Alkylphthalides with intracellular triglyceride metabolism-promoting activity from the rhizomes of Cnidium officinale Makino

Methanol extract of the Cnidium officinale Makino rhizome, which is used as a crude drug Cnidium Rhizome (Cnidii Rhizoma; "Senkyu" in Japanese) and is listed in the Japanese Pharmacopoeia XVIII, showed intracellular triglyceride metabolism-promoting activity in high glucose-pretreated HepG2 cells. Thirty-five constituents, including two new alkylphthalide glycosides, senkyunosides A (1) and B (2), and a neolignan with a new stereoisomeric structure (3), were isolated in the extract. Their stereostructures were elucidated based on chemical and spectroscopic evidence. Among the isolates, several alkylphthalides, (Z)-3-butylidene-7-methoxyphthalide (9) and senkyunolides G (10), H (14), and I (15), and a polyacetylene falcarindiol (26), were found to show significant activity without any cytotoxicity at 10 μM.

Ameliorative effect of bofutsushosan (Fangfengtongshengsan) extract on the progression of aging-induced obesity

This study aimed to compare fat accumulation in young and aged mice raised on a high-fat diet and to characterize the obesity-reducing effects of a Kampo medicine, bofutsushosan (BTS; fangfengtongshengsan in Chinese). Aged mice fed a high-fat diet containing 2% BTS extract for 28 days exhibited a significant reduction in weight gain and accumulation of visceral and subcutaneous fat, which were greater degree of reduction than those of the young mice. When the treatment period was extended to two months, the serum aspartate aminotransferase and alanine aminotransferase levels and the accumulation of fat droplets in the hepatocytes decreased. The mRNA expression of mitochondrial uncoupling protein 1 (UCP1) in the brown adipose tissue was significantly reduced in the aged mice compared to the young mice but increased by 2% in the BTS-treated aged mice. Additionally, the effect of BTS extract on oleic acid-albumin-induced triglyceride accumulation in hepatoblastoma-derived HepG2 cells was significantly inhibited in a concentration-dependent manner. Evaluation of the single crude drug extracts revealed that Forsythia Fruit, Schizonepeta Spike, and Rhubarb were the active components in BTS extract. These results suggest that BTS extract is effective against visceral, subcutaneous, and ectopic fats in the liver, which tend to accumulate with aging. Thus, BTS extract is useful in preventing and ameliorating the development of obesity and metabolic syndrome.

Hypoglycemic effects of mountain caviar extract and inhibitory mechanism of saponins, including momordin Ic, on glucose absorption

Mountain caviar is a fruit of Kochia scoparia that contains momordin Ic as a major saponin constituent. Its extract (MCE) has been shown to suppress blood glucose elevations in the human oral glucose tolerance test (OGTT) as well as increases in blood glucose in OGTT, gastric emptying (GE), and glucose incorporation in the small intestine in rats. However, the effects of MCE and momordin Ic on glucose absorption in mice and these action mechanisms have not been examined for more than 2 decades. Therefore, we herein investigated the effects of MCE, its saponin fraction, and momordin Ic on blood glucose elevations in mice. Mouse blood glucose elevation tests were performed on carbohydrate-loaded mice. The mountain caviar saponin fraction significantly delayed blood glucose elevations in glucose-, sucrose-, and soluble starch-loaded mice. In glucose-loaded mice, the saponin fraction, MCE, and momordin Ic significantly suppressed rapid glucose elevations after glucose loading, but not sucrose loading. A mouse GE study was performed by loading with glucose and phenolphthalein solution. Momordin Ic and MCE strongly suppressed mouse GE. Intestinal glucose absorption was evaluated by the incorporation of 2-deoxyglucose (2-DG) into Caco-2 cell layers and mouse duodenum wall vesicles. The results obtained showed that momordin Ic inhibited the incorporation of 2-DG into Caco-2 cells and mouse duodenum vesicles. Collectively, these results suggest that MCE, particularly the principal saponin, momordin Ic, preferably suppressed glucose-induced blood glucose elevations and delayed carbohydrate-induced glucose elevations in mice. The underlying mechanism was found to involve the suppression of GE and intestinal glucose absorption.

