Non-Selective Cannabinoid Receptor Antagonists, Hinokiresinols Reduce Infiltration of Microglia/Macrophages into Ischemic Brain Lesions in Rat via Modulating 2-Arachidonolyglycerol-Induced Migration and Mitochondrial Activity

Growing evidence suggests that therapeutic strategies to modulate the post-ischemic inflammatory responses are promising approaches to improve stroke outcome. Although the endocannabinoid system has been emerged as an endogenous therapeutic target to regulate inflammation after stroke insult, the downstream mechanisms and their potentials for therapeutic intervention remain controversial. Here we identified trans- and cis-hinokiresinols as novel non-selective antagonists for two G-protein-coupled cannabinoid receptors, cannabinoid receptor type 1 and type 2. The Electric Cell-substrate Impedance Sensing and Boyden chamber migration assays using primary microglial cultures revealed that both hinokiresinols significantly inhibited an endocannabinoid, 2-arachidonoylglycerol-induced migration. Hinokiresinols modulated 2-arachidonoylglycerol-induced mitochondrial bioenergetics in microglia as evidenced by inhibition of ATP turnover and reduction in respiratory capacity, thereby resulting in impaired migration activity. In rats subjected to transient middle cerebral artery occlusion (1.5-h) followed by 24-h reperfusion, post-ischemic treatment with hinokiresinols (2 and 7-h after the onset of ischemia, 10 mg/kg) significantly reduced cerebral infarct and infiltration of ED1-positive microglial/macrophage cells into cerebral ischemic lesions in vivo. Co-administration of exogenous 2-AG (1 mg/kg, i.v., single dose at 2 h after starting MCAO) abolished the protective effect of trans-hinokiresionol. These results suggest that hinokiresinols may serve as stroke treatment by targeting the endocannabinoid system. Alteration of mitochondrial bioenergetics and consequent inhibition of inflammatory cells migration may be a novel mechanism underlying anti-ischemic effects conferred by cannabinoid receptor antagonists.

An in situ gelling liquid crystalline system based on monoglycerides and polyethylenimine for local delivery of siRNAs

The development of delivery systems able to complex and release siRNA into the cytosol is essential for therapeutic use of siRNA. Among the delivery systems, local delivery has advantages over systemic administration. In this study, we developed and characterized non-viral carriers to deliver siRNA locally, based on polyethylenimine (PEI) as gene carrier, and a self-assembling drug delivery system that forms a gel in situ. Liquid crystalline formulations composed of monoglycerides (MO), PEI, propylene glycol (PG) and 0.1M Tris buffer pH 6.5 were developed and characterized by polarized light microscopy, Small Angle X-ray Scattering (SAXS), for their ability to form inverted type liquid crystalline phases (LC2) in contact with excess water, water absorption capacity, ability to complex with siRNA and siRNA release. In addition, gel formation in vivo was determined by subcutaneous injection of the formulations in mice. In water excess, precursor fluid formulations rapidly transformed into a viscous liquid crystalline phase. The presence of PEI influences the liquid crystalline structure of the LC2 formed and was crucial for complexing siRNA. The siRNA was released from the crystalline phase complexed with PEI. The release rate was dependent on the rate of water uptake. The formulation containing MO/PEI/PG/Tris buffer at 7.85:0.65:76.5:15 (w/w/w/w) complexed with 10 μM of siRNA, characterized as a mixture of cubic phase (diamond-type) and inverted hexagonal phase (after contact with excess water), showed sustained release for 7 days in vitro. In mice, in situ gel formation occurred after subcutaneous injection of the formulations, and the gels were degraded in 30 days. Initially a mild inflammatory process occurred in the tissue surrounding the gel; but after 14 days the tissue appeared normal. Taken together, this work demonstrates the rational development of an in situ gelling formulation for local release of siRNA.

Botanicals, selective insecticides, and predators to control Diaphorina citri (Hemiptera: Liviidae) in citrus orchards

The Asian citrus psyllid (ACP) Diaphorina citri Kuwayama vectors pathogens that cause huanglongbing (HLB) or citrus greening devastating and economically important disease present in most citrus growing regions. Young citrus shoots are required for psyllid reproduction and development. During winter citrus trees produce little or no new growth. Overwintering adults reproduce in spring on newly emerging shoots also attractive to other pests and beneficial insects. Botanicals and relatively selective insecticides could help to conserve beneficial insects and reduce pest resistance to insecticides. Sprays of Azadirachtin (Neem), Tropane (Datura), Spirotetramat, Spinetoram, and broad-spectrum Imidacloprid were evaluated to control ACP in spring and summer on 10-year-old "Kinow" Citrus reticulata Blanco trees producing new growth. Psyllid populations were high averaging 5-9 nymphs or adults per sample before treatment application. Nymphs or adults were significantly reduced to 0.5-1.5 per sample in all treatments for 3 weeks, average 61%-83% reduction. No significant reduction in ladybeetles Adalia bipunctata, Aneglei scardoni, Cheilomenes sexmaculata, and Coccinella septempunctata was observed. Syrphids, spiders and green lacewings were reduced in treated trees except with Tropane. Studies are warranted to assess impact of these predators on ACP and interaction with insecticides. Observed reduction in ACP populations may not be enough considering its reproductive potential and role in the spread of HLB. Follow-up sprays may be required to achieve additional suppression using rotations of different insecticides.

