Alstoboonine, an Ulean-Type Indole Alkaloid from Alstonia boonei Leaves.

Alstonia boonei De Wild is a common plant in West Africa used in traditional medicine for various indications. While the stem bark has frequently been investigated, not much is known about the phytochemistry and bioactivity of the leaves. Within the current study, the major alkaloids of a hydroethanolic leaf extract were therefore isolated and characterized by MS, NMR, and ECD. This led to the identification of alstoboonine 1, a new ulean-type alkaloid, along with eight previously reported indole alkaloids, 15-hydroxyangustilobine A (2), 6,7-seco-angustilobine B (3), 6,7-seco-19,20-α-epoxyangustilobine B (4), alstrostine E (5), alstrostine C (6), alstrostine D (7), 12-methoxyechitamidine (8), and 19-oxo-12-methoxyechitamidine (9). 1 was moderately active in vitro against Plasmodium falciparum NF54 (IC50 6.9 µM), but inactive against other protozoan parasites (Trypanosoma brucei, Trypanosoma cruzi, Leishmania donovani). No significant cytotoxic effects were observed in L6 rat skeletal myoblast cells and MCF-7 breast cancer cells. Similarly, compounds 3 to 9 did not show cytotoxicity in MCF-7 cells. Due to the reported traditional use of the plant as an anthelmintic, the major alkaloids 2, 5, 6, and 8 were tested against the nematode Caenorhabditis elegans. Nematicidal effects were observed for 6 (LC50 400 µM), whereas 2, 5, and 8 were inactive.

Antispasmodic Effect of Alstonia boonei De Wild. and Its Constituents: Ex Vivo and In Silico Approaches.

BACKGROUND: Alstonia boonei, belonging to the family Apocynaceae, is one of the best-known medicinal plants in Africa and Asia. Stem back preparations are traditionally used as muscle relaxants. This study investigated the antispasmodic properties of Alstonia boonei Stem back and its constituents. METHOD: The freeze-dried aqueous Stem back extract of A. boonei, as well as dichloromethane (DCM), ethyl acetate, and aqueous fractions, were evaluated for their antispasmodic effect via the ex vivo method. Two compounds were isolated from the DCM fraction using chromatographic techniques, and their antispasmodic activity was evaluated. An in silico study was conducted by evaluating the interaction of isolated compounds with human PPARgamma-LBD and human carbonic anhydrase isozyme. RESULTS: The Stem back crude extract, DCM, ethyl acetate, and aqueous fractions showed antispasmodic activity on high-potassium-induced (K+ 80 mM) contractions on isolated rat ileum with IC50 values of 0.03 ± 0.20, 0.02 ± 0.05, 0.03 ± 0.14, and 0.90 ± 0.06 mg/mL, respectively. The isolated compounds from the DCM fraction were ß-amyrin and boonein, with only boonein exhibiting antispasmodic activity on both high-potassium-induced (IC50 = 0.09 ± 0.01 µg/mL) and spontaneous (0.29 ± 0.05 µg/mL) contractions. However, ß-amyrin had a stronger interaction with the two proteins during the simulation. CONCLUSION: The isolated compounds boonein and ß-amyrin could serve as starting materials for the development of antispasmodic drugs.

Monoterpene indole alkaloids from the roots of Alstonia rupestris and their anti-inflammatory activity.

Four new monoterpene indole alkaloids (1-4) together with twelve known alkaloids (5-16) were isolated from the roots of Alstonia rupestris. Compound 1 was the first example of C2-symmetric heteroyohimbine-type indole alkaloid homodimer obtained from natural plant resource. Their structures were elucidated on the basis of spectroscopic data. The absolute configuration of 1 was determined by comparison of its calculated and experimental electronic circular dichroism (ECD) spectra. All compounds were evaluated for their anti-inflammatory activities by measuring their NO inhibitory effects in LPS-stimulated RAW 264.7 cells. Compound 2 showed strong NO inhibition with IC50 value of 4.2 ± 1.3 µM. Moreover, compound 2 could decrease the expressions of cyclooxygenase-2 (COX-2) and transforming growth factor beta-1 (TGF-ß1).

Significant anti-inflammatory aziridine-containing indole alkaloids from the Chinese medicinal plant Alstonia scholaris.

