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PubMed2006

Adulticidal activity against Stegomyia aegypti (Diptera: Culicidae) of three Piper spp.

Three Piper species, Piper longum, P. ribesoides and P. sarmentosum, were selected for investigation of adulticidal potential against Stegomyia aegypti, a main vector of dengue and dengue haemorrhagic fever. Successive extraction by maceration with 95% ethanol showed percentage yields of ethanolic extracts, which derived from P. longum, P. ribesoides and P. sarmentosum, of 8.89, 3.21 and 5.30% (w/w), respectively. All Piper extracts illustrated an impressive adulticidal activity when tested against female mosquitoes by topical application. The susceptibility of St. aegypti females to ethanol-extracted Piper was dose dependent and varied among the plant species. The highest adulticidal effect was established from P. sarmentosum, followed by P. ribesoides and P. longum, with LD50 values of 0.14, 0.15 and 0.26 microg/female, respectively. The potential of these Piper species, as possible mosquitocides, established convincing activity for further researches to develop natural substances for combat against adult mosquitoes.

Animals↗
PubMed2005

Classical and new proving methodology: provings of Plumbum metallicum and Piper methysticum and comparison with a classical proving of Plumbum metallicum.

OBJECTIVE: To study the reliability of a proving methodology and the reproducibility of proving symptoms. METHODS: Two homeopathic medicines and placebo were given, in a double-blind randomized design, to 31 healthy volunteers (13 Piper methysticum 30C, 11 placebo and 7 Plumbum metallicum 30C), 5 drops 4 times daily, until the onset of unbearable symptoms, or at most for 1 week. The primary outcome measure was the number of phrases containing unusual or new symptoms selected by supervisors (SEL) from unstructured diaries and the number of these symptoms (SYM) present in SELs. The secondary outcome measures were the number of symptoms with modalities of both verum groups concordant with symptoms reported in a previous proving of Plumbum 12C. Other parameters evaluated were repeated and crossed symptoms in SELs. RESULTS: Both medicines showed qualitative and quantitative differences from placebo. Piper: 146 SELs (median: 5), Plumbum: 118 SELs (16), placebo: 48 SELs (2), containing 260 (8), 199 (29) and 58 (2) SYMs, respectively. There was a significant difference from placebo in Plumbum but not in Piper SELs and SYMs (P < 0.05). 31, 24 and 4 'repeated' and 18, 22 and 2 'crossed' symptoms were found in Piper, Plumbum and placebo. 8 and 30 symptoms concordant with the classical proving of Plumbum were found for Piper and Plumbum, corresponding to about 10% and 45% of their total SELs. CONCLUSIONS: Open diaries, supervision and double-blind placebo are useful methods in homeopathic pathogenetic trials. Estimates of concordance should be introduced in proving methodology.

Adult↗
PubMed1985

Field and laboratory studies of the feeding behaviour of the piper Hyporhamphus ihi with reference to the role of the lateral line in feeding.

Piper school in large groups close to the water surface during daylight hours, whereas at night the schools break up and individual fish can be observed swimming slowly through the water. Analysis of gut contents indicates that during the day piper feed primarily on copepods, and terrestrial insects trapped on the water surface; after dark the demersal zooplankton which enter the water column form the major dietary component. Prey selectivity is evident in that certain groups present in the plankton are not found in the stomach contents of piper, and that the size of prey taken is biased towards the larger size classes of plankton. Laboratory experiments establish that piper are capable of locating prey in total darkness, and that under these conditions live prey are consumed in a higher proportion, and much more quickly than dead prey. These results strengthen the hypothesis that piper use their anterior lateral line to feed on zooplankton at night.

Animals↗
PubMed1983

The Piper rhythm--a phenomenon related to muscle resonance characteristics?

The purpose of the present work is to examine the causes of the Piper rhythm, i.e. the tendency towards rhytmical 40-60 Hz grouping of motor unit potentials in steadily contracting human muscles. At weak or moderate contraction strength individual motor units exhibited preferred firing rates which were subharmonically related to the Piper rhythm in the gross EMG. Microelectrode muscle nerve recordings provided no support for the hypothesis that the Piper rhythm is dependent on resonance-induced rhythmical volleys of afferent spindle impulses causing reflex entrainment of motor impulses. This hypothesis also seems inconsistent with the findings that Piper rhythms of similar frequency appear in muscles with widely different mechanical properties and that the rhythms are about equally prominent in muscles with brisk as in muscles with weak or absent stretch reflexes. The results suggest that the Piper rhythm is dependent on some kind of pace-maker in the spinal cord or the cerebrum which tends to entrain and synchronize motor impulses.

