Theaflavin 3-gallate inhibits the main protease (Mpro) of SARS-CoV-2 and reduces its count in vitro

The main protease (M^pro) of SARS-CoV-2 has been recognized as an attractive drug target because of its central role in viral replication. Our previous preliminary molecular docking studies showed that theaflavin 3-gallate (a natural bioactive molecule derived from theaflavin and found in high abundance in black tea) exhibited better docking scores than repurposed drugs (Atazanavir, Darunavir, Lopinavir). In this study, conventional and steered MD-simulations analyses revealed stronger interactions of theaflavin 3-gallate with the active site residues of M^pro than theaflavin and a standard molecule GC373 (a known inhibitor of M^pro and novel broad-spectrum anti-viral agent). Theaflavin 3-gallate inhibited M^pro protein of SARS-CoV-2 with an IC₅₀ value of 18.48 ± 1.29 μM. Treatment of SARS-CoV-2 (Indian/a3i clade/2020 isolate) with 200 μM of theaflavin 3-gallate in vitro using Vero cells and quantifying viral transcripts demonstrated reduction of viral count by 75% (viral particles reduced from Log10^6.7 to Log10^6.1). Overall, our findings suggest that theaflavin 3-gallate effectively targets the M^pro thus limiting the replication of the SARS-CoV-2 virus in vitro.

Gramicidin S and melittin: potential anti-viral therapeutic peptides to treat SARS-CoV-2 infection

The COVID19 pandemic has led to multipronged approaches for treatment of the disease. Since de novo discovery of drugs is time consuming, repurposing of molecules is now considered as one of the alternative strategies to treat COVID19. Antibacterial peptides are being recognized as attractive candidates for repurposing to treat viral infections. In this study, we describe the anti-SARS-CoV-2 activity of the well-studied antibacterial peptides gramicidin S and melittin obtained from Bacillus brevis and bee venom respectively. The EC₅₀ values for gramicidin S and melittin were 1.571 µg and 0.656 µg respectively based on in vitro antiviral assay. Significant decrease in the viral load as compared to the untreated group with no/very less cytotoxicity was observed. Both the peptides treated to the SARS-CoV-2 infected Vero cells showed viral clearance from 12 h onwards with a maximal viral clearance after 24 h post infection. Proteomics analysis indicated that more than 250 proteins were differentially regulated in the gramicidin S and melittin treated SARS-CoV-2 infected Vero cells against control SARS-CoV-2 infected Vero cells after 24 and 48 h post infection. The identified proteins were found to be associated in the metabolic and mRNA processing of the Vero cells post-treatment and infection. Both these peptides could be attractive candidates for repurposing to treat SARS-CoV-2 infection.

Triple drug therapy to manage uncontrolled BP in hypertensive patients during Covid-19 lockdown: perspectives from India

Funding Acknowledgements

Type of funding sources: None.

Background

Reportedly, hypertension (HTN) independently increases the risk of Covid-19 severity and doubles the risk of Covid-19 mortality. Also, individuals with untreated HTN remain at high risk of covid-19 complications in comparison to those managed with antihypertensive treatment.

Objective

The survey was carried out to seek the opinion of healthcare practitioners (HCPs) on the impact of Covid-19 lockdown on the blood pressure (BP) control, and the role of triple drug therapy in management of uncontrolled BP.

Method

This PAN India study was carried out through a structured web-based objective questionnaire survey involving 479 HCPs. The survey comprised questions related to the prevalence and causes of uncontrolled BP during the Covid-19 lockdown, and the use of triple drug therapy in the management of uncontrolled BP.

