Adenosine Deaminase Inhibitory Activity of Medicinal Plants: Boost the Production of Cordycepin in Cordyceps militaris.

Cordycepin, also known as 3'-deoxyadenosine, is a major active ingredient of Cordyceps militaris with diverse pharmacological effects. Due to its limited supply, many attempts have been conducted to enhance the cordycepin content. As part of this study, eight medicinal plants were supplemented with cultivation substrates of Cordyceps to increase the cordycepin content. Cordyceps cultivated on brown rice supplemented with Mori Folium, Curcumae Rhizoma, Saururi Herba, and Angelicae Gigantis Radix exhibited increased cordycepin content compared to a brown rice control. Among them, the addition of 25% Mori Folium increased the cordycepin content up to 4 times. Adenosine deaminase (ADA) modulates the deamination of adenosine and deoxyadenosine, and the inhibitors have therapeutic potential with anti-proliferative and anti-inflammatory properties. As ADA is also known to be involved in converting cordycepin to 3'-deoxyinosine, the inhibitory activity of medicinal plants on ADA was measured by spectrophotometric analysis using cordycepin as a substrate. As expected, Mori Folium, Curcumae Rhizoma, Saururi Herba, and Angelicae Gigas Radix strongly inhibited ADA activity. Molecular docking analysis also showed the correlation between ADA and the major components of these medicinal plants. Conclusively, our research suggests a new strategy of using medicinal plants to enhance cordycepin production in C. militaris.

Polyacetylenes from the adventitious roots of Centella asiatica with glucose uptake stimulatory activity.

Centella asiatica (L.) Urban is an herbaceous perennial plant of the Apiaceae family that has diverse medicinal uses. Its active components are saponin, phenolics, and polyacetylenes. Plant cell cultures have been exploited for the efficient production of metabolites with pharmacological activity. In this work, we prepared adventitious root cultures of C. asiatica and analyzed their content and biological activity. Adventitious root extracts were found to increase glucose uptake by differentiated L6 skeletal muscle cells and to be more efficient than the extract of whole plants. Chromatographic fractionation of the extracts from adventitious roots of C. asiatica led to the isolation of two known polyacetylenes, araliadiol (1) and 8-acetoxy-1,9-pentadecadiene-4,6-diyn-3-ol (2), in addition to a new polyacetylene, which we have named centellidiol (3). All the three polyacetylenes stimulated glucose uptake in a dose-dependent manner. The methanol extract of adventitious roots contained 0.53% and 0.82% of compounds 1 and 2, respectively, which are values that were 15 and 21 times higher that are found in mother plants. We therefore suggest that the high content of these polyacetylenes contributes to the high efficacy of C. asiatica adventitious root cultures. Overall, adventitious root cultures of C. asiatica can be part of a secure supply of effective ingredients including polyacetylenes.

Characterization of Antioxidant and α-Glucosidase Inhibitory Compounds of Cratoxylum formosum ssp. pruniflorum and Optimization of Extraction Condition.

Cratoxylum formosum ssp. pruniflorum (Kurz.) Gogel (Guttiferae), called kuding tea, is widely distributed in Southeast Asia. In this study, the constituents and biological activity of C. formosum ssp. pruniflorum were investigated. Extract of its leaves, roots and stems showed antioxidant and α-glucosidase inhibitory activity. Interestingly, comparison of the metabolite profiles of leaves, roots and stems of C. formosum ssp. pruniflorum by LC-MS analysis showed a great difference between the roots and leaves, whereas the roots and stems were quite similar. Purification of the roots and leaves of C. formosum ssp. pruniflorum through various chromatographic techniques resulted in the isolation of 25 compounds. The structures of isolated compounds were elucidated on the basis of spectroscopic analysis as 18 xanthones, 5 flavonoids, a benzophenone and a phenolic compound. Among them, a xanthone (16) and a benzophenone (19) were first reported from nature. Evaluation of biological activity revealed that xanthones had a potent α-glucosidase inhibitory activity, while flavonoids were responsible for the antioxidant activity. To maximize the biological activity, yield and total phenolic content of C. formosum ssp. pruniflorum, extraction conditions such as extraction solvent, time and temperature were optimized using response surface methodology with Box-Behnken Design (BBD). Regression analysis showed a good fit of the experimental data, and the optimal condition was obtained as MeOH concentration in EtOAc, 88.1%; extraction time, 6.02 h; and extraction temperature 60.0 °C. α-Glucosidase inhibitory activity, yield and total phenolic content under the optimal condition were found to be 72.2% inhibition, 10.3% and 163.9 mg GAE/g extract, respectively. These results provide useful information about C. formosum ssp. pruniflorum as functional foods for oxidative stress-related metabolic diseases.