Treatment with Azadirachta indica in diabetic pregnant rats: negative effects on maternal outcome

ETHNOPHARMACOLOGICAL RELEVANCE

The role of Azadirachta indica (neem) against Chagas disease and its antibiotic and antidiabetic action have been demonstrated in non-pregnant animals. However, the effects of neem on lipid metabolism and oxidative stress during pregnancy remain to be investigated. The objective of this study was to evaluate the effects of Azadirachta indica (neem) on maternal reproductive performance and biochemical parameters in non-diabetic and streptozotocin-induced mild diabetic rats (MD).

MATERIALS AND METHODS

Pregnant rats were randomly distributed into six experimental groups: ND=non-treated non-diabetic (n=13); NDOil=non-diabetic treated with 1.2 mL/day neem seed oil (n=12); NDPA=non-diabetic treated with 1.0mg/mL/day azadirachtin (n=12); D=non-treated diabetic (n=13); DOil: diabetic treated with neem seed oil (n=12), and DPA=diabetic treated with azadirachtin, n=13. Treatment with either neem oil (1.2 mL/day) or azadirachtin (1.0mg/mL/day) was orally administered throughout pregnancy. Glucose test tolerance (GTT) was performed at day 17 of pregnancy and used as an inclusion criterion. At term pregnancy, maternal reproductive outcomes, lipid profile and oxidative stress status were assessed.

RESULTS

Treatment with neem oil and azadirachtin during pregnancy (1) had no hypoglycemic and anti-hyperglycemic effects on non-diabetic and diabetic rats, respectively; (2) affected OGTT glycemic levels in diabetic rats; (3) increased the proportion of fetuses classified as small for pregnancy age (SPA) in all groups; and (4) did not interfere with the lipid profile in non-diabetic dams. Neem oil reduced the rate of total cholesterol and NEFA in diabetic animals. Both neem oil and azadirachtin increased lipoperoxidation, characterized by increased MDA levels in non-diabetic rats.

CONCLUSION

Both neem seed oil and azadirachtin impaired intrauterine development and altered antioxidant/oxidative status during pregnancy.

Neem oil: an herbal therapy for alopecia causes dermatitis

For more than 2,000 years, the neem tree has been considered one of the most useful and versatile plants in the world. Neem oil has been used for both homeopathic remedies and as a pesticide. Both systemic and contact reactions have occurred with the use of neem oil. We report a patient who presented with an acute case of contact dermatitis on the scalp and face after the use of neem oil for alopecia and present a review of the literature regarding its uses, toxicity, and regulation.

Assessment of skin absorption and irritation potential of arachidonic acid and glyceryl arachidonate using in vitro diffusion cell techniques

Arachidonic acid (AA), a precursor of pro-inflammatory mediators, and its glycerin ester, glyceryl arachidonate (GA), are reportedly used in cosmetic products. In vitro skin penetration of AA and GA and GA's ester hydrolysis was determined in flow-through diffusion cells. AA penetration with human and rat skin was 19.5% and 52.3% of the applied dose respectively, a substantial amount of which remained in the skin at 24h. Similar penetration results were obtained with GA in human skin. However, GA penetration through cultured skin (EpiDerm) was 51% of the applied dose, almost all of which appeared in the receptor fluid. At least 27.8% of GA penetrating skin was hydrolyzed to AA. In vitro methods were used to assess skin irritation in diffusion cells. Skin irritation of AA, sodium lauryl sulfate (SLS), and Tween 80 was determined by changes in transepidermal water loss (TEWL), skin viability (3-(4,5-dimethylthiaxol-2-yl)-2,5-diphenyltetrazolium bromide, MTT, formation), and cytokine release (IL-1alpha). SLS irritation was much less pronounced in an emulsion versus an aqueous vehicle. No significant irritation was observed in vitro from AA in an emulsion. This work predicts that AA would penetrate human skin in vivo and that it could be formed in skin from topically applied GA.

