川楝子提取物体外抗单纯疱疹病毒1型活性的实验研究

目的在体外研究川楝子提取物抗单纯疱疹病毒1型(HSV-1)的作用。方法以Vero细胞为宿主细胞,阿昔洛韦为阳性对照药物,通过观察细胞病变效应(CPE)与空斑减数实验测定川楝子提取物抗HSV-1活性,计算其IC50与治疗指数,并从药物对病毒的直接灭活作用、对病毒吸附的影响及对病毒穿膜的影响三个方面初探川楝子提取物抗HSV-1活性的机理。结果川楝子提取物能明显抑制HSV-1的致病变作用,其IC50为18.26μg/mL,TI值为18。研究显示,川楝子提取物在体外对HSV-1直接灭活的效果明显,而对HSV-1吸附与穿入细胞的抑制作用较差。结论川楝子提取物在体外有明显的抗HSV-1感染作用,且主要是通过直接灭活HSV-1而发挥作用。     

The pharmacological screening of Pentanisia prunelloides and the isolation of the antibacterial compound palmitic acid.

The uses of Pentanisia prunelloides in Zulu traditional medicine indicate that the plant is believed to be effective in relieving inflammation, bacterial and viral infections and also stimulating uterine contraction. Aqueous, ethanolic and ethyl acetate extracts of leaves and roots were screened for prostaglandin-synthesis inhibitors and antibacterial and antiviral activity. In the results of the anti-inflammatory assay all the extracts showed cyclooxygenase-1 inhibition. The ethanolic and ethyl acetate extracts showed greater antibacterial activity than the aqueous extracts against Gram-positive (Bacillus subtilis, Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli, Klebsiella pneumoniae). Both root and leaf extracts were found to inhibit viral replication of the Influenza A virus. The ethyl acetate extract was fractionated by silica vacuum liquid chromatography and anti-inflammatory activity was found to be most pronounced in the more polar fractions. The presence of antibacterial activity was confirmed by running the fractions on a thin layer chromatography (TLC) plate and performing a bioautographic assay. The active fraction was further purified by TLC and the major antibacterial compound in the ethyl acetate root extract was identified by GC/MS as palmitic acid.     

A Screening Strategy for Selection of Anti-HSV-1 and Anti-HIV Extracts from Algae

In order to find new sources of antiviral agents with different mechanisms of action, extracts of 49 algae were assayed for antiherpes simplex virus (HSV) and anti-human immunodeficiency virus (HIV) activities. Twenty-five aqueous extracts showed anti-HSV activity, four of which were found to be most potent inhibitors with a selective index more than 1000. Eight samples of the aqueous extracts were identified as having activity against HIV replication. The result suggests that the extracts from algae are a promising source of antiviral agents which may act on different stages in virus replication cycle.     

Further studies on the hepatoprotective effects of Cochlospermum tinctorium rhizomes.

The hepatoprotective activity of the rhisome of Cochlospermum tinctorium was investigated using carbon tetrachloride toxicity on mouse and tert-butyl hydroperoxide in vitro induction of lipid peroxidation and hepatocyte lysis. Aqueous, hydro-ethanolic and ethanolic extracts showed significant dose-dependent hepatoprotective actions. The ethanolic extract showed a hepatoprotective activity at lower doses than silymarin. The ethanolic and hydro-ethanolic extracts exhibited remarkable effects against the induction of lipid peroxidation and hepatocyte lysis; the aqueous extract showed comparatively weaker effects. These differences were related to the chemical composition of the extracts. Among the identified constituents of the drug, phenolic and polyphenolic compounds (gallic and ellagic acids, ellagitannins, flavonoids), carotenoids, triterpenes could be related to the biological activity.     