Cordyceps mushroom with increased cordycepin content by the cultivation on edible insects.

Cordycepin is the major constituent of Cordyceps mushroom (or Cordyceps militaris) with therapeutic potential. Insects are the direct sources of nutrients for Cordyceps in nature. Therefore, optimized condition of Cordyceps cultivation for efficient cordycepin production was explored using six edible insects as substrates. The highest yield of cordycepin was produced by the cultivation on Allomyrina dichotoma and was 34 times that on Bombyx mori pupae. Among insect components, fat content was found to be important for cordycepin production. Especially, a positive correlation was deduced between oleic acid content and cordycepin production. The transcriptional levels of cns1 and cns2, genes involved in cordycepin biosynthesis, were higher in Cordyceps grown on A. dichotoma than on other insects tested. The addition of oleic acid to the substrates increased cordycepin production together with the transcriptional levels of cns1 and cns2. Therefore, Cordyceps with high content of cordycepin can be secured by the cultivation on insects.

Therapeutic Potentials of Secoiridoids from the Fruits of Ligustrum lucidum Aiton against Inflammation-Related Skin Diseases.

Ligustrum lucidum Aiton is a flowering plant of the Oleaceae family, and its fruits have been traditionally used for skin nourishment and the treatment of skin diseases. However, the anti-inflammatory constituents for skin disease are not well-characterized. Phytochemical investigation of L. lucidum fruits resulted in the isolation of a new secoiridoid, secoligulene (1), together with (E)-3-(1-oxobut-2-en-2-yl)pentanedioic acid (2) and trans-(E)-3-(1-oxobut-2-en-2-yl)glutaric acid (3). Secoligulene (1) displayed the potent inhibitory effect on NO production with an IC50 value of 12.0 µg/mL. Secoligulene (1) also downregulated mRNA transcriptional levels of pro-inflammatory cytokines such as IL-1 α, IL-1ß, IL-6 and COX-2 in LPS-stimulated RAW264.7 cells. Further investigation showed that secoligulene (1) inhibited the phosphorylation of IκB and JNK activated by LPS. In addition, secoligulene (1) downregulated the expression of chemokines such as CXCL8 and CCL20 in the TNF-α/IL-17/IFN-γ induced HaCaT psoriasis model. Taken together, these findings support the beneficial effects of L. lucidum and its constituents on inflammation-related skin diseases and can be further developed as therapeutic treatments for related diseases.

Alpinumisoflavone ameliorates choroidal neovascularisation and fibrosis in age-related macular degeneration in in vitro and in vivo models.

Age-related macular degeneration (AMD) is a major cause of vision loss in the elderly population. Anti-vascular endothelial growth factor (VEGF) antibody therapy is applicable to neovascularisation of AMD; however, the prevention of fibrosis after anti-VEGF monotherapy is an unmet medical need. Subretinal fibrosis causes vision loss in neovascular age-related macular degeneration (nAMD) even with anti-VEGF therapy. We report the anti-fibrotic and anti-neovascularisation effects of alpinumisoflavone (AIF), an isoflavonoid derived from unripe Maclura tricuspidata fruit, in in vitro and in vivo models. For in vitro study, we treated H2O2 or THP-1 conditioned media (TCM) following activation with phorbol 12-myristate 13-acetate (PMA) and lipopolysaccharide (LPS) in a human retinal pigment epithelial cell line (ARPE-19). Choroidal neovascularisation (CNV) was induced by laser photocoagulation in mice, immediately followed by intravitreal administration of 25 µg AIF. CNV area and fibrosis were measured 7 days after laser photocoagulation. AIF showed anti-fibrosis and anti-neovascularisation effects in both the models. The laser induced CNV area was reduced upon AIF administration in nAMD mouse model. Additionally, AIF decreased the levels of the cleaved form of crystallin alpha B (CRYAB), a chaperone associated with VEGF stabilisation and fibrosis. Our results demonstrate a novel therapeutic application of AIF against neovascularisation and fibrosis in nAMD.

