Repellent activity of catmint, Nepeta cataria, and iridoid nepetalactone isomers against Afro-tropical mosquitoes, ixodid ticks and red poultry mites.

There are many herbal alternatives to DEET.  This study shows how catnip, Napeta cataria, can be a beneficial ingredient to your natural insect repellent.

Abstract

The repellent activity of the essential oilof the catmint plant, Nepetacataria (Lamiaceae), and the main iridoid compounds (4aS,7S,7aR) and (4aS,7S,7aS)-nepetalactone, was assessed against (i) major Afro-tropical pathogen vector mosquitoes, i.e. the malaria mosquito, Anopheles gambiae s.s. and the Southern house mosquito, Culex quinquefasciatus, using a World Health Organisation (WHO)-approved topical application bioassay (ii) the brown ear tick, Rhipicephalus appendiculatus, using a climbing repellency assay, and (iii) the red poultry mite, Dermanyssus gallinae, using field trapping experiments. Gas chromatography (GC) and coupled GC-mass spectrometry (GC-MS) analysis of two N. cataria chemotypes (A and B) used in the repellency assays showed that (4aS,7S,7aR) and (4aS,7S,7aS)-nepetalactone were present in different proportions, with one of the oils (from chemotype A) being dominated by the (4aS,7S,7aR) isomer (91.95% by GC), and the other oil(from chemotype B) containing the two (4aS,7S,7aR) and (4aS,7S,7aS) isomers in 16.98% and 69.83% (by GC), respectively. The sesquiterpene hydrocarbon (E)-(1R,9S)-caryophyllene was identified as the only other major component in the oils (8.05% and 13.19% by GC, respectively). Using the topical application bioassay, the oils showed high repellent activity (chemotype A RD(50)=0.081 mg cm(-2) and chemotype B RD(50)=0.091 mg cm(-2)) for An. gambiae comparable with the synthetic repellent DEET (RD(50)=0.12 mg cm(-2)), whilst for Cx. quinquefasciatus, lower repellent activity was recorded (chemotype A RD(50)=0.34 mg cm(-2) and chemotype B RD(50)=0.074 mg cm(-2)). Further repellency testing against An. gambiae using the purified (4aS,7S,7aR) and (4aS,7S,7aS)-nepetalactone isomers revealed overall lower repellent activity, compared to the chemotype A and B oils. Testing of binary mixtures of the (4aS,7S,7aR) and (4aS,7S,7aS) isomers across a range of ratios, but all at the same overall dose (0.1 mg), revealed not only a synergistic effect between the two, but also a surprising ratio-dependent effect, with lower activity for the pure isomers and equivalent or near-equivalent mixtures, but higher activity for non-equivalent ratios. Furthermore, a binary mixture of (4aS,7S,7aR) and (4aS,7S,7aS) isomers, in a ratio equivalent to that found in chemotype B oil, was less repellent than the oilitself, when tested at two doses equivalent to 0.1 and 0.01 mg chemotype B oil. The three-component blend including (E)-(1R,9S)-caryophyllene at the level found in chemotype B oilhad the same activity as chemotype B oil. In a tick climbing repellency assay using R. appendiculatus, the oils showed high repellent activity comparable with data for other repellent essential oils (chemotype A RD(50)=0.005 mg and chemotype B RD(50)=0.0012 mg). In field trapping assays with D. gallinae, addition of the chemotype A and B oils, and a combination of the two, to traps pre-conditioned with D. gallinae, all resulted in a significant reduction of D. gallinae trap capture. In summary, these data suggest that although the nepetalactone isomers have the potential to be used in human and livestock protection against major pathogen vectors, intact, i.e. unfractionated, Nepetaspp. oils offer potentially greater protection, due to the presence of both nepetalactone isomers and other components such as (E)-(1R,9S)-caryophyllene.

Phytochemistry. 2011 Jan;72(1):109-14. Epub 2010 Nov 4.

Melatonin as a natural ally against oxidative stress: a physicochemical examination.

The following information gives us a clear understanding of the relationship of melatonin and oxidative stress.