Electromyography↗
PubMed2004

Immunomodulatory and antitumor activity of Piper longum Linn. and piperine.

Alcoholic extract of the fruits of the plant Piper longum and its component piperine was studied for their immunomodulatory and antitumor activity. Alcoholic extract of the fruits was 100% toxic at a concentration of 500 microg/ml to Dalton's lymphoma ascites (DLA) cells and 250 microg/ml to Ehrlich ascites carcinoma (EAC) cells. Piperine was found to be cytotoxic towards DLA and EAC cells at a concentration of 250 microg/ml. Alcoholic extract and piperine was also found to produce cytotoxicity towards L929 cells in culture at a concentration of 100 and 50 microg/ml, respectively. Administration of alcoholic extract of Piper longum (10 mg/dose/animal) as well as piperine (1.14 mg/dose/animal) could inhibit the solid tumor development in mice induced with DLA cells and increase the life span of mice bearing Ehrlich ascites carcinoma tumor to 37.3 and 58.8%, respectively. Administration of Piper longum extract and piperine increased the total WBC count to 142.8 and 138.9%, respectively, in Balb/c mice. The number of plaque forming cells also enhanced significantly by the administration of the extract (100.3%) and piperine (71.4%) on 5th day after immunization. Bone marrow cellularity and alpha-esterase positive cells were also increased by the administration of Piper longum extract and piperine.

Adjuvants, Immunologic↗
PubMed1985

Functional morphology of the piper Hyporhamphus ihi with reference to the role of the lateral line in feeding.

As a basis for understanding the function of the halfbeak of the piper Hyporhamphus ihi (Phillips), details of the structure and dimensions of the anterior lateral line on the head and lower jaw of the piper are described. The anterior lateral line is composed of a series of cranial canals; the supraorbital-postorbital canal; the suborbital canal; and the preopercular-mandibular canal which extends along the lower jaw. Each canal opens to the surface by a series of pores, and individual neuromasts exist in specialized regions of the canals between each of the pores. Piper are nocturnal plankivores and they possess the feeding structures and digestive tract suited to this diet. The hypothesis is proposed that they use the anterior lateral line system in prey detection, and this paper shows that the piper's elongate body form, swimming behaviour, and lack of a specialized visual system are all consistent with this hypothesis.

Animals↗
PubMed2005

Antidiabetic activities of aqueous and ethanolic extracts of Piper betle leaves in rats.

Leaves of Piper betle (Piperaceae) possess several bioactivities and are used in traditional medicinal systems. However, its antidiabetic activity has not been scientifically investigated so far. The aim of this study therefore, was to investigate the antidiabetic activity of Piper betle leaves. This was tested in normoglycaemic and strepozotocin (STZ)-induced diabetic rats using oral administration of hot water extract (HWE) and cold ethanolic extract (CEE). In normoglycaemic rats, both HWE and CEE significantly lowered the blood glucose level in a dose-dependent manner. In glucose tolerance test, both extracts markedly reduced the external glucose load. The antidiabetic activity of HWE is comparable to that of CEE. Moreover, HWE failed to inhibit the glucose absorption from the small intestine of rats. Both extracts were found to be non-toxic and well tolerated after following chronic oral administration (no overt signs of toxicity, hepatotoxicity or renotoxicity). However, the weight of the spleen had increased in treated groups possibly indicating lymphoproliferative activity. It is concluded that HWE and CEE of Piper betle leaves possess safe and strong antidiabetic activity.

Animals↗
PubMed2002

Larvicidal activity of isobutylamides identified in Piper nigrum fruits against three mosquito species.

