Exogenous hydrogen sulphide alleviates copper stress impacts in Artemisia annua L.: Growth, antioxidant metabolism, glandular trichome development and artemisinin biosynthesis

A supply of plant micronutrients (some of which are metals) is necessary to regulate many plant processes; their excess, however, can have detrimental consequences and can hamper plant growth, physiology and metabolism. Artemisia annua is an important crop plant used in the treatment of malaria. In this investigation, the physio-biochemical mechanisms involved in exogenous hydrogen sulphide-mediated (H₂ S) alleviation of copper (Cu) stress in A. annua were assessed.. Two different levels of Cu (20, 40 mg·kg^-1 ), one H₂ S treatment (200 µm) and their combinations were introduced while one set of plants was retained as control. Results showed that the presence of excess Cu in the soil reduced growth and biomass, photosynthetic parameters, chlorophyll content and fluorescence, gas exchange parameters and induced antioxidant enzyme activity. Copper stress enhanced the production of thiobarbituric acid reactive substances (TBARS) and increased Cu content in both roots and shoots of affected plants. Exogenous application of H₂ S restored the physio-biochemical characteristics of Cu-treated A. annua plants by reducing lipid peroxidation and enhancing the activity of antioxidant enzymes in Cu-stressed plants as compared with the controls. Hydrogen sulphide also reduced the Cu content in different plant parts, increased photosynthetic efficiency, trichome density, average area of trichomes and artemisinin content. Therefore, our results provide a comprehensive assessment of the defensive role of H₂ S in Cu-stressed A. annua.

Exogenous Strigolactone (GR24) Positively Regulates Growth, Photosynthesis, and Improves Glandular Trichome Attributes for Enhanced Artemisinin Production in Artemisia annua

Artemisia annua is a medicinal plant particularly known for the production of a sesquiterpene lactone artemisinin; a specialty metabolite known for its efficacy in the treatment of malaria by killing different strains of Plasmodium falciparum due to radicals released upon the cleavage of its endoperoxide motif. Considering these facts and the immense medicinal value of artemisinin, the enhancement of in planta production of artemisinin is highly desirable. As strigolactones are known to regulate various aspects of plant growth and development, the effects of foliar spray of different concentrations of synthetic strigolactone analog GR24 (0, 0.5, 1, 2, 4, and 8 µM) on A. annua were studied. As compared to the control group, the foliar application of GR24 had a positive impact on general growth, photosynthesis, and other physiological indices with 4 µM GR24 showing the best results. The results indicate that GR24 application increased the plant biomass and various attributes related to photosynthesis, like total chlorophyll content, chlorophyll fluorescence, stomatal conductance, internal CO2, and net photosynthetic rate. Moreover, the activity of various enzymes related to photosynthesis like carbonic anhydrase, nitrate reductase, and RuBisCO was escalated. The GR24 also improved certain attributes related to glandular trichomes, with a significant enhancement in content and yield of artemisinin as compared to untreated plants.

Inhibitory effect of polyphenols (phenolic acids, lignans, and stilbenes) on cancer by regulating signal transduction pathways: a review

Natural products, especially polyphenols (phenolic acids, lignans, and stilbenes) are suggested to be more potent anticancer drugs because of their no or less adverse effects, excess availability, high accuracy, and secure mode of action. In the present review, potential anticancer mechanisms of action of some polyphenols including phenolic acids, lignans, and stilbenes are discussed based on clinical, epidemiological, in vivo, and in vitro studies. The emerging evidence revealed that phenolic acids, lignans, and stilbenes induced apoptosis in the treatment of breast (MCF-7), colon (Caco-2), lung (SKLU-1), prostate (DU-145 and LNCaP), hepatocellular (hepG-2), and cervical (A-431) cancer cells, cell cycle arrest (S/G₂/M/G₁-phases) in gastric (MKN-45 and MKN-74), colorectal (HCT-116), bladder (T-24 and 5637), oral (H-400), leukemic (HL-60 and MOLT-4) and colon (Caco-2) cancer cells, and inhibit cell proliferation against the prostate (PC-3), liver (LI-90), breast (T47D and MDA-MB-231), colon (HT-29 and Caco-2), cervical (HTB-35), and MIC-1 cancer cells through caspase-3, MAPK, AMPK, Akt, NF-κB, Wnt, CD95, and SIRT1 pathways. Based on accumulated data, we suggested that polyphenols could be considered as a viable therapeutic option in the treatment of cancer cells in the near future.

