Anti-stress activity of Indian Hypericum perforatum L

Indian Hypericum perforatum (IHp) was investigated on a 14-day mild, unpredictable and inescapable foot shock stress (FSS) induced perturbations in behaviour (depression), suppressed male sexual behaviour and cognitive dysfunction in albino rats. Gastric ulceration, and adrenal gland and spleen weights, were also used as the stress indices. Panax ginseng (PG) was used as the standard adaptogenic agent for comparison. FSS induced marked gastric ulceration, significant increase in adrenal gland weight with concomitant decrease in spleen weight. Chronic stress also suppressed male sexual behaviour, induced behavioural depression (Porsolt's swim despair test and learned helplessness test) and cognitive dysfunction (attenuated retention of learning in active and passive avoidance tests). All these FSS induced perturbations were attenuated dose dependently by IHp (100 and 200 mg/kg, po) and PG (100 mg/kg, po). The results indicate that IHp has significant anti-stress activity, qualitatively comparable to PG, against a variety of behavioural and physiological perturbations induced by chronic stress, which has been proposed to be a better indicator of clinical stress than acute stress, and may indicate adaptogenic activity.     

Neurochemical studies on Indian Hypericum perforatum L

The effect of acute administration of 50% standardised ethanolic extract of Indian Hypericum perforatum (IHp) was studied on the rat brain concentrations of monoamines and their metabolites in five different brain regions, viz. hypothalamus, hippocampus, striatum, pons-medulla and frontal cortex by a HPLC technique. IHp extract was administered at the doses of 50 and 200 mg/kg, p.o. and the brain monoamines were assayed after 30 min of the treatment. IHp treatment significantly decreased the levels of serotonin (5-HT) and its metabolite 5-hydroxy indole acetic acid (5-HIAA) and 5-HT turnover in all the brain regions assayed. On the other hand, IHp treatment significantly augmented the levels of norepinephrine (NE) and its metabolite methylhydroxy phenyl glycol (MHPG) and NE turnover in all the brain regions studied. Similarly, the levels of dopamine (DA) were also significantly augmented in the hypothalamus, striatum and frontal cortex. Likewise, the levels of dihydroxyphenyl acetic acid (DOPAC), the major metabolite of DA, were also increased in these brain areas. Pharmacological studies with IHp extract have shown two major behavioural actions, namely, anxiolytic and antidepressant effects. The present findings tend to rationalise these observations, reduced 5-HT activity being consonant with anxiolytic and increased NA and DA activity being consonant with antidepressant action.     

Antidepressant activity of Indian Hypericum perforatum Linn in rodents

A standardised 50% aqueous ethanolic extract of Indian Hypericum perforatum (IHp) was investigated for its antidepressant activity on various experimental paradigms of depression, viz. behavioural despair (BD), learned helplessness (LH), tail suspension (TS) and reserpine-induced hypothermia (RIH) tests in rats and mice. Pilot studies indicated that single dose administration of IHp had very little or no acute behavioural effects, hence the IHp was administered orally at two dose levels (100 and 200 mg/kg, p.o.) once daily for three consecutive days, while imipramine (15 mg/kg, i.p.), a clinically used antidepressant agent, was administered acutely to rats (CF strain, 150 +/- 10 g) and mice (Wistar strain, 23 +/- 2 g) of either sex as the standard drug. Controls animals were treated similarly with equal volume of vehicle (0.3% carboxymethyl cellulose). Indian Hypericum perforatum extract showed significant antidepressant activity on all the paradigms of depression used. Thus IHp and imipramine treatments significantly reduced the immobility time in BD and TS tests. Significant reduction in escape failures was also observed in LH test. In RIH test IHp and imipramine inhibited reserpine induced hypothermia in a dose dependent manner. The observed antidepressant activity of IHp was qualitatively comparable to that induced by imipramine.     

Anxiolytic activity of Indian Hypericum perforatum Linn: an experimental study

The putative anxiolytic activity of 50% ethanolic extract of Indian Hypericum perforatum (IHp) was investigated in rats using various experimental paradigms of anxiety viz. open field exploratory behaviour (OFB), elevated plus maze (EPM), elevated zero maze (EZM), novelty induced suppressed feeding latency (FL) and social interaction (SI) tests. Pilot studies indicated that single dose administration of IHp had little to no acute behavioural effects, hence the extract of IHp was administered orally at different dose levels once daily for three consecutive days, while lorazepam (LR) (0.5 mg/kg, i.p.) was administered acutely. IHp extract (100 and 200 mg/kg, p.o.) showed significant anxiolytic effects on all the paradigms of anxiety. The results indicate that IHp and LR induced a significant increase in open field ambulation and slight increase in rearings and activity in centre, whereas grooming and fecal droppings remain unchanged. In EPM, significant augmentation of open arm entries, open arm/closed arm entries ratio and time spent on open arms was noted in IHp treated rats. In EZM test, significant increase in time spent on open arms and entries in open arms were observed, whereas slight increase in head dips and stretched attend postures were also observed. IHp and LR significantly attenuated the novelty induced increase in feeding latency. IHp treated rats also showed significant increase in social interaction in the novel environment. The IHp extracts showed consistent and significant anxiolytic activity in all the tests. The effects induced by 50% ethanolic extract of IHp were less marked than those of lorazepam were.     