The insecticidal activity of materials derived from the fruits of Piper nigrum against third instar larvae of Culex pipiens pallens, Aedes aegypti, and A. togoi was examined and compared with that of commercially available piperine, a known insecticidal compound from Piper species. The biologically active constituents of P. nigrum fruits were characterized as the isobutylamide alkaloids pellitorine, guineensine, pipercide, and retrofractamide A by spectroscopic analysis. Retrofractamide A was isolated from P. nigrum fruits as a new insecticidal principle. On the basis of 48-h LC(50) values, the compound most toxic to C. pipiens pallens larvae was pipercide (0.004 ppm) followed by retrofractamide A (0.028 ppm), guineensine (0.17 ppm), and pellitorine (0.86 ppm). Piperine (3.21 ppm) was least toxic. Against A. aegypti larvae, larvicidal activity was more pronounced in retrofractamide A (0.039 ppm) than in pipercide (0.1 ppm), guineensine (0.89 ppm), and pellitorine (0.92 ppm). Piperine (5.1 ppm) was relatively ineffective. Against A. togoi larvae, retrofractamide A (0.01 ppm) was much more effective, compared with pipercide (0.26 ppm), pellitorine (0.71 ppm), and guineensine (0.75 ppm). Again, very low activity was observed with piperine (4.6 ppm). Structure-activity relationships indicate that the N-isobutylamine moiety might play a crucial role in the larvicidal activity, but the methylenedioxyphenyl moiety does not appear essential for toxicity. Naturally occurring Piper fruit-derived compounds merit further study as potential mosquito larval control agents or as lead compounds.

Aedes↗
PubMed2003

The anti-adherence effect of Piper betle and Psidium guajava extracts on the adhesion of early settlers in dental plaque to saliva-coated glass surfaces.

The aqueous extracts of Piper betle and Psidium guajava were prepared and tested for their anti-adherence effect on the adhesion of early plaque settlers (Strep. mitis, Strep. sanguinis and Actinomyces sp.). The saliva-coated glass surfaces were used to simulate the pellicle-coated enamel surface in the oral cavity. Our results showed that the anti-adherence activities of Piper betle and Psidium guajava extracts towards the bacteria were different between the bacterial species. Psidium guajava was shown to have a slightly greater anti-adherence effect on Strep. sanguinis by 5.5% and Actinomyces sp. by 10% and a significantly higher effect on Strep. mitis (70%) compared to Piper betle. The three bacterial species are known to be highly hydrophobic, and that hydrophobic bonding seemed to be an important factor in their adherence activities. It is therefore suggested that the plant extracts, in expressing their anti-adherence activities, could have altered the hydrophobic nature of the bonding between the bacteria and the saliva-coated glass surfaces.

Actinomyces↗
PubMed2000

Cortical drives to human muscle: the Piper and related rhythms.

During voluntary activity in humans, motor units are exposed to a number of descending drives that tend to synchronize motor unit activity at particular frequencies. In particular, the contralateral motor cortex drives muscle discharge in the beta (15-30 Hz) and Piper (30-60 Hz) bands. The cortical activity in these bands is task-specific, somatopicly distributed and generally precedes muscle discharge by an interval appropriate for conduction in fast pyramidal pathways. Coherence between cortex and muscle in the beta band is found during isometric contractions of weak to moderate strength. Thus oscillations within the beta band seem to coincide with a stable, relatively immutable state--a free running mode of the motor cortex that may maintain stable motor output with a minimum of computational effort. In contrast, coherence between cortex and muscle in the Piper band is most evident during strong isometric contractions or during movement. Demands on the motor cortex are likely to be greater and more mutable under these circumstances. Synchronisation in the gamma band may provide a means of binding together those particular, often spatially distributed, cortical elements involved in movement execution under conditions that vary from moment to moment and require some attention. Mechanisms both intrinsic and extrinsic to the cortex determine the pattern of rhythmic cortical activity. The basal ganglia have a pivotal role in this regard, and inadequate output from these nuclei leads to a disappearance of the beta and Piper drives to muscle. This may in turn contribute to slowness and weakness in Parkinson's disease.

Animals↗
PubMed2001

Constituents of Chinese Piper species and their inhibitory activity on prostaglandin and leukotriene biosynthesis in vitro.

The n-hexane extracts of 19 Piper species, predominantly from China, were screened for their 5-lipoxygenase (5-LOX) and cyclooxygenase-1 (COX-1) inhibitory potential. Many of them showed considerable inhibitory activity against at least one of these two key enzymes of the arachidonic acid metabolism, especially against COX-1. The best results in inhibiting the formation of leukotrienes were obtained with the extract of Piper kadsura. In the terms of prostaglandin synthesis inhibition, the extract of Piper boehmeriifolium var. tonkinense was found to have the strongest activity. Furthermore, an analytical investigation by means of TLC, HPLC-DAD and GC-MS resulted in the identification of 20 constituents. Most of them were amides with an interesting variety of amine moieties. Among them were pellitorine, and four higher homologues, piperlonguminine, dihydropiperlonguminine, futoamide, chingchengenamide, the retrofractamides A, B and D, guineensine, brachystamide B, piperanine, piperine, piperdardine, sarmentine, pipataline and benzylbenzoate. In 96 cases, these constituents were new for the particular plant.