Novel Biopolymers as Implant Matrix for the Deliveryof Ciprofloxacin: Biocompatibility, Degradation, and In Vitro Antibiotic Release

The purpose of this study was to investigate the in vitro-in vivo degradation and tissue compatibility of three novel biopolymers viz. polymerized rosin (PR), glycerol ester of polymerized rosin (GPR) and pentaerythritol ester of polymerized rosin (PPR) and study their potential as implant matrix for the delivery of ciprofloxacin hydrochloride. Free films of polymers were used for in vitro degradation in PBS (pH 7.4) and in vivo in rat subcutaneous model. Sample weight loss, molecular weight decline, and morphological changes were analyzed after periodic intervals (30, 60, and 90 days) to monitor the degradation profile. Biocompatibility was evaluated by examination of the inflammatory tissue response to the implanted films on postoperative days 7, 14, 21, and 28. Furthermore, direct compression of dry blends of various polymer matrices with 20%, 30%, and 40% w/w drug loading was performed to investigate their potential for implant systems. The implants were characterized in terms of porosity and ciprofloxacin release. Biopolymer films showed slow rate of degradation, in vivo rate being faster on comparative basis. Heterogeneous bulk degradation was evident with the esterified products showing faster rates than PR. Morphologically all the films were stiff and intact with no significant difference in their appearance. The percent weight remaining in vivo was 90.70 +/- 6.2, 85.59 +/- 5.8, and 75.56 +/- 4.8 for PR, GPR, and PPR films respectively. Initial rapid drop in Mw was demonstrated with nearly 20.0% and 30.0% decline within 30 days followed by a steady decline to nearly 40.0% and 50.0% within 90 days following in vitro and in vivo degradation respectively. Biocompatibility demonstrated by acute and subacute tissue reactions showed minimal inflammatory reactions with prominent fibrous encapsulation and absence of necrosis demonstrating good tissue compatibility to the extent evaluated. All implants showed erosion and increase in porosity that affected the drug release. Increase in drug loading significantly altered the ciprofloxacin release in extended dissolution studies. PPR produced drug release >90% over a period of 90 days promising its utility in implant systems. The results demonstrated the utility of novel film forming biopolymers as implant matrix for controlled/sustained drug delivery with excellent biocompatibility characteristics.

Guinea Pig Maximization Test of Tri-ethylene Glycol Mono-methacrylate

The aim of this study was to evaluate tri-ethylene glycol mono-methacrylate (TEGMA) in terms of dermatological allergic reaction using a Guinea Pig Maximization Test. Skin reaction was evaluated according to the criteria of International Contact Dermatitis Research Group. TEGMA, as a constituent in new primers, has been reported to contribute to a priming ability similar to that of highly purified glyceryl mono-methacrylate (GM). In this study, it was found that its adverse effect was less than that of 2-hydroxy ethyl methacrylate (2-HEMA), but similar to that of highly purified GM. In conclusion, it was anticipated that TEGMA would hereafter replace 2-HEMA as a primer, as it posed a lower risk of triggering dermatological allergic reaction.

Final Amended Report on the Safety Assessment of Mink Oil1

Mink Oil, obtained from the fatty tissues of minks, is a mixture of the natural glycerides of 14 to 20 carbon chain fatty acids. There are 100 current reported uses as a hair-conditioning agent, an occlusive skin-conditioning agent, and as a surfactant; up to a maximum concentration of 3%. Mink Oil is manufactured by harvesting animal hides and scraping the fat layer from the hide. It is rendered and refined using high temperature processes (230°F to 240° F) and saponification to reduce free fatty acids. Analyses demonstrate that Mink Oil can be substantially free of impurities, including pesticides. Mink Oil does not absorb significant UVA or UVB radiation. In a clinical test of skin penetration, 1 h after application, Mink Oil was detected on the skin surface of all five panelists; it was detected within the stratum corneum in 2/5 panelists. Mink Oil has an oral LD50 of >64.0 cc/kg in albino rats. No erythema or edema was noted after refined Mink Oil was applied for 24 h to intact and scarified area of albino rabbits. A 50% dilution of a Mink Oil cream did not sensitize guinea pigs in a maximization test. Mink Oil was not an ocular irritant to albino rabbits. Clinical studies using single occlusive patches found no irritation with up to 2.8% Mink Oil, although transient mild to no irritation was noted in two exaggerated-use studies. Mink Oil is used in aerosols and sprays. Although there are no inhalation toxicity data available on Mink Oil, the available data on particle sizes of cosmetic aerosols and sprays indicates diameters more than an order of magnitude larger than the diameter of respirable particles. Most of the glycerides in Mink Oil are triglycérides (glyceryl triesters), the safety of which has been substantiated in previous safety assessments; e.g., dermal absorption is nil to slight; there is little or no acute, subchronic, or chronic oral toxicity; dermal application was not associated with significant irritation or sensitization; ocular exposures were, at most, mildly irritating; most of the genotoxicity test systems are negative; use as vehicles in carcinogenicity testing of other chemicals has produced no adverse reaction; and clinical tests produce no irritation or sensitization reactions—but, they may enhance the of penetration of other chemicals. Formulators should be aware of the possible penetration-enhancing properties of Mink Oil. Although pesticide residues have been analyzed and found to be below levels of detection, the Panel is concerned that the available data suggesting the absence of pesticide residues in Mink Oil are limited. The Panel advised the industry that the total polychlorinated biphenyl (PCB)/pesticide contamination should be limited to not more than 40 ppm, with not more than 10 ppm for any specific residue.