A comprehensive review of impacts of diverse nanoparticles on growth, development and physiological adjustments in plants under changing environment

The application of nanotechnology in agriculture includes the use of nanofertilizers, nanopesticides, and nanoherbicides that enhance plant nutrition without disturbing the soil texture and protect it against microbial infections. Thus, nanotechnology maintains the plant's health by maintaining its soil health. The use of nanoparticles (NPs) in agriculture reduces the chemical spread and nutrient loss and boosts crop yield and productivity. Effect of NPs varies with their applied concentrations, physiochemical properties, and plant species. Various NPs have an impact on the plant to increase biomass productivity, germination rate and their physiology. Also, NPs change the plant molecular mechanisms by altering gene expression. Metal and non-metal oxides of NPs (Au, Ag, ZnO, Fe₂O₃, TiO₂, SiO₂, Al₂O₃, Se, carbon nanotubes, quantum dots) exert an important role in plant growth and development and perform an essential role in stress amelioration. On the other hand, other effects of NPs have also been well investigated by observing their role in growth suppression and inhibition of chlorophyll and photosynthetic efficiency. In this review, we addressed a description of studies that have been made to understand the effects of various kind of NPs, their translocation and interaction with the plants. Also, the phytoremediation approaches of contaminated soil with combined use of NPs for sustainable agriculture is covered.

Exogenous triacontanol provides tolerance against arsenic-induced toxicity by scavenging ROS and improving morphology and physiological activities of Mentha arvensis L

Arsenic (As), recognized as a toxic metalloid globally, has posed a serious threat to soil, plants and aquatic resources. Arsenic restrain fundamental processes of plant grown under the As-contaminated soil which are the worst sufferers for their sustenance. Thus, various scientific strategies are being continuously employed for reducing the soil As. In this regard, use of well-known plant growth regulators (PGRs) like triacontanol (TRIA) shown great efficiency towards heavy metals stress tolerance. TRIA is a plant growth promoter that has been proved effective for growth and development of plants under diverse environmental conditions for many decades. The research work was carried out to examine the toxic effects of As on various morphological, physio-biochemical, yield and quality parameters of Mentha arvensis L. and amelioration of the As toxicity through exogenous application of TRIA. Mentha plants were supplemented with various treatments (i) 0 (control), (ii) TRIA (10^-6 M), (iii) As (60 mg kg^-1), (iv) As (80 mg kg^-1), (v) TRIA (10^-6 M) + As (60 mg kg^-1), and (vi) TRIA (10^-6 M) + As (80 mg kg^-1). Several parameters studied during the present investigation were plant height, fresh and dry weights, herbage yield, chlorophyll and carotenoid content, carbonic anhydrase (CA) activity, several chlorophyll fluorescence parameters, superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), proline (PRO), H₂O₂ content, TBARS content, electrolyte leakage (EL), essential oil content (EO) and yield and microscopic analyses as well as PCA analysis. Arsenic treatment exhibited deleterious effects on the overall growth, photosynthetic, and quality parameters of M. arvensis. However, the toxicity of As was mitigated by the leaf-applied TRIA to the plants, proved advantageous in combating the ROS generation.

Determination of hormoligosis of organophosphate insecticides against Phenacoccus solenopsis

Abstract Cotton mealybug is a highly invasive pest of agricultural crops worldwide. Major agriculturists most rely on the use of insecticides for the control of pesticides. So, the indiscriminate use of insecticides leads to resistance development in recent years. For this purpose, an experiment was conducted using different concentrations of the three insecticides (profenfos chlorpyrifos and triazophos) to check the hormoligosis effects against cotton mealybug (CMB) in laboratory conditions. Investigation of variations for % mortality of adults of CMB after three days revealed that all treatments had statistically significant (P ˂ 0.05). The highest mortality was observed at the highest concentrations of profenofos 2.4% (38.55%). After 7 days, all the treatments were significant with difference in means (P ˂ 0.05). The highest mortality was recorded at the highest dilution of pesticide profenofos 2.4% (77.11%). The values of fecundity and longevity exposed a valid difference among treatments (P ˂ 0.05). Maximum fecundity was observed at the concentration 2.4% (181.41%) and longevity showed (38.46%). The highest mortality was observed at a concentration of triazophos 4% (27.98%). For chlorpyriphos the highest mortality was examined at concentration 4% (24.79%). The fecundity showed a statistically significant difference for different concentrations of triazophos and chlorpyriphos (P ˂ 0.05). The results of the recent study provide valuable information regarding the selection of insecticides and hormoligosis effects. The study can be helpful in the implications of integrated pest management of P. solenopsis.