Animals↗
PubMed2005

Analysis of Piperaceae germplasm by HPLC and LCMS: a method for isolating and identifying unsaturated amides from Piper spp extracts.

A method for extraction and high performance liquid chromatography-mass spectrometer (HPLC-MS) analysis of the medicinally important genus Piper (Piperaceae) was developed. This allows for a rapid and accurate measure of unsaturated amides, or piperamides, in black pepper, Piper nigrum L., and in wild species from Central America. Reflux extraction provided the highest recovery of piperine (>80%) from leaf and peppercorn material. HPLC analysis using a binary gradient of acetonitrile and water separated the major amide peaks between 5 and 12 min. Atmospheric pressure chemical ionization (APCI)-MS improved the detection limit to 0.2 ng, 10-fold below the 2 ng limit of the HPLC-diode array detector (DAD) based on linear standard curves between 0.1 and 250 microg/mL (R2 = 0.999). The HPLC-MS method identified pellitorine, piperylin, 4,5-dihydropiperlonguminine, piperlonguminine, 4,5-dihydropiperine, piperine, and pipercide. The biological activity of six Costa Rican Piper species assessed by mosquito larval bioassays correlated well with piperamide content.

Aedes↗
PubMed1999

Stimulation of mouse melanocyte proliferation by Piper nigrum fruit extract and its main alkaloid, piperine.

During a herbal screening programme to find potential repigmenting agents for the treatment of vitiligo, Piper nigrum L. fruit (black pepper) extract was found to possess growth-stimulatory activity towards cultured melanocytes. Its aqueous extract at 0.1 mg/ml was observed to cause nearly 300% stimulation of the growth of a cultured mouse melanocyte line, melan-a, in 8 days (p < 0.01). Piperine (1-piperoylpiperidine), the main alkaloid from Piper nigrum fruit, also significantly stimulated melan-a cell growth. Both Piper nigrum extract and piperine induced morphological alterations in melan-a cells, with more and longer dendrites observed. The augmentation of growth by piperine was effectively inhibited by RO-31-8220, a selective protein kinase C (PKC) inhibitor, suggesting that PKC signalling is involved in its activity. This is the first full report on such an activity of black pepper and piperine.

Alkaloids↗
PubMed1998

Cortical correlate of the Piper rhythm in humans.

Cortical correlate of the Piper rhythm in humans. J. Neurophysiol. 80: 2911-2917, 1998. The electromyogram (EMG) of healthy humans demonstrates a tendency to rhythmic oscillations at around 40 Hz (the Piper rhythm) during strong voluntary contraction. Why motor units should discharge synchronously locked to such a high-frequency is unclear. We recorded whole scalp magnetoencephalographic (MEG) signals simultaneously with surface EMG from 10 healthy subjects. In eight subjects, coherence and time domain analyses demonstrated correspondence between the MEG signal, originating near or in the hand region of the motor cortex, and the 35- to 60-Hz EMG recorded during repeated maximal isometric contractions of the contralateral forearm extensor muscles. Three of these subjects also showed similar coherence during isometric contractions of moderate strength and slow extension movements of the wrist. In addition, coherence and time domain analyses demonstrated correspondence between the MEG signals originating near or in the foot area of the motor cortex and EMG recorded during repeated maximal isometric contractions of the contralateral tibialis anterior muscle in the 30- to 60-Hz range. Most important, the frequency at the peak of the coherence spectrum differed between forearm and leg by as much as 10 Hz in the same subject. In contrast, the peak of the coherence spectrum occurred during sustained weak contraction in the 20- to 30-Hz range similarly for both forearm and foot. The lag between EMG and MEG activity in the leg was approximately 15 ms greater than that seen in the forearm, an interval appropriate for conduction in fast pyramidal pathways. It is concluded that the Piper rhythm in muscle may be driven by a comparable oscillatory activity in the contralateral motor cortex. This cortical rhythmicity can be picked up in several types of movement and seems distinct from the 20- to 30-Hz rhythmicity recorded during weak sustained contractions.

Adult↗
PubMed2006

Don't fear the social relations model: reply to Piper, Ogrodniczuk, Lamarche, and Joyce.