Two unique windmill-like aziridine-containing indole alkaloids, possessing an unprecedented 6/5/5/6/6/5/3 rigid ring system and an unusual azabicyclo[3.1.0]hexane core, were isolated from Alstonia scholaris. Their structures were established by spectroscopy, X-ray diffraction, and electronic circular dichroism calculations. The novel compounds exhibited significant anti-inflammatory bioactivity in vitro and alleviated LPS-induced acute lung injury in mice.

Anti-hyperuricemic bioactivity of Alstonia scholaris and its bioactive triterpenoids in vivo and in vitro.

ETHNOPHARMACOLOGY RELEVANCE: One folk use of Alstonia scholaris (L.) R. Br. in "Dai" ethno-medicine system is to treat gouty arthritis, which might be caused by hyperuricemia, but anti-hyperuricemic investigation of A. scholaris were rarely reported. AIM OF THE STUDY: To verify anti-hyperuricemic property of A. scholaris, and explore its bioactive compounds in vivo and in vitro. MATERIALS AND METHODS: The anti-hyperuricemic bioactivity of the non-alkaloids fraction and compounds were evaluated with potassium oxonate (PO) induced hyperuricemia mice model in vivo, and monosodium urate (MSU) induced human renal tubular epithelial cells (HK-2) was selected to test in vitro, respectively, with benzobromarone as the positive control. 11 triterpenoids were isolated by phytochemical methods and their structures were elucidated by spectroscopic analysis and ECD calculation. RESULTS: The non-alkaloids fraction of A. scholaris decreased the serum uric acid (UA) level in mice model significantly at the doses of 100 mg/kg and 200 mg/kg, and then nine ursane- and two oleanane-triterpenoids including four new compounds (1-3 and 10) were isolated from the bioactive fraction, in which compounds 1, 4, 5, 6 and 10 exhibited better anti-hyperuricemic tendency in vitro by promoting the excretion of UA in MSU-induced HK-2 cell model at a concentration of 5 µM. Furthermore, compounds 1 and 4 were proved to reduce the serum UA level in mice significantly at 5 mg/kg in vivo. CONCLUSIONS: The results supported the traditional use of A. scholaris in treating gouty arthritis, and also provided new bioactive triterpenoids for further chemical and pharmacological investigation.

New phenylpropanoids and monoterpene alkaloids with vasorelaxant activities from the branches of Alstonia scholaris.

Two new phenylpropanoids (1-2), one new nor-monoterpenoid alkaloid (3), one new monoterpene alkaloid (4), together with nine known compounds (5-13) were obtained from the branches of Alstonia scholaris. The structures of the undescribed compounds were determined by extensive spectroscopic analysis. Alkaloid 3 represented the first example of C-4 methylated nor-monoterpenoid alkaloids. A possible biosynthetic pathway for this new type of monoterpene alkaloids was proposed. All the isolates were evaluated for vasorelaxant activity against phenylephrine-induced contraction of rat mesenteric arteries. Compounds 1, 4, 9, 12, and 13 showed significant vasorelaxant activity with relaxation rates above 90% at 200 µM and exhibited moderate vasorelaxant activity with IC50 values ranging from 41.87 to 93.30 µM by further studies. It was the first report on the potential vasorelaxant activity of monoterpene alkaloids. Monoterpene alkaloids 3 and 4 may be served as the potential lead compounds for the discovery of vasodilators, due to their simple and optimizable structures.

Therapeutic potential of indole alkaloids in respiratory diseases: A comprehensive review.

BACKGROUND: Indole alkaloids are very promising for potential therapeutic purposes and appear to be particularly effective against respiratory diseases. Several experimental studies have been performed, both in vivo and in vitro, to evaluate the effectiveness of indole alkaloids for the management of respiratory disorders, including asthma, emphysema, tuberculosis, cancer, and pulmonary fibrosis. PURPOSE: The fundamental objective of this review was to summarize the in-depth therapeutic potential of indole alkaloids against various respiratory disorders. STUDY DESIGN: In addition to describing the therapeutic potential, this review also evaluates the toxicity of these alkaloids, which have been utilized for therapeutic benefits but have demonstrated toxic consequences. Some indole alkaloids, including scholaricine, 19-epischolaricine, vallesamine, and picrinine, which are derived from the plant Alstonia scholaris, have shown toxic effects in non-rodent models. METHODS: This review also discusses clinical studies exploring the therapeutic efficacy of indole alkaloids, which have confirmed the promising benefits observed in vivo and in vitro. RESULTS: The indole alkaloidal compounds have shown efficacy in subjects with respiratory diseases. CONCLUSION: The available data established both preclinical and clinical studies confirm the potential of indole alkaloids to treat the respiratory disorders.

