Skeletal and neurological risks demonstrated in zebrafish due to second-hand cigarette smoke and the neutralization of luteolin.

BACKGROUND: Cigarette smoke exposure poses significant health risks, including oxidative stress, inflammation, tissue damage, and neurodegenerative diseases. Luteolin, a natural flavonoid known for its antioxidant and anti-inflammatory properties, is of interest in countering these effects. AIM: This study aims to assess luteolin's protective potential against cigarette smoke extract (CSE) in adult zebrafish. MATERIALS AND METHODS: Adult zebrafish were exposed to CSE for 15 days, inducing smoke-related damage. Subsequent luteolin treatment assessed its impact. Evaluations included antioxidant enzymes (SOD, CAT), nitric oxide (NO), LDH activity (cellular damage), tissue integrity, fibrosis, amyloid plaque accumulation, and CSE component analysis via HPLC. KEY FINDINGS: CSE exposure heightened oxidative stress, reducing SOD and CAT activity and elevating NO levels, leading to cellular damage and tissue disruption, notably fibrosis and amyloid plaque accumulation. Inflammatory markers TNF-α and IL-1ß also increased. Luteolin treatment restored SOD and CAT activity, reduced LDH and NO activity, counteracting oxidative damage. It also mitigated fibrosis and reduced amyloid plaque deposition, preserving tissue integrity. Luteolin reduced TNF-α and IL-1ß levels and CSE components, displaying anti-inflammatory effects. SIGNIFICANCE: This study underscores luteolin's potential as a protective agent against cigarette smoke-induced harm in a zebrafish model.

Luteolin photo-protects zebrafish from environmental stressor ultraviolet radiation (UVB).

Ultraviolet B wavelength ray radiation (UVB) is an environmental stressor with detrimental effects to the aquatic and human systems but also enhances adverse effects when combined with several other environmental factors such as temperature and pollution. UV rays induce cellular oxidative damage and impair motility. This study aimed to examine the photo-protective activity of flavonoid luteolin against UV-B irradiation-induced oxidative stress and cellular damage using zebrafish. An in-vivo photoaging model was established using UV-B irradiation in zebrafish larvae exposed to 100 mJ/cm2. Data demonstrated that UV-B irradiation of swimming water enhanced production of ROS and superoxide anions as well as depleted total glutathione levels in zebrafish larvae. UV-B irradiation also triggered cellular damage and membrane rupture in zebra fish. Further, 100 mJ/cm2 of UV-B radiation exposure to adult-wild type zebrafish co-exposed with intraperitoneally (ip) injected luteolin upregulated the local neuroendocrine axes by activating vascular endothelial growth factor (VEGF) and elevating levels of pro-inflammatory cytokines IL-1ß and TNF-α. Histologically, UV-B irradiation induced skin lesions and locomotory defects with clumping and degeneration of brain glial cells. However, luteolin effectively inhibited the excess production of reactive oxygen species (ROS) and decreased superoxide anion levels induced by UV-B irradiation. Luteolin restored the depleted glutathione levels. In addition, luteolin blocked apoptosis and lipidperoxidation. Luteolin protected adult zebrafish by downregulating the pro-inflammatory cytokine protein expression levels and diminishing VEGF activation. Luteolin also alleviated locomotory defects by inhibiting activation of microglia and inflammatory responses by preventing accumulation of glial cells and vacuolation. Data demonstrate that luteolin may protect zebrafish from UV-B-induced photodamage through DNA-protective, antioxidant and anti-inflammatory responses.

Ophthalmic Intervention of Naringenin Decreases Vascular Endothelial Growth Factor by Counteracting Oxidative Stress and Cellular Damage in In Vivo Zebrafish.

Diabetes Mellitus is a metabolic disease that leads to microvascular complications like Diabetic retinopathy (DR), a major cause of blindness worldwide. Current medications for DR are expensive and report multiple side effects; therefore, an alternative medication that alleviates the disease condition is required. An interventional approach targeting the vascular endothelial growth factor (VEGF) remains a treatment strategy for DR. Anti-VEGF medicines are being investigated as the main therapy for managing vision-threatening complications of DR, such as diabetic macular oedema. Therefore, this study investigated the effect of flavonoid naringenin (NG) from citrus fruits on inhibiting early DR in zebrafish. When exposed to 130 mM glucose, the zebrafish larvae developed a hyperglycaemic condition accompanied by oxidative stress, cellular damage, and lipid peroxidation. Similarly, when adult zebrafish were exposed to 4% Glucose, high glucose levels were observed in the ocular region and massive destruction in the retinal membrane. High glucose upregulated the expression of VEGF. In comparison, the co-exposure to NG inhibited oxidative stress and cellular damage and restored the glutathione levels in the ocular region of the zebrafish larvae. NG regressed the glucose levels and cellular damage along with an inhibition of macular degeneration in the retina of adult zebrafish and normalized the overexpression of VEGF as a promising strategy for treating DR. Therefore, intervention of NG could alleviate the domestication of alternative medicine in ophthalmic research.