By studying actual therapy groups and using a sophisticated design to determine that clients who are held in higher esteem by their fellow group members show greater improvement over the course of therapy, Piper, Ogrodniczuk, Lamarche, and Joyce (this issue) have made a significant contribution to the group psychotherapy literature. Unfortunately, Piper et al. focused much of their discussion on the difficulties they faced using the social relations model (SRM) and the statistical program SOREMO. Although the SRM is not simple and it takes practice to run SOREMO, the analytic alternative proposed by Piper et al. has a number of serious limitations that prevents it from being a viable alternative. There is much to be gained from learning the SRM; for those group therapists and researchers who do not want to learn the SRM, they can always consult or collaborate with SRM researchers.

Fear↗
PubMed2006

Factor analysis of the Revised Piper Fatigue Scale in a caregiver sample.

The Revised Piper Fatigue Scale (R-PFS) is an instrument designed to measure subjective fatigue that was developed in samples with physical illness. Its psychometric properties in nonclinical samples are unknown. The purpose of this study was to examine the psychometric properties of the R-PFS in a sample of caregivers of stroke survivors. The convenience sample of 132 caregivers was primarily women (74%), White (71%), college-educated (73%), and employed (52%), with a mean age of 56.7 years (SD = 13.71). Internal consistency reliabilities for the four R-PFS subscales and the total scale were excellent, ranging from .90 to .97. Principal axis factor analysis with oblique rotation was conducted to examine construct validity of the R-PFS. A three-factor solution explained 75.9% of the common variance. Two factors totally replicated the behavioral/severity and affective meaning subscales of the R-PFS. The third factor incorporated a combination of Piper's sensory and cognitive/mood subscales and appeared to summarize how fatigue makes the caregiver feel. The R-PFS demonstrated strong internal consistency reliability and construct validity in this sample. However, data suggest that caregivers may perceive certain feelings associated with fatigue as conceptually similar when these feelings are conceptually distinct in Piper's breast cancer sample. The study supports the need for psychometric evaluation of instruments developed in clinical populations prior to their use in nonclinical populations.

Adult↗
PubMed2001

Phylogeny and patterns of floral diversity in the genus Piper (Piperaceae).

With ∼1000 species distributed pantropically, the genus Piper is one of the most diverse lineages among basal angiosperms. To rigorously address the evolution of Piper we use a phylogenetic analysis of sequences of the internal transcribed spacers (ITS) of nuclear ribosomal DNA based on a worldwide sample. Sequences from a total of 51 species of Piper were aligned to yield 257 phylogenetically informative sites. A single unrooted parsimony network suggested that taxa representing major geographic areas could potentially form three monophyletic groups: Asia, the South Pacific, and the Neotropics. The position of Pothomorphe was well supported among groups of New World taxa. Simultaneous phylogenetic analysis of an expanded alignment including outgroups suggested that taxa from the South Pacific and Asia formed a monophyletic group, provisionally supporting a single origin of dioecy. Within the Neotropical sister clade, resolution was high and strong bootstrap support confirmed the monophyly of several traditionally recognized infrageneric groups (e.g., Enckea [including Arctottonia], Ottonia, Radula, Macrostachys). In contrast, some of the species representing the highly polytypic subgroup Steffensia formed a clade corresponding to the previously recognized taxon Schilleria, while others were strongly associated with several of the more specialized groups of taxa. The distribution of putatively derived inflorescence and floral character states suggested that both umbellate and solitary axillary inflorescences have multiple origins. Reduction in anther number appears to be associated with highly packaged inflorescences or with larger anther primordia per flower, trends that are consistent with the suppression of later stages of androecial development.

Journal Article↗
PubMed1988

Effects of Piper sp extract on pregnancy in rats.

Abortive effects on cattle have been attributed to Piper sp, popularly called Pariparoba. In the present study we tested the possible toxicity of this plant by analyzing gestational outcome parameters in female rats given 300 mg/kg of an aqueous extract of Piper sp leaves and stalks per os, daily, between the 9th and the 21st day of pregnancy. The animals were killed just before delivery and the following features were observed: numbers of corpora albicantia, fetuses and reabsorptions; weights of fetuses, placentae and fetal membranes; fetal sex and the presence of overt malformations in fetuses; and implantation and reabsorption indices. No significant differences were detected between control and treated groups. The results suggest that Piper sp does not modify gestational outcome in rats.

Abortion, Spontaneous↗