Pharmacological effects of indole alkaloids from Alstonia scholaris (L.) R. Br. on pulmonary fibrosis in vivo.

ETHNOPHARMACOLOGICAL RELEVANCE: Alstonia scholaris (L.) R. Br. (Apocynaceae) is a Dai folk medicine for the treatment of lung diseases in China. AIM OF THE STUDY: The present study investigated the anti-pulmonary fibrosis effects of total alkaloids (TA) and the potential active ingredients and its possible mechanism. MATERIALS AND METHODS: After intratracheal instillation of bleomycin (BLM, 5 mg/kg), mice were divided into ten groups, and orally treated with the corresponding samples once daily for 28 days. The effect of indole alkaloids was determined through analysis of cytokines, as well as histopathological examinations and gene expressions. RESULTS: Severe lung fibrosis was observed in the BLM-treated mice on day 28. However, the administration of TA significantly ameliorated the pathological changes in the lungs, decreased the content of Krebs von den Lungen-6, lactate dehydrogenase, transforming growth factor-ß (TGF-ß), hydroxyproline, type I collagen, and malonaldehyde, and enhanced the activity of superoxide dismutase in the serum and lung tissues. In addition, the enhanced TGF-ß and matrix metalloproteinase-1 (MMP-1) expressions in BLM-induced mice were obviously weakened by indole alkaloids, as well as the ratio of matrix metalloproteinase-1 to tissue inhibitor of metalloproteinase-1 was decreased. Moreover, picrinine and scholaricine yielded markedly better values in the aforementioned indices than those in other samples, indicating that they may be the active ingredients of alkaloids. CONCLUSIONS: TA exerted protective effects against BLM-induced pulmonary fibrosis by reducing collagen deposition through TGF-ß/MMP-1 pathway.

In vitro screening of plant extracts traditionally used as cancer remedies in Ghana - 15-Hydroxyangustilobine A as the active principle in Alstonia boonei leaves.

ETHNOPHARMACOLOGICAL RELEVANCE: Cancer represents a major health burden and drain on the global healthcare systems. Traditional African medicine widely use a variety of plant species for treatment of different kinds of cancer. A previous systematic survey by traditional healers in the Ashanti region of Ghana revealed a good overview on the plant species and herbal materials used for the different types of cancer. AIMS OF THE STUDY: The following study aimed to investigate 18 herbal materials from 10 plant species based on the cancer survey in Ghana regarding potential cytotoxicity against different cancer cell lines under in vitro conditions followed by subsequent bioassay-guided fractionation towards the active principle. MATERIALS AND METHODS: Ethanol-water (1:1) extracts were tested (1-100 µg/mL) against a panel of cancer cell lines according to their respective traditional use. Selected extracts with relevant cytotoxicity in this screening were also tested against common pediatric malignancies (leukemias (HL-60, REH) and Ewing sarcoma (RD-ES and CADO-ES1)). Bioassay-guided fractionation of the hydroalcoholic extract from Alstonia boonei was performed by liquid-liquid chromatography and preparative HPLC. Preliminary mechanistic studies on the mode of action were performed by flow cytometric cell cycle analysis as well as apoptosis and necrosis staining. RESULTS: Screening of plant extracts revealed relevant cytotoxicity against all tested cancer cell lines for Alstonia boonei leaves and stem of Paulinia pinnata. The A. boonei extract was additionally found to be active against common pediatric tumor types (leukemias and Ewing sarcoma). Bioassay-guided fractionation of the A. boonei extract revealed the presence of 15-hydroxyangustilobine A 1 as the active principle (IC50 26 µM against MCF-7 cells). This is the first report of this compound in A. boonei. 1 was shown to lead to cell cycle arrest in the G2/M-phase (MCF-7 cells), triggering cells at least partially into apoptosis. CONCLUSION: In summary, an appreciable in vitro activity was revealed for the leaf extract from A. boonei and the isolated vallesamine type indole alkaloid 1, which has to be investigated in future studies towards a potential clinical use.

