Occurrence and Distribution of Heavy Metals in Mining Degraded Soil and Medicinal Plants: A Case Study of Pb/Zn Sulfide Terrain Northern Areas, Pakistan.

Mining activities have serious environmental impacts, thus releasing heavy metals (HMs) such as cadmium (Cd), lead (Pb), chromium (Cr), zinc (Zn) and nickel (Ni) into the surrounding environment. The current paper investigated the impacts of mining activities of Pb-Zn sulfide on soil and medicinal plants. Hence, soil samples (n = 36) and medicinal plants (n = 36) samples were collected, acid extracted and were analyzed through Inductively Coupled Plasma Mass Spectrometry (ICP-MS) for HMs quantification. Our results showed that mineralized zones showed high HMs enrichment levels as compared to non-mineralized zones. Various Indices for HMs assessment revealed that the contaminated soil of the study area had low to extreme level. The mean concentrations of HMs in mining degraded soil and medicinal plants were significantly higher (p ≤ 0.01) and were found in order of Zn > Pb > Cr > Ni > Cd and Cr > Zn > Pb > Ni > Cd respectively. Similarly, some widely consumable medicinal plants showed good metal accumulation for Cd, Cr and Pb i.e., 3.57 mg kg1, 350 mg kg-1 and 335 mg kg-1 in C. sativa, while 5.9 mg kg-1, 276.9 mg kg-1 and 188.7 mg kg-1 in R. hestatus respectively. Hence, the present study recommended that medicinal plants grown in mining areas should be analyzed for HMs concentration before consumption.

Pollution Characteristics, Sources, and Health Risk Assessments of Potentially Toxic Elements in Community Garden Soil of Lin'an, Zhejiang, China.

The characteristics, sources and risk assessment of heavy metal pollution in community garden soil of Lin'an District were evaluated. The 28 soil samples from community garden were collected for determination of 7 heavy metal elements. The Geostatistical analysis, Spearman correlation coefficient, Principal component analysis and PMF model have explored sources of heavy metal pollution. The health risk assessment model has assessed ecological risk of heavy metals. The results revealed that average concentration of As, Cd, Cr, Cu, Ni, Pb and Zn were 16.0, 0.158, 76.1, 34.6, 45.8, 20.9 and 166 mg kg-1, respectively. Whereas As, Cd, Cr, Cu, Ni and Zn were higher than background values. The spatial distribution of heavy metal pollution in the southwest of the study area was higher than northeast. The pollution sources of Cd, Cu, Ni and Zn in the study area were due to agricultural activities (42.9%), Cr and Pb were from traffic sources (36.2%), and As was domestic pollution (20.9%) according to Spearman correlation coefficient, Principal component analysis and PMF model. The non-carcinogenic risks of As (5.39), Cr (3.53) and Ni (2.07) have a value of 1, which indicated significant risk. The potentially toxic elements have not exceeded maximum threshold of USEPA, with regard to carcinogenic risk, while As (3.37E-05) and Cr (5.74E-05) have exceeded the safety range. It is concluded that soils of community gardens are facing pollution problem due to potentially toxic elements which require environmental monitoring of the soil to reduce risk of human health.

Effect of Hypoxic Stress and Levels of Mn on the Physiology and Biochemistry of Phyllostachys praecox.

Hypoxic environments have an adverse effect on the growth and development of P. praecox, and this is accompanied by the production of reducing substances such as Fe and Mn. In this study, the effect of hypoxic stress and Mn concentrations on leaf chlorophyll contents, root morphology, root activity, element absorption, antioxidant enzymes, and respiratory enzyme system of P. praecox were evaluated in a hydroponics environment. The results revealed that application of Mn2+ during hypoxic stress enhanced leaf chlorophyll contents and boosted up the indexes of the root system. The root activity of P. praecox was reduced with stresses of hypoxia. The treatment of Mn2+ initially improved and then decreased the root activity of P. praecox, and attained its maximum with application of 300 µmol/L Mn2+ compared with control. The indexes of antioxidant enzymes of P. praecox were higher than that of 8 mg/L oxygen concentrations except for variable superoxide dismutase (SOD) in the treatment of 300 µmol/L Mn2+ with hypoxia stress. The application of Mn had inhibited the absorption of mineral elements in P. praecox. The activities of pyruvate decarboxylase (PDC), alcohol dehydrogenase (ADH), and lactic dehydrogenase (LDH) were initially improved and then diminished with hypoxia stress. It is concluded that hypoxia is a key factor affecting the growth and degradation of P. praecox, while combining it with the increase of Mn concentration enhances the damage to Phyllostachys pubescens. Our research is helpful for the sustainable management and scientific fertilization management of Phyllostachys praecox.

Effects of Hypoxia Stress on Growth, Root Respiration, and Metabolism of Phyllostachys praecox.