A comprehensive review of adaptations in plants under arsenic toxicity: Physiological, metabolic and molecular interventions

Arsenic (As) is recognized as a toxic metalloid and a severe threat to biodiversity due to its contamination. Soil and groundwater contamination with this metalloid has become a major concern. Large fractions of cultivable lands are becoming infertile gradually due to the irrigation of As contaminated water released from various sources. The toxicity of As causes the generation of free radicals, which are harmful to cellular metabolism and functions of plants. It alters the growth, metabolic, physiological, and molecular functions of the plants due to oxidative burst. Plants employ different signaling mechanisms to face the As toxicity like phosphate cascade, MAPK (Mitogen-Activated Protein Kinase), Ca-calmodulin, hormones, and ROS-signaling. The toxicity of As may significantly be reduced through various remediation techniques. Among them, the microbial-assisted remediation technique is cost-effective and eco-friendly. It breaks down the metalloid into less harmful species through various processes viz. biovolatilization, biomethylation, and transformation. Moreover, the adaptation strategies towards As toxicity are vacuolar sequestration, involvement of plant defense mechanism, and restricting its uptake from plant roots to above-ground parts. The speciation, uptake, transport, metabolism, ion dynamics, signaling pathways, crosstalk with phytohormones and gaseous molecules, as well as harmful impacts of the As on physiological processes, overall development of plants and remediation techniques are summarized in this review.

Frequency and factors associated with thyroid dysfunctions: An analytical cross-sectional study from a tertiary care center in Kabul, Afghanistan

Introduction/Objective

Endocrinopathies are a commonly occurring entity, particularly those of the thyroid gland, however there is lack of scientific literature from Afghanistan, a country with very limited health care facilities and resources. This is the first study aimed to describe the frequency of occurrence and factor associated with thyroid dysfunction in Afghan population. The aim of this study is to estimate the frequency and to identify factors associated with thyroid dysfunction among individuals coming to a tertiary care facility in Kabul, Afghanistan.

Methods/Case Report

A cross-sectional study was conducted from July to Sep 2018 at the Department of Clinical Pathology, French Medical Institute for Mothers and Children (FMIC), Kabul, Afghanistan. Blood samples were obtained, serum TSH levels were analyzed, and the patients were divided into three diagnostic categories according to their serum TSH concentrations: 1) Hypothyroidism 2) Hyperthyroidism 3) normal.

Results (if a Case Study enter NA)

A total of 127 individuals were included in the final analysis. Majority study participants (77%) were females. A large number of the participants (92%) did not have family history of thyroid dysfunction. (74%) participants in the study had normal TSH levels classified as normal thyroid function, (14%) had lower TSH levels and (12%) higher TSH levels (Table 1) classified as hyper and hypothyroid respectively.

Conclusion

The findings of the current study showed a high frequency of thyroid dysfunctions from a single center. Further large scale studies are needed to find out the prevalence and document this entity for better health outcomes in the country.

Early Antibiotic Exposure Is Not Detrimental to Therapeutic Effect from Immunotherapy in Hepatocellular Carcinoma

BACKGROUND AND RATIONALE

Immune checkpoint inhibitor (ICI) therapy is an expanding therapeutic option for hepatocellular carcinoma (HCC). Antibiotics (ATB) taken prior to or early during ICI therapy can impact immunotherapy efficacy across indications; however, the effect of ATB is undefined in HCC.

METHODS

In a large international cohort of 450 ICI recipients from Europe, North America, and Asia, we categorized patients according to timing of ATB focusing on exposure within -30 to +30 days from ICI (early immunotherapy period [EIOP]). EIOP was evaluated in association with overall survival (OS), progression-free survival (PFS), and best radiologic response using RECIST 1.1 criteria.