Pharmacological insights and prediction of lead bioactive isolates of Dita bark through experimental and computer-aided mechanism.

Dita bark (Alstonia scholaris (L.) R. Br.) is an ethnomedicine used for the management of various ailments. This study aimed to investigate the biological properties of methanol extract of A. scholaris bark (MEAS), through in vivo, in vitro and in silico approaches alongside its phytochemical profiling. Identification and nature of the bioactive secondary metabolites were studied by the established qualitative tests and GC-MS analysis. The antidepressant activity was determined by forced swimming test (FST) and tail suspension test (TST) in mice. The anti-inflammatory and thrombolytic effect was evaluated using inhibition of protein denaturation technique and clot lysis technique, respectively. Besides, computational studies of the isolated compounds and ADME/T analysis were performed by Schrödinger-Maestro (v11.1) software, and PASS prediction was conducted through PASS online tools. The GC-MS analysis revealed the presence of several secondary metabolites in MEAS. Treatment with MEAS revealed a significant reduction of immobility time in a dose-dependent manner in FST and TST. Besides, MEAS showed substantial anti-inflammatory effects at the higher dose (400 µg/mL) as well as revealed notable clot lysis effect as compared to control. In the case of computer-aided investigation, all compounds meet the condition of Lipinski's rule of five. PASS study also predicted for all compounds, and among these safe compound furazan-3-amine showed the most spontaneous binding energy for both antidepressant and thrombolytic activities, as well as 5-dimethylamino-6 azauracil, found promising for anti-inflammatory activity. Taken together, the investigation concludes that MEAS can be a potent source of antidepressant, anti-inflammatory, and thrombolytic agents.

Total alkaloids from Alstonia scholaris inhibit influenza a virus replication and lung immunopathology by regulating the innate immune response.

BACKGROUND: Alstonia scholaris is a folk medicine used to treat cough, asthma and chronic obstructive pulmonary disease in China. Total alkaloids (TA) from A. scholaris exhibit anti-inflammatory properties in acute respiratory disease, which suggests their possible anti-inflammatory effect on influenza virus infection. PURPOSE: To assess the clinical use of TA by demonstrating their anti-influenza and anti-inflammatory effects and the possible mechanism underlying the effect of TA on influenza A virus (IAV) infection in vitro and to reveal the inhibitory effect of TA on lung immunopathology caused by IAV infection. METHODS: Antiviral and anti-inflammatory activities were assessed in Madin-Darby canine kidney (MDCK) and A549 cells and U937-derived macrophages infected with influenza A/PR/8/34 (H1N1) virus. Proinflammatory cytokine levels were measured by real-time quantitative PCR and Bio-Plex assays. The activation of innate immune signaling induced by H1N1 virus in the absence or presence of TA was detected in A549 cells by Western blot. Furthermore, mice were infected intranasally with H1N1 virus and treated with TA (50, 25 and 12.5 mg/kg/d) or oseltamivir (60 mg/kg/d) for 5 days in vivo. The survival rates and body weight were recorded, and the viral titer, proinflammatory cytokine levels, innate immune cell populations and histopathological changes in the lungs were analyzed. RESULTS: TA significantly inhibited viral replication in A549 cells and U937-derived macrophages and markedly reduced cytokine and chemokine production at the mRNA and protein levels. Furthermore, TA blocked the activation of pattern recognition receptor (PRR)- and IFN-activated signal transduction in A549 cells. Critically, TA also increased the survival rate, reduced the viral titer, suppressed proinflammatory cytokine production and innate immune cell infiltration and improved lung histopathology in a lethal PR8 mouse model. CONCLUSION: TA exhibits anti-viral and anti-inflammatory effects against IAV infection by interfering with PRR- and IFN-activated signal transduction.

Phytochemical screening of Alstonia venenata leaf and bark extracts and their antimicrobial activities.