Results

The respondent pool of 479 HCPs consisted of consulting physicians (51.5%), family physicians (19%), diabetologists (15%), cardiologists (14%) and nephrologists (0.5%). In this study a majority (40%) of HCPs agreed that stress was the most common reason behind uncontrolled BP during Covid-19 lockdown followed by non-compliance of treatment and sedentary lifestyle, each opined by 30% of HCPs. Almost 54% and 40% of the HCPs respectively, mentioned that 10-40% and 40-80% of their patients with hypertension have reported uncontrolled BP levels following the Covid-19 lockdown. 4% of the HCPs reported that all of their patients lost BP control, while 2% of HCPs mentioned that none of their patients reported uncontrolled BP after the Covid-19 lockdown. Of all the HCPs, 12% opined that they will choose a triple drug combination (TDC) for patients uncontrolled with high dose monotherapy, ∼75% opined that they will chose TDC for patients uncontrolled with dual therapy while 13% mentioned that they will chose TDC for patients at high risk. Regarding the TDC of choice, more than half (51%) of the HCPs opted for Telmisartan + Amlodipine + Hydrochlorothiazide as the preferred combination. Among other TDCs, Telmisartan + Amlodipine + Chlorthalidone, Telmisartan + Cilnidipine + Chlorthalidone, and Olmesartan + Amlodipine + Hydrochlorothiazide were ranked as the next three choices opted by 28%, 17.5% and 2.5% of HCPs for the management of uncontrolled BP. A majority of HCPs (58%) also agreed that they would adopt TDC early in the treatment, during the ongoing Covid-19 pandemic.

Conclusion

This study underlined the negative impact of Covid-19 lockdown on the blood pressure control in patients with hypertension. It also highlighted the HCPs perspectives on the early use of TDC, and that Telmisartan + Amlodipine + Hydrochlorothiazide is the most commonly preferred TDC in patients with uncontrolled BP levels in Indian settings.

An indian clinician outlook on hypertension care during Covid-19 pandemic

Funding Acknowledgements

Type of funding sources: None.

Background

Hypertension (HTN) has been found to increase the risk of Covid-19 mortality when compared with normotensives, and those discontinuing the antihypertensive treatment have an additional fatality risk.

Objective

The survey was carried out to seek the opinion of Indian healthcare practitioners (HCPs) on the risk factors, challenges and management of HTN during the ongoing Covid-19 pandemic.

Method

This was a structured web-based objective questionnaire survey involving 2545 HCPs PAN-India. The survey comprised questions related to the risk factors for HTN, home blood pressure monitoring (HBPM), BP control, treatment, complications and challenges of uncontrolled HTN during Covid-19.

Results

This study showed that tobacco use, obesity and comorbidities are top three modifiable risk factors for HTN followed by emotional stress, during Covid-19 pandemic. A majority of HCPs (44%) reported that <30% of their hypertensive patients check BP at home while 36% and 20% reported that 30-50% and >50% of their patients respectively, practice HBPM. 20%, 63%, and 17% of HCPs respectively, reported that <20%, 20-40% and >40% of their patients presented with BP > 150/100 mmHg during lockdown. Of all the HCPs, 53% and 33% respectively, reported BP increase in <20% and 20-40% of their patients on monotherapy while 14% of HCPs reported BP increase in >40% of their patients on monotherapy during the lockdown. As compared to high dose monotherapy, dual and triple combination therapies (TDC) were selected as most preferred for the management of uncontrolled BP opted by 56% and 34% of the HCPs, respectively. The dual combination antihypertensives were ranked as angiotensin receptor blockers (ARB) + diuretic (DU) > ARB + calcium channel blockers (CCB) > ARB + beta-blocker. The TDC with ARB + CCB + DU was the most favored TDC antihypertensive therapy during Covid-19 era. Acute coronary syndrome was anticipated as the most common complication of HTN in the Covid-19 pandemic, followed by renal dysfunction, cerebral ischemia and cerebral hemorrhage reported by 47%, 17%, 14% and 14% of HCPs, respectively. Multiple challenges in HTN care during Covid-19 as opined by HCPs included BP measurement while avoiding the risk of infection (57%), advising treatment via teleconsultation (48%), dose modification (41%), patient compliance (32%) and transport-related issues (30%). Most of the HCPs believed that self-monitoring of BP (32%) and economical medicines (24%) can improve medication adherence in patients with HTN.

Conclusion

The study underlined that the provision of economic medicines, single pill combinations, doctor-patient digital connect, and patient education can help in improving medication adherence leading to better outcomes in patients with HTN during Covid-19.  The study also suggested the need to enhance HBPM and the use of ARB-based dual and triple combination therapies to improve BP control in patients uncontrolled on monotherapy during Covid-19 pandemic.

