Hachimijiogan, a traditional herbal medicine, modulates adipose cell function and ameliorates diet-induced obesity and insulin resistance in mice.

Hachimijiogan (HJG) has originally been used to ameliorate a variety of symptoms associated with low ambient temperatures. However, its pharmacological action in metabolic organs remains unclear. We hypothesized that HJG may modulate metabolic function and have a potential therapeutic application to metabolic diseases. To test this hypothesis, we investigated metabolic action of HJG in mice. Male C57BL/6J mice chronically administered with HJG showed a reduction in adipocyte size with increased transcription of beige adipocyte-related genes in subcutaneous white adipose tissue. HJG-mixed high-fat diet (HFD)-fed mice showed alleviation of HFD-induced weight gain, adipocyte hypertrophy, liver steatosis with a significant reduction in circulating leptin and Fibroblast growth factor 21 despite no changes in food intake or oxygen consumption. Feeding an HJG-mixed HFD following 4-weeks of HFD feeding, while a limited effect on body weight, improved insulin sensitivity with a reversal of decreased circulating adiponectin. In addition, HJG improved insulin sensitivity in the leptin-deficient mice without significant effects on body weight. Treatment with n-butanol soluble extracts of HJG potentiated transcription of Uncoupling protein 1 mediated by ß3-adrenergic agonism in 3T3L1 adipocytes. These findings provide evidence that HJG modulates adipocyte function and may exert preventive or therapeutic effects against obesity and insulin resistance.

Corrigendum: Identification of an alternative glycyrrhizin metabolite causing liquorice-induced pseudohyperaldosteronism and the development of ELISA system to detect the predictive biomarker.

[This corrects the article DOI: 10.3389/fphar.2021.688508.].

Evaluation of the Amounts of Sennosides A and B in Rhubarb-containing Kampo Medicines to Create a Ranking of Kampo Medicines for Appropriate Selection of Laxatives.

OBJECTIVES: To evaluate 20 Kampo medicines, which comprised 6 formulas, Otsujito, Junchoto, Tokakujokito, Bofutsushosan, Mashiningan, and Keishikashakuyakudaioto, from 7 brands, to create a ranking of Kampo medicines for appropriate selection of laxatives. METHODS: The amounts of sennosides A and B, the important components showing laxative effects contained in Kampo medicines, were analysed using High Performance Liquid Chromatography. RESULTS: We found that the amounts of sennosides A and B were different among brands, even when they had the same formula. Furthermore, the amounts of sennosides differed when the same amounts of rhubarb were used. CONCLUSIONS: These results suggest that the differences in amounts of sennosides are caused by the quality of the rhubarb used. Kampo medicines containing laxatives other than rhubarb, including disodium sulphate and hemp seed, had synergistic laxative effects. Thus, in the future, it may be possible to adjust laxative potency of Kampo medicines through further clinical tests.

Identification of an Alternative Glycyrrhizin Metabolite Causing Liquorice-Induced Pseudohyperaldosteronism and the Development of ELISA System to Detect the Predictive Biomarker.

Liquorice is usually used as crude drug in traditional Japanese Kampo medicine and traditional Chinese medicine. Liquorice-containing glycyrrhizin (GL) can cause pseudohyperaldosteronism as a side effect. Previously, we identified 18ß-glycyrrhetyl-3-O-sulfate (3) as a GL metabolite in Eisai hyperbilirubinuria rats (EHBRs) with the dysfunction of multidrug resistance-related protein (Mrp2). We speculated that 3 was associated with the onset of liquorice-induced pseudohyperaldosteronism, because it was mainly detected in serum of patients with suspected to have this condition. However, it is predicted that other metabolites might exist in the urine of EHBRs orally treated with glycyrrhetinic acid (GA). We explored other metabolites in the urine of EHBRs, and investigated the pharmacokinetic profiles of the new metabolite in EHBRs and normal Sprague-Dawley rats. We further analyzed the serum concentrations of the new metabolite in the patients of pseudohyperaldosteronism. Finally, we developed the analyzing method of these metabolites as a preventive biomarker for the onset of pseudohyperaldosteronism using an enzyme-linked immunosorbent assay (ELISA). We isolated a new GL metabolite, 18ß-glycyrrhetyl-3-O-sulfate-30-O-glucuronide (4). Compound 4 significantly inhibited rat type-2 11ß-hydroxysteroid dehydrogenase (11ß-HSD2) and was a substrate of both organic anion transporter (OAT) 1 and OAT3. Compound 4 was also detected in the serum of patients with suspected pseudohyperaldosteronism at an approximately 10-fold lower concentrations than 3, and these concentrations were positively correlated. Compound 4 showed a lower serum concentration and weaker inhibitory titer on 11ß-HSD2 than 3. We developed an enzyme-linked immunosorbent assay system using an anti-18ß-glycyrrhetyl-3-O-glucuronide (3MGA) monoclonal antibody to measure the serum concentration of 3 to facilitate the measurement of biomarkers to predict the onset of pseudohyperaldosteronism. Although we found 4 as the secondary candidate causative agent, 3 could be the main potent preventive biomarker of liquorice-induced pseudohyperaldosteronism. Compound 3 was detected in serum at a higher concentration than GA and 4, implying that 3 may be a pharmacologically active ingredient mediating not only the development of pseudohyperaldosteronism but anti-inflammatory effects in humans administered GL or other liquorice-containing preparations.