RESULTS

Our study comprised mostly cirrhotic (329, 73.3%) males (355, 79.1%) with a Child-Turcotte Pugh class of A (332, 73.9%), receiving ICI after 1 therapy line (251, 55.9%) for HCC of Barcelona clinic liver cancer stage C (325, 72.4%). EIOP (n = 170, 37.9%) was independent of baseline clinicopathologic features of HCC and correlated with longer PFS (6.1 vs. 3.7 months, log-rank p = 0.0135). EIOP+ patients had similar OS, overall response, and disease control rates (DCRs) compared to EIOP. The effect of EIOP persisted in landmark time analyses and in multivariable models, confirming the independent predictive role of EIOP in influencing PFS following adjustment for covariates reflective of tumor burden, liver function, and ICI regimen administered. In patients receiving programmed cell death-1 receptor/ligand inhibitors monotherapy, EIOP was also associated with higher DCRs (61.4% vs. 50.9%, p = 0.0494).

CONCLUSIONS

Unlike other oncological indications, ATB in the 30 days before or after ICI initiation is associated with improved benefit from immunotherapy, independent of disease and treatment-related features. Evaluation of the immune microbiologic determinants of response to ICI in HCC warrants further investigation.

Molecular Mechanisms of Nitric Oxide (NO) Signaling and Reactive Oxygen Species (ROS) Homeostasis during Abiotic Stresses in Plants

Abiotic stressors, such as drought, heavy metals, and high salinity, are causing huge crop losses worldwide. These abiotic stressors are expected to become more extreme, less predictable, and more widespread in the near future. With the rapidly growing human population and changing global climate conditions, it is critical to prevent global crop losses to meet the increasing demand for food and other crop products. The reactive gaseous signaling molecule nitric oxide (NO) is involved in numerous plant developmental processes as well as plant responses to various abiotic stresses through its interactions with various molecules. Together, these interactions lead to the homeostasis of reactive oxygen species (ROS), proline and glutathione biosynthesis, post-translational modifications such as S-nitrosylation, and modulation of gene and protein expression. Exogenous application of various NO donors positively mitigates the negative effects of various abiotic stressors. In view of the multidimensional role of this signaling molecule, research over the past decade has investigated its potential in alleviating the deleterious effects of various abiotic stressors, particularly in ROS homeostasis. In this review, we highlight the recent molecular and physiological advances that provide insights into the functional role of NO in mediating various abiotic stress responses in plants.

Salicylic acid-mediated alleviation of soil boron toxicity in Mentha arvensis and Cymbopogon flexuosus: Growth, antioxidant responses, essential oil contents and components

Boron (B) toxicity is a notable abiotic hindrance that restricts crop productivity by disturbing several physiological and biochemical processes in plants. This study was aimed to elucidate the role of salicylic acid (SA) in conferring tolerance to B stress in Mentha arvensis and Cymbopogon flexuosus. Boron toxicity led to a considerable decrease in shoot height and root length, fresh and dry mass of shoot and root, and physiological and biochemical parameters. However, exogenously applied SA relieved the adverse effects caused by B toxicity and led to an increase in growth parameters under B stress and non-stress conditions. The treatment of B resulted in its increased accumulation in roots and shoots of both the plants which, in turn, caused oxidative damage as evident by increased content of malondialdehyde and catalase, peroxidase, superoxide dismutase and glutathione reductase enzyme activities. However, exogenous SA supply significantly affected antioxidant enzyme activities and protected the plants from excess B. Moreover, the essential oil content of two selected plants declined under B toxicity and significantly enhanced in SA-treated stressed plants. The contents of menthol and menthyl acetate in M. arvensis were lowered in B stressed plants which significantly improved in SA treated B-stressed and in their respective SA alone treatment. Similarly, citral-A and citral-B content of C. flexuosus declined under B toxicity, however, SA reversed the negative effects of B toxicity on essential oil components. This assessment stipulated the promising role of exogenously applied SA in alleviating B toxicity in M. arvensis and C. flexuosus by improving antioxidant machinery and limiting B uptake which protects the structural integrity of leaves and also helps in increasing essential oil content.

