Inhibitory Effect of Stevioside on Tumor Promotion by 12-O-Tetradecanoylphorbol-13-acetate in Two-Stage Carcinogenesis in Mouse Skin.

Abstract

The leaves of Stevia rebaudiana BERTONI (Compositae), known colloquially as Caa-ehe, have been used for centuries by the Paraguayan Indians as a sweetening agent with maté tea.1) The steviol (ent-kaurene type diterpene) glycosides, stevioside, rebaudiosides A, C, and F, and dulcoside A have been isolated from S. rebaudiana and are widely used as sweeteners.2,3) In a previous paper we reported the inhibitory effect of the methanol extract of S. rebaudiana and its active component, lupeol palmitate, on inflammatory ear edema caused by 12-O-tetradecanoylphorbol-13-acetate (TPA) in mouse skin.4) Steviol inhibited Epstein-Barr virus early antigen (EBV-EA) induced by TPA in Raji cells, although stevioside did not inhibit the induction of EBV-EA by TPA.5) In this paper we examine the antiinflammatory effect of steviol glycosides, stevioside, rebaudiosides A and C and dulcoside A against TPA-induced inflammation and found these compounds to possess a marked inhibitory effect. The 50% inhibitory dose (ID 50 ) of these compounds for TPA-induced inflammation was 54.1-291.6 mg/ear. Furthermore, the stevioside mixture (the steviol glycosides from S. rebaudiana) was found to suppress markedly the tumor-promoting effect of TPA on skin tumor formation initiated with 7,12-dimethylbenz[a]anthracene (DMBA) in mouse skin. MATERIALS AND METHODSChemicals Stevioside, rabaudiosides A and C, dulcoside A, and stevioside mixture was obtained from Tokiwa Phytochemical (Chiba, Japan). These compounds were identified by chromatographic and spectroscopic comparison with authentic samples.6) The stevioside mixture contained stevioside (48.9%), rebaudioside A (24.4%), rebaudioside C (9.8%), dulcoside A (5.6%), and unidentified components (11.3%). DMBA, indomethacin, hydrocortisone, quercetin, and dimethylsulfoxide were purchased from Sigma Chemical (St. Louis, MO, U.S.A.). TPA was obtained from Chemicals for Cancer Research (Minneapolis, MN, U.S.A.).Animals Female ICR mice (7 weeks old) were obtained from the Japan SLC (Shizuoka, Japan). The animals were housed in an air-conditioned specific pathogen-free room (22-23°C), lit from 08:00 to 20:00. Food and water were available ad libitum.Assay of TPA-Induced Inflammation TPA (1 mg/ear) dissolved in acetone (20 ml) was applied to the right ear only of ICR mice using a micropipette. A volume of 10 ml was delivered to both the inner and outer surfaces of the ear. The sample, or its vehicle (20 ml), chloroform-methanol-water (1 : 2 : 1) or methanol-water (1 : 1), as a control, was applied topically about 30 min before each TPA treatment. For thickness determinations, a pocket thickness gauge (Mitsutoyo, Tokyo, Japan) with a range of 0-9 mm, graduated at 0.01-mm intervals and modified so that the contact surface area was increased to reduce the tension, was applied to the tip of the ear.The ear thickness was measured before treatment (a). Edema was measured 6 h after TPA treatment (b: TPA alone; bЈ: TPA plus sample). The following values were then calculated: Pharmacy, Nihon University; 7-7-1 Narash...

Insulin-mimetic activity of stevioside on diabetic rats: biochemical, molecular and histopathological study

“…Stevioside has an ability to decrease the bad effect of hyperglycemia probably through enhancing insulin secretion and utilization in diabetic rats (Jeppesen et Seema, 2010). Many searches reported that stevioside has been used for treatment of various diseases such as cancer (Yasukawa et al 2002), diabetes (Lailerd et al 2004), obesity, cavities, hypertension (Dyrskog et al 2005), fatigue, depression, and in cosmetic and dental preparations (Duke 2006). …”

Rapid HPLC Method for Determination of Rebaudioside D in Leaves of <i>Stevia rebaudiana</i> Bertoni Grown in the Southeast of México

“…Besides the sweetness of Stevia rebaudiana, there are important biological properties that have been identified, such as anti-cariogenic capacity [5], antineoplastic [6], antihyperglycemic [7], antihypertensive [8] and anti-inflammatory activity [9]. However, one of simplest and most reliable method is HPLC and hence in 2010, the FAO/WHO Joint Expert Committee on Food Additives (JECFA) in the 73rd meeting recommended an HPLC method for determination of steviol glycosides [22].…”

Stevioside and rebaudioside A - predominant ent-kaurene diterpene glycosides of therapeutic potential: a review

“…In a two-stage model of mouse skin carcinogenesis with subsequent sequential exposure to 12-O-tetradecanoylphorbol-13-acetate (TPA) and 7,12-dimethylbenz [a] anthracene (DMBA) have been reported to inhibit and reduce the tumour formation and tumour promotion by blocking the Epstein-Barr virus early antigen (EBV-EA) induction (Konoshima & Takasaki 2002;Yasukawa et al 2002;Takasaki et al 2009). …”

“…Besides sweetness, various medicinal activities of stevioside and rebaudioside A have been identified which include antihyperglycaemic ( Jeppesen et al 2002;Gregersen et al 2004), antineoplastic (Mizushina et al 2005), anticariogenic (Das et al 1992), antihypertensive (Chan et al 2000), antiinflammatory (Yasukawa 2002), and antioxidant activity (Žlabur et al 2015). Currently, numerous reviews have been published concerning the valuable and abundant potential of steviol glycosides as a sweetener in beverages and variety of food products including soy sauce, sea foods, pickled vegetables, and confectionary or bakery products.…”