[Synthesis of glucuronides in the flavonoid-series. 3. Isolation of apigenin-7- -D-glucuronide from Ruellia tuberosa L. and its synthesis]

Antioxidant and Anti-Inflammatory Activities of Phytochemicals from Ruellia tuberosa

In Vietnam, the aerial parts of Ruellia tuberosa L. are used to treat stress oxidation and inflammatory symptoms in diabetes mellitus. The present study was designed to determine the antioxidant and inflammatory inhibition activities of Ruellia tuberosa L. extract (RTE) and those of the isolated compounds by column chromatography. The crude ethanol extract and ethyl acetate fraction exhibited potent antioxidant activity in the 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and 2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) assays with an IC50 of 25.18 and 14.71 (DPPH test) and 18.22 and 15.27 µg/ml (ABTS test), respectively. The RTE contained high concentrations of polyphenols (308.21 mg GAE/g) and moderate concentrations of flavonoids (97.80 mg QE/g). In the anti-inflammatory screening assay, the crude ethanol extract, ethyl acetate, and methanol fractions suppressed the release of IL-6 and nitric oxide production, but the production of IL-10 was not enhanced in LPS-induced RAW 264.7 cells. Three potential anti-inflammatory compounds as hispidulin (6), physalin E (7), and physalin D (8) along with five other compounds named myricitrin (1), afzelin (2), apigenin (3), taraxerol (4), and lupeol (5) were isolated and identified from the ethyl acetate fraction. Physalin D (8) exhibited a strong, dose-dependent anti-inflammatory activity by inhibiting the production of IL-6 proinflammatory cytokines; however, the IL-10 expression was independent of its concentration in macrophages at noncytotoxic concentrations ranging from 5 to 40 μg/mL. Based on the data obtained, compounds 6–8 sourced from Ruellia tuberosa L are potentially bioactive compounds for the treatment of inflammation symptoms in type 2 diabetes mellitus.

Nutrition in the management of type 2 diabetes mellitus: review

Type 2 diabetes mellitus (T2DM) is the most prevalent disease and becoming a serious public health threat worldwide. In recent years, numerous effective T2DM intervention regimens have been developed, with promising results. However, these regimens are not usually economically available, and they are not well tolerated due to treatment-related toxicities. The focus nowadays is to identify new effective therapeutic agents, with relatively low cost and low toxicity, which can be used regularly to control a progression of T2DM in the prediabetic population. Accordingly, there has been growing attention in herbal remedies that can be presented into the general population with the tiniest side effects and the maximal preventive outcome. This article reviews recent publications in experimental models of T2DM not revised before, and supporting the potential use of nutraceuticals and phytochemicals through different mechanisms with promising results in the context of T2DM.

Alfa glucosidase inhibitory, anti inflammatory activities and a new furanocoumarin derivative of Ruellia tuberosa

Rullia tuberosa L. is used for treatment of diabetes mellitus, anti-inflammation, etc. However, its hypoglycaemic and anti inflammatory activities has not been investigated so far. In the present study, the α-glucosidase inhibitory, anti inflammatory activities of the extract of this plant were investigated. Our results showed that the crude extract as well as ethyl acetate and methanol fractions showed α-glucosidase inhibitory activity with IC₅₀ of 15.84, 4.73 and 8.27 µg/ml, respectively. In addition, the hexane and ethyl acetate fractions are capable of inhibiting LPS-induced NO production with IC₅₀ of 17.41 and 23.95 µg/mL, respectively. From the ethyl acetate and methanol fractions, eight compounds, including isobargaptol 5-O-β-D-glucopyranoside (1), syringaresinol (2), catechin (3), pulmatin (4), stigmast-4-en-3-on (4), verbascoside (5), hydroxymethylfurfural (6), rutin (7), and homoplantaginin (8) were extracted and isolated. Their chemical structures were elucidated by spectroscopic method including MS, 1 D and 2 D- NMR and comparison with the literature values.

Ameliorative effect of Ruellia tuberosa L. on hyperglycemia in type 2 diabetes mellitus and glucose uptake in mouse C2C12 myoblasts

Ruellia tuberosa L. (RTL) exhibits a wide range of phytochemical activities, for example, on treatment of diabetes mellitus (DM), in Orient. There is, however, few study regarding the effect of RTL on glycemic-related homeostasis in type 2 DM (T2DM). We investigated the effect of RTL aqueous and ethanolic extracts on hypoglycemia in high-fat diet (HFD)-fed plus streptozotocin (STZ)-induced T2DM rats, and examined the effect of RTL on glucose uptake in tumor necrosis factor-α-induced insulin-resistant mouse C2C12 myoblasts, a mouse skeletal muscle cell line. The administration of 100 or 400 mg kg BW-1 day-1 of RTL aqueous or ethanolic extracts once a day for 4 weeks significantly ameliorated hyperglycemia, hyperinsulinemia, and the insulin resistance (IR) index in diabetic rats. RTL either aqueous or ethanolic extract at a concentration of 25-800 μg/ml significantly improved glucose uptake in insulin-resistant mouse C2C12 myoblasts, indicating inhibiting the IR in skeletal muscles. These evidences suggest that RTL ameliorates hyperglycemia in HFD/STZ-induced T2DM rats may be attributed to the alleviation of IR in skeletal muscles.

