Insulin secretagogue effect of Ichnocarpus frutescence leaf extract in experimental diabetes: a dose-dependent study

Ichnocarpus frutescence (L.) R.Br. is an evergreen plant and many preparations have been used in traditional Indian medicine for centuries to treat several illnesses including diabetes. However, scientific evidence supporting these actions is lacking. In the present study we prepared various extracts of I. frutescence (IF) leaves which were tested against streptozotocin-induced diabetic rats. IF leaf methanolic extract (IFLMExt) showed significant plasma glucose lowering effect. Therefore, we prepared IFLMExt, which was tested against different types of glycemia (normal, glucose-fed hyperglycemic and streptozotocin-induced diabetic rats) for their potential to induce insulin secretion and cellular insulin responses. Fasting plasma glucose (FPG) levels were determined at different doses and times following treatment with IFLMExt or with vehicle in normal, glucose fed-hyperglycemic and diabetic rats. Oral administration of IFLMExt led to a significant blood glucose-lowering effect in glucose-fed hyperglycemic and diabetic rats. The hypoglycemic effect was observed at doses of 100 and 200 mg/(kg bw) after 6 and 2 h administration, respectively, in glucose-fed hyperglycemic rats. The maximum effect of IFLMExt was detected at 2 h with 200 mg/(kg bw) in diabetic animals and this profile was maintained for the next 6 h (37.23%) but increased after that at 24 h. Oral administration of IFLMExt daily for 45 days to diabetic rats significantly reduced the FPG (54.5%) to near normal. After 7 days of streptozotocin administration plasma insulin decreased in diabetic controls compared to normal controls. Treatment with IFLMExt significantly prevented the decrease in plasma insulin levels from day 0 to 45 in comparison to diabetic controls. Oral administration of n-hexane fraction led to a significant glucose-lowering effect in diabetic rats (54.50%). Histopathological examination showed that IFLMExt extract protected the pancreatic tissue from streptozotocin-induced damage enormously. Oral administration of IFLMExt extract and n-hexane fraction to normal and streptozotocin-induced diabetic rats decreased plasma glucose levels without hypoglycemic effect. The results suggest that methanolic extract and n-hexane fraction of IF may provide new therapeutic avenues against diabetes.     

Biological effects of active fraction isolated from Hydnocarpus pentandra (Bunch. –Ham.) Oken seeds against Helicoverpa armigera (Hub.) (Lepidoptera: Noctuidae)

Hexane, chloroform, ethyl acetate and methanol extracts of Hydnocarpus pentandra (Flacourtiaceae) seeds were tested for antifeedant, larvicidal, pupal mortality and adult deformations activities against Helicoverpa armigera. Crude extracts were screened at 0.5, 1.0, 1.5 and 2.0% concentrations. Bioassay-guided fractionation method was followed to isolate the active fraction from the crude extract. Active fraction was analysed by FT-IR, ¹H NMR, ¹³C NMR and GC-MS. Hexane extract presented the highest antifeedant (87.89%), pupal mortality (41.67%) and adult malformation activities at 2% concentration. Seven different fractions were isolated from hexane extract, among which fraction-2 showed the highest antifeedant (81.43%) activity and recorded the lowest LC₅₀ of 792.07 ppm. The fraction-2 contained two cyclopentenyl carboxylic acids, such as hydnocarpic acid (1) and chaulmoogric acid (2) in the ratio of 2:1. These compounds were major constituents in the active fraction of hexane extract of H. pentandra seeds. Fraction-2 can be used for agricultural pest management.     

Resistance of legume seeds to the bruchid, Callosobruchus maculatus: metabolites relationship

A study was initiated to categorize the seeds of various wild and cultivar legume varieties on the basis of their relative resistance to the bruchid, C. maculatus, and to correlate the important primary and secondary metabolites (non-protein anti-metabolites) in these seeds to the developmental parameters of the bruchid. In general, the wild seed varities showed greater amount of resistance to the bruchid attack when compared to that of the cultivar varieties. All the cultivar varieties studied showed higher amounts of primary metabolites, namely, proteins, carbohydrates, lipids and free amino acids thus showing a positive correlation between the primary metabolites content and the infestation rate. The wild varieties, however, showed significantly lower amounts of these primary metabolites and consequently a lower level of infestation. The non-protein anti-metabolites such as total phenols, ortho- dihydroxy phenols and tannis were significantly lower in the cultivars. The wild varieties, in contrast, revealed higher amounts of these secondary metabolites showing a negative correlation between these secondary metabolites content and the infestation rate. The study revealed that these non-protein anti-metabolites are important in conferring resistance to the seeds.     