Inhibitory effect of trans-tiliroside on very low-density lipoprotein secretion in HepG2 cells and mouse liver

An acylated flavonol glycoside, trans-tiliroside (1), is found in certain parts of different herbs, including the seeds of Rosa canina (Rosaceae). Previous studies on compound 1 have focused on triglyceride (TG) metabolism, including its anti-obesity and intracellular TG reduction effects. In the present study, the effects of compound 1 on cholesterol (CHO) metabolism were investigated using human hepatocellular carcinoma-derived HepG2 cells and mice. Compound 1 decreased CHO secretion in HepG2 cells, which was enhanced by mevalonate in a concentration-dependent manner and decreased the secretion of apoprotein B (apoB)-100, a marker of very low-density lipoprotein (VLDL). Compound 1 also inhibited the activity of microsomal triglyceride transfer proteins, which mediate VLDL formation from cholesterol and triglycerides in the liver. In vivo, compound 1 inhibited the accumulation of Triton WR-1339-induced TG in the blood of fasted mice and maintained low levels of apoB-100. These results suggest that compound 1 inhibits the secretion of CHO as VLDL from the liver and has the potential for use for the prevention of dyslipidemia.

Aromatase inhibitors isolated from a flowering tea, snow Chrysanthemum (the capitula of Coreopsis tinctoria Nutt.)

Methanol extract from the capitula of Coreopsis tinctoria Nutt. (Asteraceae), which is also known as a flowering tea or blooming tea "Snow Chrysanthemum," was found to inhibit the enzymatic activity of aromatase. A total of 24 known isolates (1-24) were identified from the extract, including three chalcones (1-3), an aurone (4), five flavanones (5-9), four flavanols (10-13), a flavonol (14), and two biflavanones (15, 16). Among them, okanin (1, Ki = 1.6 μM), (2S)-naringenin (5, 0.90 μM), isookanin (6, 0.81 μM), (2S)-7,3',5'-trihydroxyflavaone (7, 0.13 μM), and (2S)-5,7,3',5'-tetrahydroxyflavanone (8, 0.32 μM) exhibited relatively potent competitive inhibition. Specifically, the isolates 7 and 8, having a common 3',5'-resorcinol moiety at the B ring in their flavanone skeleton, exhibited potent inhibitory activities compared to those of a clinically applied aminoglutethimide (0.84 μM) and naturally occurring flavone, chrysin (0.23 μM), which is a common non-steroidal aromatase inhibitor. Importantly, the active flavonoid constituents (1 and 5-8) did not inhibit the activity of 5α-reductase enzyme, which normally reacts with the same substrate "testosterone," thus, these compounds were suggested to be specific to aromatase.

Hepatoprotective Principles from the Rhizomes of Picrorhiza kurroa

A methanol extract of rhizomes of Picrorhiza kurroa Royle ex Benth. (Plantaginaceae) showed hepatoprotective effects against D-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced liver injury in mice. We had previously isolated 46 compounds, including several types of iridoid glycosides, phenylethanoid glycosides, and aromatics, etc., from the extract. Among them, picroside II, androsin, and 4-hydroxy-3-methoxyacetophenone exhibited active hepatoprotective effects at doses of 50-100 mg/kg, per os (p.o.) To characterize the mechanisms of action of these isolates and to clarify the structural requirements of phenylethanoid glycosides for their hepatoprotective effects, their effects were assessed in in vitro studies on (i) D-GalN-induced cytotoxicity in mouse primary hepatocytes, (ii) LPS-induced nitric oxide (NO) production in mouse peritoneal macrophages, and (iii) tumor necrosis factor-α (TNF-α)-induced cytotoxicity in L929 cells. These isolates decreased the cytotoxicity caused by D-GalN without inhibiting LPS-induced macrophage activation and also reduced the sensitivity of hepatocytes to TNF-α. In addition, the structural requirements of phenylethanoids for the protective effects of D-GalN-induced cytotoxicity in mouse primary hepatocytes were evaluated.

