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Environmental pollutants like heavy metals are toxic, persistent, and bioaccumulative in nature. Contamination of agricultural fields with heavy metals not only hampers the quality and yield of crops but also poses a serious threat to human health by entering the food chain. Plants generally cope with heavy metal stress by regulating their redox machinery. In this context, nitric oxide (NO) plays a potent role in combating heavy metal toxicity in plants. Studies have shown that the exogenous application of NO donors protects plants against the deleterious effects of heavy metals by enhancing their antioxidative defense system. Most of the studies have used sodium nitroprusside (SNP) as a NO donor for combating heavy metal stress despite the associated concerns related to cyanide release. Recently, NO-releasing nanoparticles have been tested for their efficacy in a few plants and other biomedical research applications suggesting their use as an alternative to chemical NO donors with the advantage of safe, slow and prolonged release of NO. This suggests that they may also serve as potential candidates in mitigating heavy metal stress in plants. Therefore, this review presents the role of NO, the application of chemical NO donors, potential advantages of NO-releasing nanoparticles, and other NO-release strategies in biomedical research that may be useful in mitigating heavy metal stress in plants. [ABSTRACT FROM AUTHOR]

Environmental pollutants like heavy metals are toxic, persistent, and bioaccumulative in nature. Contamination of agricultural fields with heavy metals not only hampers the quality and yield of crops but also poses a serious threat to human health by entering the food chain. Plants generally cope with heavy metal stress by regulating their redox machinery. In this context, nitric oxide (NO) plays a potent role in combating heavy metal toxicity in plants. Studies have shown that the exogenous application of NO donors protects plants against the deleterious effects of heavy metals by enhancing their antioxidative defense system. Most of the studies have used sodium nitroprusside (SNP) as a NO donor for combating heavy metal stress despite the associated concerns related to cyanide release. Recently, NO-releasing nanoparticles have been tested for their efficacy in a few plants and other biomedical research applications suggesting their use as an alternative to chemical NO donors with the advantage of safe, slow and prolonged release of NO. This suggests that they may also serve as potential candidates in mitigating heavy metal stress in plants. Therefore, this review presents the role of NO, the application of chemical NO donors, potential advantages of NO-releasing nanoparticles, and other NO-release strategies in biomedical research that may be useful in mitigating heavy metal stress in plants.

In the prevailing covid times, scientific community is busy in developing vaccine against COVID-19. Under such fascination this article describes the possible role of nitric oxide (NO) releasers in aiding the immune system of a human body against this dreadful pandemic disease. Despite some prodrug antiviral compounds are in practice to recover the patients suffering from covid-19, however, co-morbidity deaths are highest among the total deaths happened so far. This concurrence of a number of diseases in a patient along with this viral infection is indicative of the poor immunity. Literature background supports the use of NO as immunity boosting agent and hence, the nitric oxide releasing compounds could act as lucrative in this context. Some dietary suggestions of NO-containing food items have also been introduced in this article. Also, the profound effect of NO in relieving symptomatic severity of covid-19 has been opined in this work.Communicated by Ramaswamy H. Sarma.

Abstract: Water-soluble photosensitizing pharmaceutical of hypocrellin A (HA), prepared by embedding HA into porous hollow silica nanospheres, exhibited high singlet oxygen generation yield, good light stability and good thermal stability. Further, the in-vitro experiments indicated that such silica nanospheres containing HA can be efficiently taken up by HeLa cells, and light irradiation of such impregnated cells might result in significant cell death. Especially, HA cannot be released from silica nanospheres, which is beneficial to minimizing phototoxic side effects. Thus, these properties of HA-silica nanospheres could possibly make it especially promising to be used in clinical photodynamic therapy. [Copyright &y& Elsevier]

The cyclam with anthracenyl fluorophore (L) in the trans -[Ru(NO)(H 2 O)(L)]3+ complex tune the properties of this potential trackable NO donor. The complex trans -[Ru(NO)(H 2 O)(L)](ClO 4) 3 (L = (1-anthracen-9-ylmethyl)-1,4,8,11-tetraazacyclotetradecane) (RuNOL) was synthesized and characterized, and its photophysics and reactivity were investigated. The FTIR spectrum displays a ν NO band at 1840 cm−1, indicating a nitrosonium character. 1H and 13C signals in 1D and 2D NMR spectra were assigned and are consistent with the trans configuration. The UV–Vis spectrum displays maximal absorption bands at 341 nm (log ε 3.74), 363 nm (log ε 3.91), 378 nm (log ε 3.97) and 397 nm (log ε 3.91). Coordination of the [RuNO] moiety to the L ligand strongly quenches the anthracenyl fluorescence, and thus RuNOL exhibits only very weak emission at 390, 418, 440 and 472 nm. Electrochemical studies indicate that cathodic peak potentials at +1.10 V(I c), −0.1 V(II c) and −0.4 V(III c) (vs Ag/AgCl) are related to An+/An, {RuNO}6/7 and {RuNO}7/8 reduction processes, respectively. The p K a of coordinated water was estimated as 2.8 ± 0.2 by DPV. The emission of the pendant fluorophore increases upon electrochemical or chemical reduction of RuNOL, and the resulting switch-ON fluorescence is possibly due to NO release from the target complex. Spectroscopic titrations with DNA resulted in hypochromism and red shifts and allowed estimation of binding constants of 1.9 × 103 (L) and 1.8 × 103 (RuNOL). Molecular docking showed that RuNOL complex has a great affinity with DNA. The RuNOL complex showed low cytotoxicity toward MCF-7 and NIH-3T3 and was ineffective in healthy HUVEC and A7r5 cell lines in the range of concentration of 1 × 10−7–1 × 10−4 mol L−1. [ABSTRACT FROM AUTHOR]