Alstonia venenata is a plant commonly found in South India and used in traditional medicine. The aim of this study was to characterize the phytochemicals present in A. venenata leaf and bark extracts and study their antimicrobial activities. Solvent extractions with Soxhlet apparatus of leaves and bark were obtained using hexane, benzene, isopropanol, methanol, and water. The crude extracts were concentrated and screened for qualitative phytochemical content and analyzed by thin layer chromatography. The antibacterial, antifungal and antiviral activities of crude extracts were measured by in vitro methods. Alkaloids, carbohydrates, tannins, phenolic compounds, terpenoids, cardiac glycosides and amino acids were found in the different crude extracts analyzed. Isopropanol extracts showed antifungal activity and it was more pronounced in the bark extract than the leaf extract. Moreover, the isopropanol extract exhibited antibacterial and antiviral activity. In conclusion, the leaves and bark of A. venenata have antimicrobial components which are more present in the isopropanol fraction.

Phytochemical screening of Alstonia scholaris leaf and bark extracts and their antimicrobial activities.

Alstonia sholaris is an evergreen tree commonly found in South East Asia. In traditional medicine pharmacological activities are attributed to the leaves and bark of this plant. The aim of this study is characterizing the chemicals present in A. sholaris leaves and bark extracts and study their antimicrobial activities. Solvent extractions with Soxhlet apparatus of leaves and bark were obtained using hexane, benzene, isopropanol, methanol, and water. The crude extracts were concentrated and screened for qualitative phytochemical analysis and thin layer chromatography, and the antibacterial, antifungal an antiviral activity of crude extracts were measured by in vitro methods. Isopropanol and methanol extracts showed significant antibacterial activity and it was more pronounced against Gram positive than against Gram negative bacteria. Hexane, benzene, isopropanol and methanol fractions of A. scholaris bark and leaf showed activity against Enterobacter cloacae. Isopropanol extract showed maximum activity against selected human pathogenic fungus. In conclusion, the leaves and bark of A. scholaris are rich in phytochemicals with antimicrobial activities against human pathogens, being the isopropanol fraction the one with the highest antibacterial, antifungal, antiviral and anti-mycobacterial activities.

Indole alkaloids from leaves of Alstonia scholaris (L.) R. Br. protect against emphysema in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Alstonia scholaris (L.) R. Br. (Apocynaceae) is a medicinal plant in China traditionally used to treat pulmonary diseases, including bronchitis, whooping cough, asthma and chronic obstructive pulmonary disease. AIM OF THE STUDY: To provide experimental data supporting clinical adaptation of total indole alkaloids ( TA) from A. scholaris leaves for treating emphysema. MATERIALS AND METHODS: An emphysema model was induced by a single intratracheal instillation of porcine pancreatic elastase followed by administration of TA and four main alkaloid components (scholaricine, 19-epischolaricine, vallesamine, and picrinine) for 30 consecutive days. Cytokine levels, histopathological parameters and protein expression in lung tissues were examined. RESULTS: Administering the TA, picrinine, scholaricine, 19-epischolaricine and vallesamine for 30 days effectively inhibited inflammatory cell accumulation and invasion in the lung tissue and relieved pulmonary tissue injury. Oxygen saturation was enhanced, and interleukin (IL)-1ß, monocyte-chemo attractive peptide 1, IL-11, matrix metalloproteinase-12, transforming growth factor-ß and vascular endothelial growth factor levels were significantly reduced, likely by suppressing overactivation of alveolar macrophages and pulmonary fibrosis. The elastin content was markedly elevated, and fibronectin was reduced. Bcl-2 expression was significantly increased, and nuclear factor-κB and ß-catenin levels were decreased. CONCLUSIONS: TA can be potentially used as an effective novel drug for pulmonary emphysema and exerts its effects through not only inhibiting inflammation of the airway wall and airflow resistance but also promoting lung elastic recoil and protease/anti-protease balance.

In vivo studies on the biochemical indices of Plasmodium berghei infected mice treated with Alstonia boonei leaf and root extracts.

BACKGROUND: A study on the biochemical indices of albino mice infected with Plasmodium berghei and treated with Alstonia boonei aqueous and ethanolic extracts was undertaken. METHODS: 216 males mice were randomly assigned to six treatment groups each containing six mice for both aqueous and ethanolic extracts experiments. P. berghei NK-65 was inoculated into the mice intraperitoneally and establishment of infection confirmed. Administration of extracts of was done after phytochemical and acute toxicity tests at varying concentrations, for both suppressive and curative tests. Blood samples collected by ocular puncturing were examined for the biochemical indices; ALT, AST, ALP, creatinine and total protein using the standard procedures. RESULTS: A. boonei extracts suppression of P. berghei in mice was comparable to the standard drug. Significantly higher (p<0.05) recovery of mice treated with A. boonei extracts was observed. The biochemical indices examined all had significantly (p<0.05) increased concentration after 7 days post-infection, except for total protein concentration which had no significant increase or decrease due to A. boonei extracts administration. CONCLUSION: The antiplasmodial potentials of A. boonei leaf and root extracts were dosage and duration-dependent, and have demonstrated satisfactory normalization of altered biochemical indices due to malaria.