Generation of iPSC from fetal fibroblast cells obtained from an abortus with type-I tri-allelic variants

An integration free iPSC line was generated from fibroblast obtained from the skin of an aborted fetus in feeder free conditions using episomal based vectors expressing the pluripotency factors. The cell line generated was characterized and tested for pluripotency both in vitro and in vivo by teratoma formation and differentiation into defined lineages and brain organoids. Cell line reported here is shown to be mycoplasma free.

Differential expression of virulence genes and role of gyrA mutations in quinolone resistant and susceptible strains of Salmonella Weltevreden and Newport isolated from seafood

AIMS

To investigate the differential expression of virulence genes and role of gyrA mutations in quinolone resistant and susceptible strains of Salmonella isolated from seafood.

METHODS AND RESULTS

Forty Salmonella isolates from seafood were tested for antibiotic sensitivity. Minimal inhibitory concentration (MIC) was determined and two nalidixic acid-resistant isolates, viz Salmonella Weltevreden (SW9) and Salmonella Newport (SN36) were selected for identifying the mechanism of resistance. SW9 showed mutation in the gyrA gene at codon 83 (Ser to Tyr) while SN36 presented at codon 87 (Asp to Asn). Experimental induction of resistance to a sensitive Salm. Newport (SN71) showed point mutation at codon 87 (Asp to Gly) in the gyrA gene, and was designated SN71R. All the isolates resistant to nalidixic acid had a single mutation at different positions in the gyrA gene. However, induction of resistance to a sensitive Salm. Weltevreden (SW30) was exceptional in that it did not show any mutation in the gyrA region. Use of Phe-Arg-β-naphthylamide (PAβN) also could not reduce MIC below the Clinical and Laboratory Standards Institute guidelines revealing the absence of efflux mediated resistance. Thus, the resistance mechanism in SW30R is unknown. The growth rate of quinolone resistant isolates was slower than the susceptible ones. The resistant isolates showed decreased epithelial cell invasion and intracellular replication. The mRNA expression levels of some of the genes were significantly (P < 0·005) reduced in SN71R compared to the sensitive strain (SN71).

CONCLUSIONS

Nalidixic acid-resistant Salmonella strains are associated with lower virulence and pathogenicity than the sensitive strains.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provided valuable information on the difference in the growth, cytotoxicity, infectivity and expression of virulence genes in resistant and susceptible strains. Furthermore, the gyrA mutation was shown to be the main mechanism of quinolone resistance in Salmonella other than the overexpression of efflux pumps or the presence of plasmid mediated quinolone resistance genes.

Presence of T3SS2β genes in trh⁺ Vibrio parahaemolyticus isolated from seafood harvested along Mangalore coast, India

Vibrio parahaemolyticus is a seafood-borne pathogen autochthonous to the marine and estuarine ecosystem, responsible for gastroenteritis when contaminated raw seafood is consumed. The pathogenicity has been associated with thermostable direct haemolysin (TDH) and TDH-related haemolysin (TRH). Of late, the presence of T3SS2α and T3SS2β gene clusters has been well documented in clinical isolates of Vibrio parahaemolyticus and known to play an essential role in pathogenesis. However, reports on the presence of T3SSβ genes in V. parahaemolyticus isolated from the seafood and/or environmental samples are scanty. In this study, we have identified and analysed the distribution of the T3SS2β genes in V. parahaemolyticus isolated from seafood harvested along southwest coast of India. Results showed that T3SS2β genes are solely associated with trh⁺ and tdh⁺ /trh⁺ strains of V. parahaemolyticus. Reverse transcriptase PCR (RT-PCR) showed that the T3SS2β genes identified in trh⁺ V. parahaemolyticus were transcriptionally active. To our knowledge, this study appears to be the first description on the presence of T3SS2β-positive V. parahaemolyticus isolated from seafood in India. The study of T3SS2 along with other virulence factors will help in better understanding of the risk of seafood-borne illness due to V. parahaemolyticus.