Enhancing artemisinin content in and delivery from Artemisia annua: a review of alternative, classical, and transgenic approaches

This review analyses the most recent scientific research conducted for the purpose of enhancing artemisinin production. It may help to devise better artemisinin enhancement strategies, so that its production becomes cost effective and becomes available to masses. Malaria is a major threat to world population, particularly in South-East Asia and Africa, due to dearth of effective anti-malarial compounds, emergence of quinine resistant malarial strains, and lack of advanced healthcare facilities. Artemisinin, a sesquiterpene lactone obtained from Artemisia annua L., is the most potent drug against malaria and used in the formulation of artemisinin combination therapies (ACTs). Artemisinin is also effective against various types of cancers, many other microbes including viruses, parasites and bacteria. However, this specialty metabolite and its derivatives generally occur in low amounts in the source plant leading to its production scarcity. Considering the importance of this drug, researchers have been working worldwide to develop novel strategies to augment its production both in vivo and in vitro. Due to complex chemical structure, its chemical synthesis is quite expensive, so researchers need to devise synthetic protocols that are economically viable and also work on increasing the in-planta production of artemisinin by using various strategies like use of phytohormones, stress signals, bioinoculants, breeding and transgenic approaches. The focus of this review is to discuss these artemisinin enhancement strategies, understand mechanisms modulating its biosynthesis, and evaluate if roots play any role in artemisinin production. Furthermore, we also have a critical analysis of various assays used for artemisinin measurement. This may help to develop better artemisinin enhancement strategies which lead to decreased price of ACTs and increased profit to farmers.

Abstract 485: Early antibiotic exposure delays disease progression following immune checkpoint inhibitor therapy for hepatocellular carcinoma: Evidence from an observational study

Background: Immune checkpoint inhibition (ICI) is an expanding option in hepatocellular carcinoma (HCC). Antibiotics (ATB) have been shown to reduce response and survival after ICI in other cancers.

Methods: Efficacy of ICI is described in patients (pt) from 11 centres (246 USA, 100 Asia, 68 Europe), with median overall (OS), progression-free survival (PFS) and best response (RECIST 1.1) compared between pt with and without ATB exposure in the early immunotherapy period (EIOP) of 30 days before and after ICI initiation.

Results: Most of our 414 pt were cirrhotic (297, 71.7%) due to hepatitis C (162, 391.1%) with Barcelona Clinic Stage C (294, 71.0%), Child-Pugh class (CP) A (313, 76.3%) and AFP>400 IU/mL (158, 39.3%). OS was 15.4 mo (95%CI 13.1-17.7) and PFS was 5.3 months (95% CI 4.5-6.0). Most ICI was anti-PD-1 monotherapy (358, 86.5%) and given as 1st (173, 41.8%) or 2nd line (208, 50.2%). Best response to ICI was complete response in 27 pt (6.5%), partial response in 45 (10.9%), stable disease (SD) in 160 (38.6%) and progressive disease (PD) in 161 (38.9%). ATB was given to 167 pt (40.3%), prior to or early after (30 d) ICI initiation (EIOP, 157, 38.0%) or beyond 30 days (21, 5.1%), mostly as beta-lactams (27, 10.9%) or quinolones (26, 10.5%). ATB use was independent of CP class (p=0.76), ECOG performance status (p=0.58) and BCLC stage (p=0.60). mOS in the EIOP+ group was similar to the EIOP- group (13.1 vs 15.5 mo, p=0.92). mPFS in the EIOP+ group was significantly longer than the EIOP- group (7.9 vs 4.2 mo, p=0.004). Observations persisted when stratified by CP class (p=0.42) and ICI type (p=0.92). Partial response rate was higher in the EIOP+ group (17.3% vs 8.6%, p=0.01), although overall objective response and disease control rates were similar between EIOP groups (ORR: 22.7% vs 15.9%, p=0.10; DCR: 64.0% vs 56.6%, p=0.15). Pt in the EIOP+ group were not more likely to experience gastrointestinal AE (EIOP +/- 9.2%/5.4%, p=0.12) or hepatic AE (EIOP +/-, 17.9%/16.5%, p=0.92) of any grade, while severe liver AE (grade 2 or above) were less common in the EIOP+ group (EIOP+/- 2.8%/9.5%, p=0.01).

Conclusions: ATB in the 30 d before or after ICI initiation in HCC is associated with prolonged PFS. This is contrary to findings in other solid tumors. Evaluation of the immune-microbiologic determinants of response to ICI in HCC a key research question.

