Saffron Supplementation Protects against the Development of Glaucoma

by | Jul 7, 2020 | 2019, Botanicals, Eye Health

Written by Joyce Smith, BS. This study demonstrated that saffron extract standardized to 3% crocin content offers anti-inflammatory and neuroprotective effects against retinal damage due to increased intraocular pressure (IOP).

botanicals - saffronGlaucoma is a neurodegenerative disease characterized by a progressive increase in IOP and the subsequent death of retinal ganglion cells (RGCs) which do not regenerate and are irreplaceable. RGC death leads to a progressive loss of vision and eventually blindness, making glaucoma the second leading cause of irreversible blindness in the world1. The principal modifiable risk factor for controlling vision loss is IOP, yet controlling IOP does not guarantee preservation of RGCs 2. When IOP increases, it incites a microbial immune response 3. The resulting neuroinflammation causes RGCs to die and triggers the onset of glaucoma; thus, inhibiting microbial activity can slow down RGC death 4.

Saffron, the dried stigmas of Crocus sativa L, are neuroprotective, antioxidative, anti-inflammatory, and anti-apoptotic (apoptosis is a type of programmed cell death) 5. According to animal model studies, the saffron extracts of crocin and crocetin decreased neuroinflammation by reducing the neurotoxic effects of activated microglia such as the production of nitric oxide and reactive oxygen species, and the release of cytokines tumor necrosis factor (TNF-α) and interleukin (IL)-ß 6. Both of these saffron extracts have shown benefit  in treating animal models with aged-related macular degeneration (AMD), diabetic retinopathy  7, and retinitis pigmentosa 8 as well as patients with AMD 9 and diabetic maculopathy 10. Studies focusing on glaucoma are scarce; however, a study revealed that in retinas damaged by high intensity light exposure, crocin was able to reach the retinal tissue via the damaged blood retinal barrier and be of benefit 11. Neuro-degenerative conditions such as Alzheimer’s and Parkinson’s diseases have also benefited from saffron’s components 12.

Researchers, in the present study, explored whether a hydrophilic saffron extract standardized to 3% crocin could suppress retinal microbial activation and prevent RCG death in a mouse model of unilateral, laser-induced ocular hypertension (OHT). The animal study consisted of glaucoma-induced male Swiss albino mice, aged 12–16 weeks, who received a single oral daily dose of saffron over a period of seven days and their respective controls. Saffron (60mg/kg) was given 15 days prior to unilateral laser induction to induce OHT. Animals were than anesthetized and immune-histochemical analysis was performed, including retinal staining analysis. IOPs in the laser treated groups were significantly higher than in the matched control groups.

Analysis revealed that saffron extract had no effect on the retinol tissues in the control groups; however, in the laser-induced OHT animals, saffron prevented RGC death and significantly decreased the damage to RGC cells resulting from increased IOP and its activation of the microglial immune system. Saffron reduced the morphological signs of microglial activated damage that resulted from increased IOP and, in addition, significantly reduced the down-regulation of microbial P2RY12 expression in the OHT eyes, a further indication of its ability to inhibit immune activation. Saffron’s anti-inflammatory, antioxidative and neuroprotective properties could be related to its strong radical-scavenging properties 13. The researchers suggest that saffron’s ability to protect against retinol cell damage may be useful as a treatment to protect RGCs from the damaging effects of Glaucoma.

Source: Fernández-Albarral, Jose A., Ana I. Ramírez, Rosa de Hoz, Nerea López-Villarín, Elena Salobrar-García, Inés López-Cuenca, Ester Licastro et al. “Neuroprotective and anti-inflammatory effects of a hydrophilic saffron extract in a model of glaucoma.” International journal of molecular sciences 20, no. 17 (2019): 4110.

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution(CC BY) license (http://creativecommons.org/licenses/by/4.0/).

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Posted July 7, 2020.

Joyce Smith, BS, is a degreed laboratory technologist. She received her bachelor of arts with a major in Chemistry and a minor in Biology from  the University of Saskatchewan and her internship through the University of Saskatchewan College of Medicine and the Royal University Hospital in Saskatoon, Saskatchewan. She currently resides in Bloomingdale, IL.

References:

  1. Quigley HA, Broman AT. The number of people with glaucoma worldwide in 2010 and 2020. The British journal of ophthalmology. 2006;90(3):262-267.
  2. Qu J, Wang D, Grosskreutz CL. Mechanisms of retinal ganglion cell injury and defense in glaucoma. Exp Eye Res. 2010;91(1):48-53.
  3. Ramirez AI, de Hoz R, Salobrar-Garcia E, et al. The Role of Microglia in Retinal Neurodegeneration: Alzheimer’s Disease, Parkinson, and Glaucoma. Front Aging Neurosci. 2017;9:214.
  4. Bosco A, Crish SD, Steele MR, et al. Early reduction of microglia activation by irradiation in a model of chronic glaucoma. PLoS One. 2012;7(8):e43602.
  5. Yamauchi M, Tsuruma K, Imai S, et al. Crocetin prevents retinal degeneration induced by oxidative and endoplasmic reticulum stresses via inhibition of caspase activity. Eur J Pharmacol. 2011;650(1):110-119.
  6. Nam KN, Park YM, Jung HJ, et al. Anti-inflammatory effects of crocin and crocetin in rat brain microglial cells. Eur J Pharmacol. 2010;648(1-3):110-116.
  7. Yang X, Huo F, Liu B, et al. Crocin Inhibits Oxidative Stress and Pro-inflammatory Response of Microglial Cells Associated with Diabetic Retinopathy Through the Activation of PI3K/Akt Signaling Pathway. Journal of molecular neuroscience : MN. 2017;61(4):581-589.
  8. Fernández-Sánchez L, Lax P, Noailles A, Angulo A, Maneu V, Cuenca N. Natural Compounds from Saffron and Bear Bile Prevent Vision Loss and Retinal Degeneration. Molecules. 2015;20(8):13875-13893.
  9. Piccardi M, Marangoni D, Minnella AM, et al. A longitudinal follow-up study of saffron supplementation in early age-related macular degeneration: sustained benefits to central retinal function. Evid Based Complement Alternat Med. 2012;2012:429124.Controlled Randomized Clinical Trial. Am J Ophthalmol. 2018;190:89-98.
  10. Bisti, S.; Maccarone, R.; Falsini, B. Saffron and retina: neuroprotection and pharmacokinetics. Vis. Neurosci. 2014, 31, 355–361. [CrossRef]
  11. Akhondzadeh S, Sabet MS, Harirchian M, et al. Saffron in the treatment of patients with mild to moderate Alzheimer’s disease: a 16‐week, randomized and placebo‐controlled trial. Journal of clinical pharmacy and therapeutics. 2010;35(5):581-588.
  12. Poma A, Fontecchio G, Carlucci G, Chichiriccò G. Anti-inflammatory properties of drugs from saffron crocus. Anti-inflammatory & anti-allergy agents in medicinal chemistry. 2012;11(1):37-51.