Prostaglandin synthetase inhibition by alkaloids of Heimia salicifolia

Two alkaloids from Heimia salicifolia, cryogenine and nesodine, were respectively 2.48 and 2.24 times as potent as aspirin as inhibitors of prostaglandin synthetase prepared from bovine seminal vesicles. Reference compounds, indomethacin and phenylbutazone, were respectively 2800 and 8.75 times as potent while a synthetic analogue of cryogenine, JB-1-0, was 0.656 times the potency of aspirin. This activity may help to explain the traditional medicine use of H. salicifolia in the Americas.     

The in vitro anti-plasmodial and in vivo anti-malarial efficacy of combinations of some medicinal plants used traditionally for treatment of malaria by the Meru community in Kenya

The use of herbal drugs as combinations has existed for centuries in several cultural systems. However, the safety and efficacy of such combinations have not been validated. In this study, the toxicity, anti-plasmodial and antimalarial efficacy of several herbal drug combinations were investigated. Lannea schweinfurthii, Turraea robusta and Sclerocarya birrea, used by traditional health practitioners in Meru community, were tested for in vitro anti-plasmodial and in vivo anti-malarial activity singly against Plasmodium falciparum and Plasmodium berghei, respectively. Methanolic extract of Turraea robusta was the most active against Plasmodium falciparum D6 strain. Aqueous extracts of Lannea schweinfurthii had the highest anti-plamodial activity followed by Turraea robusta and Sclerocarya birrea. D6 was more sensitive to the plant extracts than W2 strain. Lannea schweinfurthii extracts had the highest anti-malarial activity in mice followed by Turraea robusta and Sclerocarya birrea with the methanol extracts being more active than aqueous ones. Combinations of aqueous extracts of the three plants and two others (Boscia salicifolia and Rhus natalensis) previously shown to exhibit anti-plasmodial and anti-malarial activity singly were tested in mice. Marked synergy and additive interactions were observed when combinations of the drugs were assayed in vitro. Different combinations of Turraea robusta and Lannea schweinfurthii exhibited good in vitro synergistic interactions. Combinations of Boscia salicifolia and Sclerocarya birrea; Rhus natalensis and Turraea robusta; Rhus natalensis and Boscia salicifolia; Turraea robusta and Sclerocarya birrea; and Lannea schweinfurthii and Boscia salicifolia exhibited high malaria parasite suppression (chemo-suppression >90%) in vivo when tested in mice. The findings are a preliminary demonstration of the usefulness of combining several plants in herbal drugs, as a normal practice of traditional health practitioners.     

Analgesic and antipyretic effects of Myrica salicifolia (Myricaceae)

Myrica salicifolia Hoechst (Myricaceae) root extract was found to have analgesic activity in mice. In rats there was antipyretic but no antiinflammatory activity.     

The phenyl- and biphenyl-quinolizidines of in-vitro-grown Heimia salicifolia

Under the conditions delineated in this paper, alkaloid synthesis was not detectable in heterotrophic callus and suspension cultures of Heimia salicifolia. However, in vitro-grown shoots are active in alkaloid biosynthesis, yielding the biphenylquinolizidine lactones vertine (1), lytrine (5), and lyfoline (7), the ester alkaloids demethoxyabresoline (14) and epidemethoxylabresoline (11), the phenylquinolizidinols demethyllasubine-I (10) and demethyllasubine-II (12), and several minor alkaloids that had not been previously shown to occur in H. salicifolia.     

New stigmastane sterols from Ajuga salicifolia

A new sterol, ajugasalicigenin (1), and three new sterol glycosides, ajugasaliciosides F-H (2-4), were isolated and characterized from the aerial parts of Ajuga salicifolia. Compounds 1-4 are further representatives of the stigmastane type of sterols. Their cytotoxicity against KB (HeLa) and Jurkat T cancer cells was evaluated.     