SIGNIFICANCE AND IMPACT OF THE STUDY

T3SSs (α or β) are the important virulence factors of Vibrio parahaemolyticus that contribute to their pathogenicity in humans. This study demonstrated the presence of T3SS2β genes in V. parahaemolyticus isolated from the seafood harvested along Mangalore coast. RT-PCR showed that the T3SS2β genes identified in seafood isolates of V. parahaemolyticus were found to be functional. To the best of our knowledge, this is the first description of T3SS2β genes in trh⁺ V. parahaemolyticus isolated from seafood in India. The presence of T3SS2 along with other virulence factors such as TDH and/or TRH highlights a potential health risk for seafood consumers.

The Effect of Agmatine on Expression of IL-1β and TLX Which Promotes Neuronal Differentiation in Lipopolysaccharide-Treated Neural Progenitors

Differentiation of neural progenitor cells (NPCs) is important for protecting neural cells and brain tissue during inflammation. Interleukin-1 beta (IL-1β) is the most common pro- inflammatory cytokine in brain inflammation, and increased IL-1β levels can decrease the proliferation of NPCs. We aimed to investigate whether agmatine (Agm), a primary polyamine that protects neural cells, could trigger differentiation of NPCs by activating IL-1β in vitro. The cortex of ICR mouse embryos (E14) was dissociated to culture NPCs. NPCs were stimulated by lipopolysaccharide (LPS). After 6 days, protein expression of stem cell markers and differentiation signal factors was confirmed by using western blot analysis. Also, immunocytochemistry was used to confirm the cell fate. Agm treatment activated NPC differentiation significantly more than in the control group, which was evident by the increased expression of a neuronal marker, MAP2, in the LPS-induced, Agm-treated group. Differentiation of LPS-induced, Agm-treated NPCs was regulated by the MAPK pathway and is thought to be related to IL-1β activation and decreased expression of TLX, a transcription factor that regulates NPC differentiation. Our results reveal that Agm can promote NPC differentiation to neural stem cells by modulating IL-1β expression under inflammatory condition, and they suggest that Agm may be a novel therapeutic strategy for neuroinflammatory diseases.

Agmatine enhances neurogenesis by increasing ERK1/2 expression, and suppresses astrogenesis by decreasing BMP 2,4 and SMAD 1,5,8 expression in subventricular zone neural stem cells

AIM

Our study aimed to demonstrate whether agmatine (Ag) could regulate proliferation and cell fate determination of subventricular zone neural stem cells (SVZ NSCs).

MAIN METHODS

SVZ NSCs were grown in the presence of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) (20ng/ml) until 4days in vitro (DIV) and later the culture medium was replaced without EGF and bFGF until 11 DIV in the absence (EGF/bFGF(+/-)/Ag(-)) or presence of agmatine (EGF/bFGF(+/-)/Ag(+)). Another set SVZ NSCs were maintained with EGF and bFGF until 11 DIV without (EGF/bFGF(+/+)/Ag(-)) or with agmatine treatment (EGF/bFGF(+/+)/Ag(+)). Agmatine's effect on proliferation and cell death (H and PI staining and Caspase-3 immunostaining) was examined at DIV 4 and 11. Agmatine's (100μM) effect on cell fate determination was confirmed by immunostaining and Western blot at 11 DIV.

KEY FINDINGS

Agmatine treatment reduced the neurosphere size and total cell count number dose-dependently in all the experimental groups both at DIV 4 and11. Immunoblotting and staining results showed that agmatine increased the Tuj1 and Microtubule-associated protein 2 (MAP2) and decreased the Glial fibrillary acidic protein (GFAP) with no change in the Oligo2 protein expressions. This neurogenesis effect of agmatine seems to have a relation with Extracellular-signal-regulated kinases (ERK1/2) activation and anti-astrogenesis effect is thought to be related with the suppression of Bone morphogenetic proteins (BMP) 2,4 and contraction of Sma and Mad (SMAD) 1,5,8 protein expression.

SIGNIFICANCE

This model could be an invaluable tool to study whether agmatine treated SVZ NSC transplantation to the central nervous system (CNS) injury could trigger neurogenesis and decrypt the full range of molecular events involved during neurogenesis in vivo as evidenced in vitro.

