Optimization Extraction Conditions with Ultrasound for Anti-hyperglycemic Activities from <i>Psidium guajava</i> Leaf

Abstract

The present study evaluated the optimal parameters for Psidium guajava leaf extraction by ultrasound to obtain maximal anti-hyperglycemic activities in the extract. The response surface methodology was employed for empirical model building. The maximum inhibition of the two starch-digesting enzymes α-amylase and α-glucosidase was determined. The optimized extraction parameters of solvent-to-solid ratio, extraction time, and extraction temperature for obtaining the maximum inhibitory activity for 50 µg/mL extract were determined to be the following: 12.07 (v/w), 5.22 min, and 59.77℃ for α-amylase (47.23% ± 0.76%) and 12 (v/w), 5.22 min, and 59.94℃ for α-glucosidase (59.42% ± 0.65%), respectively. The F values for the lack-of-fit were not significant ( p > 0.05) for both second-order models, indicating them to be appropriate for describing the response surface. In conclusion, our study presents the optimal conditions for ultrasound-assisted extraction of guava leaf as a potential substance for use in diabetes treatment.

Antidiabetic activity screening and nmr profile of vegetable and spices commonly consumed in Indonesia

“…The Pearson analysis showed that GIA had strong positive correlation with TPC (r = 0.92, p <0.05), indicating the TPC was responsible for the GIA. This finding was in agreement with Liu et al (2015) who reported that there was a strong correlation between GIA and TPC of guava leaves water extract.…”

Effects of guava leaf extract on glucose and lipid homeostasis in diet-induced insulin-resistant C57BL/6J mice

“…After 10-week treatment, the metabolic syndrome status of high-fructosehigh-fat fed mice were ameliorated by high dose GvEx. Our previous study has demonstrated that GvEx could improve high-glucose induced insulin resistant conditions in mouse FL83B cells via enhancing the levels of signals involved in insulin transduction, including phospho-tyrosine of insulin receptor, phospho-tyrosine of insulin receptor substrate, p85 regulatory subunit of phospho-inositide 3 kinase, pAkt (Ser), Glut 2, and glycogen synthase (Liu et al, 2015a). These results were also confirmed in the present study by a diet-induced insulin resistant animal models.…”

“…Homogenates were then centrifuged at 27,000 x g for 10 min at 4°C. The supernatant was isolated and immunoblotting and was performed as described previously (Liu et al, 2015a). The supernatant was used for the determination of protein abundance, including phospho-tyrosine of AMPK (p-AMPK (Thr)), phosphor-serine of protein kinase B (p-Akt (Ser)), PPAR-α, PPAR-γ, PPAR-δ, adiponectin, glucose transporter (Glut) 2, and Glut 4. β -Actin was used as an internal control to ensure adequate sample loading for all lands.…”

“…Oral administration of high dose GvEx in the last 10 weeks reduced serum insulin levels ( Figure 3B) and HOMA-IR ( Figure 3C), suggesting the effectiveness of GvEx that improve insulin sensitivity. Our previous studies indicate that polyphenols of GvEx may effectively inhibit the activities of α-amylase and α-glucosidase Liu et al, 2015b), so that the amount of glucose can be released slowly to avoid postprandial blood sugar rise sharply, thus preventing the excessive secretion of insulin. Furthermore, GvEx can also increase the sensitivity of…”

“…insulin receptor, including phosphorylated insulin receptor substrate 1, phosphoinositide 3-kinase, phosphorylated protein kinase B, etc., that will activate the insulin signaling pathways and promote glucose metabolism (Guo et al, 2013;Liu et al, 2015a). As described by Mathur et al, to induce insulin resistance, the 4 weeks old male rats were provided with 15% (w/ v) fructose as drinking water, while parallel treatment groups were administered with guava leaf extract for 8 weeks.…”