Inhibitory activity of flavonoids from Lychnophora sp. on generation of reactive oxygen species by neutrophils upon stimulation by immune complexes

Formation of circulating immune complexes (ICs) is essential for clearance of invading agents. In some circumstances ICs might deposit on host tissues, leading to an inflammatory process that involves massive activation of neutrophils (PMNs), release of reactive oxygen species (ROS) and lysosomal enzymes and damage to the host tissue. Extracts of plants from Lychnophora sp. are used in Brazilian folk medicine as antiinflammatory agents. In this study, we evaluated the effect of eight flavonoids isolated from L. granmongolense, L. salicifolia and L. ericoides on the generation of ROS by rabbit PMNs stimulated with two kinds of ICs: particles of serum-opsonized zymosan (OZ) and insoluble ICs (ICIgG). ROS production was measured by chemiluminescence (CL) assay. We observed that 5- and 7- dihydroxylated compounds at 5 micromol/L inhibited almost totally ICIgG- and OZ-triggered luminol-CL and OZ-triggered lucigenin-CL. The degree of inhibitory effect among the other flavonoids was different, depending on the kind of ICs used to trigger ROS generation by PMNs and the number and position of methoxy groups. Moreover, under the conditions assessed, the studied flavonoids were not toxic to the rabbit PMNs. These results suggest that the actions of flavonoids on ROS generation by stimulated PMNs are highly dependent on their structures.     

Plant-derived sweetening agents: saccharide and polyol constituents of some sweet-tasting plants

Samples of the sweet-tasting species Acanthospermum hispidum DC. (Compositae) (aerial parts), Boscia salicifolia Oliv. (Capparidaceae) (stem bark), Hovenia dulcis Thunb. (Rhamnaceae) (peduncles) and Inga spectabilis Willd. (Leguminosae) (arils) were acquired as part of a continuing search for high-intensity natural sweeteners of plant origin. Following their preliminary safety evaluation, the sweetness of these plants was traced to large amounts of sugars and polyols by taste-guided fractionation, which were identified and quantified using gas chromatography/mass spectrometry. The combined yields of sugars and polyols in the A. hispidum, B. salicifolia, H. dulcis, and I. spectabilis samples investigated were 6.9, 10.1, 18.4 and 12.1% w/w, respectively. These yields are much higher than the total saccharide and polyol content (2.4% w/w) of the sweet dried fruits of Thladiantha grosvenorii (Swingle) C. Jeffrey (Cucurbitaceae), a species which has previously been reported to contain more than 1% w/w of the intensely sweet triterpene, mogroside V. The dried leaves of Symplocos tinctoria (L.) L'Hérit. (Symplocaceae), which were not appreciably sweet, were found to contain only 2.0% w/w of sugars. The results of this investigation, therefore, suggest that unless the saccharide and/or polyol content of a plant part is well over 5% w/w, then it is unlikely to exhibit an overtly sweet taste, unless an intense sweetener is present.     

The phenylquinolizidines of the seedlings of Heimia salicifolia.

Two isomeric 2-hydroxy-4-(3-hydroxy-4-methoxyphenyl)quinolizidines (3 and 9a), differing in the configuration of the bridgehead carbon, have been isolated from 5 to 10-day-old seedlings of Heimia salicifolia. The phenylquinolizidol with the cis ring juncture is shown to exist, in solution, as an equilibrium of conformers. 2-Keto-4-(3-hydroxy-4-methoxyphenyl)quinolizidine (5) has been isolated from the seedlings by radioactive dilution.     

Ethnobotany in the search for vasoactive herbal medicines.

Plant samples derived from ethno-directed and random collections were screened to determine their effect on pre-contracted rat aortic tissue. Of the 31 ethno-directed species, four were found to be potent relaxants of vascular smooth muscle. The vasoactive species were Chamguava gentlei, Alseis yucatanensis, Licaria peckii and Nectandra salicifolia. None of the 32 randomly collected samples produced a relaxation response. These data support the hypothesis that ethno-directed collection is a more efficient means of drug discovery than random plant screens.     

