Immunocontraceptive activity guided fractionation and characterization of active constituents of neem (Azadirachta indica) seed extracts

A novel approach for immunocontraception by intervention of local cell mediated immunity in the reproductive system by using single intrauterine application of neem oil has been described earlier. The reversible block in fertility was reported to last for 107–180 days in female Wistar rats (Upadhyay et al., 1990. Antifertility effects of neem oil by single intrauterine administration: A novel method of contraception. Proceedings Of The Royal Society Of London B 242, 175–180) and 7–11 months in monkeys (Upadhyay et al., 1994. Long term contraceptive effects of intrauterine neem treatment (IUNT) in bonnet monkeys: An alternative to intrauterine contraceptive devices. Contraception 49, 161–167). The present study, describes the identification and characterization of the biologically active fraction from neem seeds (Azadirachta indica A. Juss. Family Meliaceae), responsible for the above activity in adult female Wistar rats. Initial studies with the mechanically extracted oil and solvent extracts of neem seeds have revealed that the antifertility activity was present in constituents of low to intermediate polarity. A hexane extract of neem seeds was reported to be biologically active (Garg et al., 1994. Comparison of extraction procedures on the immunocontraceptive activity of neem seed extracts. Journal of Ethnopharmacology 22, 87–92). Subsequently, hexane extract was sequentially fractionated through the last active fraction using various separation techniques and tested for antifertility activity at each step. Preparative HPLC was used for isolating individual components of the active fraction in quantities, sufficient for characterization. An analytical HPLC method was developed for standardization of the fraction. The active fraction was identified to be a mixture of six components, which comprises of saturated, mono and di-unsaturated free fatty acids and their methyl esters. Dose response study was performed with the last active fractions. The antifertility activity with the active fraction was reversible in nature and it was completely active until 5% concentration. There was no systemic toxic effect following the administration of the active fraction. This study, for the first time, proposes an active fraction from neem seeds, responsible for long term and reversible blocking of fertility after a single intrauterine administration with high efficacy.     

短棒状杆菌菌体细胞与细胞代谢产物生物学活性的比较

欲提高短棒状杆菌制剂的临床应用效果,为该产品进一步精制奠定基础,进行了短棒状杆菌有效成份的研究。在适宜的培养基中,以厌氧法培养短棒状杆菌,分别收获菌体及培养上清,做生物学活性检测。结果显示,菌体细胞内脾激活和抑瘤试验生物学活性显著,细胞代谢产物无生物学活性。实验证实,短棒状杆菌的有效成份在菌体细胞内,与细胞代谢产物无关。     

Multi-constituent synergism is responsible for anti-inflammatory effect of Azadirachta indica leaf extract

Context: Azadirachta indica A. Juss. (Meliaceaes) leaves have been used traditionally to treat swelling and rheumatism in Indian cultures.

Objective: To fractionate A. indica leaf extracts using bioactivity guided manner for identification of the active anti-inflammatory principles.

Materials and methods: Polarity-gradient sequential extracts (petroleum ether, chloroform, methanol, and water) of A. indica leaves were screened for their anti-inflammatory potential using the carrageenan-induced rat paw edema model (1?g/kg). The chloroform extract was sequentially fractionated to obtain n-hexane (F-1), n-hexane-chloroform (F-2), and chloroform (F-3) fractions and their inhibitory effect on rat paw edema was evaluated (500?mg/kg). Inhibitory effect of F-2 on granuloma formation, plasma interleukin (IL-1), and tumor necrosis factor (TNF-α) was assessed at the doses of 100, 200, and 400?mg/kg using the cotton pellet assay in rats. Three sub-fractions (SF-1, SF-2, and SF-3) were obtained upon chromatography of F-2, and their inhibitory effect on cyclooxygenase was assessed at 200?µg/mL concentration. The sub-fractions were subjected to gas chromatography–mass spectrometry (GC-MS).

Results: All the extracts showed significant anti-inflammatory effect; however, chloroform extract was the most effective against paw edema (53.25% inhibition). The three fractions of chloroform extract showed significant effect, while F-2 being the most potent (51.02%). F-2 demonstrated dose-dependent inhibition of granuloma and cytokines. Interestingly, all the sub-fractions of F-2 inhibited COX-1 and COX-2 with almost equal potential. GC-MS revealed that chemically the sub-fractions were totally different from each other.