Hypoxia affects plant growth, hormone content, various enzyme activities, cell structure, peroxide production, and metabolic level, therefore reducing crop yield. This study assessed the physiological, biochemical, and metabolic characteristics of Phyllostachys praecox. Results revealed that hypoxia stress treatment significantly inhibited plant growth. Leaf chlorophyll contents was initially improved and then reduced with plant growth time. Under hypoxia stress, the root activity significantly was reduced, leading to the decrease in the nutrient absorption and transport. Yet, with low oxygen concentration, the contents of ethanol, acetaldehyde, and lactic acid were improved. With hypoxia stress, phospholipids and amino acids were the main metabolites of Phyllostachys praecox. Glycosphospholipid metabolism is the key pathway in responding to hypoxia stress significantly (p < 0.05), and lysophosphatidlycholine (lysoPC) and phosphatidylcholines (PC) in the metabolites of this metabolic pathway were significantly enhanced. Our study reveals the mechanism of Phyllostachys praecox cell membrane responding to hypoxia stress based on molecular level. This is conducive to finding targeted solutions to improve the productivity of Phyllostachys praecox to better optimize a mulching approach in the bamboo forest.

Vaccines for Covid-19: An insight on their effectiveness and adverse effects.

An era of SARS-COVID-19 outbreak with a high contagious percentage around the globe has been the subject of multi-agency research aimed at generating vaccines for active immunization. Scientists across the world are joining hands for advanced tie-ups between medical start-ups and pharmaceutical industries for devices and vaccines development to hinder the progress of this outbreak. Moreover, the questions that need to be answered are how to improve the effectiveness and efficacy of vaccines with reduced side effects and the required doses of vaccines for enhanced surveillance. In this review article, we have discussed the effectiveness and efficacy of different Covid-19 vaccines.

Photo-dependent somatic embryogenesis from non-embryogenic calli and its polyphenolics content in high-valued medicinal plant of Ajuga bracteosa.

Ajuga bracteosa (A. bracteosa) is one of the critically endangered and high-valued medicinal plants worldwide. Light is one of the major factor or stimulus involved in the morphogenic responses and bioactive compounds production in various medicinal plants. In this study, unique properties of colored lights have been observed on induction of somatic embryos from non-embryonic calli cultures of A. bracteosa. The maximum callogenic response (92.32%) from leaf explants was observed on Murashige and Skoog (MS) medium augmented with benzyl adenine (BA; 2.0 l-1) and 2, 4-Dichlorophenoxy acetic acid (2.4-D; 1.0 mg l-1). Calli cultures with same hormonal concentrations were placed under different spectral lights for somatic embryogenesis and photochemical variations. Red lights were found effective for maximum somatic embryos induction (92.75%) with optimum biomass accumulation (152.64 g l-1) on day 40. Similarly, among all the spectral lights, red light exhibited the highest DPPH-radical scavenging activity (DRSA; 92.86%). In contrast, blue lights induced maximum biosynthesis of chemically important total phenolics content and total flavonoids content (TPC; 0.264 and TFC; 0.06 mg/g-DW), respectively. Furthermore, blue, green and red lights also enhanced phenolics and production, polyphenolics content and total polyphenolics production in somatic embryos. It is concluded that exposure of calli cultures to colored lights provides an effective and promising in vitro technique for conservation of endangered A. bracteosa species and enhancement of its bioactive compounds. Steps should be taken to adopt these strategies/ techniques at a larger scale in order to yield maximum benefits from this highly valued medicinal plant species.

Alleviative effect of quercetin on rat testis against arsenic: a histological and biochemical study.

The preventive effect of quercetin on arsenic stimulated reproductive ailments in male Sprague Dawely (SD) rats was investigated. Twenty rats were divided into four groups. The first group served as a control and was provided tap water. The second group of rats was treated with sodium arsenite at the dose of 50 ppm in drinking water. The third group served as a positive control and received an oral dose of quercetin (50 mg/kg). In the fourth group, quercetin (50 mg/kg) was co-administered orally with arsenic (50 ppm in drinking water). All the treatments were carried out for 49 days. Arsenic treatment resulted in adverse morphological and histopathological changes in testis of rats including reduced epithelial height and tubular diameter, and increased luminal diameter. In contrast, these adverse effects of arsenic were eliminated by co-administration of quercetin. Additionally arsenic treatment significantly increased testicular thiobarbituric acid reactive substance (TBARS) levels while catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), and glutathione reductase (GSR) activities, and plasma and intra-testicular testosterone concentrations, were decreased significantly. Lipid peroxidation (LPO) was significantly suppressed and depleted antioxidant defense mechanism was restored by the quercetin co-treatment. Also quercetin treatment resulted in a marked increase in plasma and testicular testosterone concentrations. On the basis of these findings, it was concluded that quercetin may be used as a potential therapeutic drug against arsenic induced reproductive toxicity.