Appetite-enhancing effects of inhaling cinnamon, clove, and fennel essential oils containing phenylpropanoid analogues.

Cinnamon, clove, and fennel are commonly used as spices and herbal medicines, and one of their medicinal uses is as aromatic stomachics. We investigated the effect on appetite in mice of inhaling volatile compounds contained in essential oils extracted from herbal medicines used as aromatic stomachics. The appetite-enhancing effects of cinnamon and fennel essential oils were similar to those of their main components trans-cinnamaldehyde and trans-anethole, respectively. The appetite-enhancing effects of clove essential oil were observed over a wide range of doses (4.5 × 10-4 to 4.5 × 10-3 mg/cage), even though the active compounds showed effects within a narrow range of doses (eugenol: 4.5 × 10-4 to 2.5 × 10-3 mg/cage; eugenol acetate: 1.1 × 10-3 to 4.5 × 10-3 mg/cage). The increase in appetite at doses that differed by tenfold in mice administered clove oil was due to synergistic effects between eugenol and eugenol acetate in clove oil. Thus, loss of appetite could be treated more effectively using essential oil containing both eugenol and eugenol acetate compared with the active compounds administered separately. Administering essential oils, such as cinnamon and clove, could improve loss of appetite without strict dosage adjustment.

Appetite-enhancing effects of nutmeg oil and structure-activity relationship of habituation to phenylpropanoids.

Nutmeg (Myristica fragrans) is widely used to flavour sweet and savoury foods and has been used as a herbal medicine to enhance appetite in Asian countries. Nutmeg oil contains compounds such as myristicin and methyl eugenol. Previously, we found that inhalation of phenylpropanoid compounds increased appetite in mice. These volatile aroma compounds with appetite-enhancing effects have attracted the attention of healthcare professionals who care for older people with dementia because many of these older people have hypophagia, which leads to frailty and becoming bedridden. Thus, appetite-enhancing agents that are inexpensive and easy to administer are particularly desirable. In this study, we showed that the inhalation of nutmeg oil, myristicin and methyl eugenol produced appetite-enhancing effects in mice. Methyl eugenol alone has shown appetite-enhancing effects and locomotor-reducing effects at the same dose. In a previous study, benzylacetone produced those two effects at the same dose and also increased the body weight of mice significantly; methyl eugenol, however, did not because the mice experienced olfactory habituation after repeated inhalations of methyl eugenol. A structure-activity study showed that a carbonyl group on the aliphatic chain prevented habituation to aroma compounds, which is important information for identifying suitable phenylpropanoid compounds for long-term treatment of loss of appetite.

Possible involvement of the µ opioid receptor in the antinociception induced by sinomenine on formalin-induced nociceptive behavior in mice.

Sinomenine, an alkaloid originally isolated from the roots and the rhizome of Sinomenium acutum is used as a traditional Chinese herbal medicines for rheumatoid arthritis and neuralgia. The aims of this study were to investigate the effects of oral administration of shinomenine on formalin-induced nociceptive behavior in mice and the opioid receptor subtypes involved in the antinociceptive effects of sinomenine. Our findings showed that a single dose of oral-administrated sinomenine inhibited the formalin induced licking and biting responses in a dose-dependent manner. Intraperitoneal pretreatment with naloxone hydrochloride, an opioid receptor antagonist, and ß-funaltrexamine hydrochloride (ß-FNA), a selective µ-opioid receptor antagonist, significantly attenuated sinomenine induced antinociception, but not by naltrindole, a nonselective δ-opioid receptor antagonist and nor-binaltorphimine, a selective κ-opioid receptor antagonist. Furthermore, in western blot analysis, oral administration of sinomenine resulted in a significant blockage of spinal extracellular signal-regulated protein kinase (ERK1/2) activation induced by formalin. Naloxone hydrochloride and ß-FNA significantly reversed the blockage of spinal ERK1/2 activation induced by sinomenine. These results suggest that sinomenine-induced anti nociceptive effect and blockage of spinal ERK1/2 activation may be triggered by activation of µ-opioid receptors.