Four new corynanthe-type alkaloids from the roots of Alstonia scholaris.

Four new corynanthe-type alkaloids, meloslines C-F (1-4), together with four known ones (5-8) were isolated from the roots of Alstonia scholaris. Their structures including absolute configurations were elucidated by extensive spectroscopic analysis and electronic circular dichroism (ECD) calculation. Compounds 1 and 2 exhibited potent vasorelaxant activity on endothelium-intact renal arteries precontracted with KCl.

Phytochemical and antimicrobial study of Alstonia scholaris leaf extracts against multidrug resistant bacterial and fungal strains.

In the present study, Alstonia scholaris leaves were explored for phytochemical constituents, antibacterial and antifungal potentials. Phytochemical screening of the extracts established the presence of glycosides, alkaloids, saponins, terpenoids, anthraquinones, reducing sugars and steroids which later on confirmed through fourier transform infrared spectroscopic analysis. The extract was applied against eight multidrug resistant bacterial and five fungal strains using standard protocols. Methanol and ethyl acetate extracts of the leaves showed highest diameter of inhibition zone (DIZ) of 28mm and 26mm respectively against Enterobacter. Ethanolic extract exhibited prominent DIZ of 26.33mm and 23.67mm against Enterobacter and Pseudomonas respectively. The n-Hexane extract showed DIZ of 23.67mm against Enterobacter. Aqueous extract showed 19.33mm DIZ against methicillin resistant Staphylococcus aureus. Similarly, the n-hexane extract showed highest DIZ of 20.33mm against Aspergillus fumigatus and this activity was highly effective than the control. Ethyl acetate extract showed 18.67mm DIZ against Aspergillus niger whereas methanolic extract showed marked inhibition against Rhizopus and Acremonium with a DIZ of 20mm and 17.03mm respectively. The current study on A. scholaris unveils about the presence of valuable phytochemicals in it having significant antimicrobial properties and further suggests to investigate for the minimum inhibitory concentration (MIC) value of the extracts in prospective research.

Effects of a novel isoflavonoid from the stem bark of Alstonia scholaris against fructose-induced experimental cataract.

OBJECTIVE: The present study investigated the anticataract activity of a novel isoflavonoid, isolated from stem bark of Alstonia scholaris, against fructose-induced experimental cataract. METHODS: The bioactivity of fractions extracted from A. scholaris, an isolated isoflavonoid (ASII) was screened using in vitro (goat lens) and in vivo (albino rats) experimental cataract models. For the in vivo evaluation, albino rats (12-15 weeks old) were divided into five groups (n = 6). Group I (normal) received 0.3% carboxymethyl cellulose solution (10 mL/[kg·d], p.o.). Group II (control) received 10% (w/v) fructose solution in their drinking water. Groups III-V received ASII at three different doses, 0.1, 1.0 and 10 mg/(kg·d), concurrently with 10% (w/v) fructose solution. Treatment was given daily for 8 consecutive weeks. During the protocol, systolic blood pressure, diastolic blood pressure, blood glucose level and lenticular opacity were monitored at 2-week intervals. Pathophysiological markers (catalase, superoxide dismutase, glutathione peroxidase, reduced glutathione and malondialdehyde) in eye lenses were examined at the end of the 8-week treatment period. RESULTS: The results of in vitro study showed that A. scholaris extract and the active fraction (A3) reduced the lenticular opacity as compared to toxic control group. The in vivo study showed that 8-week administration of ASII (0.1, 1.0 and 10 mg/[kg·d], p.o.) led to significant reduction in blood pressure and blood glucose level and retarded the initiation and evolution of cataractogenesis, compared to the fructose-induced cataract model control. Additionally, ASII treatment led to significant improvement in lens antioxidants (catalase, superoxide dismutase, glutathione peroxidase and reduced glutathione) and decreased lens malondialdehyde, compared to the control group (group II). CONCLUSION: Results revealed that administration of ASII played a crucial role in the reduction of cataract formation in diabetic and hypertensive models.

