Anti‐Diabetic Effects of Gynura Bicolor Aqueous Extract in Mice

Abstract

The effects of Gynura bicolor aqueous extract (GAE) upon glycemic control, coagulation disorder, lipid accumulation, and glycative, oxidative, and inflammatory stresses in diabetic mice were investigated. Mice were treated with streptozotocin to induce type 1 diabetes. Diabetic mice were divided into four groups, consumed GAE at 0%, 0.25%, 0.5%, or 1%. Normal group consumed standard mouse basal diet. After 8‐week treatments, mice were sacrificed after overnight fasting. Results showed that GAE supplement at 0.5% and 1% decreased plasma glucose level and increased plasma insulin level. Diabetes lowered plasma level of protein C and anti‐thrombin III; and raised plasminogen activator inhibitor‐1 activity and fibrinogen level in plasma. GAE supplement at 0.5% and 1% reversed these alterations. Histological data, assayed by Oil Red O stain, indicated that GAE supplement decreased lipid accumulation in liver. GAE supplement at 0.5% and 1% reduced aldose reductase activity in heart and kidney; and lowered the levels of carboxymethyllysine and pentosidine in plasma and two organs. Diabetes decreased glutathione content, and increased reactive oxygen species, interleukin (IL)‐1β, IL‐6, and tumor necrosis factor‐α production in heart and kidney. GAE supplement at three test doses reversed these changes. Diabetes upregulated the mRNA expression of p38 and nuclear factor kappa (NF‐κ)B in heart and kidney. GAE supplement suppressed the mRNA expression of both p38 and NF‐κB. These novel findings suggest that Gynura bicolor is a potent functional food for diabetic prevention or alleviation.

Antioxidant and Anti-Inflammatory Effects of Genus Gynura: A Systematic Review

“…The reporting completeness of the material in all selected studies was assessed using information of the Gynura species material, voucher specimens, quality control, and chemical analysis. Naming inconsistency between studies was detected as full botanical taxonomic names were not stated in 13 selected studies ( Iskander et al, 2002 ; Siriwatanametanon and Heinrich, 2011 ; Akowuah et al, 2012 ; Seow et al, 2014 ; Chao et al, 2015 ; Wong et al, 2015 ; Xu et al, 2015 ; Rerknimitr et al, 2016 ; Yin et al, 2017 ; Rahman et al, 2018 ; Pai et al, 2019 ; Yang et al, 2019 ; Chandradevan et al, 2020 ). All plant species need to be validated taxonomically, and the full names have to be clearly stated as the incomplete name of plant species can lead to confusion of readers and any recorded uses or properties attributed may, in fact, correlate to different species.…”

“… Yuanshan Village, Ilan, Taiwan + No Yes—HPLC Chao et al (2015) Gynura bicolor DC. Farms in Puli Town, Nanton county, Taiwan + No No Yin et al (2017) Gynura bicolor DC Farms in Puli Town, Nanton county, Taiwan + No No Pai et al (2019) Gynura bicolor Farms, unknown location − No No Yang et al (2019) Gynura bicolor DC. Farms, unknown location − No No Siriwatanametanon et al (2010) Gynura pseudochina (L.) DC.…”

“…Six selected studies ( Iskander et al, 2002 ; Xu et al, 2015 ; Ma et al, 2017 ; Dong et al, 2019 ; Liu M. et al, 2019 ; Liu Y. et al, 2019 ) reported the information of the Gynura species source but did not provide voucher specimens. Four selected studies ( Siriwatanametanon and Heinrich, 2011 ; Rerknimitr et al, 2016 ; Pai et al, 2019 ; Yang et al, 2019 ) were inadequate on material information as the Gynura species source was not reported and voucher specimens were missing. The absence of voucher specimens seriously makes the reliability of the article suspicious.…”

“…Of the 27 selected studies, there are seven species of genus Gynura , which are G. procumbens , G. bicolor , G segetum , G. divaricata , G. formosana , G. nepalensis , and G. pseudochina. Among these Gynura species, 11 out of 27 selected studies focused on G. procumbens ( Iskander et al, 2002 ; Kim et al, 2011 ; Akowuah et al, 2012 ; Shwter et al, 2014 ; Wong et al, 2015 ; Huang et al, 2019 ; Liu M. et al, 2019 ; Liu Y. et al, 2019 ; Nazri et al, 2019 ; Ning et al, 2019 ; Chandradevan et al, 2020 ), five studies on G. bicolor ( Wu et al, 2013 ; Chao et al, 2015 ; Yin et al, 2017 ; Pai et al, 2019 ; Yang et al, 2019 ), four studies on G. pseudochina ( Siriwatanametanon et al, 2010 ; Siriwatanametanon and Heinrich, 2011 ; Rerknimitr et al, 2016 ; Sukadeetad et al, 2018 ), two studies on G. segetum ( Seow et al, 2014 ; Yuandani et al, 2017 ), two studies on G. nepalensis ( Yu et al, 2016 ; Rahman et al, 2018 ), two studies on G. divaricata ( Xu et al, 2015 ; Dong et al, 2019 ), and one study on G. formosana ( Ma et al, 2017 ) .…”

“…Five studies used the aqueous extract of G. procumbens and G. bicolor to determine their antioxidant or anti-inflammatory activities in human endothelial cells ( Chao et al, 2015 ), murine adrenal gland pheochromocytoma ( Yang et al, 2019 ), murine hepatocytes ( Liu Y. et al, 2019 ), diabetic mice ( Pai et al, 2019 ), and liver-injured mice ( Yin et al, 2017 ; Liu Y. et al, 2019 ). The ethyl acetate extract of G. formosana was studied for its antioxidant and anti-inflammatory activities in granuloma model rats ( Ma et al, 2017 ).…”