Antiviral and antimicrobial activities of Colombian medicinal plants

Strong antiviral and antimicrobial activities were detected in methanolic extracts of 24 plants used medicinally in the treatment of skin infections in four different regions of Colombia. Thirteen extracts displayed activity against herpes simplex virus (HSV) whereas none was active against poliovirus. The antiviral activity was indicated by a total inhibition of viral cytopathic effects (CPE) at a non-cytotoxic concentration of the extract. The most potent extract was obtained from Byrsonima verbascifolia (L.) HBK. which showed anti-HSV activity at a concentration as low as 2.5 microg/ml. Antimicrobial screening was conducted using the disc diffusion assay against Klebsiella pneumoniae, Escherichia coli, Streptococcus faecalis, Mycobacterium phlei, Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhimurium and the human pathogenic yeast, Candida albicans. Anti-Candida activity was observed for Piper lanceaefolium HBK. and Juglans neotropica Diels. Twenty-two extracts displayed activity against Gram-positive bacteria whereas none was active against the Gram-negative species. We concluded that these Colombian medicinal plants represent an untapped source of potentially useful antivirals and are worthy of further study.     

Investigation of some Hypericum species native to Southern of Brazil for antiviral activity

Three plant species, Hypericum connatum, Hypericum caprifoliatum, Hypericum polyanthemum (Guttiferae), growing in Southern of Brazil were chemically investigated and tested for their antiviral activity against feline immunodeficiency virus (FIV). The chemical analysis revealed the presence of polyphenolic compounds such as tannins and flavonoids. Hypericin was not detected in these species. The aqueous extract (AE), the aqueous extract with low tannin concentration (LTCAE) and the methanolic extract (ME) were tested for their cytotoxic properties in concentrations of 50-150 microg/ml. AE was toxic to CRFK for the three species in all concentrations. LTCAE and ME varied between different concentrations being not toxic or allowing 80% of cell growth. LTCAE and ME (10-50 microg/ml) were analyzed for antiviral activity by inhibition of CPE and measuring FIV genome from cell culture supernatant. LTCAE of all species in this work did not cause any inhibition of FIV. Although no difference was seen in CPE, a lower number of viral particles in the supernatant was observed when FIV infected cells were treated with ME of H. connatum. These results suggest that some plants of the genus Hypericum from Southern Brazil contain compounds with potential antiviral activity against lentiviruses.     

Attachment and Penetration of Acyclovir‐resistant Herpes Simplex Virus are Inhibited by Melissa officinalis Extract

Medicinal plants are increasingly of interest as novel source of drugs for antiherpetic agents, because herpes simplex virus (HSV) might develop resistance to commonly used antiviral drugs. An aqueous extract of Melissa officinalis and the phenolic compounds caffeic acid, p‐coumaric acid and rosmarinic acid were examined for their antiviral activity against herpes simplex virus type 1 (HSV‐1) acyclovir‐sensitive and clinical isolates of acyclovir‐resistant strains in vitro. When drugs were added during the intracellular replication of HSV‐1 infected cells, no antiviral effect was observed by plaque reduction assay. However, Melissa extract interacted directly with free viral particles of two acyclovir‐resistant HSV strains at low IC₅₀ values of 0.13 and 0.23 µg/mL and high selectivity indices of 2692 and 1522, respectively. The Melissa extract and rosmarinic acid inhibited HSV‐1 attachment to host cells in a dose‐dependent manner for acyclovir‐sensitive and acyclovir‐resistant strains. These results indicate that mainly rosmarinic acid contributed to the antiviral activity of Melissa extract. Penetration of herpes viruses into cells was inhibited by Melissa extract at 80% and 96% for drug‐sensitive and drug‐resistant viruses, respectively. Melissa extract exhibits low toxicity and affects attachment and penetration of acyclovir‐sensitive and acyclovir‐resistant HSVs in vitro. Copyright © 2014 John Wiley & Sons, Ltd.     

Screening of indigenous plants from South Africa for affinity to the serotonin reuptake transport protein

Seventy five extracts from 34 indigenous plant species used in South African traditional medicine or taxonomically related to these were investigated for their affinity to the serotonin reuptake transport protein, making use of an in vitro serotonin reuptake transport protein binding assay. Aqueous and 70% ethanolic extracts of various plant parts were screened and 45 extracts derived from 15 plant species showed affinity. The affinity of 12 extracts from four plants was characterized as high (more than 50% inhibition at 5, 1, and 0.5 mg/ml). Plant species with high affinity to the serotonin reuptake transport protein included Agapanthus campanulatus, Boophane disticha, Datura ferox and Xysmalobium undulatum. Agapanthus campanulatus yielded high activity in aqueous extracts from leaves and flowers. Boophane disticha showed high activity both in aqueous and ethanolic extracts of leaves and bulbs. Datura ferox showed high activity in aqueous extracts from the seeds and Xysmalobium undulatum showed high activity in the ethanolic extract of the whole plant.     