Pharmacokinetics and safety evaluation in healthy Chinese volunteers of alkaloids from leaf of Alstonia scholaris: A multiple doses phase I clinical trial.

BACKGROUND: Alstonia scholaris (Apocynaceae) was reported to be a rich source of indole alkaloids, which exhibited remarkably bioactivities. The leaf of A. scholaris has been used in 'dai' ethno-medicine for treatment of respiratory diseases, and the defined indole alkaloids from leaf of A. scholaris has been registered as investigational new botanical drug (No. 2011L01436) and was approved for phase I/II clinical trials by China Food and Drug Administration (CFDA). PURPOSE: The aim of the trial is to evaluate the safety and explore the relationship of dosing frequency and pharmacokinetics after oral administration of capsule of alkaloids from leaf of A. scholaris (CALAS) at different doses. METHODS: In this randomized, open-labelled, single-center clinical trial, the safety and pharmacokinetics of CALAS were assessed in eligible healthy Chinese volunteers after oral administration of different doses. Each volunteer (n = 10 per group) received single dose of CALAS from 20 mg, 40 mg, 80 mg to 120 mg orally. The pharmacokinetics of CALAS was investigated in healthy Chinese subjects' plasma by a fully-validated LC-MS/MS method. Safety was assessed biochemically and clinically throughout the study, and drug re-excitation research was conducted to verify the correlation between investigational product and minor adverse events. The trial was registered on August 26, 2015 (http://www.chictr.org.cn/showproj.aspx?proj=11736), number ChiCTR-IPR-15006976. RESULTS: 40 subjects completed the study, and as a result, vallesamine had the highest concentration in plasma of healthy volunteers, and the AUC exposure level in each compounds in turn is vallesamine > scholaricine > 19-epischolaricine > picrinine. For the safety evaluation of CALAS, two cases of minor adverse events were observed during the trial, but the drug re-excitation research indicated that these two adverse events were related to the individual's physiological variation. CONCLUSION: Pharmacokinetic characteristics of each ingredient showed different patterns. 19-epischolaricine, vallesamine and picrinine were match to the linear pharmacokinetic characteristics, but scholaricine conformed to the characteristics of nonlinear pharmacokinetics. The CALAS was safe in healthy subjects under the current dose regimen.

Novel nor-monoterpenoid indole alkaloids inhibiting glioma stem cells from fruits of Alstonia scholaris.

BACKGROUND: Glioblastoma multiforme (GBM) is a highly aggressive and frequently recurrent malignant brain tumor, and to date, the clinically effective drugs against GBM remain scarce. Natural products play an important role in drug discovery, and might be the resource of antitumor agents for GSCs. Alstonia scholaris (L.) R. Br. is rich in monoterpenoid indole alkaloids (MIAs) and used extensively for treatment of tumor in the traditional medicine system of Asia. PURPOSE: To search for new MIAs with antitumor activity against glioma stem cells from clinical patients and explore their mechanism. METHODS: Compounds were obtained from the fruits of A. scholaris by chromatographic separation, including silica gel, Sephadex LH-20 and recrystallization. Their structures were elucidated by the use of UV, IR, NMR and MS spectra. The antitumor activity of the compounds against the glioma stem cells (GSC-3#, GSC-12#, GSC-18#) were investigated by phenotypic screening and MTS assays. Cell proliferation assay by BrdU immunofluorescence staining, and apoptosis assay by cleaved-caspase-3 immunofluorescence staining and real-time PCR assay. The soft-agar clonal formation assay was performed to determine the antitumor efficacy of the compounds in vitro. RESULTS: Two new nor-monoterpenoid indole alkaloids were isolated from the fruits of A. scholaris. They exhibited selective antitumor activity against glioma stem cells (GSC-3#, GSC-12#, GSC-18#) with IC50 values of 15-25 µg/ml. Furthermore, they inhibited GSCs proliferation, induced GSCs apoptosis by increasing the expression of TNF-α and cleavage of caspase-3, and significantly damaged colony forming capacity of GSCs. CONCLUSION: New nor-monoterpenoid indole alkaloids from the fruits of A. scholaris provide new type promising molecule for the selective killing of human glioma stem cells.