Discussion and conclusion: Anti-inflammatory effect of A. indica is a result of cumulative and synergistic effects of diversified constituents with varying polarities that collectively exert the effect via suppression of cyclo-oxygenases and cytokines (IL-1 and TNF-α).     

Beta-glucans from edible and medicinal mushrooms: Characteristics,physicochemical and biological activities

One of the main active components from mushrooms was recently identified as β-glucan. Health-promoting β-glucans are an auspicious group of polysaccharides. β-Glucans from different sources such as cereals, yeast and grass have previously been documented. However, information on mushroom β-glucan is limited. This review summarizes the extraction, purification, quantification, and structural characterization of β-glucans, along with chemical and biological activities from this compound from mushrooms, and the current status of this research area with a view for future directions.     

Hazard identification of cis/trans-zearalenone through the looking-glass

Among the food-related health issues, the presence of contaminants has a prominent role, due to the wide range of exogenous compounds that can occur in food commodities and to their large differences in structure and biological activity. A comprehensive assessment of the related risk is thus actually demanding in terms of time and facilities involved. In this context, the use of computational strategies can be an effective choice for supporting the hazard identification procedure at the early stage. In this work, we focused on the food contaminant zearalenone by comparing the trans and cis isomers, respectively the well-known mycoestrogen and its still largely understudied isomer. We estimated the possible effects exerted by human metabolism on the xenoestrogenicity of cis-ZEN by using a validated in silico strategy based on docking simulations and rescoring procedures. Similarly, the exploitation of the most promising enzymatic detoxifying routes designed for trans-ZEN – which relies on the enzyme lactono hydrolase from Clonostachys rosea – has been assessed for the cis-isomer as well. Our results showed that both isomers can act as functional analogues with respect to xenoestrogenic activity, and several cis-ZEN metabolites with high biological potential have been identified. On the contrary, in spite of the high degree of structural analogy, the cis isomer showed a pattern of interaction with the degrading enzyme in stark contrast with that observed for trans-ZEN. For these reasons, the outcomes presented herein strongly support the inclusion of cis-ZEN in further studies of occurrence, metabolism and bioactivity assessment, and suggest the need for a dedicated handling for the cis isomer in risk assessment studies.     

Antiplasmodial activity of extracts of 25 cyanobacterial species from coastal regions of Tamil Nadu

Context: Marine cyanobacteria offer considerable potential to isolate new antimalarials to meet a pressing need of our times.

Objective: To explore the antiplasmodial properties of marine cyanobacteria.

Materials and methods: Cyanobacterial samples collected from the coastal regions of Tamil Nadu were identified using light microscopy, and the strains were cultivated in ASN-III medium. Organic extracts (0–100?µg?mL^?1) of 25 in vitro mass-cultivated cyanobacteria, prepared using methanol: chloroform mixture (1:1?v/v) were evaluated for their antiplasmodial activity against chloroquine-sensitive and -resistant strains of Plasmodium falciparum by fluorescence-based SYBR Green I assay where chloroquine was used as a control. To detect the toxic effects of cyanobacterial extracts against red blood cells, the invasion, maturation, and growth rate of malarial parasites in cyanobacterial extracts pre-treated versus untreated erythrocytes were quantified microscopically. Mammalian cell line (HeLa) was used to determine cyanobacterial extract toxicity using the MTT assay.

Results: The extracts of Lyngbya aestuarii Liebm. ex Gomont CNP 1005 (C12) Oscillatoria boryana BDU 91451 (C22) and Oscillatoria boryana Bory ex Gomont BDU 141071 (C18) showed promising antiplasmodial activity (IC₅₀?=?18, 18, and 51?μg?mL^?1 respectively) against Pf3D7. Pretreatment of red blood cells with IC₁₀₀ of C12, C18, and C22 (40, 100, and 40?µgmL^?1, respectively) did not significantly influence the invasion, maturation, and growth rate of malarial parasites in comparison with untreated RBC controls suggesting a lack of toxicity to host cells. MTT assay based IC₅₀ (>200?μg?mL^?1) of these extracts against HeLa cell line also indicates their high selectivity against the malaria parasite.

Discussion and conclusion: These exploratory studies suggest the possibilities of development of new antimalarial compounds from marine cyanobacteria.     