Pharmacodynamic study of Hypericum perforatum L.

The effects of Hypericum perforatum L. (Hypericaceae) crude ethanol extract (A), ethyl acetate extract (B), aqueous extract (C) and infusion (I), on pentobarbital induced sleeping time, intestinal motility, and their analgesic activity, have been investigated. Extracts A and B exhibited significant stimulatory and antidepressant effects on the CNS. Both extracts prolonged sleep, increasing time up to more than 25 min. The antidepressive activity of extract A was also achieved by significant reduction of the myorelaxant activity of diazepam. Extract B exhibited strong analgesic activity reducing abdominal stretching induced by acetic acid by nearly 50 %. Extracts A, B and C exhibited spasmolytic activity, significantly reducing intestine motility.     

Antilipoxygenase activity of compounds from Hypericum perforatum

The main biologically active constituents of Hypericum species are flavonoids (quercetin, isoquercitrin, hyperoside, rutin), biflavonoids and naphthodianthrones (hypericin, pseudohypericin). Lipoxygenase is the key enzyme in the biosynthesis of leukotriens, which have been postulated to play an important role in the pathophysiology of several inflammatory and allergic diseases. This work deals with the investigation of potential antilipoxygenase activity of different compounds and extracts isolated from Hypericum perforatum L. The highest inhibitory effect was exhibited by flavonoid derivative hyperoside (IC₅₀ 5.768 × 10⁻⁶ M). Acetone and ethanolic extracts caused also an inhibition of lipoxygenase. On the basis of inhibitory effect of compounds tested we assume that the most of them may be involved in the antiinflammatory principles of Hypericum perforatum L.     

Chromosome number stability and mitotic activity of cryopreserved Hypericum perforatum L. meristems

Meristems of in vitro-grown Hypericum perforatum L. plants were precultured for 3, 10, or 14 days in the presence of 0.5 M mannitol, or 0.076 µM or 0.76 µM abscisic acid, in RM basal liquid culture medium supplemented with 0.5 mg/l 6-benzylaminopurine and subsequently subjected to cryopreservation by the slow freezing method. The survival rate - determined as the percentage of meristems capable of differentiating plantlets - varied between 10% and 48%. Chromosome number stability of the cryopreserved meristems was determined by chromosome counting. The mitotic index of the control did not significantly differ from that of the treated samples.     

In vitro pollen germination in Hypericum perforatum L. and Hypericum rumeliacum Boiss

In vitro pollen germination and pollen tube growth investigations are valuable tools used in identification of the effects of environmental factors and genotypic differences on pollen viability, pollen germination and tube elongation. In this study pollen viability, in vitro pollen germination capacity, abnormality ratios and tube length in germinated pollens of Hypericum perforatum L. and H. rumeliacum Boiss. were investigated. Both of these species has spheroid-shaped and tricolporate pollen grains. The diameters of Hypericum perforatum and H. rumeliacum pollens were found as 24 +/- 3 microm and 19 +/- 2 microm, respectively. Pollen viability of H. perforatum and H. rumeliacum was found as 83% and 72%, respectively. The germination percentages were found as 12.85% for H. perforatum and 64.42% for H. rumeliacurm. Tube lengths in germinated pollens of both taxa were measured approximately as 95.25 +/- 38 microm in H. perforatum and 165.92 +/- 53 microm in H. rumeliacium 4 h after inoculation. In germinated pollen grains of H. perlbratum and H. rumeliacumn abnormality percentages were determined as 13.23% and 43.97%, respectively. In germinated pollens of these two species, highly significant (P < 0.00001) differences in in vitro germination percents and abnormality percents were observed. Abnormalities such as swollen tube tip, branched tube, spiralled tube and excessive tube formation were observed in pollen tubes. The results of this study showed that there were obvious differences in pollen germinability between these two species growing under the same environmental conditions.     

