Heavy metals, which have widespread environmental distribution and originate from natural and anthropogenic sources, are common environmental pollutants. In recent decades, their contamination has increased dramatically because of continuous discharge in sewage and untreated industrial effluents. Because they are non-degradable, they persist in the environment; accordingly, they have received a great deal of attention owing to their potential health and environmental risks. Although the toxic effects of metals depend on the forms and routes of exposure, interruptions of intracellular homeostasis include damage to lipids, proteins, enzymes and DNA via the production of free radicals. Following exposure to heavy metals, their metabolism and subsequent excretion from the body depends on the presence of antioxidants (glutathione, α-tocopherol, ascorbate, etc.) associated with the quenching of free radicals by suspending the activity of enzymes (catalase, peroxidase, and superoxide dismutase). Therefore, this review was written to provide a deep understanding of the mechanisms involved in eliciting their toxicity in order to highlight the necessity for development of strategies to decrease exposure to these metals, as well as to identify substances that contribute significantly to overcome their hazardous effects within the body of living organisms.

The current study deals with the use of Terminalia arjuna natural dye as an ecofriendly finishing agent for producing highly functional antimicrobial and fluorescent woolen yarn along with the evaluation of kinetic and thermodynamic adsorption characteristics. The effect of pH on the adsorption was investigated, showing an increase in adsorption capacity with decreasing pH over the range of 2–9, with maximum adsorption at pH 3.5. Two kinetic equations pseudo-first order and pseudo-second order were employed for determining adsorption rates. The pseudo-second order equation provided the best fit to experimental data with an activation energy of 105.58 kJ mol⁻¹, indicating chemisorption. The equilibrium adsorption data was fitted to Langmuir, Freundlich and Redlich–Peterson adsorption isotherms. The adsorption behavior accorded with the Redlich–Peterson isotherm with exceptionally high regression coefficients for dyeing temperatures of 50, 70 and 90 °C with dye concentration varying from 0.5–10% (o.w.f). Comparative results of the colorimetric properties (CIEL*a*b* and K/S) using a spectrophotometer under D65 illuminant (10° standard observer) and color fastness (light, wash, and rub) of dyed woolen yarns were studied to quantify the effect of metal mordants. The antimicrobial potential of Terminalia arjuna solution and dyed woolen yarn were assessed in terms of percentage inhibition of bacterial growth against a wide variety of bacterial strains, showing more than 85% inhibition. Reduction in antimicrobial activity of dyed woolen yarn was observed with mordanted samples, however they were found to retain more antimicrobial activity as compared to unmordanted samples as a function of successive washing cycles. The chemical nature of different mordants and wool–mordant–dye complex forming ability were found to have significant impact on the colorimetric and fluorescence characteristics of dyed woolen yarn.

Plants being sessile are shaped by evolution to adapt themselves and tolerate various stresses, be it salinity stress, drought, high/low temperature in nature. They have evolved with every alternate strategy to tackle serious abiotic stresses through considerable degree of developmental plasticity, including adaptation via cascades of molecular networks. Understanding the mechanism of genes responsible for plant adaptation to environment will help in predicting the scenarios, expanding the genetic aspect of abiotic stress-regulating genes to protect and extrapolate the level of tolerance or vulnerability conferred in natural ecosystems. Complementing the agronomic need for greater tolerance to abiotic stress, studying plant abiotic stress response can help in gaining insight into plant biology that can be practically applied to unlock the secrets in order to improve plant productivity to feed the ever increasing population of human beings.

Despite the vast availability of antibiotics, bacterial infections remain a leading cause of death worldwide. In an effort to enhance the armamentarium against resistant bacterial strains, 1,2,3-triazole (5a–x) and sulfonate (7a–j) analogues of natural bioactive precursors were designed and synthesized. Preliminary screening against two Gram-positive (Streptococcus pneumoniae and Enterococcus faecalis) and four Gram-negative bacterial strains (Pseudomonas aeruginosa, Salmonella enterica, Klebsiella pneumoniae, and Escherichia coli) was performed to assess the potency of these analogues as antibacterial agents. Among all triazole analogues, 5e (derived from carvacrol) and 5u (derived from 2-hydroxy 1,4-naphthoquinone) bearing carboxylic acid functionality emerged as potent antibacterial agents against S. pneumoniae (IC₅₀: 62.53 and 39.33 μg/mL), E. faecalis (IC₅₀: 36.66 and 61.09 μg/mL), and E. coli (IC₅₀: 15.28 and 22.57 μg/mL). Furthermore, 5e and 5u also demonstrated moderate efficacy against multidrug-resistant E. coli strains and were therefore selected for further biological studies. Compound 5e in combination with ciprofloxacin displayed a synergistic effect on multidrug-resistant E. coli MRA11 and MRC17 strains, whereas compound 5u was selective against E. coli MRA11 strain. Growth kinetic studies on S. pneumoniae and E. coli treated with 5e and 5u showed an extended lag phase. 5e and 5u did not show significant cytotoxicity up to 100 μg/mL concentration on human embryonic kidney (HEK293) cells. Transmission electron microscopic (TEM) analysis of bacterial cells (S. pneumoniae and E. coli) exposed to 5e and 5u clearly showed morphological changes and damaged cell walls. Moreover, these compounds also significantly inhibited biofilm formation in S. pneumoniae and E. coli strains, which was visualized by scanning electron microscopic (SEM) analysis. Treatment of larvae of Galleria mellonella (an in vivo model for antimicrobial studies) with 5e and 5u did not cause an alteration in the hemocyte density, thereby indicating lack of an immune response, and were nontoxic up to a concentration of 2.5 mg/mL.

Leishmaniasis significantly affects the population of the tropics and subtropics. Clinical features and infective species of Leishmania are the primary factors driving the direction of diagnosis. The rise in incidences of atypical presentations present a challenge in patient treatment. Knowledge of unusual/rare presentations can aid in having a broader perspective for including the different aspects during the examination and thus avoid misdiagnosis. A comprehensive literature survey was performed to present the array of atypical presentations confounding clinicians which have been seen in leishmaniasis. Case reports of unusual findings based on the localizations and morphology of lesions and infective species and the predominant geographical sites over almost five decades highlight such presentations in the population. Information regarding the clinical features recorded in the patient and the chosen treatment was extracted to put forward the preferred drug regimen in such cases. This comprehensive review presents various unusual observations seen in visceral leishmaniasis, post-kala-azar dermal leishmaniasis, cutaneous leishmaniasis, and mucocutaneous leishmaniasis. It highlights the need to consider such features in association with differential diagnosis to facilitate proper treatment of the patient.