Inflammatory-stimuli-responsive turn-on NIR fluorogenic theranostic prodrug: adjuvant delivery of diclofenac and hydrogen sulfide attenuates acute inflammatory disorders

Prolonged use of very commonly prescribed non-steroidal anti-inflammatory drugs (NSAIDs) is often associated with undesired side effects, including gastrointestinal ulcers due to the non-selective inhibition of cyclooxygenases. We describe the development of an inflammatory-stimuli-responsive turn-on fluorogenic theranostic prodrug DCF-HS for adjuvant drug delivery. Upon activation by reactive oxygen species (ROS), the prodrug releases diclofenac DCF (active drug) and the NIR fluorophore DCI-NH2 along with carbonyl sulfide (COS). The second activation of COS by the enzyme carbonic anhydrase (CA) generates hydrogen sulfide (H2S). The prodrug was conveniently synthesized using multi-step organic synthesis. The UV-Vis and fluorescence studies revealed the selective reactivity of DCF-HS towards ROS such as H2O2 in the aqueous phase and the desired uncaging of the drug DCF with turn-on NIR fluorescent reporter under physiological conditions. Furthermore, the release of fluorophore DCI-NH2 and drug DCF was confirmed using the reverse phase HPLC method. Compatibility of prodrug activation was studied next in the cellular medium. The prodrug DCF-HS was non-toxic in a representative cancer cell line (HeLa) and a macrophage cell line (RAW 264.7) up to 100 μM concentration, indicating its biocompatibility. The intracellular ROS-mediated activation of the prodrug with the release of NIR dye DCI-NH2 and H2S was investigated in HeLa cells using the H2S-selective probe WSP2. The anti-inflammatory activity of the active drug DCF from the prodrug DCF-HS was studied in the lipopolysaccharide (LPS)-induced macrophage cell line and compared to that of the parent drug DCF using western blot analysis and it was found that the active drug resulted in pronounced inhibition of COX-2 in a dose-dependent manner. Finally, the anti-inflammatory potential of the prodrug and the turn-on fluorescence were validated in the inflammation-induced Wister rat models.

Association of COVID-19 with Comorbidities: An Update

Coronavirus disease (COVID-19) is caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) which was identified in Wuhan, China in December 2019 and jeopardized human lives. It spreads at an unprecedented rate worldwide, with serious and still-unfolding health conditions and economic ramifications. Based on the clinical investigations, the severity of COVID-19 appears to be highly variable, ranging from mild to severe infections including the death of an infected individual. To add to this, patients with comorbid conditions such as age or concomitant illnesses are significant predictors of the disease's severity and progression. SARS-CoV-2 enters inside the host cells through ACE2 (angiotensin converting enzyme2) receptor expression; therefore, comorbidities associated with higher ACE2 expression may enhance the virus entry and the severity of COVID-19 infection. It has already been recognized that age-related comorbidities such as Parkinson's disease, cancer, diabetes, and cardiovascular diseases may lead to life-threatening illnesses in COVID-19-infected patients. COVID-19 infection results in the excessive release of cytokines, called "cytokine storm", which causes the worsening of comorbid disease conditions. Different mechanisms of COVID-19 infections leading to intensive care unit (ICU) admissions or deaths have been hypothesized. This review provides insights into the relationship between various comorbidities and COVID-19 infection. We further discuss the potential pathophysiological correlation between COVID-19 disease and comorbidities with the medical interventions for comorbid patients. Toward the end, different therapeutic options have been discussed for COVID-19-infected comorbid patients.

Nutraceutical prospects of Houttuynia cordata against the infectious viruses

The novel enveloped β-coronavirus SARS-CoV-2 (COVID-19) has offered a surprising health challenge all over the world. It develops severe pneumonia leading to acute respiratory distress syndrome (ARDS). Like SARS-COV-2, other encapsulated viruses like HIV, HSV, and influenza have also offered a similar challenge in the past. In this regard, many antiviral drugs are being explored with varying degrees of success to combat the associated pathological conditions. Therefore, upon scientific validation & development, these antiviral phytochemicals can attain a futuristic nutraceutical prospect in managing different encapsulated viruses. Houttuynia cordata (HC) is widely reported for activities such as antioxidant, anti-inflammatory, and antiviral properties. The major antiviral bioactive components of HC include essential oils (methyl n-nonyl ketone, lauryl aldehyde, capryl aldehyde), flavonoids (quercetin, rutin, hyperin, quercitrin, isoquercitrin), and alkaloids (norcepharadione B) & polysaccharides. HC can further be explored as a potential nutraceutical agent in the therapy of encapsulated viruses like HIV, HSV, and influenza. The review listed various conventional and green technologies that are being employed to extract potent phytochemicals with diverse activities from the HC. It was indicated that HC also inhibited molecular targets like 3C-like protease (3CLPRO) and RNA-dependent RNA polymerase (RdRp) of COVID-19 by blocking viral RNA synthesis and replication. Antioxidant and hepatoprotective effects of HC have been evident in impeding complications from marketed drugs during antiviral therapies. The use of HC as a nutraceutical is localized within some parts of Southeast Asia. Further technological advances can establish it as a nutraceutical-based functional food against pathogenic enveloped viruses like COVID 19.

Energy auditing and carbon footprint under long-term conservation agriculture-based intensive maize systems with diverse inorganic nitrogen management options

A greater energy grant in diesel-fed machinery driven farming substantiate the higher GHGs emission along with improper input (fertilizer, pesticide and irrigation) use and intensive soil management. Practicing conservation tillage, residue retention and diversified crop rotations were advocated because of their multiple benefits. Hence we explored the energy requirement and carbon footprint of conservation agriculture (CA) based maize production systems. Coated N fertilizer [sulphur coated urea (SCU) and neem coated urea (NCU)] were compared with unfertilized and uncoated prilled urea (PU) in the scenario of with and without residue retention on permanent beds (PB) under diversified maize systems [MMuMb, maize-mustard-mungbean and MWMb, maize-wheat-mungbean] in search of a sustainable and energy efficient production system with lesser C-footprint. Results of the 4-year study showed that crops planted on permanent bed with crop residue (PB+R) registered 11.7% increase in system productivity compared to PB without residue (PB-R). N management through Neem coated urea (NCU) recorded 2.3 and 10.9% higher system productivity compared with non-coated prilled urea plot under PB-R and PB+R, respectively. MMuMb was marginally superior than MWMb system in terms of cropping sequence yield, profitability, and energy and carbon use efficiency. Crop residue retention in zero tilled PB increased cost of cultivation by 125 and 147 USD/ha in MMuMb and MWMb systems, respectively. The quantified carbon footprint value was higher in MWMb system. In CA-based practices, crop residues management contributed the highest energy input (61.5-68.4%) followed by fertilizer application (17-20%). Among N management practices, neem coated urea (NCU) significantly improved system productivity and profitability in all the residue applied plots compared to un-fertilized and prilled urea (PU) applied plots. Similarly, higher energy output was also observed in NCU treated plots. However, carbon footprint value was higher in PU (268-285 CO₂-e kg/Mg) plots than NCU (259-264 CO₂-e kg/Mg) treated plots. Thus, the study supports and recommends that the CA-based MMuMb system with efficient N management through NCU is an environmentally safe, clean and energy efficient one, hence can reduce carbon footprint, will ensure food security and will mitigate climate change.