Stevisalioside A, a novel bitter-tasting ent-atisene glycoside from the roots of Stevia salicifolia.

A new acetylated ent-atisene glycoside, stevisalioside A [1], has been isolated as a bitter-tasting principle from Stevia salicifolia roots. The structure was established by the interpretation of spectral data, with the nmr assignments of this compound being based on 1H-1H COSY, 1H-13C HETCOR, and selective INEPT experiments. A rearrangement product 4 of the aglycone moiety obtained by alkaline hydrolysis supported the structure of 1. This is the first report of the occurrence of an atisane-type diterpene from the genus Stevia.     

Anti-plasmodial activity and toxicity of extracts of plants used in traditional malaria therapy in Meru and Kilifi Districts of Kenya

The methanol and aqueous extracts of 10 plant species (Acacia nilotica, Azadirachta indica, Carissa edulis, Fagaropsis angolensis, Harrissonia abyssinica, Myrica salicifolia, Neoboutonia macrocalyx, Strychnos heningsii, Withania somnifera and Zanthoxylum usambarensis) used to treat malaria in Meru and Kilifi Districts, Kenya, were tested for brine shrimp lethality and in vitro anti-plasmodial activity against chloroquine-sensitive and chloroquine-resistant strains of Plasmodium falciparum (NF54 and ENT30). Of the plants tested, 40% of the methanol extracts were toxic to the brine shrimp (LD(50)<100micro/ml), while 50% showed in vitro anti-plasmodial activity (IC(50)<100microg/ml). The methanol extract of the stem bark of N. macrocalyx had the highest toxicity to brine shrimp nauplii (LD(50) 21.04+/-1.8microg/ml). Methanol extracts of the rest of the plants exhibited mild or no brine shrimp toxicity (LD(50)>50microg/ml). The aqueous extracts of N. macrocalyx had mild brine shrimp toxicity (LD(50) 41.69+/-0.9microg/ml), while the rest were lower (LD(50)>100microg/ml). The methanol extracts of F. angolensis and Zanthoxylum usambarense had IC(50) values <6microg/ml while the aqueous ones had values between 6 and 15microg/ml, against both chloroquine-sensitive and resistant P. falciparum strains. The results support the use of traditional herbs for anti-malarial therapy and demonstrate their potential as sources of drugs.     

Quirogane,prenopsane, and patzcuarane skeletons obtained by photochemically induced molecular rearrangements of longipinene derivatives

Ultraviolet irradiation of (1R,3S,4S,5S,10R,11R)-1-acetyloxy-7-oxolongipin-8-ene (6), prepared from longipinene diesters isolated from Stevia salicifolia, afforded the new quirogane (7) and prenopsane (8) derivatives, as the major products, together with the minor secondary photoproduct (1R,3R,5R,8S,11S)-1-acetyloxy-7-oxopatzcuar-9-ene (9), which possesses a novel tricyclic sesquiterpene skeleton. The stereostructures of the new compounds 7-9 were mainly determined by NMR techniques including COSY, HSQC, HMBC, and NOESY in combination with molecular modeling obtained by density functional theory calculations. A reaction mechanism accounting for the observed transformations is proposed.     

Screening for acetylcholinesterase inhibitory activity in plants used in Thai traditional rejuvenating and neurotonic remedies

Acetylcholinesterase (AChE) inhibitor has been used as a drug for the symptomatic treatment of Alzheimer's disease. In order to search for new AChE inhibitors, 32 plants used in Thai traditional rejuvenating and neurotonic remedies were collected. The plant methanolic extracts were tested for AChE inhibitory activity using Ellman's colorimetric method in 96-welled microplates. The results showed that the methanolic extracts from roots of Stephania suberosa Forman. and Tabernaemontana divaricata (L.) R.Br. ex Roem. & Schult. at concentration of 0.1 mg/ml inhibited more than 90% of AChE activity. At the same concentration, four extracts, i.e. stems of Piper interruptum Opiz., seeds of Piper nigrum L., rootbarks of Butea superba Roxb. and roots of Cassia fistula L. extracts showed 50-65% inhibitory activity on AChE. The rest of the extracts showed the AChE inhibitory activity below 50%.     

