered group and MCE/Al-treated group. Animals were continuously fed ad-libitum their specific diets for 4 weeks. At the end of the experiment, all rats were sacrificed and the brain tissues were homogenized and examined for biochemical measurements of neurocellular oxidative stress indices [glutathione (GSH), Total Antioxidant Capacity (TAC), antioxidant enzymes and oxidized dichlorofluorescein (DCF)]. Al-administration caused inhibition of antioxidant enzymes and a significant decrease in GSH and TAC levels, meanwhile it positively increased cellular oxidized DCF level, as well as Al concentration in brain tissues. Feeding animals with MCE had completely offset the Al-induced oxidative stress and significantly restrict the Al accumulation in brain tissues of Al-administered rats. The results obtained suggest that MCE acted as a potent dietary antioxidant and protects against Al-mediated neurotoxicity, by abrogating neuronal oxidative stress.