Citation Format: Petros Fessas, Muntaha Naeem, Thomas U. Marron, David Szafron, Elad Sharon, Anwar Saeed, Tomi Jun, Sirish Dharmapuri, Abdul R. Naqash, Thoetchai Peeraphatdit, Anuhya Gampa, Yinghong Wang, Uqba Khan, Mahvish Muzaffar, Musharraf Navaid, ChiehJu Lee, Pei-Chang Lee, Anushi Bulumulle, Bo Yu, Sonal Paul, Neil Nimkar, Dominik Bettinger, Hannah Hildebrand, Yehia I. Abugabal, Tiziana Pressiani, Nicola Personeni, Naoshi Nishida, Masatoshi Kudo, Ahmed Kaseb, Yi-Hsiang Huang, Celina Ang, Anjana Pillai, Lorenza Rimassa, David J. Pinato. Early antibiotic exposure delays disease progression following immune checkpoint inhibitor therapy for hepatocellular carcinoma: Evidence from an observational study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 485.

Review of potential risk groups for coronavirus disease 2019 (COVID-19)

The current pandemic of coronavirus disease 19 (COVID-19) is a global issue caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Studies have revealed that this virus results in poorer consequences and a higher rate of mortality in older adults and those with comorbidities such as cardiovascular disease, hypertension, diabetes and prolonged respiratory illness. In this review, we discuss in detail the potential groups at risk of COVID-19 and outline future recommendations to mitigate community transmission of COVID-19. The rate of COVID-19 was high in healthcare workers, smokers, older adults, travellers and pregnant women. Furthermore, patients with severe medical complications such as heart disease, hypertension, respiratory illness, diabetes mellitus and cancer are at higher risk of disease severity and mortality. Therefore, special effort and devotion are needed to diminish the threat of SARS-CoV-2 infection. Proper vaccination, use of sanitizers for handwashing and complete lockdown are recommended to mitigate the chain of COVID-19 transmission.

Antacid exposure and immunotherapy outcomes among patients with advanced hepatocellular carcinoma

BACKGROUND

Antibiotic exposure has been associated with worse outcomes with immune checkpoint inhibitors (ICIs) in cancer patients, likely due to disruption of the gut microbiome. Other commonly prescribed medications, such as proton pump inhibitors (PPIs) and histamine-2-receptor antagonists (H2RAs), are also known to disrupt the microbiome, but data on their association with ICI outcomes are conflicting.

METHODS

We conducted a retrospective, multicenter, international cohort study including 314 hepatocellular carcinoma (HCC) patients treated with ICIs from 2017 to 2019 to assess the association between PPI or H2RA exposure (up to 30 days before ICI) and overall survival. Secondary outcomes included overall response rate (ORR) and development of any treatment-related adverse events (AEs).

RESULTS

Baseline PPI/H2RA exposure was not associated with overall survival in univariable (HR 1.01, 95% CI 0.75-1.35) or multivariable analysis (HR 0.98, 95% CI 0.71-1.36). Baseline PPI/H2RA exposure was not associated with either ORR (OR 1.32, 95% CI 0.66-2.65) or AEs (OR 1.07, 95% CI 0.54-2.12) in multivariable analysis.

CONCLUSIONS

Our results suggest that exposure to PPI/H2RA prior to ICIs does not adversely affect outcomes in HCC patients.

Exogenous abscisic acid mediates ROS homeostasis and maintains glandular trichome to enhance artemisinin biosynthesis in Artemisia annua under copper toxicity

One of the major abiotic stresses that cause environmental pollution is heavy metal stress. In the present investigation, copper (Cu) toxicity caused morphological and cellular damages to the Artemisia annua L. plants but supplementation of abscisic acid (ABA) ameliorated the damaging effect of Cu. Copper toxicity significantly reduced the shoot and root lengths; fresh and dry weights of shoot. However, exogenous application of ABA to Cu-treated plants significantly attenuated the damaging effects on plants caused by Cu toxicity. Copper stress also reduced the physiological and biochemical parameters, but ABA application ameliorated the negative effects of Cu in the affected plant. Accumulation of Cu in plant tissues significantly increased the membrane damage and oxidative enzyme activities such as catalase (CAT), peroxidase (POX) and superoxide dismutase (SOD). Further, the impact of high concentration of Cu on density, area and ultrastructure of glandular trichomes and artemisinin content was studied. Moreover, the foliar application of ABA improved the area, density of glandular trichomes and secured the plant cells from Cu toxicity. Therefore, this investigation indicated that the exogenous application of ABA protects A. annua plant by increasing antioxidant enzymes activity, which helps in maintaining cell integrity of leaves and results in increased artemisinin production.

