Psidium guajava L. leaf extract inhibits adipocyte differentiation and improves insulin sensitivity in 3T3-L1 cells

Abstract

BACKGROUND/OBJECTIVES Psidium guajava L. (guava) leaves have been shown to exhibit hypoglycemic and antidiabetic effects in rodents. This study investigated the effects of guava leaf extract on adipogenesis, glucose uptake, and lipolysis of adipocytes to examine whether the antidiabetic properties are mediated through direct effects on adipocytes. MATERIALS/METHODS 3T3-L1 cells were treated with 25, 50, 100 µg/mL of methanol extract from guava leaf extract (GLE) or 0.1% dimethyl sulfoxide as a control. Lipid accumulation was evaluated with Oil Red O Staining and AdipoRed assay. Immunoblotting was performed to measure the expression of adipogenic transcription factors, fatty acid synthase (FAS), and AMP-activated protein kinase (AMPK). Glucose uptake under basal or insulin-stimulated condition was measured using a glucose analog 2-[ N -(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-D-glucose. Lipolysis from fully differentiated adipocytes was measured by free fatty acids release into the culture medium in the presence or absence of epinephrine. RESULTS Oil Red O staining and AdipoRed assay have shown that GLE treatment reduced lipid accumulation during adipocyte differentiation. Mitotic clonal expansion, an early essential event for adipocyte differentiation, was inhibited by GLE treatment. GLE inhibited the expression of transcription factors involved in adipocyte differentiation, such as peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer-binding protein α (C/EBPα), and sterol regulatory element-binding protein-1c (SREBP-1c). FAS expression was also decreased while the phosphorylation of AMPK was increased by GLE treatment. In addition, GLE increased insulin-induced glucose uptake into adipocytes. In lipid-filled mature adipocytes, GLE enhanced epinephrine-induced lipolysis but reduced basal lipolysis dose-dependently. CONCLUSIONS The results show that GLE inhibits adipogenesis and improves adipocyte function by reducing basal lipolysis and increasing insulin-stimulated glucose uptake in adipocytes, which can be partly associated with antidiabetic effects of guava leaves.

Hypoglycemic and Antioxidant Properties of Extracts and Fractions from Polygoni Avicularis Herba

“…3T3-L1 cell line is considered a classic cell line that has been frequently used in research such as adipocytes differentiation, glucose uptake, and lipid metabolism [ 42 ]. In recent years, more and more studies have reported the hypoglycemic activity of the plant extracts or active ingredients via glucose uptake experiments in 3T3-L1 adipocytes [ 43 , 44 ]. Our results showed that NBF possessed a significant dose-dependent effect on promoting glucose uptake in 3T3-L1 adipocytes, and the difference was statistically significant (*** p < 0.001).…”

In Vitro and In Vivo Evaluation of Antidiabetic Properties and Mechanisms of Ficus tikoua Bur.

“…The glucose uptake model of 3T3-L1 cells is commonly used to study hypoglycemic ability. Recently, existing studies have reported that plant extracts or active components can promote glucose uptake in 3T3-L1 adipocytes to reduce blood glucose [ 23 , 32 ]. The results exhibited that NBF and NBF2 significantly promoted glucose uptake in 3T3-L1 adipocytes with dose-dependent effects, and the effect of NBF2 was more potent than NBF.…”

Natural products for the treatment and management of diabetes mellitus in Zimbabwe-a review

“…Their findings suggested that polysaccharides from guava leaves could provide health benefits for diabetic patients. ( Choi et al, 2021 ) investigated the effects of guava leaf extract on adipogenesis, glucose uptake, and lipolysis of adipocytes and demonstrated that the extracts inhibits adipogenesis and improves adipocyte function by reducing basal lipolysis and increased insulin-stimulated glucose uptake in adipocytes, indicating the antidiabetic effects of guava leaves. These findings show that Psidium guajava L. can lower blood glucose and ameliorate body weight loss in diabetic mice.…”