Dendrobium chrysotoxum Lindl. alleviates diabetic retinopathy by preventing retinal inflammation and tight junction...

Area of Science:

• Ophthalmology
• Pharmacology
• Diabetology

Background:

• Diabetic retinopathy (DR) is a severe complication of diabetes mellitus.
• Maintaining the integrity of the blood retinal barrier (BRB) is crucial for preventing DR progression.
• Inflammation and compromised tight junction proteins contribute to BRB breakdown in DR.

Purpose of the Study:

• To investigate the therapeutic effects of Dendrobium chrysotoxum Lindl. (DC) ethanol extract on diabetic retinopathy (DR).
• To elucidate the underlying mechanisms by which DC influences DR pathology, focusing on inflammation and BRB integrity.

Main Methods:

• Streptozotocin (STZ)-induced diabetic rats were orally administered DC (30 or 300 mg/kg).
• Blood retinal barrier (BRB) integrity was assessed.
• Retinal mRNA and protein expression of tight junction proteins (occludin, claudin-1) and inflammatory markers (ICAM-1, TNFα, IL-6, IL-1β) were analyzed using RT-qPCR, Western blot, and immunofluorescence.
• NF-κB signaling pathway components (p65, IκB, IKK) and serum cytokine levels were measured.

Main Results:

• DC administration attenuated BRB breakdown in diabetic rats.
• DC reversed the decreased expression of tight junction proteins (occludin, claudin-1) in the retina.
• DC reduced elevated retinal mRNA levels of inflammatory mediators (ICAM-1, TNFα, IL-6, IL-1β) and suppressed NF-κB pathway activation.
• DC significantly decreased serum levels of pro-inflammatory cytokines (TNFα, IFN-γ, IL-6, IL-1β, etc.).

Conclusions:

• Dendrobium chrysotoxum Lindl. (DC) demonstrates a protective effect against diabetic retinopathy.
• DC alleviates DR by inhibiting retinal inflammation and preserving the integrity of tight junction proteins, thereby preventing BRB breakdown.