Phytochemicals with Chemopreventive Activity Obtained from the Thai Medicinal Plant Mammea siamensis (Miq.) T. Anders.: Isolation and Structure Determination of New Prenylcoumarins with Inhibitory Activity against Aromatase

With the aim of searching for phytochemicals with aromatase inhibitory activity, five new prenylcoumarins, mammeasins K (1), L (2), M (3), N (4), and O (5), were isolated from the methanolic extract of Mammea siamensis (Miq.) T. Anders. flowers (fam. Calophyllaceae), originating in Thailand. The stereostructures of 1–5 were elucidated based on their spectroscopic properties. Among the new compounds, 1 (IC₅₀ = 7.6 µM) and 5 (9.1 µM) possessed relatively strong inhibitory activity against aromatase, which is a target of drugs already used in clinical practice for the treatment and prevention of estrogen-dependent breast cancer. The analysis through Lineweaver–Burk plots showed that they competitively inhibit aromatase (1, Ki = 3.4 µM and 5, 2.3 µM). Additionally, the most potent coumarin constituent, mammea B/AB cyclo D (31, Ki = 0.84 µM), had a competitive inhibitory activity equivalent to that of aminoglutethimide (0.84 µM), an aromatase inhibitor used in therapeutics.

Oryza Ceramide®, a rice-derived extract consisting of glucosylceramides and β-sitosterol glucoside, improves facial skin dehydration in Japanese subjects

Background and objective: The ingestion of plant-derived glucosylceramides (GlcCer) has been reported to contribute to skin barrier function and hydration of the epidermis. b-sitosterol glucoside (BSG) colocalized with GlcCer in the rice hydrophobic fraction has been shown to increase ceramides in the stratum corneum in vitro. Although clinical studies demonstrated that GlcCer reduced transepidermal water loss (TEWL), the contribution of BSG to epidermal dehydration when applied with GlcCer remains unknown. Therefore, we herein conducted a clinical trial on the effects of a rice-derived mixed fraction of GlcCer and BSG (Oryza Ceramide®) on TEWL and other skin parameters. Methods: A randomized, double-blind, placebo-controlled study design was used. Oryza Ceramide® (type PCD, 40 mg daily) containing 1.2 mg of GlcCer and 40 mg of BSG was used as the active sample. We enrolled 44 healthy Japanese women with epidermal dehydration. All subjects were randomly allocated to an active group (n=22) or placebo group (n=22) using a computerized random number generator. Capsules containing the active sample or placebo were administered for 12 weeks between August and December 2020. Cheek TEWL after 12 weeks was assessed as the primary outcome, and TEWL on a different part of the skin and various skin parameters, including epidermal moisture, pigmentation, pores, and elasticity, were measured before and after 4, 8, and 12 weeks of the intervention. Blood, urine, and body parameters were also examined to evaluate safety.Results: Forty-four subjects completed the trial, and the per protocol set comprised 22 each in the active and placebo groups. Cheek TEWL significantly reduced after the Oryza Ceramide® intervention for 4 and 12 weeks. Among the secondary outcomes examined, lip moisture (12 weeks) and visible pore number (4 weeks) were improved by Oryza Ceramide®. Laboratory tests revealed no abnormalities to suggest any adverse effects of Oryza Ceramide®.Conclusions: Oryza Ceramide® (40 mg/day) consisting of GlcCer and BSG improved facial TEWL, lip moisture, and visible pores, and these effects may be attributed to increases in epidermal ceramides. The combination of rice GlcCer and BSG appears to be beneficial for improving facial skin conditions.Trial Registration: UMIN-CTR: UMIN000041295Foundation: The study was funded by Oryza Oil & Fat Chemical Co., Ltd. and Aichi Prefectural Subsidies for Research and Development of Creative Products in 2020.Keywords: rice; glucosylceramide; β-sitosterol glucoside; trans epidermal water loss; pore 

Indole Glycosides from Calanthe discolor with Proliferative Activity on Human Hair Follicle Dermal Papilla Cells

A methanol extract from the underground part of Calanthe discolor Lindl. (Orchidaceae) demonstrated significant proliferative activity on human hair follicle dermal papilla cells (HFDPC, % of control: 120.8 ± 0.2%) at 100 µg/mL against HFDPC. Through bioassay-guided separation of the extract, a new indole glycoside named 6'-O-β-D-apiofuranosylindican (1) was isolated along with six known compounds (2-7) including three indole glycosides. The stereostructure of 1 was elucidated based on its spectroscopic properties and chemical characteristics. Among the isolates, 1 (110.0 ± 1.0%), glucoindican (3, 123.9 ± 6.8%), and calanthoside (4, 158.6 ± 7.1%) showed significant proliferative activity at 100 µM. Furthermore, the active indole glycosides (1, 3, and 4) upregulated the expression of vascular endothelial growth factor (VEGF) and fibroblast growth factor-7 (FGF-7) mRNA and protein in HFDPC, which could be the mechanism of their proliferative activity.