Terpenoid content of Valeriana wallichii extracts and antidepressant‐like response profiles

Three extracts of Valeriana wallichii DC (Valerianaceae) rhizome and fluoxetine were studied for antidepressant‐like activity in two behavioral models, namely the forced swim test (FST) and the tail suspension test (TST). Fluoxetine as well as methanolic and aqueous extracts of V. wallichii induced monophasic dose‐related decrements in immobility times in both tests. However, the aqueous‐ethanolic fraction induced a biphasic dose‐response profile since it produced a graded effect up to 200 mg/kg but the highest dose (250 mg/kg) was inactive in the FST. This extract also exhibited significantly reduced activity at 200 mg/kg compared to lower doses in the TST. The highest doses of aqueous‐ethanolic extract also reduced locomotor activity which will have led to a negative functional interaction with antidepressant‐like effects. Qualitative phytochemical analysis revealed that the aqueous‐ethanolic extract of V. wallichii was the only separated rhizome fraction containing terpenoids. Furthermore, since the methanolic and aqueous extracts were active in the tests, it is suggested that the antidepressant‐like action of this herbal plant is not contingent upon its terpenoid constituents. Copyright © 2009 John Wiley & Sons, Ltd.     

Antiviral activity of Achyrocline flaccida Wein DC aqueous extract

Aqueous extracts (AE) of chyrocline flaccida exhibit true antiviral activity in vitro against different members of the Herpesvirus family (herpes simplex virus type 1 and 2, human cytomegalovirus, bovine herpesvirus and lower activity with pseudorabies virus). The extract had no activity against some RNA (naked and enveloped) viruses and adenoviruses. The extract was not virucidal but its antiviral index (AI) was sufficiently high to justify further analysis. A preliminary characterization indicates that an early step of viral replication was affected by the aqueous extract.     

Anti-bacterial activity of Euphorbia fusiformis--a rare medicinal herb

Euphorbia fusiformis Buch.-Ham. ex. D.Don (Euphorbiaceae) is a rare medicinal herb. Aqueous and organic solvent extracts of the leaves and rootstocks were investigated for anti-bacterial properties by using disc diffusion and well-in agar methods, against pathogenic strains of Gram positive (Bacillus subtilis and Staphylococcus aureus) and Gram negative bacteria (Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, Pseudomonas aeruginosa, Salmonella typhii A and Salmonella typhii B). The different extracts differed significantly in their anti-bacterial properties with the methanolic extract being very effective followed by acetone and chloroform extracts. Aqueous and ethanolic extract showed very least activity. The result highlights that rootstock extracts had good anti-bacterial properties than leaf extracts. The results of this study support the use of this plant in traditional medicine to treat fever, wound infections and intestinal disorders.     

Anti-inflammatory and analgesic activities of ethanolic extract and two limonoids from Melia toosendan fruit

AIM OF STUDY: The fruit of Melia toosendan Sieb. et Zucc. (MTF) is a traditional Chinese herbal medicine in the treatment of stomachache and many acute or chronic inflammations, as well as ascariasis. This paper aimed to investigate the anti-inflammatory and analgesic activities of the MTF extract and two main limonoid-type triterpenoids isolated from MTF. MATERIALS AND METHODS: The ethanolic extract of MTF and two limonoids, isotoosendanin (1) and 1-O-tigloyl-1-O-debenzoylohchinal (2) were evaluated for their anti-inflammatory and analgesic activities. Acetic acid-induced vascular permeability and lambda-carrageenan-induced hind paw edema tests in mice were used to investigate anti-inflammatory activity; and acetic acid-induced writhing and hot-plate tests in mice were used to determine analgesic effect. RESULTS: Both the ethanolic extract and two limonoids displayed significant anti-inflammatory effects. Although the ethanolic extract showed remarkable analgesic effects in both writhing and hot-plate tests, the two limonoids had analgesic effects just in writhing test. CONCLUSION: The results suggested that the ethanolic extract of MTF had obvious anti-inflammatory and analgesic activities, and the two limonoids were the active constituents contributing to the anti-inflammatory and analgesic effects of MTF.     