Bonding efficacy and side effects of the high purity glyceryl mono-methacrylate

The purpose of this study was to examine the efficacy of experimentally developed high purity glyceryl mono-methacrylate (GM) as a dentine primer and to evaluate the possibility of allergic reaction. The efficacy of experimental dentine primers was evaluated by measuring the polymerization contraction gap width and the tensile bond strength. Allergic reaction was evaluated by the guinea-pig maximization test. The skin reaction was evaluated according to the criteria of the International Contact Dermatitis Research Group. Contraction gap formation was completely prevented and the tensile bond strength was not significantly affected by priming with GM on high-purity GM. The allergic response decreased when high-purity GM was employed as the challenger. It was concluded that the clinical use of the high-purity GM is beneficial as the delayed allergic reaction could be avoided with no detrimental effect on the dentine bonding.

Genotoxicity of a crude leaf extract of neem in male germ cells of mice

The oral administration of a soxhlated crude ethanolic extract of leaves of neem (Azadirachta indica Ajuss; family Meliaceae) to adult male mice for 6 weeks (one spermatogenic duration) at the rate of 0.5, 1.0 or 2.0 g/kg body weight per day increased the incidences of structural changes and synaptic-disturbances in meiotic chromosomes and also caused more disruptions of meiosis. The extract reduced the sperm count and increased the frequency of spermatozoa with abnormal head morphology. It is suggested that at least one of the constituents of the extract may have interfered with the DNA. The result was chromosome strand breakages, or spindle disturbances, and the regulation of genes responsible for sperm shaping was affected.

Downward trend of sensitization to glyceryl monothioglycolate in German hairdressers. IVDK study group. Information Network of Departments of Dermatology

BACKGROUND

Due to a high incidence of cases of (occupational) sensitization to glyceryl monothioglycolate (GMT), products containing this compound were withdrawn from the German market some 8 years ago.

METHODS

We analyzed the data of the Information Network of Departments of Dermatology in Germany which included 1, 336 hairdressers who had been tested with GMT (1% in petrolatum) between 1992 and 1998.

RESULTS

The proportion of hairdressers reacting positively to GMT fell from initially 45% in 1992 to less than 20% in 1997 and 1998.

CONCLUSION

This most likely reflects the above-mentioned preventive action.

Preliminary evaluation of safety aspects of neem oil in kerosene lamp

Kerosene lamps containing one per cent neem oil were used for mosquito repellent action in a village near Delhi. The safety aspects of this personal protection method developed by Malaria Research Centre were evaluated by animal studies and clinical examination of population before and after exposure. Single application of neem oil (1%) did not produce skin irritation in rabbits and adverse effect on guinea pigs after exposure to aerosol. Clinical examination of 156 adults and 110 children did not reveal any major adverse effects after one year of exposure to 1% neem oil.

Contact dermatitis caused by 2-HEMA and GM dentin primer solutions applied to guinea pigs and humans

The purposes of this study were to examine whether 2-HEMA, GM, and methacrylic acid cause contact dermatitis, and to determine the optimum concentrations of these primers for sensitization and challenge in guinea pigs. A sensitizing concentration of 0.2% 2-HEMA resulted in strong rubefaction and several vesiculopapules in response to the challenge, and a sensitizing concentration of 0.5% GM produced strong rubefaction at 24 hours. We also observed the development of contact dermatitis on human brachia in a closed-patch test. Skin that was treated with both 2-HEMA and GM clearly showed the onset of rubefaction and itchiness. 2-HEMA caused sensitized delayed allergic reactions at all the concentrations tested.

Operational feasibility of malaria control by burning neem oil in kerosene lamp in Beel Akbarpur village, District Ghaziabad, India

A field trial in Beel Akbarpur village, Dadri PHC, District Ghaziabad (U.P.) was carried out to test the impact of burning neem oil in kerosene lamp from dusk-to-dawn in living rooms on vector populations and incidence of malaria. Results revealed that burning 1% neem oil in kerosene lamps resulted in the deviation of An. culicifacies from living rooms to cattlesheds. This was also reflected when malaria incidence was compared in experimental and control villages. Cases/000 and Pf/000 were 1.03 and 0.0 in experimental village as against 9.6 and 4.3 in control village. Discontinuation of burning 1% neem oil in kerosene lamp resulted in recurrence of An. culicifacies in living rooms and increase in malaria incidence in experimental village.