Antioxidant Activity, Delayed Aging, and Reduced Amyloid-β Toxicity of Methanol Extracts of Tea Seed Pomace from Camellia tenuifolia

Abstract

There is a growing interest in the exploitation of the residues generated by plants. This study explored the potential beneficial health effects from the main biowaste, tea seed pomace, produced when tea seed is processed. DPPH radical scavenging and total phenolic content assays were performed to evaluate the in vitro activities of the extracts. Caenorhabditis elegans was used as in vivo model to evaluate the beneficial health effects, including antioxidant activity, delayed aging, and reduced amyloid-β toxicity. Among all soluble fractions obtained from the extracts of tea seed pomace from Camellia tenuifolia, the methanol (MeOH)-soluble fraction has the best in vivo antioxidant activities. The MeOH-soluble extraction was further divided into six fractions by chromatography with a Diaion HP-20 column eluted with water/MeOH, and fraction 3 showed the best in vitro and in vivo antioxidant activities. Further analysis in C. elegans showed that the MeOH extract (fraction 3) of tea seed pomace significantly decreased intracellular reactive oxygen species, prolonged C. elegans lifespan, and reduced amyloid-β (Aβ) toxicity in transgenic C. elegans expressing human Aβ. Moreover, bioactivity-guided fractionation yielded two potent constituents from fraction 3 of the MeOH extract, namely, kaempferol 3-O-(2″-glucopyranosyl)-rutinoside and kaempferol 3-O-(2″-xylopyranosyl)-rutinoside, and both compounds exhibited excellent in vivo antioxidant activity. Taken together, MeOH extracts of tea seed pomace from C. tenuifolia have multiple beneficial health effects, suggesting that biowaste might be valuable to be explored for further development as nutraceutical products. Furthermore, the reuse of agricultural byproduct tea seed pomace also fulfills the environmental perspective.

Camellia oleifera seed extract attenuated abdominal and hepatic fat accumulation in rats fed a high-fat diet

“…However, studies on the physiological effects of CSE are very few and limited. Recent studies have reported that C. oleifera seed extract may show antioxidative and anti-inflammatory effects in vivo due to its saponin constituents (Wei et al, 2014;Ye et al, 2013). Although plant-derived saponins D r a f t were reported to have potentials in regulating lipid metabolism and modulating adipokine balance (Elekofehinti et al, 2017;Marrelli et al, 2016), to our knowledge, this is the first study to investigate the effects of CSE on diet-induced fat accumulation in vivo.…”

A literature review of flavonoids and lifespan in model organisms

“…Alternatively, components of the extract could have attenuated the lifespan-prolonging action of tamarixetin or may be slightly toxic (42) . Interestingly, some of the extracts used in worms such as the tea seed pomace or the Taiwan hinoki extract increased lifespan at lower concentrations than single compounds (51,52) . Assuming these extracts consisted entirely of a flavonoid with the molecular mass of catechin, 1-2 mg/l would correspond to 3·5-7 µM flavonoid/l.…”

Remedial Effects of Tea and Its Phytoconstituents on Central Nervous System

“…There scientific correlation suggests that the reduction in amyloid beta (Aβ) fibril production in the presence of EC and EGCG is suspected to regulate the amyloid protein precursor (APP) enzyme activity [50]. Additionally, it been also suggested that the regular consumption of tea (green and black) may lead to the acetyl cholinesterase (AChE) activity inhibition, further causing halt in acetylcholine production [51,52]. Besides this, it was found that there was inhibition of butyrylcholinesterase (BuChE) enzyme deposits in the brain of AD subjects after consuming green tea or black tea for certain time [53].…”