Green tea extract modulates lithium-induced thyroid follicular cell damage in rats.

BACKGROUND: The aim of the current work was to clarify the modulation role of green tea extract (GTE) over structural and functional affection of the thyroid gland after long term use of lithium carbonate (LC). The suggested underlying mechanisms participating in thyroid affection were researched. MATERIALS AND METHODS: Twenty-four Sprague-Dawley adult albino rats were included in the work. They were divided into three groups (control, LC, and concomitant LC + GTE). The work was sustained for 8 weeks. Biochemical assays were performed (thyroid hormone profile, interleukin 6 [Il-6]). Histological, histochemical (Periodic Acid Schiff [PAS]) and immunohistochemical (caspase-3, tumour necrosis factor alpha [TNF-α], proliferating cell nuclear antigen [PCNA]) evaluations were done. Oxidative/antioxidative markers (malondialdehyde [MDA]/gluthathione [GSH], superoxide dismutase [SOD]) and Western blot evaluation of the Bcl2 family were done. RESULTS: Lithium carbonate induced hypothyroidism (decreased T3, T4/increased thyroid-stimulating hormone [TSH]). The follicles were distended, others were involuted. Some follicles were disorganised, others showed detached follicular cells. Apoptotic follicular cells were shown (BAX and caspase-3 increased, Bcl2 decreased, BAX/Bcl2 ratio increased). The collagen fibres' content and proinflammatory markers (TNF-α and IL-6) increased. The proliferative nuclear activity was supported by increased expression of PCNA. Oxidative stress was established (increased MDA/decreased GSH, SOD). With the use of GTE, the thyroid hormone levels increased, while the TSH level decreased. Apoptosis was improved as BAX decreased, Bcl2 increased, and BAX/Bcl2 ratio was normal. The collagen fibres' content and proinflammatory markers (TNF-α and IL-6) decreased. The expression of PCNA and caspase-3 were comparable to the control group. The oxidative markers were improved (decreased MDA/increased GSH, SOD). CONCLUSIONS: In conclusion, prolonged use of LC results in hypothyroidism, which is accompanied by structural thyroid damage. LC induced thyroid damage through oxidative stress that prompted sterile inflammation and apoptosis. With the use of GTE, the thyroid gland regained its structure and function. The protecting role of GTE is through antioxidant, antifibrotic, anti-inflammatory, and antiproliferative effects.

Evaluation of antioxidant and anti-lipid peroxidation potentials of Nigella sativa and onion extract on nicotine-induced lung damage.

BACKGROUND: The present work aimed to compare the protective effect of Nigella sativa (NS) and onion extract on the nicotine-induced lung damage in rats. The antioxidant and anti-lipid peroxidation potentials of both agents on nicotine-induced lung damage were studied. MATERIALS AND METHODS: Thirty-six Sprague-Dawley albino rats, treated for 18 weeks, were divided into six groups: one negative control group, two positive control groups (oral onion and oral NS), nicotine-treated group, onion extract-treated group (concomitant nicotine and onion extract) and NS-treated group (concomitant nicotine and NS oil). The assessment of lung structure was based on haematoxylin and eosin and transmission electron microscopy. Lung malondialdehyde (MDA), superoxide dismutase activity (SOD), catalase (CAT), lung glutathione (GSH), and epithelial lining fluid GSH (ELF GSH) were used for assessment of the antioxidant and anti-lipid peroxidation potentials of NS and onion extract. RESULTS: The lung of the nicotine-treated group exhibited emphysematous air spaces, collapsed corrugated alveoli with ruptured interalveolar septa in some specimen and thickened septa in the others, massive congestion, extravasation of red blood cells, inflammatory cellular infiltration and fluid exudate. Much improvement was observed in the onion-treated group despite the presence of residual pathological affection. The lung in the NS-treated group showed the nearly normal architecture with slight congestion. Administration of nicotine promoted lipid peroxidation (elevation of MDA) and decreased the level of the antioxidant markers (SOD, CAT, lung GSH and ELF GSH). With the use of onion extract and NS, the level of MDA decreased by 17.85% and 35.71% while the levels of SOD, CAT, GSH, and ELF GSH increased. The increase was more prominent in the NS-treated group. The levels in the NS-treated group reached nearly the level markers of the control group. CONCLUSIONS: Nigella sativa and onion extract attenuate the pathological effect of nicotine in the lung rats through antioxidative and anti-lipid peroxidative mechanisms with higher protection to NS.