Oxidative stress has been proven to be related to the onset of a large number of health disorders. This chemical stress is triggered by an excess of free radicals, which are generated in cells because of a wide variety of exogenous and endogenous processes. Therefore, finding strategies for efficiently detoxifying free radicals has become a subject of a great interest, from both an academic and practical points of view. Melatonin is a ubiquitous and versatile molecule that exhibits most of the desirable characteristics of a good antioxidant. The amount of data gathered so far regarding the protective action of melatonin against oxidative stress is overwhelming. However, rather little is known concerning the chemical mechanisms involved in this activity. This review summarizes the current progress in understanding the physicochemical insights related to the free radical-scavenging activity of melatonin. Thus far, there is a general agreement that electron transfer and hydrogen transfer are the main mechanisms involved in the reactions of melatonin with free radicals. However, the relative importance of other mechanisms is also analyzed. The chemical nature of the reacting free radical also has an influence on the relative importance of the different mechanisms of these reactions. Therefore, this point has also been discussed in detail in the current review. Based on the available data, it is concluded that melatonin efficiently protects against oxidative stress by a variety of mechanisms. Moreover, it is proposed that even though it has been referred to as the chemical expression of darkness, perhaps it could also be referred to as the chemical light of health.

Evaluation of the effect of Neptune Krill Oil on chronic inflammation and arthritic symptoms.

Suppression of growth and invasive behavior of human prostate cancer cells by ProstaCaid™: mechanism of activity.

The following information offers clear evidence that herbs and vitamins should be considered in the prevention as well as treatment of prostate cancer.

Since the use of dietary supplements as alternative treatments or adjuvant therapies in cancer treatment is growing, a scientific verification of their biological activity and the detailed mechanisms of their action are necessary for the acceptance of dietary supplements in conventional cancer treatments. In the present study we have evaluated the anti-cancer effects of dietary supplement ProstaCaid™ (PC) which contains mycelium from medicinal mushrooms (Ganoderma lucidum, Coriolus versicolor, Phellinus linteus), saw palmetto berry, pomegranate, pumpkin seed, green tea [40% epigallocatechin-3-gallate (EGCG)], Japanese knotweed (50% resveratrol), extracts of turmeric root (BCM-95®), grape skin, pygeum bark, sarsaparilla root, Scutellaria barbata, eleuthero root, Job’s tears, astragalus root, skullcap, dandelion, coptis root, broccoli, and stinging nettle, with purified vitamin C, vitamin D3, selenium, quercetin, citrus bioflavonoid complex, β sitosterolzinc, lycopene, α lipoic acid, boron, berberine and 3.3′-diinodolymethane (DIM). We show that PC treatment resulted in the inhibition of cell proliferation of the highly invasive human hormone refractory (independent) PC-3 prostate cancer cells in a dose- and time-dependent manner with IC50 56.0, 45.6 and 39.0 µg/ml for 24, 48 and 72 h, respectively. DNA-microarray analysis demonstrated that PC inhibits proliferation through the modulation of expression of CCND1, CDK4, CDKN1A, E2F1, MAPK6 and PCNA genes. In addition, PC also suppresses metastatic behavior of PC-3 by the inhibition of cell adhesion, cell migration and cell invasion, which was associated with the down-regulation of expression of CAV1, IGF2, NR2F1, and PLAU genes and suppressed secretion of the urokinase plasminogen activator (uPA) from PC-3 cells. In conclusion, the dietary supplement PC is a promising natural complex with the potency to inhibit invasive human prostate cancer.

Blood pressure lowering, cardiovascular inhibitory and bronchodilatory actions of Achillea millefolium.

The study below supports the use of yarrow in asthma and hypertension.