马齿苋提取物体外抗Ⅱ型单纯疱疹病毒的活性评价

目的利用体外细胞培养技术初步筛选马齿苋抗Ⅱ型单纯疱疹病毒（HSV-2）的有效部位。方法以选择性指数（Selectivity-Index,SI）为活性评价指标,通过细胞毒实验及抗病毒活性评价实验,对马齿苋的不同提取部位进行了体外抗HSV-2病毒活性的筛选研究。结果马齿苋50%乙醇提取部位显示了潜在的抗HSV-2病毒活性,IC50值为120μg/mL,SI值为15;水提取物以醋酸纤维素膜分离后的粗多糖部位则显示了较强的抗HSV-2病毒活性,IC50值为55μg/mL,SI值为34。结论马齿苋抗HSV-2病毒活性成分为多糖类成分。     

Antibacterial activity of crude extracts from Mexican medicinal plants and purified coumarins and xanthones

Thirty-two extracts from 22 Mexican medicinal plants of 15 different families were assayed to determine their antibacterial activity against Escherichia coli and Staphylococcus aureus. Seventeen plants showed antibacterial activity, while five plants showed no activity against both bacteria. All of the extracts showed higher activity against Staphylococcus aureus (methicillin-sensitive and methicillin-resistant) than against Escherichia coli, except one. Among the plants examined, Bursera simaruba (L.) Sarg. (Burseraceae), Haematoxylum brasiletto H. Karst. (Fabaceae), Calophyllum brasiliense Cambess. (Clusiaceae), and Mammea americana L. (Clusiaceae) were highly active against Staphylococcus aureus. Coumarins (mammea A/BA and mammea A/AA) and xanthones, namely jacareubin and 1,3,5,6-tetrahydroxy-2-(3,3-dimethylallyl) xanthone, were isolated as the principle compounds from the last two plants.     

Research of enzymatic activities of fresh juice and water infusions from dry herbs

Research was done on the presence of enzymes in juice obtained from fresh plant material from Chamomilla recutita L. (Rauschel)-anthodium, Lamium album L.-flos, Calendula officinalis L.-flos, Plantaginis lanceolata L.-folium and Euphrasiae rostkoviana Hayne-herba, and in the prepared water infusion of these materials; the objective was to determine the activity of enzymes which beside biologically active substances may have an influence of the final therapeutic effect of the applied plant preparations. The research was conducted by means of the API ZYM system (bioMerieux). Higher enzymatic activities were found in fresh juices of the examined plant material than in prepared water infusions from dried plants. In both cases naphthol-AS-BI-phosphohydrolase should have highest activity. The second one in terms of activity out of 17 studied enzymes was acidic phosphatase. The highest enzymatic activity of fresh juice was found in Lamii albi flos and Calendulae officinalis flos. Water infusions showed the highest enzymatic activity in Lamii albi flos, Chamomille recutita anthodium and Plantaginis lanceolata folium. Drying the plant material resulted in decreased enzymatic activities but not in the case of naphthol-AS-BI-phosphohydrolase and acidic phosphatase which showed very low activities. The complex composition of plant materials in terms of content of biologically active substances may imply that the therapeutic effect might be directly related to the quantity and activity of plant enzymes present in preparations applied in therapeutics.     