Antisecretory activity of plants used to treat gastrointestinal disorders in Mexico

Aqueous and methanolic extracts from 26 medicinal plants used in Mexico to treat gastrointestinal disorders were screened to evaluate their antisecretory activity on cholera toxin-induced intestinal secretion in rat jejunal loops model. Extracts were tested at a dose of 300 mg/kg. From 56 samples tested, both extracts from Chiranthodendron pentadactylon, Hippocratea excelsa and Ocimum basilicum were the most potent with inhibition values ranging from 68.0 to 87.6%. On the other hand, the methanolic extract of Geranium mexicanum (aerial parts) and the aqueous extract of Bocconia frutescens showed the highest activity with inhibition values of 93.4 and 86.0%, respectively. The results obtained in this study give some scientific support to the use of the Mexican medicinal plants employed for the treatment of gastrointestinal disorders such as diarrhea.     

叶底珠枝叶水提物对小鼠急性肝损伤的保护作用

目的:叶底珠水提取物对四氯化碳引起小鼠急性肝损伤的保护作用。方法:60只小鼠随机分为正常组、模型组、高剂量组、中剂量组、低剂量组、阳性对照组。高、中、低剂量组分别按2.0,1.0,0.5g/kg-1灌胃叶底珠水提取物;阳性对照组按0.1g/kg-1水飞蓟宾灌胃;正常组和模型组给予等体积生理盐水。第5天给药1小时后,模型组、高、中、低剂量组和阳性对照组按0.015ml.g-1腹腔注射0.1%CCl4,正常对照组腹腔注射等体积生理盐水。测定小鼠血清天冬氨酸转氨酶(aspartate transaminase,AST)、丙氨酸氨基转移酶(alanine transaminase,ALT)活性和肝组织超氧化歧化酶(superoxide dismutase,SOD)活性及丙二醛(malondialdehyde,MDA)含量。结果:叶底珠水提取物能显著降低CCl4所致小鼠血清ALT和AST活性(P0.01),同时升高肝组织SOD活性(P0.01),降低肝组织MDA的含量(P0.01)。结论:叶底珠水提取物对CCl4所致小鼠急性肝损伤具有保护作用。     

Screening of plants used in southern Africa for epilepsy and convulsions in the GABAA-benzodiazepine receptor assay

A number of plants are traditionally used to treat mental diseases in South Africa. Aqueous and ethanol extracts of 43 plants that are traditionally used to treat against epilepsy and convulsions, were tested in the GABAA-benzodiazepine receptor binding assay, where the binding of 3H-Ro 15-1788 (flumazenil) to the benzodiazepine site is measured. The GABAA-benzodiazepine receptor complex is involved in epilepsy and convulsions. Out of the 118 extracts tested, one aqueous and 18 ethanol extracts showed activity. The most active extracts were the ethanolic leaf extracts of Rhus tridentata, Rhus rehmanniana and Hoslundia opposita and the ethanolic corm extract of Hypoxis colchicifolia, which all showed good dose-dependent activity.     

Anticancer and antiviral activities of Youngia japonica (L.) DC (Asteraceae, Compositae)

Aqueous and ethanol extracts of Youngia japonica (also known as Oriental hawksbeard) were tested in vitro for anti-tumor activity against three cell lines, human promyelocytic leukaemia (HL-60), human myelogenous leukaemia (chronic K-562) and mouse Sarcoma 180 (S-180), and for antiviral activity against respiratory syncytial virus (RSV), influenza A virus (Flu A) and herpes simplex virus type 1 (HSV-1) by cytopathic effect (CPE) reduction assay. Hot water extract of Youngia japonica inhibited cell proliferation and growth of all cancer cell lines to various extent. K-562 cells were the most sensitive to the extract whereas S-180 cells were the least. It did not show any significant cytotoxic effects on normal mammalian Vero cells up to the concentration of 450 microg/mL. The ethanol extract of whole plant of Youngia japonica exhibited antiviral activity against RSV cultured in HEp-2 cells, but did not have any activity against Flu A and HSV-1. Two partially purified fractions (Fr.10 and Fr.11) from the 95% ethanol extract exhibited significant anti-RSV with 50% inhibitory concentration (IC50) in the range of 3.0-6.0 microg/mL. The ratio of the viral titer reduction in the absence (viral control) and presence of the maximal non-cytotoxic concentration (MNCC) of the Fr.10 and Fr.11 was both estimated to be 1 x 10(4) (RF, viral titer reduction factors), indicating that their anti-RSV activity was high enough to justify for further analysis. Our preliminary analysis showed that the antiviral ingredients were likely to contain phenolic compounds including tannins by chemical tests.     