Achillea millefolium Linn. (Asteraceae) is used in folk medicine for the treatment of overactive cardiovascular and respiratory ailments. This study describes its hypotensive, cardio-depressant, vasodilatory and bronchodilatory activities. The crude extract of Achillea millefolium (Am.Cr) caused a dose-dependent (1-100 mg/kg) fall in arterial blood pressure of rats under anaesthesia. In spontaneously beating guinea-pig atrial tissues, Am.Cr exhibited negative inotropic and chronotropic effects. In isolated rabbit aortic rings, Am.Cr at 0.3-10 mg/mL relaxed phenylephrine (PE, 1 µm) and high K(+) (80 mm)-induced contractions, as well as suppressed the PE (1 µm) control peaks obtained in Ca(++) -free medium, like that caused by verapamil. The vasodilator effect of Am.Cr was partially blocked by N(ω) -nitro-l-arginine methyl ester in endothelium intact preparations. In guinea-pig tracheal strips, Am.Cr inhibited carbachol (CCh, 1 µm) and K(+) -induced contractions. These results indicate that Achillea millefolium exhibits hypotensive, cardiovascular inhibitory and bronchodilatory effects, thus explaining its medicinal use in hyperactive cardiovascular and airway disorders, such as hypertension and asthma.

Phytother Res. 2011 Apr;25(4):577-83. doi: 10.1002/ptr.3303. Epub 2010 Sep 20.

Green Tea Reduces Prostate Cancer Risk

Observational studies on tea consumption and prostate cancer (PCa) risk
are still inconsistent. The authors conducted a meta-analysis to
investigate the association between green tea and black tea consumption
with PCa risk. Thirteen studies providing data on green tea or black tea
consumption were identified by searching PubMed and ISI Web of Science
databases and secondary referencing qualified for inclusion. A
random-effects model was used to calculate the summary odds ratios (OR)
and their corresponding 95% confidence intervals (CIs). For green tea,
the summary OR of PCa indicated a borderline significant association in
Asian populations for highest green tea consumption vs. non/lowest (OR =
0.62; 95% CI: 0.38-1.01); and the pooled estimate reached statistically
significant level for case-control studies (OR = 0.43; 95% CI:
0.25-0.73), but not for prospective cohort studies (OR = 1.00; 95% CI:
0.66-1.53). For black tea, no statistically significant association was
observed for the highest vs. non/lowest black tea consumption (OR =
0.99; 95% CI: 0.82-1.20). In conclusion, this meta-analysis supported
that green tea but not black tea may have a protective effect on PCa,
especially in Asian populations. Further research regarding green tea
consumption across different regions apart from Asia is needed.

http://www.ncbi.nlm.nih.gov/pubmed/21667398

Therapy options in irritable bowel syndrome.

Antibiotic Use in Children Is Associated With Increased Risk of Asthma

This study demonstrates why parents should speak with their pediatricians for alternative options to antibiotics.

BACKGROUND. Antibiotic exposure in early childhood is a possible contributor to the increasing asthma prevalence in industrialized countries. Although a number of published studies have tested this hypothesis, the results have been conflicting.

 OBJECTIVE. To explore the association between antibiotic exposure before 1 year of age and development of childhood asthma.

 METHODS. Using administrative data, birth cohorts from 1997 to 2003 were evaluated (N = 251817). Antibiotic exposure was determined for the first year of life. After the first 24 months of life, the incidence of asthma was determined in both those exposed and not exposed to antibiotics in the first 12 months of life. Cox proportional hazards models were used to adjust for potential confounders and determine the hazard ratios associated with antibiotic exposure for the development of asthma.

 RESULTS. Antibiotic exposure in the first year of life was associated with a small risk of developing asthma in early childhood after adjusting for gender, socioeconomic status at birth, urban or rural address at birth, birth weight, gestational age, delivery method, frequency of physician visits, hospital visit involving surgery, visits to an allergist, respirologist, or immunologist, congenital anomalies, and presence of otitis media, acute, or chronic bronchitis, and upper and lower respiratory tract infections during the first year of life. As the number of courses of antibiotics increased, this was associated with increased asthma risk, with the highest risk being in children who received >4 courses. All antibiotics were associated with an increased risk of developing asthma, with the exception of sulfonamides.

 CONCLUSIONS. This study provides evidence that the use of antibiotics in the first year of life is associated with a small risk of developing asthma, and this risk increases with the number of courses of antibiotics prescribed.

Pediatrics Vol. 123 No. 3 March 1, 2009.
pp. 1003 -1010

Improvement in cochlear flow with Pycnogenol® in patients with tinnitus: a pilot evaluation.

Anti-inflammatory activity of edible oyster mushroom is mediated through the inhibition of NF-kB and AP-1 signaling.

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