Anti-α-glucosidase and anti-oxidative isoflavonoids from the immature fruits of Maclura tricuspidata.

The composition of a plant, together with its efficacy, vary depending on its maturity and plant parts. In this study, the chemical constituents of immature fruits of Maclura tricuspidata (Moraceae) were investigated together with their anti-diabetic and antioxidant effects. A total of 34 compounds were isolated from the immature fruits of M. tricuspidata using various chromatographic methods. Structure elucidation using extensive spectroscopic analysis led to the characterization of isolated compounds as isoflavonoids with prenyl substituents. Among them, macluraisoflavones A-O were first isolated from nature. The anti-diabetic and antioxidant activity of the isolated compounds were also suggested by α-glucosidase inhibitory activity and DPPH radical scavenging activity, respectively. In particular, macluraisoflavone I, an isoflavonoid with 2,2-dimethylpyran and 2-hydroperoxy-3-methylbut-3-enyl moieties, showed potent α-glucosidase inhibitory activity and DPPH radical scavenging activity. Further molecular docking analysis suggested hydrogen bond and alkyl interactions between α-glucosidase and macluraisoflavone I. Therefore, the immature fruits of M. tricuspidata can be used as an important natural product with antioxidant and anti-diabetic properties.

Aromatic Constituents from the Leaves of Actinidia arguta with Antioxidant and α-Glucosidase Inhibitory Activity.

As the leaf of Actinidia arguta has shown antioxidant activity, a study was conducted to identify the active ingredients. Forty-eight compounds were isolated from the leaves of A. arguta through various chromatographic techniques. Further characterization of the structures on the basis of 1D and 2D NMR and MS data identified several aromatic compounds, including phenylpropanoid derivatives, phenolics, coumarins, flavonoids and lignans. Among them, five compounds were newly reported, naturally occurring, and named argutosides A-D (1-4), which consist of phenylpropanoid glycosides that are conjugated with a phenolic moiety, and argutoside E (5), which is a coumarin glycoside that is conjugated with a phenylpropanoid unit. The isolated compounds showed good antioxidant and α-glucosidase inhibitory activity with differences in activity depending on the structures. Molecular docking analysis demonstrated the interaction between the hydroxyl and carbonyl groups of compounds 1 and 5 with α-glucosidase. Taken together, the leaves of A. arguta are rich in aromatic compounds with diverse structures. Therefore, the leaves of A. arguta and their aromatic components might be beneficial for oxidative stress and glucose-related diseases.

Anti-diabetic potential of Masclura tricuspidata leaves: Prenylated isoflavonoids with α-glucosidase inhibitory and anti-glycation activity.

Investigation of chemical constituents of Masclura tricuspidata leaves resulted in the isolation of 47 isoflavonoids possessing prenyl groups with different numbers and structures. Among them, sixteen compounds named cudracusisoflavones A-P (1-16) were first isolated from nature. The isoflavonoids isolated from M. tricuspidata leaves showed anti-diabetic effects as measured by inhibition on α-glucosidase activity and advanced glycation end-products (AGEs) formations. Especially, cudracusisoflavone L (12), a new compound, together with gancaonin M (27), erysenegalensein E (41) and millewanin G (44) showed strong α-glucosidase inhibition with IC50 values <10.0 µM. In addition, cudracusisoflavones A (1), D (4), M (13) and N (14), together with known prenylated isoflavonoids efficiently inhibited methylglyoxal (MGO)- or glyoxal (GO)-induced AGE formations. Structure activity relationship together with molecular docking analysis suggested the importance of hydroxy group and linear type of prenyl moiety for α-glucosidase inhibition. Conclusively, diverse prenylated isoflavonoids in M. tricuspidata leaves might ameliorate glycotoxicity-induced metabolic diseases.

Neurotrophic isoindolinones from the fruiting bodies of Hericium erinaceus.

Four compounds, hericerin (1), isohericerinol A (2), N-de-phenylethyl isohericerin (3) and corallocin A (4) were isolated from the fruiting bodies of Hericium erinaceus, a lion's mane mushroom (Hericiaceae). Among them, isohericerinol A (2) was newly reported in nature. Further investigation of the neurotrophic effect of isolated compounds demonstrated that isohericerinol A (2) strongly increased the nerve growth factor (NGF) production in C6 glioma cells followed by corallocin A (4) and hericerin (1). Increased NGF production by these compounds promoted the neurite outgrowth in N2a neuronal cells. Western blot analysis also showed the increased protein expression of NGF, brain-derived neurotrophic factor (BDNF) and synaptophysin (SYP) in C6-N2a cells. Taken together, our present study characterized the neurotrophic constituents of H. erinaceus, which may support the potential use of memory improvement.