Collagen synthesis-promoting and collagenase inhibitory activities of constituents isolated from the rhizomes of Picrorhiza kurroa Royle ex Benth

Three new acylated phenylethanoid glycosides, kurroaosides A (14), B (15), and C (16), and a new acylated cucurbitane-type triterpene glycoside, kurroaoside D (17), were isolated from a methanol extract of the rhizomes of Picrorhiza kurroa Royle ex Benth. (Plantaginaceae) along with 29 known isolates including 10 acylated phenylethanoid glycosides (18-27), three cucurbitane-type triterpene glycosides (32-34), and a nortriterpene glycoside (35). The structures of these new compounds (14-17), including their stereochemistry, were determined based on chemical and physicochemical evidence derived from NMR and MS analysis. Among the isolates, acylated iridoid glycosides, picrosides I (8), II (9), III (10), and IV (11) and 6-feruloylcatalpol (12), phenylethanoid glycosides (14-16), triterpene glycosides, cucurbitacin B 2-O-β-D-glucopyranoside (32) and 25-acetoxy-2-β-D-glucopyranosyloxy-3,16,20-trihydroxy-9-methyl-19-norlanosta-5-en-22-one (35), and an acetophenone glycoside, picein (36), significantly promoted collagen synthesis at 10-30 μM, with no cytotoxicity being observed at the effective concentrations. Furthermore, acylated phenylethanoid glycosides, calceolarioside A (19, IC₅₀ = 69.2 μM), plantamajoside (20, 51.8 μM), isoplantamajoside (21, 76.8 μM), and scroside E (23, 65.5 μM), exhibited collagenase inhibitory activity equivalent to that of positive agents caffeic acid (75.6 μM) and epigallocatechin 3-O-gallate (75.4 μM).

Geranylated Coumarins From Thai Medicinal Plant Mammea siamensis With Testosterone 5α-Reductase Inhibitory Activity

Geranylated coumarin constituents, kayeassamin I (1) and mammeasins E (2) and F (3) were newly isolated from the methanol extract of the flowers of Mammea siamensis (Calophyllaceae) originating in Thailand, along with five known isolates, such as mammea E/BC (23), deacetylmammea E/AA cyclo D (31), deacetylmammea E/BB cyclo D (32), mammea A/AA cyclo F (34), and mammea A/AC cyclo F (35). These compounds (1–3) were obtained as an inseparable mixture (ca. 1:1 ratio) of the 3″R and 3″S forms, respectively. Among the isolated coumarins from the extract, mammeasins E (2, 22.6 μM), A (4, 19.0 μM), and B (5, 24.0 μM), kayeassamins E (9, 33.8 μM), F (10, 15.9 μM), and G (11, 17.7 μM), surangin C (13, 5.9 μM), and mammeas A/AA (17, 19.5 μM), E/BB (22, 16.8 μM), and A/AA cyclo F (34, 23.6 μM), were found to inhibit testosterone 5α-reductase.

Acylated iridoid glycosides with hyaluronidase inhibitory activity from the rhizomes of Picrorhiza kurroa Royle ex Benth

Seven new acylated iridoid glycosides, picrorhizaosides A-G (1-7), were isolated from the methanol extract of the rhizomes of Picrorhiza kurroa Royle ex Benth. (Plantaginaceae), in addition to six known iridoid glycosides (8-13). The structures of these new iridoids, including their stereochemistry, were determined based on chemical and physicochemical evidence derived from NMR and MS analysis. Of the isolates, picrorhizaosides D (4, IC₅₀ = 43.4 μM) and E (5, 35.8 μM); picrosides I (8, 60.7 μM), II (9, 22.3 μM), and IV (11, 59.2 μM); and minecoside (13, 57.2 μM), exhibited a similar or stronger hyaluronidase inhibitory activity than those of the antiallergic medicines disodium cromoglycate (64.8 μM), ketotifen fumarate (76.5 μM), and tranilast (227 μM).