Hepatoprotective effect of coumestans isolated from the leaves of Wedelia calendulacea Less. in paracetamol induced liver damage

Effect of coumestans isolated form the leaves of W. calendulacea was evaluated in paracetamol induced liver damage. The increased serum enzyme levels (lactate dehydrogenase, alanine and aspartate transaminase and alkaline phophatase) by paracetamol induction were significantly lowered due to coumestans treatment. Results of this study revealed that coumestans of W. calendulacea afforded a significant protective action in the alleviation of paracetamol induced hepatocellular injury.     

Array-comparative genomic hybridization reveals loss of SOCS6 is associated with poor prognosis in primary lung squamous cell carcinoma

Background

Primary tumor recurrence commonly occurs after surgical resection of lung squamous cell carcinoma (SCC). Little is known about the genes driving SCC recurrence.

Methods

We used array comparative genomic hybridization (aCGH) to identify genes affected by copy number alterations that may be involved in SCC recurrence. Training and test sets of resected primary lung SCC were assembled. aCGH was used to determine genomic copy number in a training set of 62 primary lung SCCs (28 with recurrence and 34 with no evidence of recurrence) and the altered copy number of candidate genes was confirmed by quantitative PCR (qPCR). An independent test set of 72 primary lung SCCs (20 with recurrence and 52 with no evidence of recurrence) was used for biological validation. mRNA expression of candidate genes was studied using qRT-PCR. Candidate gene promoter methylation was evaluated using methylation microarrays and Sequenom EpiTYPER analysis.

Results

18q22.3 loss was identified by aCGH as being significantly associated with recurrence (p = 0.038). Seven genes within 18q22.3 had aCGH copy number loss associated with recurrence but only SOCS6 copy number was both technically replicated by qPCR and biologically validated in the test set. SOCS6 copy number loss correlated with reduced mRNA expression in the study samples and in the samples with copy number loss, there was a trend for increased methylation, albeit non-significant. Overall survival was significantly poorer in patients with SOCS6 loss compared to patients without SOCS6 loss in both the training (30 vs. 43 months, p = 0.023) and test set (27 vs. 43 months, p = 0.010).

Conclusion

Reduced copy number and mRNA expression of SOCS6 are associated with disease recurrence in primary lung SCC and may be useful prognostic biomarkers.     

Antimicrobial and Antimycobacterial Activities of Methyl Caffeate Isolated from Solanum torvum Swartz. Fruit

Abstract

Solanum torvum Swartz. (Solanaceae) fruit is traditionally used for the treatment of bacterial and fungal infections. The methanolic extract was subjected to activity guided fractionation by column chromatography over silica gel. The structure of the compound was elucidated using physical and spectroscopic data. The antimicrobial activity was screened using five Gram-positive bacteria, six Gram-negative bacteria, seven clinical isolates and four fungi. Antimycobacterial activity was screened against two Mycobacterium strains. The zone of inhibition by methyl caffeate ranged from 0 to 22 mm. The lowest minimum inhibitory concentration (MIC) values of methyl caffeate were: 50 μg/ml against P. vulgaris, 25 μg/ml against K. pneumoniae (ESBL-3971), 8 μg/ml against M. tuberculosis (H³⁷Rv) and 8 μg/ml against M. tuberculosis (Rif^R). Methyl caffeate showed moderate antimicrobial and prominent antimycobacterial activities. Methyl caffeate can be evaluated further for drug development.     

