Lipoxygenase inhibitory synthetic derivatives of methyl gallate regulate gene expressions of COX-2 and cytokines to reduce animal model arthritis

Mammalian lipoxygenases (LOXs) are involved in the biosynthesis of mediators of anaphylactic reactions and have been implicated in cell maturation, the pathogenesis of bronchial asthma, atherosclerosis, rheumatoid arthritis, cardiovascular diseases, Alzheimer's disease and osteoporosis. Hence LOX inhibition in chronic conditions can lead to reducing the disease progression, which can be a good target for treating these diseases. The present study deals with designing methyl gallate derivatives and their anti-inflammatory effect by in silico, in vitro and in vivo methods. Designed derivatives were docked against LOX enzyme, and molecular dynamic simulations were carried out. Following the synthesis of derivatives, in vitro LOX inhibition assay, enzyme kinetics and fluorescence quenching studies were performed. One of the derivatives of methyl gallate (MGSD 1) was demonstrated as an anti-inflammatory agent for the treatment of rheumatoid arthritis in the animal model. Amelioration of Freund's complete adjuvant (FCA)-induced arthritis by methyl gallate and its derivative with a concentration of 10-40 mg.kg-1 has been assessed in vivo in a 28-day-long study. TNF-α and COX-2 gene expression were also studied. Methyl gallate synthetic derivatives (MGSDs) inhibited LOX with an IC50 of 100 nM, 304 nM, and 226 nM for MGSD 1, MGSD 2, and MGSD 3, respectively. Fluorescence quenching methods also prove their binding characteristics, and 200 ns simulations studies showed that the RMSDs for the entire complex were less than 2.8 Å. The in vivo results showed that methyl gallate was required approximately five times diclofenac for the same level of effect, and the synthesised (MGSD 1) compound required only approximately 1/12 of diclofenac for the same level of effect in in-vivo studies. The preeminent expression of COX-2 and TNF-α genes was significantly decreased after the treatment of the methyl gallate derivative. Hence, the in vivo results showed that the referenced synthetic derivative might have more arthritis-reducing properties than the parent compound methyl gallate and is more potent than the standard drug diclofenac, with no apparent induced toxicity.

Long term survival of antenatally diagnosed functionally single ventricle congenital heart disease

Funding Acknowledgements

Type of funding sources: None.

Background

Antenatal diagnosis of single ventricle congenital heart disease (CHD) allows prenatal counselling, better parental preparation and support as well as improved perinatal management. Expectant parents frequently ask about likely outcomes and expected longer term survival. Our aim is to review the survival of antenatally diagnosed single ventricle CHD presenting at our institutions between January 2000 and July 2022.

Methods

Retrospective data was collected from the fetal cardiac and paediatric cardiology databases. Maternal data, fetal cardiac diagnosis, postnatal cardiac diagnosis and management were collected for each patient. The outcomes were separated into 2 groups – Cohort 1 (CO1) [2000 to 2007] and Cohort 2 (CO2) [2008 to 2022].

Results

A total of 495 fetuses were diagnosed with single ventricle CHD in the 21 years and 7 months period, with outcomes illustrated in Table 1.

For the small LV group with intention to treat at birth, there was 46% survival at over 10 years for the CO1 group and 69% survival at over 10 years for CO2 group. There was however no significant difference in the survival between the CO1 and CO2 groups (log rank test p=0.12).

For the small RV group with intention to treat at birth, there was 71% survival at over 10 years for the CO1 group and 91% survival at over 10 years for CO2 group. There was significant difference in the survival between the CO1 and CO2 groups (log rank test p=0.03).

No analysis was made for the unspecified hypoplasia as the numbers were too small.

Conclusions

For both the antenatal small LV and small RV groups, the termination rate and compassionate care option remained unchanged between both cohorts.

Overall, there has been improvement in the survival for the antenatal small LV and RV groups with intention to treat. This is likely due to improved perinatal management with detailed management plan and designated delivery at tertiary neonatal hospital close to the cardiac surgical centre, improved surgical expertise and experience, improved cardiac intensive care management as well as availability of ECMO for the sicker patients.

In the antenatal small LV groups, although there has been improvement in survival, this is not yet statistically significant due to more complex patients with more co-morbidity being accepted for surgery.