Characterization of α-glucosidase inhibitory constituents of the fruiting body of lion's mane mushroom (Hericium erinaceus).

ETHNOPHARMACOLOGICAL RELEVANCE: Hericium erinaceus, commonly called lion's mane mushroom, is an edible and medicinal mushroom that has been traditionally used for the treatment of metabolic disorders, gastrointestinal diseases and memory impairment. In this study, potential anti-hyperglycemic constituents were identified to support the traditional usage of H. erinaceus. MATERIALS AND METHODS: The components of H. erinaceus were purified using various column chromatography techniques. The structure of the separated compounds was determined based on spectroscopic data analysis, i.e., 1D and 2D NMR analysis. The anti-hyperglycemic activity of the isolated compounds was evaluated by measuring the inhibitory effects on α-glucosidase activity. Molecular docking analysis was also conducted for elucidation of α-glucosidase inhibitory activity of isolated compounds. RESULTS: Ten compounds including four new compounds, erinacenols A-D (1-4), were isolated from the fruiting bodies of H. erinaceus. Investigation of the anti-hyperglycemic effect of isolated compounds demonstrated that erinacenol D (4), 4-[3',7'-dimethyl-2',6'-octadienyl]-2-formyl-3-hydroxy-5-methyoxybenzylalcohol (6), hericene A (7), hericene D (8) and hericenone D (9) strongly inhibited α-glucosidase activity with IC50 values of <20 µM. The structure activity relationship suggested the importance of long side chain for α-glucosidase inhibitory activity. Further analysis by molecular docking demonstrated the interaction of α-glucosidase and isolated compounds, which supported the inhibitory activity of α-glucosidase. CONCLUSION: Our present study demonstrated the beneficial effect of H. erinaceus by characterization of α-glucosidase inhibitory compounds, including four new compounds. This approach can be valuable support for the traditional use of H. erinaceus for the treatment of diabetes and metabolic diseases, which needs to be clarified by further in-vivo study.

Phenylpropanoid-Conjugated Triterpenoids from the Leaves of Actinidia arguta and Their Inhibitory Activity on α-Glucosidase.

Actinidia arguta, commonly called hardy kiwifruit or kiwiberry, has cold-resistant properties and can be cultivated in Asia, including Korea. Seven new triterpenoids (2-4 and 8-11) along with eight known triterpenoids were isolated from the leaves of A. arguta through various chromatographic techniques. The new triterpenoids were defined as actiniargupenes A-C (2-4), actinidic acid derivatives with phenylpropanoid constituent units, dehydroisoactinidic acid (8), and actiniargupenes D-F (9-11), asiatic acid derivatives with phenylpropanoid substituents, on the basis of 1D and 2D NMR and MS data. Among the triterpenoids, those with a phenylpropanoid constituent unit showed inhibitory activity on α-glucosidase, which suggested the importance of the phenylpropanoid moiety. Molecular docking analysis demonstrated the interaction between the 4'-OH group of the phenylpropanoid moiety and α-glucosidase.

Organic acid conjugated phenolic compounds of hardy kiwifruit (Actinidia arguta) and their NF-κB inhibitory activity.

Nine new compounds, argutinosides A-I (1-9) together with 20 known compounds (10-29), were isolated from the fruits of Actinidia arguta. Using spectral analysis, the structures of the isolated compounds were identified as 10 succinic acid derivatives, 11 quinic acid derivatives, two shikimic acid derivatives and six citric acid derivatives. The NF-κB transcriptional inhibitory activity of the compounds was evaluated using RAW 264.7 macrophages cells induced by lipopolysaccharide. Among four groups of different organic acid derivatives, the quinic acid derivatives inhibited NF-κB transcriptional activity with an IC50 value of 4.0 µM. Fruit is rich in organic acid and secondary metabolites, which differ depending on the type of fruit. Our present study showed the presence of various organic acids conjugates including nine new 2-methylsuccinic acid phenolic conjugates in kiwiberry and compared their biological activities. This will contribute to application of kiwiberry and also the diversity of different fruits.