Characterization of synthesized silver nanoparticles and assessment of its genotoxicity potentials using the alkaline comet assay

Nano-silver (Nano-Ag) particles were synthesized and then characterized using transmission electron microscopy (TEM) and X-ray diffractometry. TEM showed that Nano-Ag were spherical in shape and their size ranged from 40 to 60nm. X-ray diffractometry indicated that the sample was crystalline and had a face centered cubic structure of pure silver. Genotoxicity of this Nano-Ag was evaluated in human peripheral blood cells using the alkaline comet assay. Results indicated that Nano-Ag (50 and 100μg/mL) caused DNA damage following a 3h treatment. Subsequently, a short treatment of 5min also showed DNA damage. In conclusion, we have shown that the synthesized Nano-Ag induced DNA damage in human peripheral blood cells as detected by the alkaline comet assay. Results further indicated that treatment of cells with Nano-Ag in the presence of hydrogen peroxide did not induce any DNA damage.     

Karyomorphological effects of two new oil formulations on Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae)

The cotton bollworm Helicoverpa armigera is a serious pest of many economically important crops. Since this pest has become resistant to the conventional synthetic insecticides, newer compounds and formulations are being developed against this insect pest. Many natural compounds isolated from the plants were tested against this pest. Among them Hyptis suaveolens and Melochia corchorifolia showed insecticidal properties against H. arnigera. Based on bioefficacy studies, caryophyllene and β-sitosterol were isolated from H. suaveolens and M. corchorifolia respectively. The isolated natural compounds were further developed as formulations in various combinations with neem (Azadirachta indica) and karanj (Pongamia pinnata) oils. The present study indicated that the formulations influenced the karyomorphology of H. armigera.     

Microbicidal and anti-inflammatory effects of Actinomadura spadix (EHA-2) active metabolites from Himalayan soils, India

Actinomycetes play an essential role in producing several bioactive compounds. In the present study, microbicidal and anti-inflammatory effects of metabolites from actinomycetes were investigated. Actinomycetes were isolated from north eastern Himalayan soil samples, India. The actinomycetes were investigated for their microbicidal property by conventional method and the active actinomycetes were identified by 16s rDNA sequence analyses. Further the metabolites were extracted and fractionated to evaluate the antimicrobial potency; they were subjected to GC–MS analysis. The active fraction was evaluated for selective toxicity and anti-inflammatory potential. Among isolated actinomycetes, EHA-2 showed potent antimicrobial activity and was identified as Actinomadura spadix. Fraction-8 from ethyl acetate extract of EHA-2 showed 100 % inhibition against Candida sp. (MIC—80 μg/mL) and Enterococcus faecalis (MIC—80 μg/mL). The expression of GAPDH in primary cells and 16s rRNA levels on E. faecalis treated with fraction-8 revealed no toxicity to the primary cells. Fraction-8 also suppressed the paw thickness on carrageenan induced animals and also controlled the release of NO, TNFα and IL-1β levels on LPS induced RAW 264.7 cell lines. GC–MS profile of fraction-8 showed the presence of an antimicrobial agent 3,6 di-isobutyl 2,5 piperazinedione, which is the first report in A. spadix. The actinomycetes isolate EHA-2 can be proceed further to produce antibiotics.     

Agrobacterium-mediated transformation of chickpea with α-amylase inhibitor gene for insect resistance

Chickpea is the world’s third most important pulse crop and India produces 75% of the world’s supply. Chickpea seeds are attacked byCallosobruchus maculatus andC. chinensis which cause extensive damage. The α-amylase inhibitor gene isolated fromPhaseolus vulgaris seeds was introduced into chickpea cultivar K850 throughAgrobacterium- mediated transformation. A total of 288 kanamycin resistant plants were regenerated. Only 0.3% of these were true transformants. Polymerase chain reaction (PCR) analysis and Southern hybridization confirmed the presence of 4.9 kb α-amylase inhibitor gene in the transformed plants. Western blot confirmed the presence of α-amylase inhibitor protein. The results of bioassay study revealed a significant reduction in the survival rate of bruchid weevilC. maculatus reared on transgenic chickpea seeds. All the transgenic plants exhibited a segregation ratio of 3:1.