Inhibition of fowlpox virus by an aqueous acetone extract from galls of Guiera senegalensis J. F. Gmel (Combretaceae)

An aqueous acetone extract from the galls of Guiera senegalensis was screened for in vitro antiviral activity against fowlpox virus (FPV). Cytopathic effect (CPE) inhibition and plaque inhibition assays were used to show presence of antiviral effects against FPV, whilst cytotoxicity assays established the relative safety of the extract for cells in vitro. Phytochemical analyses revealed the presence of phenolic compounds including flavonoids, tannins and anthocyanins as well as steroids and alkaloids. Thin-layer chromatographical (TLC) analysis also revealed the presence of quercitrin, quercetin, kaempferol, apigenin, rutin, gallic acid as well as unknown flavonoids and unknown phenolic acids. The antiviral effect of the extract was partially attributed to phenolic components including flavonoids.     

Biological evaluation of proanthocyanidin dimers and related polyphenols.

A series of dimeric procyanidins (1-9) and some related polyphenols (10-15) were chosen as model compounds in a comparative investigation for various biological activities in order to obtain structure-activity relationships. Antiviral [herpes simplex virus (HSV) and human immunodeficiency virus (HIV)], antibacterial, superoxide radical-scavenging, and complement-modulating properties were assessed. In general, more pronounced activities were seen with epicatechin-containing dimers for anti-HSV, anti-HIV, and radical-scavenging effects, while the presence of ortho-trihydroxyl groups in the B-ring was important in compounds exhibiting anti-HSV and radical-scavenging effects and complement classical pathway inhibition. Double interflavan linkages gave rise to interesting antiviral effects (HSV and HIV) and complement inhibition. The influence of the degree of polymerization or the type of interflavan linkage (4-->6 or 4-->8) differed in the different biological systems evaluated. Only minor or moderate antibacterial effects were observed for the compounds under investigation.     

Antiviral activities of medicinal herbs traditionally used in southern mainland China

The aqueous extracts from 21 medicinal herbs traditionally used in southern mainland China were screened for antiviral activities against human herpes simplex virus type 1 (HSV-1) and human respiratory syncytial virus (RSV) using a cytopathic effect (CPE) reduction assay. Three extracts from Agrimonia pilosa, Pithecellobium clypearia and Punica granatum, respectively, showed anti-HSV-1 activity, which was possibly contributed by the polyphenolic compounds in the herbal extracts. Six of the extracts, from Blumea laciniata, Elephantopus scaber, Laggera pterodonta, Mussaenda pubescens, Schefflera octophylla and Scutellaria indica, respectively, exhibited anti-RSV activity with 50% inhibition (IC50) concentrations ranging from 12.5 to 32 microg/mL, and selective indices (SI) ranging from 11.2 to 40. In addition to polyphenolic compounds, other constituents present in these extracts may also contribute to their anti-RSV activity.     

A promising peptide antibiotic from Terfezia claveryi aqueous extract against Staphylococcus aureus in vitro

The antimicrobial activity of aqueous and methanolic extracts, as well as partially purified proteins extracted from Terfezia claveryi aqueous extract were investigated against Staphylococcus aureus in vitro. A 5% aqueous extract inhibited the growth of S. aureus by 66.4%, while a methanolic extract was ineffective. Partial protein purification of the aqueous extract using ammonium sulphate precipitation revealed that antimicrobial activity was within the third fraction. This fraction was then subjected to gel filtration using Sephadex G-100. Two peaks were obtained. Peak one possessed higher antimicrobial activity. This peak was then subjected to ion exchange chromatography using DEAE Sephadex. Only peak 4 from the six peaks obtained showed a slight antimicrobial activity. Antimicrobial activities of the aqueous extract and the fractions that showed antimicrobial activity were compared with reference antibiotics.