Antidiabetic Activity of Ruellia tuberosa L., Role of α-Amylase Inhibitor: In Silico, In Vitro, and In Vivo Approaches

Ruellia tuberosa L. is a folk remedy in the treatment of diabetes mellitus. However, its hypoglycemic activity has not been investigated so far. In the present study, the antidiabetic mechanism of the n-hexane fraction of methanolic extract (HFME) of this plant was investigated in silico, in vitro, and in vivo. In silico study was performed using AutoDock4.2 software. In vitro   α-amylase inhibitory activity was investigated by starch-iodine method. A single dose of 450 mg/kg HFME for 14 days was subjected to an antidiabetic screening in vivo by a multiple low dose streptozotocin (MLD-STZ) induced rats. Molecular modeling results show that Betulin exhibited noncompetitive α-amylase inhibitory activities. The effect of HFME elicited significant reductions of diabetic rat blood glucose. A single dose administration of HFME inhibited α-amylase activity in vivo (P < 0.01) compared to a diabetic control group. Moreover, this extract strongly inhibited the α-amylase activity in vitro (IC₅₀ 0.14 ± 0.005 mg/mL). It is concluded that HFME exerted an antidiabetic effect via α-amylase inhibitor. Our findings provide a possible hypoglycemic action of R. tuberosa L. as an alternative therapy in the management of diabetes.

Molecular modeling of Ruellia tuberosa L compounds as a-amylase inhibitor: an in silico comparation between human and rat enzyme model

Inhibition of α-amylase is an important strategy to control post-prandial hyperglycemia. The present study on Ruellia tuberosa, known as traditional anti-diabetic agent, is being provided in silico study to identify compounds inhibiting α-amylase in rat and human. Compounds were explored from PubChem database. Molecular docking was studied using the autodock4. The interactions were further visualized and analyzed using the Accelrys Discovery Studio version 3.5. Binding energy of compounds to α-amylase was varying between -1.92 to -6.66 kcal/mol in rat pancreatic alpha amylase and -3.06 to -8.42kcal/mol in human pancreatic alpha amylase, and inhibition konstanta (ki) was varying between 13.12- 39460µM in rat and 0.67-5600µM in human. The docking results verify that betulin is the most potential inhibitor of all towards rat model alpha amylase and human alpha amylase. Further analysis reveals that betulin could be a potential inhibitor with non-competitive pattern like betulinic acid. In comparison, betulin has smaller Ki (0.67µM) than acarbose (2.6 µM), which suggesting that betulin is more potential as inhibitor than acarbose, but this assumption must be verified in vitro.

Estrogenic and cholinergic properties of the methanol extract of Ruellia praetermissa Sceinf. ex. Lindau (Acanthaceae) in female rats

In search for alternative drugs with pharmacological profile to replace hormone replacement therapy, the effects of MeOH extract of Ruellia praetermissa on the uterus and gestation in rats was investigated. 350 mg/kg/day of extract from days 1-9, 1-17 and 9-17 respectively, resulted in increase of the number of implantation sites (56 to 64) and the percentage of implantation (68.6 +/- 2.7 to 90.5 +/- 0.5%). There was also an increase in body weight (1-9 and 1-17) followed by a slight decrease (154 +/- 15.5 to 125 +/- 10) in the body weight at term. The number and the mean value of corpora lutea per female decreased from 25.4 +/- 1.6 to 14.00 +/- 1.6. The extract produced dose-related contraction of the isolated uterine muscle in vitro comparable to ACh. Atropine in doses from 3.4 x 10(-6) to 3 x 10(-3) microM antagonized the response of the uterus to ACh at 2 microM. It induced an increase (0.03 +/- 0.002 to 0.34 +/- 0.001 g) of the uterine weight comparable to that produced by using 3 microM estradiol (0.03 +/- 0.001 to 0.35 +/- 0.005 g). It could therefore be postulated that this extract possesses estrogenic and possible cholinergic effects. The estrogenic effect could have been generated by plant sterols (beta-sitosterol and stigmasterol) and flavonoids (luteolin and apigenin) while cholinergic effect could be due to iridoid glycosides.