贯叶连翘中金丝桃素的合成与积累研究进展

金丝桃素是贯叶连翘的主要药理活性成分。本文概述了金丝桃素的化学与生物合成途径,介绍了金丝桃素在贯叶连翘个体发育过程中的积累以及利用贯叶连翘的细胞和组织培养技术生产与积累金丝桃素的研究进展。最后,指出分子生物学和电子显微镜技术的发展为深入研究金丝桃素的产生和积累提供了有利工具。     

Anti-Influenza A Virus Effect of Hypericum perforatum L. Extract

To study the antiviral effect of Hypericum perforatum L. extract (HPE) on influenza A virus (IAV) (H1N1) in vitro and in vivo. Cytopathic effect (CPE) and neutral red (NR) dye uptake were used to examine the antiviral effect of HPE on Madin Darby Canine Kidney (MDCK) cells which were infected with IAV in vitro. HPE was effective against influenza A virus (IAV) in vitro, with a 50% effective concentration (EC50) of 40 μg/mL. The mean 50% cytotoxic concentration (CC50) in the MDCK used in these experiments was 1.5 mg/mL. Ribavirin was run in parallel with EC50 values of 5.0 μg/mL; the mean CC50 for ribavirin was 520 μg/mL. Oral gavage administrations of HPE or ribavirin to mice infected with the IAV were highly effective in preventing death, slowing the decline of arterial oxygen saturation, inhibiting lung consolidation and reducing lung virus titers. The minimum effective dose of HPE in these studies was 31.25 mg/kg/day, which was administered twice daily for 5 d beginning 4 h prior to virus exposure. Below a dosage of 2000 mg/kg/day, almost all treated mice survived, which suggests that HPE is of low toxicity. Ribavirin's minimum effective dose was 40 mg/kg/day with the LD50 determined to be 200 mg/kg/day. Delay of the initiation of either HPE or ribavirin therapy, using approximately 1/3 LD50 dose each time, could still be protective as late as 48 h after exposure to the IAV. While both agents appeared to have similar efficacy against IAV infections, HPE was considered to be less toxic and may warrant further evaluation as a possible therapy for influenza.     

Anti-influenza A virus effect of Hypericum perforatum L. extract

To study the antiviral effect of Hypericum perforatum L. extract (HPE) on influenza A virus (IAV) (H₁N₁) in vitro and in vivo. Cytopathic effect (CPE) and neutral red (NR) dye uptake were used to examine the antiviral effect of HPE on Madin Darby Canine Kidney (MDCK) cells which were infected with IAV in vitro. HPE was effective against influenza A virus (IAV) in vitro, with a 50% effective concentration (EC₅₀) of 40 μg/mL. The mean 50% cytotoxic concentration (CC₅₀) in the MDCK used in these experiments was 1.5 mg/mL. Ribavirin was run in parallel with EC₅₀ values of 5.0 μg/mL; the mean CC₅₀ for ribavirin was 520 μg/mL. Oral gavage administrations of HPE or ribavirin to mice infected with the IAV were highly effective in preventing death, slowing the decline of arterial oxygen saturation, inhibiting lung consolidation and reducing lung virus titers. The minimum effective dose of HPE in these studies was 31.25 mg/kg/day, which was administered twice daily for 5 d beginning 4 h prior to virus exposure. Below a dosage of 2000 mg/kg/day, almost all treated mice survived, which suggests that HPE is of low toxicity. Ribavirin’s minimum effective dose was 40 mg/kg/day with the LD50 determined to be 200 mg/kg/day. Delay of the initiation of either HPE or ribavirin therapy, using approximately 1/3 LD₅₀ dose each time, could still be protective as late as 48 h after exposure to the IAV. While both agents appeared to have similar efficacy against IAV infections, HPE was considered to be less toxic and may warrant further evaluation as a possible therapy for influenza. Foundation items: One Hundred Person Project of The Chinese Academy of Sciences (2008-287); The Project of Basic Scientific Research Fund for Central Public-Welfare of Institute of Sciences (BRF070402).     

激素对贯叶连翘器官分化的影响

贯叶连翘 (ＨｙｐｅｒｉｃｕｍｐｅｒｆｏｒａｔｕｍＬ .)为多年生草本 ,中国民间主要用于止血、抗炎、妇科病等[1] ,欧洲民间用于治疗创伤也有相当长的历史。近年来 ,欧、美等国家和地区将其应用于抑郁症的治疗 ,取得了很好的疗效。 80年代后期 ,由于发现该植物体内含有显著抗     

Reproduction pathway analysis of several Hypericum perforatum L. somaclonal families

Flow cytometry seed screen of mature seeds originating from several in vitro regenerated Hypericum perforatum L. somaclones and their seed progenies were used to screen the ways of reproduction of 4 subsequent generations of several somaclonal families and to search for the relation between the ploidy and prevalent mode of reproduction. The prevalent reproduction pathway of diploid plants was sexual reproduction. Seed samples of plants with higher ploidy levels showed an extensive variation in the mode of reproduction: BII and BIII hybrid formation and/or aposporous pseudogamy including parthenogenetic development of a reduced embryo sac.     

