Tea and depression

Comparative analysis of antioxidant activities and chemical compositions in the extracts of different edible parts from Camellia tetracocca Zhang (C. tetracocca) with two distinct color characteristics

The Camellia tetracocca Zhang is a rare and ancient plant, exclusively found in the vicinity of Puan County, Guizhou Province, China. According to leaf color, two distinct variations have been identified: purple C. tetracocca Zhang (PCTZ) and green C. tetracocca (GCTZ). This research was conducted to investigate the antioxidant activities and chemical compositions of different edible parts of PCTZ and GCTZ. Antioxidant activity was evaluated using DPPH, ABTS, HSA, and T-AOC assays, while the content of compounds was determined by HPLC. The findings demonstrated that the antioxidant capacity of PCTZ leaves is significantly superior to that of GCTZ leaves. Notably, theacrine, a rare compound, contains up to 2.075% in PCTZ leaves, indicating potential as a novel natural antidepressant and antioxidant. In conclusion, PCTZ is a distinctive tea beverage and a valuable genetic material for tea tree breeding due to its high theacrine and low caffeine characteristics.

A review on linking stress, depression, and insulin resistance via low-grade chronic inflammation

Stress is a disturbance in homeostasis caused by psychological, physiological, or environmental factors. Prolonged reactions to chronic stress can be detrimental, resulting in various metabolic abnormalities, referred to as metabolic syndrome (MS). There is a reciprocal increased risk between MS and major depressive disorder. Recent studies established an association between inflammation and insulin signaling in type 2 diabetes mellitus with depression. In the present review, we discuss chronic low-grade inflammation, pathways of insulin resistance, and brain glucose metabolism in the context of neuroinflammation and depression. Specific attention is given to psychotropic drugs such as bupropion, mirtazapine, and nefazodone, anti-inflammatory drugs like Celecoxib (COX-2 inhibitor), Etanercept, adalimumab, IL-4Ra antagonist, Anti-IL- 17A antibody (Ixekizumab) and lifestyle modifications including exercise, dietary changes, and sleep hygiene. These therapeutic solutions offer potential in treating depression by targeting metabolic conditions like insulin resistance and inflammatory pathways. The article further explains the significance of a nutrition and antioxidants-rich diet, emphasizing the role of omega-3 fatty acids, vitamin D, zinc, and polyphenols, to improve immunity and activate anti-inflammatory signaling pathways.