Psychological Correlates of Outcome after Coronary Artery Bypass Graft

BACKGROUND

Psychological effects of Coronary Artery Bypass graft (CABG) have been of interest all over the world but there is a paucity of Indian work.

METHODS

30 patients undergoing CABG at a service hospital were included. All patients filled a specially designed proforma. Mini Mental Status Examination, Hospital anxiety and depression scale, Coronary scale, Seattle angina questionnaire and Euro-QOL 5D were performed before and seven days after CABG.

RESULTS

43.3% had significant anxiety and 30% had significant depression before CABG. Following CABG, 36.67% of the patients had significant anxiety while 40% had significant depression. On the Seattle angina questionnaire, physical limitation reduced from 71.6 ± 7.9 to 53.1 ± 14.6. There was significant improvement in treatment satisfaction from 37.8 ± 6.1 to 59.4 ± 4.2 following CABG. On th euro quality of life scale (EQ5D) health status improved from 38.17 ± 9.51 before CABG to 68.5 ± 5.28 after CABG.

CONCLUSION

There is a significant incidence of anxiety and depression in patients undergoing CABG, both before and after surgery.

In vitro effect of lead on Na+, K+-ATPase activity in different regions of adult rat brain

Lead interferes with cellular energy metabolism by inhibiting ATP (Adenosine triphosphate) synthesis and hydrolysis. This study was conducted to determine in vitro effects of lead on Na+, K+-ATPase activity in four regions of adult rat brain: the cerebellum, the hippocampus, the frontal cortex and the brain stem. Male rats (Wistar strain) weighing 125-150 g were sacrificed, whole brain excised and the four regions were isolated. Each tissue was homogenized separately in sucrose (0.25 M) and imidazole (10 mM) buffer (pH 7.5) and P2 fraction was prepared by following established methods. The activity of ATPase was determined by measuring inorganic phosphate (Pi) liberated from ATP hydrolysis. The delineation of Na+, K+-activated component of ATPase was obtained by the difference between total ATPase and Mg2+-ATPase using 1 mM ouabain. The P2 fraction was incubated with 0, 5, 10, 25, 50 and 100 microM of lead at 37 degrees C for 10 min. The enzyme activity was expressed as micromoles of Pi liberated/mg protein/hr. The results indicated a concentration-dependent and region-specific response to lead. In vitro lead at 50 and 100 microM significantly inhibited ATPase activity in all regions of the brain. It was also observed that in the control rats, the enzyme activity was high in cerebellum and hippocampus regions of the brain. In vitro dithiothreitol (DTT) protected the enzyme activity from IC50 lead in four regions of brain. In cerebellum and hippocampus, a 5 microM DTT provided 100% protection against IC50 lead. These results suggest that lead interferes with the ion transport mechanism and cellular energy metabolism of the brain and this effect is region specific.

Modelling epidemiology of leprosy

A simulation model for leprosy transmission and control has been developed with specific objectives. Several sensitivity experiments have been carried out by altering the various inputs based on empirical data combined with intelligent guessing. The outputs generated through these exercises were on the expected lines. While incremental exercises would improve the model, it can be used even at the existing stage as a tool for programme managers.

Stochastic compartmental models with Prendville growth mechanisms

We consider a stochastic compartmental model in which cells reproduce in accordance with a regulated birth and death process. We find expressions for the mean vector and covariance matrix for the number of cells in these compartments. We obtain the asymptotic behavior of the mean vector in the general case and explicit expressions for two compartmental and mammillary systems.

Efficacy and limitations of QBC acridine orange staining as a routine diagnostic technique for malaria in developing countries

The recently developed QBC technique has been reported to be rapid, sensitive and specific for the detection of malaria infection. We evaluated this technique in comparison with thin and thick Giemsa stained blood films for the diagnosis of malaria in acute fever and PUO cases. The technique was slightly more sensitive than thin blood film but equal to thick blood film examination. Identification of species of malaria posed some difficulties. Due to its high cost and requirement for a fluorescent microscope this technique, in spite of its speed and sensitivity, may not have the potential to be a substitute for the conventional blood film examination for the diagnosis of malaria, especially in developing countries.