Essential oil composition and variability of Hypericum perforatum L. growing in Lithuania

The composition of essential oils obtained from flowers and leaves in 11 accessions of Hypericum perforatum L. was analysed by GC and GC–MS. All the analysed oils were dominated by their oxygenated sesquiterpene fraction. Differences were attributed to the main components: caryophyllene oxide, spathulenol and viridiflorol. There were only a few monoterpenes in essential oil of all accessions. The data indicated some differences in sesquiterpene and aliphatic hydrocarbons, as well as in oxygenated aliphatics biosynthesis in flowers and leaves. The concentrations of β-caryophyllene and caryophyllene oxide in essential oils from leaves were higher than those from flowers, whereas dodecanol, spathulenol, viridiflorol, carotol and tetradecanol were present in higher quantities in flowers. Cluster analysis of all identified components grouped oils from flowers and from leaves into three clusters that corresponded with their major components: caryophyllene oxide, tetradecanal, tetradecanol and manool. Chemical variability of the analysed accessions seems likely to result from the genetic variability, since the influence of different environmental factors has been eliminated.     

Identification and genetic analysis of the APOSPORY locus in Hypericum perforatum L.

The introduction of apomixis – seed formation without fertilization – into crop plants is a long‐held goal of breeding research, since it would allow for the ready fixation of heterozygosity. The genetic basis of apomixis, whether of the aposporous or the diplosporous type, is still only poorly understood. Hypericum perforatum (St John’s wort), a plant with a small genome and a short generation time, can be aposporous and/or parthenogenetic, and so represents an interesting model dicot for apomixis research. Here we describe a genetic analysis which first defined and then isolated a locus (designated HAPPY for H ypericum AP OSP ORY ) associated with apospory. Amplified fragment length polymorphism (AFLP) profiling was used to generate a cleaved amplified polymorphic sequence (CAPS) marker for HAPPY which co‐segregated with apospory but not with parthenogenesis, showing that these two components of apomixis are independently controlled. Apospory was inherited as a dominant simplex gene at the tetraploid level. Part of the HAPPY sequence is homologous to the Arabidopsis thaliana gene ARI7 encoding the ring finger protein ARIADNE7. This protein is predicted to be involved in various regulatory processes, including ubiquitin‐mediated protein degradation. While the aposporous and sexual alleles of the HAPPY component HpARI were co‐expressed in many parts of the plant, the gene product of the apomict’s allele is truncated. Cloning HpARI represents the first step towards the full characterization of HAPPY and the elucidation of the molecular mechanisms underlying apomixis in H. perforatum.     

Genetic and biochemical analysis of Hypericum perforatum L. plants regenerated after cryopreservation

Shoot-tips from in vitro cultured Hypericum perforatum L. genotypes were subjected to assessments of developmental competence, genetic stability, and biosynthetic ability to identify critical points during cryopreservation. Survival rate, chromosome number stability, alteration in VNTR sequences and hypericin content were evaluated, in plants after pre-culture, and two subsequent cryogenic steps (cryoprotection and cooling) and those recovered from cryopreserved meristems. Pre-culture and cryoprotection treatments, did not reveal any significant differences, in these studied characteristics. Genetic stability was assessed by chromosome counts and analysis of variability in the VNTR sequences. No changes in chromosome number were detected in comparison with the untreated control but minor alterations were revealed in non-coding sequences. The content of hypericin after the recovery of cryopreserved meristems remained comparable with the unfrozen control. The controlled rate freezing technique used for cryopreservation was relevant for restoration of genetic and biochemical stability in Hypericum perforatum L. shoot-tips.     

The antidepressant mechanism of Hypericum perforatum

Clinical data indicate that hydroalcoholic extracts of Hypericum perforatum might be as valuable as conventional antidepressants in mild-to-moderate depression, with fewer side effects. One clinical trial using two extracts with different hyperforin contents indicated it as the main active principle responsible for the antidepressant activity. Behavioural models in rodents confirm the antidepressant-like effect of Hypericum extracts and also of pure hyperforin and hypericin. A hydroalcoholic extract lacking hyperforin also lacks the antidepressant-like effect. According to pharmacokinetic data and binding studies, it appears that the antidepressant effect of Hypericum extract is unlikely be due to an interaction of hypericin with central neurotransmitter receptors. The main in vitro effects of hyperforin (at concentrations of 0.1-1 microM) are non-specific presynaptic effects, resulting in the non-selective inhibition of the uptake of many neurotransmitters, and the interaction with dopamine D1 and opioid receptors. However, it is still not clear whether these mechanisms can be activated in vivo, since after administration of Hypericum extract brain concentrations of hyperforin are well below those active in vitro. In the rat, Hypericum extract might indirectly activate sigma receptors in vivo (through the formation of an unknown metabolite or production of an endogenous ligand), suggesting a new target for its antidepressant effects.