Exogenous abscisic acid mediates ROS homeostasis and maintains glandular trichome to enhance artemisinin biosynthesis in Artemisia annua under copper toxicity

One of the major abiotic stresses that cause environmental pollution is heavy metal stress. In the present investigation, copper (Cu) toxicity caused morphological and cellular damages to the Artemisia annua L. plants but supplementation of abscisic acid (ABA) ameliorated the damaging effect of Cu. Copper toxicity significantly reduced the shoot and root lengths; fresh and dry weights of shoot. However, exogenous application of ABA to Cu-treated plants significantly attenuated the damaging effects on plants caused by Cu toxicity. Copper stress also reduced the physiological and biochemical parameters, but ABA application ameliorated the negative effects of Cu in the affected plant. Accumulation of Cu in plant tissues significantly increased the membrane damage and oxidative enzyme activities such as catalase (CAT), peroxidase (POX) and superoxide dismutase (SOD). Further, the impact of high concentration of Cu on density, area and ultrastructure of glandular trichomes and artemisinin content was studied. Moreover, the foliar application of ABA improved the area, density of glandular trichomes and secured the plant cells from Cu toxicity. Therefore, this investigation indicated that the exogenous application of ABA protects A. annua plant by increasing antioxidant enzymes activity, which helps in maintaining cell integrity of leaves and results in increased artemisinin production.

Salicylic acid restrains arsenic induced oxidative burst in two varieties of Artemisia annua L. by modulating antioxidant defence system and artemisinin production

Arsenic is a harmful and toxic substance to the growth and development of plants. Salicylic acid (SA) acts as a signaling molecule, plays pivotal roles in the overall growth and development of plants under various environmental stresses. Artemisinin extracted from the leaves of A. annua helps in malarial treatment. The present investigation is aimed to find out the possible ameliorative role of exogenously-applied salicylic acid (SA) on two varieties of Artemisia annua L., namely 'CIM-Arogya' and 'Jeevan Raksha' under arsenic (As) stress conditions. For this, growth, physiological and biochemical characterization, and artemisinin production was assessed. The various treatments applied on the plants were Control, 10^-6 M SA, 10^-5 M SA, 45 mg kg^-1As, 45 mg kg^-1 As + 10^-6 M SA, and 45 mg kg^-1 As + 10^-5 M SA. Arsenic at 45 mg kg^-1 of soil, reducing the overall performance of both varieties at 90 and 120 DAP. However, the levels of antioxidants were enhanced in As-stressed plants, and the supplementation of SA further increased these antioxidants in SA-treated plants. It has been observed that minimum reduction in growth and yield occurs with enhanced production of artemisinin in the case of 'CIM-Arogya' compared to 'Jeevan Raksha' under As stress (45 mg kg^-1 of soil). Leaf-applied SA significantly increased the content (49.0% & 43.4%) and yield (53.3% & 46.3%) of artemisinin in both tolerant and sensitive varieties as compared to their respective controls. Thus, the variety 'CIM-Arogya' showed tolerant behavior over 'Jeevan Raksha' and is much adapted to higher As stress.

Concomitant medications and immune checkpoint inhibitor therapy for cancer: causation or association?

The majority of cancer patients assume concomitant medications for the treatment of cancer-related symptoms or co-morbidities. As immune checkpoint inhibitors expand in the treatment of a widening range of malignancies, drug-drug interactions have become an area of increasing interest due to the potential for some concomitant medications to exert immune-modulatory effects and influence outcomes from immunotherapy. Here, we review the evidence supporting this association across selected drug classes including antibiotics, proton pump inhibitors, metformin, and opioids.

