Callogenesis and Antibacterial Activity of Balanites aegyptiaca

B. aegyptiaca, it is a species of economic and cultural importance in various countries, with diverse uses that include: medicinal, charcoal, pesticides and forage and in vitro callus production is important to have many applications in both basic and industrial research on this specie. For the induction of callus, B. aegyptica seed cotyledons were surface sterilized with 90% ethanol for 1 minute and cultivated in MS media supplemented with 2,4-D, BAP and NAA. Both the callus and seed were collected and dried in an oven at 40°C - 45°C. Cotyledon’s seed and callus were grounded into the powdered form using mortar and pestle and stored at room temperature for further use. Five grams (5 g) each of the powder were mixed with 50 ml of the solvents: methanol and n-hexane (1:10) w/v, agitated vigorously and kept on an orbital shaker at 150 rpm for 24 h, then filtered. The extracts of the plant sample were evaluated in agar dilution method which was used to determine the MIC and MBC of the extracts. The auxin NAA in low concentrations (0.5 mg/L) in the presence of a dose of 0.5 mg/L of the cytokinin BAP induced 100% callus formation. The 50 and 100 mg/ml methanolic extracts were more effective than the n-hexane extracts for both the gram-positive and gram-negative bacteria. By callus extracts under 100 and 50 mg/ml reveals that methanolic extracts of callus had the highest zone of inhibition. An effective protocol for callus induction has been developed that can use for germplasm conservation or for genetic engineering. Evidence from the present study revealed both extracts possess strong broad-spectrum antibacterial effect. Therefore, methanolic extract of seed kernel callus of B. aegyptiaca can be utilized as a new source of broad spectrum antibacterial drugs for effective control of bacteria related diseases.

Optimizing soil dissolved organic matter extraction by grey relational analysis

Dissolved organic matter(DOM)in soil plays an important role in the fate and transport o f contaminants.It is typically composed of many compounds,but the effect of different extraction factors on the abundance of different DOM components is unknown.In this study,DOM was extracted from three soils(paddy field,vegetable field and forest soils)with various extraction time,liquid to solid ratios(LSRs).extractant types,and extractant concentrations.The LSR had a significant effect on DOM content,which increased by 0.5-4.0 times among the three soils when LSR increased from 2:1 to 10:1(P<0.05).Dissolved organic matter content increased by 4%-53%when extraction time increased from 10 to 300 min(P<0.05).Extractant concentration had different effects on DOM content depending on the extractant.Higher concentrations of KC1 promoted DOM extraction,while higher concentrations o f KH2PO4 inhibited DOM extraction.Therefore,grey relational analysis was used to further quantitatively evaluate the effect of extraction time,LSR,and extractant concentration on DOM,using KC1 as an extractant.For the paddy field and forest soils,the impact of these three factors on DOM extraction efficiency was in the following order:KC1 concentration>LSR>extraction time.However,the effect was different for the vegetable field soil:LSR>extraction time>KCI concentration.Taking all these factors into account,1.50 mol L^-1 KC1 and an LSR of 10:1 with a shaking time of 300 min was recommended as the most appropriate method for soil DOM extraction.

Cytotoxicity of six copper-bearing intrauterine devices on Chinese hamster ovary cells: the influence of frame, shape and copper surface area

Objective To evaluate the cytotoxicity of six commonly used copper-bearing intrauterine devices （Cu-IUDs） on Chinese hamster ovary （CHO-K1） cells and to investigate the influence of frame, shape and copper surface area of Cu-IUDs on cell toxicity.Methods Cu-IUDs were incubated in 10% FBS-DMEM/F12 culture medium at 37 ℃ for 24 h. The extracts were analyzed by flame atomic absorption spectrometer and were then diluted into different concentrations with culture medium. Finally, cytotoxicity of these original and diluted extracts on CHO-K1 cells was detected by cell counting kit-8 （CCK-8） assay.Results The viabilities of cells treated with the original extracts of six Cu-IUDs （TCu220C bulb, TCu220C, GCu220, GCu300, Yuangong Cu270 and Yuangong Ⅱ- 300） were all below 10% and the cupric ion concentrations in these extracts were 28.22 mg/L, 31.80 mg/L, 92.80 mg/L, 99.74 mg/L, 114.90 mg/L and 119.20 mg/L, respectively. After these original extracts were diluted, significant differences in cytotoxicity were exhibited. IUDs with larger copper surface areas （GCu300 and Yuangong Ⅱ-300） showed more cytotoxicity than those with smaller areas （GCu220 and Yuangong Cu270） respectively; When different shapes of Cu-IUDs were compared, TCu220C bulb showed lower cytotoxicity than TCu220C, and GCu300 exhibited higher toxicity than Yuangong Ⅱ-300; TCu220C displayed significantly lower cytotoxicity than GCu220 due to their differences in frames.Conclusion We presented evidence on the cytotoxic effects of copper ions released from Cu-IUDs on CHO-K1 cells and found that shape, frame together with copper surface area of Cu-IUDs had obvious influence on the cytotoxicity.