Appetite-enhancing effects of vanilla flavours such as vanillin.

Vanilla flavour is familiar to consumers through foods, cosmetics, household products and some medicines. Vanilla flavouring agents typically contain vanillin or its analogue ethyl vanillin. Our previous study revealed that the inhalation of eugenol, which contains a vanillyl group, has an appetite-enhancing effect, and the inhalation of aroma compounds containing the vanillyl group or its analogues led to increased food intake in mice. Here, we found that vanillin, ethyl vanillin and eugenol showed appetite-enhancing effects, whereas isoeugenol and safrole did not. These results suggest that the appetite-enhancing effects could be attributable to the vanillyl group and could be affected by the position of the double bond in the aliphatic chain. Furthermore, the results of intraperitoneal administration of eugenol and vanillin suggest that their appetite-enhancing effects could occur via stimulation of olfactory receptors.

Appetite-Enhancing Effects of Curry Oil.

Inhalation of scent compounds with phenylpropanoidal structures, such as trans-cinnamaldehyde, is expected to increase the appetite. The scent of curry powder is well known for its appetite-enhancing effect on humans. In this work, we show that the appetite of mice after inhalation of curry powder essential oil or benzylacetone showed a similar increase. The components of curry oil, trans-cinnamaldehyde, trans-anethole, and eugenol, each showed appetite-enhancing effects; therefore, these three scent compounds may be the active compounds in curry powder oil.

Locomotor-Reducing Activity of Sesquiterpenes Related to Zingiber zerumbet Essential Oil and Hexahydrozerumbone Derivatives.

Zerumbone derivatives 1-4 are 11-membered cyclic compounds synthesised from a sesquiterpene zerumbone obtained from the rhizomes of Zingiber zerumbet SMITH (Zingiberaceae). In this study, we investigated the locomotor-reducing effects of hexahydrozerumbone derivatives 1-3 and zerumbol 4, and those of ß-caryophyllene 5 and caryophyllene oxide 6, which are present in Z. zerumbet essential oil. The absence of the double bond at C6 weakened the locomotor-reducing effects. ß-Caryophyllene 5 and caryophyllene oxide 6 showed locomotor-reducing effects in mice at 4.5×10(-3) mg/cage. Moreover, locomotor activity increased significantly at 0.45 mg/cage of caryophyllene oxide 6.

Appetite-Enhancing Effects: The Influence of Concentrations of Benzylacetone and trans-Cinnamaldehyde and Their Inhalation Time, as Well as the Effect of Aroma, on Body Weight in Mice.

Benzylacetone has appetite-enhancing and locomotor-reducing effects. The effective doses for these two outcomes overlap, and the weight gain of mice exposed to benzylacetone is caused by both appetite-enhancement and a reduction in locomotor activity. The appetite-enhancing effects of trans-cinnamaldehyde and benzylacetone have been reported previously. In this study, these appetite-enhancing effects were seen in mice after short-term, high-dose exposure.

Appetite-enhancing Effects of trans-Cinnamaldehyde, Benzylacetone and 1-Phenyl-2-butanone by Inhalation.

Fragrance in the air and odours of foods and drinks are reported to affect feeding behaviours of humans and other animals. Many previous studies focusing on the relationship between fragrance and appetite have described a reduction of food intake by fragrance administration to help prevent lifestyle diseases. Aromatic herbal medicines, such as cinnamon bark and fennel fruit, are considered to have appetite-enhancing effects and they are often blended in stomachics for relief of asitia and gastric distress in Japan. These fragrant herbal medicines contain many essential oils and their fragrances are hypothesised to be active substances. In this study, food intake and the expression of neuropeptide Y and proopiomelanocortin in the hypothalamus after inhalation of fragrant compounds or essential oils were investigated in mice. Food intake was increased 1.2-fold and the neuropeptide Y mRNA expression in the hypothalamus was increased significantly in mice that inhaled trans-cinnamaldehyde, benzylacetone or 1-phenyl-2-butanone, compared with the control group. These compounds might be effective for treating loss of appetite (anorexia) or eating disorders in elderly and infirm people via a non-invasive route of administration, namely, inhalation.

Locomotor-reducing effects and structural characteristics of inhaled zerumbone and tetrahydrozerumbone derivatives.

Zerumbone 1 is an 11-membered cyclic sesquiterpene obtained from the rhizomes of Zingiber zerumbet SMITH (Zingiberaceae). In this study, we investigated the structure-activity relationship of 1, α-humulene (2), tetrahydrozerumbone stereoisomers (3-5), and tetrahydrozerumbone derivatives (6-9). The oxygen-containing functional groups and the configurations at C1 and C2 contributed to the spontaneous locomotor activity reduction of zerumbone 1 and derivatives 2-9.