Whereas for the antenatal small RV groups, we see statistically significant improvement with survival reaching 90% at 10 years, due to increased use of non-surgical intervention like ductal stenting over conventional BT shunts which carry higher morbidity and mortality risk.

Our survival outcomes are comparable with other published data across the world.

Potent phytochemicals against COVID-19 infection from phyto-materials used as antivirals in complementary medicines: a review

Background

Following the outbreak of the COVID-19 pandemic, there was a surge of research activity to find methods/drugs to treat it. There has been drug-repurposing research focusing on traditional medicines. Concomitantly, many researchers tried to find in silico evidence for traditional medicines. There is a great increase in article publication to commensurate the new-found research interests. This situation inspired the authors to have a comprehensive understanding of the multitude of publications related to the COVID-19 pandemic with a wish to get promising drug leads.

Main body

This review article has been conceived and made as a hybrid of the review of the selected papers advertised recently and produced in the interest of the COVID-19 situation, and in silico work done by the authors. The outcome of the present review underscores a recommendation for thorough MDS analyses of the promising drug leads. The inclusion of in silico work as an addition to the review was motivated by a recently published article of Toelzer and colleagues. The in silico investigation of free fatty acids is novel to the field and it buttresses the further MDS analysis of drug leads for managing the COVID-19 pandemic.

Conclusion

The review performed threw light on the need for MDS analyses to be considered together with the application of other in silico methods of prediction of pharmacologic properties directing towards the sites of drug-receptor regulation. Also, the present analysis would help formulate new recipes for complementary medicines.

Process development for the enhanced production of bio-nematicide Purpureocillium lilacinum KU8 under solid-state fermentation

Response surface methodology (RSM) was used to optimize the process parameters for maximizing the biomass production of Purpureocillium lilacinum KU8 using wheat bran as substrate under solid-state fermentation (SSF). The experiments of one-factor-at-a-time approach (OFAT) for central composite design (CCD) to analyze the response pattern brought out the parameters for maximum biomass production. Moisture content, yeast extract and incubation time were found to be the three significant, independent variables responsible for maximum biomass production. The biomass production was 107.46 mg/gdfs which was 1.35 times higher than that of OFAT method and 3.01 times higher than the randomly selected conditions. The optimum conditions established by RSM method for the maximum biomass production are 67.98%, 2.29% and 142.2 h respectively for moisture content, yeast extract and incubation time. The biomass thus produced had quantitatively comparable results in bio-nematicide effectiveness.

Hesperetin and Naringenin sensitize HER2 positive cancer cells to death by serving as HER2 Tyrosine Kinase inhibitors

AIM

Aberrant human epidermal growth factor receptor-2 (HER2) expression and constitutive mutant activation of its tyrosine kinase domain account for tumor aggression and therapy resistance in many types of cancers with major share in breast cancer cases. HER2 specific treatment modalities still face challenges owing to the side effects and acquired resistance of available therapeutics. Recently, the anti-proliferative and pro-apoptotic potential of phytochemicals, especially of flavonoids have become increasingly appreciated as powerful chemo preventive agents. Consequently, the major goal of our study is to identify flavonoids capable of inhibiting HER2 Tyrosine Kinase (HER2-TK) activity and validate their anti-tumor activity against HER2 positive tumors.

MAIN METHODS

Molecular docking studies for identifying flavonoids binding at HER2 kinase domain, ADP-Glo™ Kinase Assay for determining kinase activity, MTT assay to measure growth inhibition, various apoptotic assays and cell cycle analysis by FACS were performed.

KEY FINDINGS

Among the flavonoids screened, Naringenin (NG) and Hesperetin (HP) possessed high glide scores from molecular docking studies of enzyme-inhibitor mode. The interaction analysis revealed their ability to establish stable and strong interaction at the ATP binding site of HER2-TK. These compounds also inhibited in vitro HER2-TK activity suggesting their role as HER2 inhibitors. The study also unraveled the anti-proliferative, pro-apoptotic and anti-cancerous activity of these flavonoids against HER2 positive breast cancer cell line.