Preserved bioactivity and tunable release of a SDF1-GPVI bi-specific protein using photo-crosslinked PEGda hydrogels

Chemokine-induced stem cell recruitment is a promising strategy for post myocardial infarction treatment. Injection of stromal cell-derived factor 1 (SDF1) has been shown to attract bone marrow-derived progenitor cells (BMPCs) from the blood that have the potential to differentiate into cardiovascular cells, which support angiogenesis, enabling the improvement of myocardial function. SDF1-GPVI bi-specific protein contains a glycoprotein VI (GPVI)-domain that serves as an anchor for collagen type I (Col I) and III, which are exposed in the wall of injured vasculature. In this study, we generated a cytocompatible hydrogel via photo-crosslinking of poly(ethylene glycol) diacrylate that serves as a reservoir for SDF1-GPVI. Controlled and sustained release of SDF1-GPVI was demonstrated over a period of 7 days. Release features were modifiable depending on the degree of the crosslinking density. Functionality of the GPVI-domain was investigated using a GPVI-binding ELISA to Col I. Activity of the SDF1-domain was tested for its CXCR4 binding potential. Preserved functionality of SDF1-GPVI bi-specific protein after photo-crosslinking and controllable release was successfully demonstrated in vitro supporting the implementation of this drug delivery system as a powerful tool for therapeutic protein delivery in the treatment of cardiovascular ischemic disease.     

Characterization of grass carp (Ctenopharyngodon idella) IL-17D: Molecular cloning,functional implication and signal transduction

Although the roles of IL-17 family members during inflammation have been extensively studied in mammals, their knowledge in lower vertebrates is limited. In particular, the biological activities of fish IL-17 and their functional roles are largely unknown. In this study, we cloned grass carp IL-17D (gcIL-17D) and found that its putative protein possessed the conserved features of IL-17 family members. Tissue distribution analysis showed that gcIL-17D was preferentially expressed in the mucosal tissues, including skin, gill and intestine. Subsequently, the involvement of gcIL-17D in inflammatory response was demonstrated by examining the expression profiles of gcIL-17D in head kidney and head kidney leukocytes following in vivo bacterial infection and in vitro LPS treatment, respectively. Furthermore, recombinant gcIL-17D (rgcIL-17D) was prepared in grass carp kidney cells and was able to promote the gene expression of some pro-inflammatory cytokines (IL-1β, TNF-α and CXCL-8) in grass carp primary head kidney cells, revealing gcIL-17D can function as a pro-inflammatory cytokine. Moreover, rgcIL-17D appeared to activate NF-κB signaling by modulating the phosphorylation of IκBα and up-regulated CXCL-8 mRNA expression possibly through NF-κB pathway. Our data shed new light on the functional role of teleost IL-17D in inflammatory response.     

In vitro and in vivo evaluation of a nanoparticulate bioceramic paste for dental pulp repair

Bioactive materials play an important role in facilitating dental pulp repair when living dental pulp is exposed after injuries. Mineral trioxide aggregate is the currently recommended material of choice for pulp repair procedures though has several disadvantages, especially the inconvenience of handling. Little information is yet available about the early events and molecular mechanisms involved in bioceramic-mediated dental pulp repair. We aimed to characterize and determine the apatite-forming ability of the novel ready-to-use nanoparticulate bioceramic iRoot BP Plus, and investigate its effects on the in vitro recruitment of human dental pulp stem cells (DPSCs), as well as its capacity to induce dentin bridge formation in an in vivo model of pulp repair. It was found that iRoot BP Plus was nanosized and had excellent apatite-forming ability in vitro. Treatment with iRoot BP Plus extracts promoted the adhesion, migration and attachment of DPSCs, and optimized focal adhesion formation (Vinculin, p-Paxillin and p-Focal adhesion kinase) and stress fibre assembly. Consistent with the in vitro results, we observed the formation of a homogeneous dentin bridge and the expression of odontogenic (dentin sialoprotein, dentin matrix protein 1) and focal adhesion molecules (Vinculin, p-Paxillin) at the injury site of pulp repair model by iRoot BP Plus. Our findings provide valuable insights into the mechanism of bioceramic-mediated dental pulp repair, and the novel revolutionary ready-to-use nanoparticulate bioceramic paste shows promising therapeutic potential in dental pulp repair application.     

山茱萸多糖的研究进展

山茱萸多糖是山茱萸中的一种主要活性成分之一,具有多种药理作用和生物活性功能,是目前的一个研究热点。笔者对山茱萸多糖的提取、分离纯化、化学结构及生物活性等多方面进行了综述,为山茱萸资源的深入开发起一定借鉴作用。