Quantitative Determination of Principal Aporphine and Benzylisoquinoline Alkaloids Due to Blooming State in Lotus Flower (Flower Buds of Nelumbo nucifera) and Their Hyaluronidase Inhibitory Activity

Using a recently developed analytical protocol, distributions of 5 aporphine alkaloids, nuciferine (1), nornuciferine (2), N-methylasimilobine (3), asimilobine (4), and pronuciferine (5), and 5 benzylisoquinoline alkaloids, armepavine (6), norarmepavine (7), N-methylcoclaurine (8), coclaurine (9), and norjuziphine (10), in lotus flowers (the flower buds of Nelumbo nucifera) were analyzed. The flowers were collected at different blooming states (beginning of blooming, one-third in bloom, half in bloom, three-quarters in bloom, and in full bloom) from Saga prefecture, Japan (NN-S1–5). The samples from the beginning of blooming state (NN-S1, 16.35 mg/g in dried material) were found to possess the richest total alkaloid content (1-10). The samples of half in bloom (NN-S3, 52.69 mg per flower of dried material) had the highest total alkaloid content per flower. Among the alkaloid constituents, nornuciferine (2, IC50 = 22.5 µM), asimilobine (4, 11.7 μM), norarmepavine (7, 26.4 μM), coclaurine (9, 11.4 μM), and norjuziphine (10, 24.3 μM) exhibited hyaluronidase inhibitory activity, which was more potent than that of the antiallergic medicine disodium cromoglycate (DSCG, 64.8 μM).

Total Synthesis of γ-Alkylidenebutenolides, Potent Melanogenesis Inhibitors from Thai Medicinal Plant Melodorum fruticosum

A hitherto unreported member of γ-alkylidenebutenolides in Melodorum fruticosum (Annonaceae), (4 E)-6-benzoyloxy-7-hydroxy-2,4-heptadiene-4-olide, named as isofruticosinol (4) was isolated from the methanol extract of flowers, along with the known related butenolides, namely, the (4 Z)-isomer (3) of 4, melodrinol (1), and its (4 E)-isomer (2). To unambiguously determine the absolute configuration at the C-6 position in these butenolides, the first total syntheses of both enantiomers of 2-4 were achieved over 6-7 steps from commercially available D- or L-ribose (D- and L-5). Using the same protocol, both enantiomers of 1 were also synthesized. Based on chiral HPLC analysis of all synthetic compounds ( S- and R-1-4), all naturally occurring butenolides were assigned as partial racemic mixtures with respect to the chiral center at C-6 (enantiomeric ratio, 6 S/6 R = ∼83/17). Furthermore, the melanogenesis inhibitory activities of S- and R-1-4 were evaluated, with all shown to be potent inhibitors with IC₅₀ values in the range 0.29-2.9 μM, regardless of differences in the stereochemistry at C-6. In particular, S-4 (IC₅₀ = 0.29 μM) and R-4 (0.39 μM) showed potent inhibitory activities compared with that of reference standard arbutin (174 μM).

Melanogenesis Inhibitory Activity of Diterpenoid and Triterpenoid Constituents from the Aerial Part of Isodon trichocarpus

A methanol extract from the aerial part of Isodon trichocarpus (Labiatae) demonstrated inhibitory effects on melanogenesis in theophylline-stimulated murine B16 melanoma 4A5 cells (IC50 = 1.6 μg/mL). From the extract, nine diterpenoids (1–9) and four triterpenoids (10–13) were isolated. Among the isolates, enmein (1, IC50 = 0.22 μM), isodocarpin (2, 0.19 μM), nodosin (4, 0.46 μM), and oridonin (6, 0.90 μM) showed an inhibitory effect without notable cytotoxicity at the effective concentrations. These diterpenoids (1, 2, 4, and 6) inhibited the expression of tyrosinase, tyrosine-related protein (TRP)-1, and TRP-2 mRNA, which could be the mechanism of melanogenesis inhibitory activity.

Acetoxybenzhydrols as highly active and stable analogues of 1'S-1'-acetoxychavicol, a potent antiallergic principal from Alpinia galanga

Through SAR studies on 1'S-1'-acetoxychavicol acetate (1) against Type I antiallergic activity by indexing release of beta-hexosaminidase, a marker of antigen-IgE-mediated degranulation in RBL-2H3 cells, more stable and potent analogue, 4-(methoxycarbonyloxyphenylmethyl)phenyl acetate (16), has been developed. The compound 16 also strongly inhibited the antigen-IgE-mediated TNF-alpha and IL-4 production.