SIGNIFICANCE

The study identified two citrus fruit flavonoids, NG and HP as HER2-TK inhibitors and this is the first report on their potential to target preferentially and sensitize HER2 positive cancer cells to cell death.

Cuminaldehyde as a lipoxygenase inhibitor: in vitro and in silico validation

The search for lipoxygenase (LOX) inhibitors has been carried out for decades due to its importance in inflammatory diseases. In the present study, it was observed that the methanolic extract of Cuminum cyminum L. inhibited LOX activity. Activity-guided screening of the C. cyminum crude extracts helped the identification and isolation of cuminaldehyde as a 15-LOX inhibitor. The enzyme kinetics analysis suggested cuminaldehyde to be a competitive inhibitor and the IC 50 value derived from LB plots is 1,370 μM. Binding constants of cuminaldehyde on LOX was deduced by isothermal titration calorimetry. The combined thermodynamics and molecular modeling analyses suggested cuminaldehyde as a competitive LOX inhibitor. It is proposed from the present study that the coordinate bond between the Fe(2+) atom in the active site of the enzyme and the cuminaldehyde may be responsible for the enzyme inhibition. The study suggests that cuminaldehyde may be acting as an anti-inflammatory compound and may be therefore included in the category of leads for developing dual COX-LOX inhibitors as non-steroidal anti-inflammatory drugs (NSAIDs).

Tamarind seed powder and palm kernel cake: two novel agro residues for the production of tannase under solid state fermentation by Aspergillus niger ATCC 16620

Palm kernel cake (PKC), the residue obtained after extraction of palm oil from oil palm seeds and tamarind seed powder (TSP) obtained after removing the fruit pulp from tamarind fruit pod were tested for the production of tannase under solid-state fermentation (SSF) using Aspergillus niger ATCC 16620. The fungal strain was grown on the substrates without any pretreatment. In PKC medium, a maximum enzyme yield of 13.03 IU/g dry substrate (gds) was obtained when SSF was carried out at 30 degrees C, 53.5% initial substrate moisture, 33 x 10(9) spores/5 g substrate inoculum size and 5% tannic acid as additional carbon source after 96 h of fermentation. In TSP medium, maximum tannase yield of 6.44 IU/gds was obtained at 30 degrees C, 65.75% initial substrate moisture, 11 x 10(9) spores/5 g substrate inoculum, 1% glycerol as additional carbon source and 1% potassium nitrate as additional nitrogen source after 120 h of fermentation. Results from the study are promising for the economic utilization and value addition of these important agro residues, which are abundantly available in many tropical and subtropical countries.

Synthesis of alpha-amylase by Aspergillus oryzae in solid-state fermentation

Spent Brewing Grains (SBG) was evaluated for its efficacy to be used as sole carbon source for the synthesis of alpha-amylase in solid-state fermentation using a fungal strain of Aspergillus oryzae NRRL 6270. Enzyme production was superior when the culture grew on mesophilic temperatures and best yields were at 25 degrees C. At 30 degrees C, yields were almost comparable. Maximum production of alpha-amylase [6870 U/g dry substrate (gds)] was obtained when SSF was carried out at 30 degrees C for 96 h using SBG medium, which had initial moisture of 70% and was inoculated using a spore suspension containing 1 x 10(7) spores/ml. Supplementation of SBG with external carbon sources such as mono-, di and polysaccharides caused repression in enzyme synthesis by the fungal culture.

Microbial production of extra-cellular phytase using polystyrene as inert solid support

Aspergillus ficuum TUB F-1165 and Rhizopus oligosporus TUB F-1166 produced extra-cellular phytase during solid-state fermentation (SSF) using polystyrene as inert support. Maximal enzyme production (10.07 U/g dry substrate (U/gds) for A. ficuum and 4.52 U/gds for R. oligosporus) was observed when SSF was carried out with substrate pH 6.0 and moisture 58.3%, incubation temperature 30 degrees C, inoculum size of 1.3 x 10(7) spores/5 g substrate, for 72 h for A. ficuum and with substrate pH 7.0 and moisture 58.3%, incubation temperature 30 degrees C, inoculum size of 1 x 10(6) spores/5 g substrate for 96 h for R. oligosporus. Results indicated scope for production of phytase using polystyrene as inert support.