仙茅及其有效成分对不同状态L02细胞PXR-CYP3A的影响研究

目的: 明确仙茅水提液及其有效成分苔黑酚葡萄糖苷对正常、虚寒状态L02细胞中PXR-CYP3A的影响,为探讨仙茅在不同状态下药效表达差异的机制奠定基础. 方法: 分别用正常、虚寒大鼠血清培养L02细胞,诱导正常、虚寒2种状态细胞.仙茅水提液及其有效成分苔黑酚葡萄糖苷作用于不同状态细胞后,检测不同状态L02细胞PXR蛋白表达和CYP3A活性. 结果: MTT法结果显示,仙茅水提液和苔黑酚葡萄糖苷能使L02细胞活力明显增强;仙茅水提液能使正常组L02细胞PXR蛋白表达水平显著降低,苔黑酚葡萄糖苷能使正常组L02细胞CYP3A活性和PXR蛋白表达水平均显著降低;而仙茅水提液能使虚寒组L02细胞CYP3A活性和PXR蛋白表达升高,苔黑酚葡萄糖苷能使虚寒组L02细胞CYP3A活性水平显著降低,使虚寒组细胞PXR蛋白表达水平升高. 结论: 仙茅作用于虚寒状态L02细胞,能激活PXR诱导CYP3A活性,但对正常L02细胞的PXR及其介导的CYP3A活性没影响或作用相反.     

鬼针草不同提取物对醛糖还原酶的抑制作用

为了从鬼针草中发现治疗糖尿病合并症的天然物质,对鬼针草5种不同提取物对人醛糖还原酶筛选实验结果表明：EtOAc提取物对人醛糖还原酶抑制作用最强。     

Larvicidal activity of some Labiatae (Lamiaceae) plant extracts from Turkey

Ethanol extracts of the aerial parts from five Labiatae (Lamiaceae) species, obtained from Antalya, Turkey, were tested for larvicidal activity against the house mosquito Culex pipiens L. (Diptera: Culicidae) under laboratory conditions. Third and fourth instar mortality from six concentrations (5, 10, 25, 50, 100 and 200 ppm) of each plant extract were compared against the organophosphorus insecticide, temephos which is currently used for larval control. All plant extracts showed high larvicidal activity in 24 h exposure tests. Teucrium divaricatum Sieber was the most toxic, followed by Mentha longifolia (L.) Huds., Melissa officinalis L., Salvia sclarea L. and Mentha pulegium L. with LC(50) values of 18.6, 26.8, 39.1, 62.7 and 81.0 ppm, respectively. This study is the first to report on the larvicidal activity of ethanol extracts of these five plant species against C. pipiens.     

Antiulcer activity of Utleria salicifolia rhizome extract

The effect of 50% ethanolic extract of Utleria salicifolia (USE) was assessed in different acute and chronic gastric ulcer models in rats. USE, 50-200 mg/kg administered orally, twice daily for 5 days showed dose-dependent ulcer protective effect in pylorus ligation (14.48-51.03% protection, P < 0.5 to P < 0.01), aspirin (28.80-56.52% protection, P < 0.5 to P < 0.001), ethanol (13.22-60.74% protection, P < 0.5 to P < 0.001), cold-restraint stress (21.22-77.14% protection, P < 0.05 to P < 0.001), and acetic acid (20.0-84.37% protection, P < 0.5 to P < 0.001)-induced acute and chronic ulcers. USE also significantly (P < 0.001) reduced the ulcer incidence (50 and 10%) and severity (67.83 and 91.34% protection) of duodenal ulcer, induced by cysteamine. Besides USE offered protection (53.52 and 60.58%) against ethanol-induced depletion of gastric wall mucus. However, USE reduced the ulcer index with significant decrease in plasma corticosterone (25.53 and 39.52% protection, P < 0.1 and P < 0.05), lipid peroxidation (18.75 and 47.92% protection, P < 0.01 and P < 0.001), superoxide dismutase (15.80 and 26.61% protection, P < 0.05 and P < 0.001) and increased in catalase (28.42 and 71.0% protection, P < 0.05 and P < 0.001) activity, respectively. Preliminary phytochemical screening of the USE gave the positive test for steroids, alkaloids, terpenoids, saponins and tannins. The HPTLC studies in the toluene: ethyl acetate: formic acid and the densitometric scanning at 254 nm gave three major spots with area corresponding to 28.16, 17.17, and 13.79% at 0.69, 0.78, and 0.88 R(f) values, respectively. The results indicate that USE possesses antiulcer activity.