Elemental analysis of sage (herb) using calibration-free laser-induced breakdown spectroscopy

In this work, laser-induced breakdown spectroscopy (LIBS) has been used for the quantitative and qualitative analysis of the sage sample using the calibration-free LIBS (CF-LIBS) technique. The sage plasma is generated by focusing the second harmonics (532 nm) of a Q-switched Nd:YAG laser with a repetition rate of 10 Hz and pulse duration of 5 ns. The emission spectra are recorded using a LIBS 2000 detection system spectrometer consisting of five high-resolution spectrometers covering a wavelength range from 200 to 720 nm. The optical emission spectra of the sage sample reveal the spectral lines of Fe, Ca, Ti, Co, Mn, Ni, and Cr. The plasma temperature and electron number density of the neutral spectral lines of the pertinent elements have been deduced using the Boltzmann plot and Stark-broadening line profile method, with average values 8855±885K and 3.89×10¹⁶cm^-3, respectively. The average values of the plasma parameters were used for the quantification of the detected elements in the sample. Based on the calibration-free method, the measured results demonstrate that Fe is the major constituent in the sample, having a percentage concentration of 48.1%, while the remaining elements are Ca, Ti, Co, Mn, Ni, and Cr, with percentage concentrations 0.7%, 5.3%, 8%, 11%, 12.3%, and 14.6%, respectively. This study demonstrates the feasibility of LIBS for the compositional analysis of major and trace elements present in the plant samples and its further applications in medicine.

Impact of Long-Term Copper Exposure on Growth, Photosynthesis, Antioxidant Defence System and Artemisinin Biosynthesis in Soil-Grown Artemisia annua Genotypes

The effects of copper (Cu) exposure on growth and physiological characteristics of three genotypes (CN-12, Cim-Sanjeevani and Cim-Arogya) of Artemisia annua L. were elucidated. The plants were grown under naturally illuminated greenhouse conditions and were harvested after physiological maturity (120 days after sowing). Results suggest that 10 mg kg^- 1 Cu significantly enhanced the growth and physiological parameters like enzyme activities, photosynthesis. At higher concentrations, Cu inhibited the growth, biomass, photosynthetic parameters; while increased lipid peroxidation in all the genotypes. The activities of antioxidant enzymes viz. catalase, peroxidase and superoxide dismutase were upregulated by the Cu stress. The highest applied concentration of Cu (60 mg kg^- 1) proved most toxic for plants. Moreover, artemisinin content was increased upto 10 mg kg^- 1 of Cu treatment, compared with control, however, the artemisinin accumulation decreased at higher doses of Cu in all the genotypes. On the basis of studied parameters, Cim-Arogya was found to be most tolerant among all for Cu toxicity.

Oligomers of carrageenan regulate functional activities and artemisinin production in Artemisia annua L. exposed to arsenic stress

Recently, a promising technique has come forward in field of radiation-agriculture in which the natural polysaccharides are modified into useful oligomers after depolymerization. Ionizing radiation technology is a simple, pioneering, eco-friendly, and single step degradation process which is used in exploiting the efficiency of the natural polysaccharides as plant growth promoters. Arsenic (As) is a noxious and toxic to growth and development of medicinal plants. Artemisinin is obtained from the leaves of Artemisia annua L., which is effective in the treatment of malaria. The present study was undertaken to find out possible role of oligomers of irradiated carrageenan (IC) on two varieties viz. 'CIM-Arogya' (As-tolerant) and 'Jeevan Raksha' (As-sensitive) of A. annua exposed to As. The treatments applied were 0 (control), 40 IC (40 mg L^-1 IC), 80 IC (80 mg L^-1 IC), 45 As (45 mg kg^-1 soil As), 40 IC + 45 As (40 mg L^-1 IC + 45 mg kg^-1 soil As), and 80 IC + 45 As (80 mg L^-1 IC + 45 mg kg^-1 soil As). The present study was based on various parameters namely plant fresh weight (FW), dry weight (DW), leaf area index (LAI), leaf yield (LY), chlorophyll and carotenoid content, net photosynthetic rate (P_N), stomatal conductance (G_s), carbonic anhydrase activity (CA), proline content (PRO), lipid peroxidation (TBARS), endogenous ROS production (H₂O₂ content), catalase activity (CAT), peroxidase activity (POX), superoxide dismutase activity (SOD), ascorbate peroxidase activity (APX), As content, and artemisinin content in leaves. Plant growth and other physiological and biochemical parameters including enzymatic activities, photosynthetic activity, and its related pigments were negatively affected under As stress. Leaf-applied IC overcame oxidative stress generated due to As in plants by activating antioxidant machinery. Interestingly, leaf-applied IC enhanced the production (content and yield) of artemisinin under high As stress regardless of varieties. The oligomers of IC and As were found to be responsible for the production of endogenous H₂O₂ which has a pivotal role in the biosynthesis of artemisinin in A. annua.