Publications by authors named "Titi Liu"

The interaction between the receptor activator of nuclear factor-κB ligand (RANKL) and its receptor RANK is known to regulate osteoclastogenesis in bone remodelling and has become an important therapeutic target for the treatment of osteoporosis. Stephanine (SA), an isoquinoline aporphine-type alkaloid isolated from Stephania plants, possesses excellent anti-inflammatory effects and can be used for rheumatoid arthritis treatment. However, its specific role in osteoclastogenesis and osteoporosis remains unknown.

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Article Synopsis
  • ATP supplementation was studied for its effects on UVB-induced skin photoaging in HaCaT cells, with findings indicating no toxicity to the cells.
  • UVB exposure led to increased cell apoptosis and elevated levels of harmful reactive oxygen species (ROS), while ATP effectively reduced both apoptosis and ROS levels.
  • The beneficial effects of ATP appear to be linked to the upregulation of protective proteins SIRT3 and SOD2, which helps combat the damage from UVB irradiation.
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The tumor necrosis factor alpha (TNF-α)-TNF-α receptor (TNFR) interaction plays a central role in the pathogenesis of various autoimmune diseases, particularly rheumatoid arthritis, and is therefore considered a key target for drug discovery. However, natural compounds that can specifically block the TNF-α-TNFR interaction are rarely reported. (-)-Epigallocatechin-3-gallate (EGCG) is the most active, abundant, and thoroughly investigated polyphenolic compound in green tea.

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Excessive osteoclast differentiation and activation are closely associated with the development and progression of osteoporosis. Natural plant-derived compounds that can inhibit osteoclastogenesis are an efficient strategy for the prevention and treatment of osteoporosis. Tereticornate A (TA) is a natural terpene ester compound extracted from the leaves and branches of Eucalyptus gracilis, with antiviral, antibacterial, and anti-inflammatory activities.

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Dysregulation of osteoclasts or excessive osteoclastogenesis significantly -contributes to the occurrence and development of osteolytic diseases, including osteoporosis, inflammatory bone erosion, and tumor-induced osteolysis. The protein-protein interaction between the receptor activator of nuclear factor (NF)-κB (RANK) and its ligand (RANKL) mediates the differentiation and activation of osteoclasts, making it a key therapeutic target for osteoclastogenesis inhibition. However, very few natural compounds exerting anti-osteoclastogenesis activity by inhibiting the RANKL-RANK interaction have been found.

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Tumor necrosis factor (TNF)-stimulated nuclear factor-kappa B (NF-κB) signaling plays very crucial roles in cancer development and progression, and represents a potential target for drug discovery. Roburic acid is a newly discovered tetracyclic triterpene acid isolated from oak galls and exhibits anti-inflammatory activity. However, whether roburic acid exerts antitumor effects through inhibition of TNF-induced NF-κB signaling remains unknown.

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Consuming green tea has many health benefits, including regulating bone metabolism and ameliorating osteoporosis, mainly in older and postmenopausal women. This osteoprotective effect has been attributed to the biologically active polyphenol (-)-epigallocatechin-3-gallate (EGCG). Although EGCG inhibits osteoclastogenesis, its underlying molecular mechanism remains to be elucidated.

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Glucose-6-phosphate dehydrogenase (G6PDH) is the rate-limiting enzyme in the pentose phosphate pathway (PPP) and plays a crucial role in the maintenance of redox homeostasis by producing nicotinamide adenine dinucleotide phosphate (NADPH), the major intracellular reductant. G6PDH has been shown to be a biomarker and potential therapeutic target for renal cell carcinoma (RCC). Here, we report a previously unknown biochemical mechanism through which caffeine, a well-known natural small molecule, regulates G6PDH activity to disrupt cellular redox homeostasis and suppress RCC development and progression.

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Acanthopanax senticosus (Ciwujia) has broad-spectrum pharmacological activities, including osteoprotective effects. However, the mechanisms underlying these effects remain unclear. We investigated whether Acanthopanax senticosus aqueous extract (ASAE) ameliorates ovariectomy-induced bone loss in middle-aged mice through inhibition of osteoclastogenesis.

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Ellagic acid (EA) is a naturally occurring polyphenolic compound that has been shown to exhibit diverse beneficial pharmacological activities including anti-osteoclastogenesis effect. However, the molecular mechanism by which EA inhibits osteoclastogenesis remains to be elucidated. The protein-protein interaction between receptor activator of nuclear factor (NF)-κB ligand (RANKL) and its receptor RANK contributes to osteoclast differentiation and activation in bone remodeling, and is regarded as an important therapeutic target for the treatment of osteoporosis.

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Galloylated catechins, the most important secondary metabolites in green tea including (-)-epigallocatechin-3-gallate (EGCG) and (-)-epicatechin-3-gallate, constitute nearly 75% of all tea catechins and have stronger health effects than non-galloylated catechins such as (-)-epigallocatechin and (-)-epicatechin. EGCG is the most abundant, active, and thoroughly investigated compound in green tea, and its bioactivity might be improved by complexing with β-cyclodextrin (β-CD). We investigated interactions between four catechins and β-CD in a PBS buffer solution of pH 6.

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Tea consumption has positive effects on the skeletal system and prevents postmenopausal osteoporosis, mainly by inhibiting osteoclastogenesis. In green tea, (-)-epigallocatechin-3-gallate (EGCG) is the most abundant and active compound and has been shown to inhibit RANKL-induced osteoclast formation. Taking into account the highly oxidizable and unstable nature of EGCG, we hypothesized that EGCG oxidation product exhibits greater anti-osteoclastogenesis potential than EGCG.

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Caffeine (1,3,7-trimethylxanthine) is a naturally occurring plant xanthine alkaloid present in many commonly consumed beverages worldwide, including tea, coffee, and cocoa. Although moderate caffeine intake is generally considered to exert positive effects on human health, its effect on bone metabolism remains controversial. The aim of this study was to systematically evaluate the pharmacological effect of long-term administration of caffeine on ovariectomy-induced postmenopausal osteoporosis in female rats.

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Drinking tea exhibits beneficial effects on bone health and may protect against osteoporosis, particularly in postmenopausal women. Theabrownin (TB) is the main component responsible for the biological activities of Pu-erh tea, but whether it possesses anti-osteoporotic potential remains unknown. Here we investigated the in vitro and in vivo anti-osteoporotic effects of TB in the RAW 264.

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Background And Purpose: Tea drinking has positive effects on bone health and may prevent and treat osteoporosis, especially in older and postmenopausal women. Tea polysaccharide (TPS) is a major bioactive constituent in tea. Despite its profound effects on human health, whether TPS has anti-osteoporotic effects remains largely unknown.

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Tea drinking is associated with positive effects on bone health and may protect against osteoporosis, especially in elderly women. Pu-erh tea has many beneficial effects on human health; however, whether Pu-erh tea has anti-osteoporotic potential remains unclear. Thus, we investigated the effects of Pu-erh tea extract (PTE) on ovariectomy-induced osteoporosis in rats and on osteoclastogenesis .

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Article Synopsis
  • A neutral heteropolysaccharide called DOP-1-1, composed of mannose and glucose in a 5.9:1 ratio, was extracted from Dendrobium officinale, with an average molecular weight of about 178,000 Da.
  • Structural analysis through FT-IR and NMR indicated that DOP-1-1 resembles an O-acetylated glucomannan with a β-d configuration.
  • DOP-1-1 exhibited significant immune-modulating activities by enhancing cytokine production (IL-1β, TNF-α) and activating signaling pathways (ERK1/2 and NF-кB), but it did not show strong antioxidant activity compared to other polysaccharides
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