Structure-based assortment of herbal analogues against spike protein to restrict COVID-19 entry through hACE2 receptor : an in-silico approach

On-going global pandemic COVID-19 has spread all over the world and has led to more than 1.97 million deaths till date. Natural compounds may be useful to protecting health in this perilous condition. Mechanism of shuttle entry of SARS-COV-2 virus is by interaction with viral spike protein with human angiotensin-converting enzyme-2 (ACE-2) receptor. To explore potential natural therapeutics, 213 important phytochemi-cals of nine medicinal plants Aconitum heterophyllum, Cassia angustifolia, Cymbopogon flexuosus, Cymbopogon martinii, Nux vomica, Phyllanthus urinaria, Swertia chirayita, Justicia adhatoda, Vetiveria zizanioides were selected for in-silico molecular docking against the spike protein of SARS-COV-2 and compared with recently prescribed drug chloroquine, ramdesivir, lopinavir and hydroxychloroquine. Results revealed that rhamnocitrin of P. urinaria, 1,5-dihydroxy-3,8-dimethoxyxanthone of S. chirayita and laevojunenol of V. zizanioides potentially binds with the receptor binding site of SARS-COV-2 spike glycoprotein and more robustly destabilized the RBD-ACE-2 binding over chloroquine, ramdesivir, lopinavir and hydroxychloroquine. It was also found that laevojunenol, rhamnocitrin, and 1,5-dihydroxy-3,8-dimethoxyxanthone qualified the criteria for drug-likeness as per Lipinski rule. After attachment of the selected phytochemical with the spike protein the affinity of the later towards ACE-2 was minimized and the effect of 1,5-dihydroxy-3,8-dimethoxyxanthone and laevojunenol was superior. Hence, rhamnocitrin of P. urinaria, 1,5-dihydroxy-3,8-dimethoxyxanthone of S. chirayita and laevojunenol of V. zizanioides, are potential therapeutic molecules for SARS-COV-2, which upon binding with spike protein changes the affinity of the spike towards ACE-2 and therefore restrict the entry of the virus into a human cell. Subsequent clinical validation is needed to confirm these phytochemicals as drugs to combat COVID-19

Evaluation of some effective potentialities of newly formulated rice fermented food using Elephantopus scaber L. rhizome as herbal starter

Traditionally, fermented food and beverages are prepared by adding a mixture of plant residues as a starter or source of microbes. Most of the conventional fermented foods use a local starter which contains a mixture of herbs or old ferment or otherwise cereal dust-coated tablet. In this study, we have made an attempt to prepare a rice-based fermented food with the herbal starter (0.5% w/w) of Elephantopus scaber L. rhizome, and also examined its microbial and nutrient profiles. The food product is fortified with organic acid and titratable acidity of 0.58% and also contained an excellent source of microbes (LAB and Bifidobacterium sp.). The fermented food contains significant amount of fat, protein, minerals, vitamins, oligosaccharide, unsaturated fatty acids (ω3, ω6, ω7 and ω9) and a pool of free amino acids. The presence of phytochemical contents in the fermented rice was also exhibited significant effects against commercially available free radicals (DPPH, ABTS, FRAP and OH-radicals). Thus, food-grade microbes containing newly formulated fermented food would provide essential macro-and micro-nutrients to the individuals and convey the sustainability of good health. Therefore, the mentioned plant part would be used as an effective starter for aiding rice-based food products

Ethnic Preparation of Haria, a Rice-Based Fermented Beverage, in the Province of Lateritic West Bengal, India

Haria is a rice-based fermented beverage that is popular among tribal and low income people in lateritic West Bengal and East-Central India. The principal ingredient of this beverage is low grade boiled rice (Oryza sativa L.), which is mixed with a traditional starter, called bakhar, and fermented within a heat-sterilized earthen pot for 3-4 days. The main aim of this study was to investigate the ethnobotanical importance and traditional process of haria preparation. The method adopted for this study was based on interactive questionnaires and laboratory experiments. It was found that the pH decreased during the course of fermentation with increased titratable acidity of 1.42%. The alcohol content was 2-3% (v/v) in the consumable beverages. This documentation will be useful for further exploitation of haria as a health drink

Overexpressed PKCδ downregulates the expression of PKCα in B16F10 melanoma: induction of apoptosis by PKCδ via ceramide generation.

In the present study, we observed a marked variation in the expression of PKCα and PKCδ isotypes in B16F10 melanoma tumor cells compared to the normal melanocytes. Interestingly, the tumor instructed expression or genetically manipulated overexpression of PKCα isotype resulted in enhanced G1 to S transition. This in turn promoted cellular proliferation by activating PLD1 expression and subsequent AKT phosphorylation, which eventually resulted in suppressed ceramide generation and apoptosis. On the other hand, B16F10 melanoma tumors preferentially blocked the expression of PKCδ isotype, which otherwise could exhibit antagonistic effects on PKCα-PLD1-AKT signaling and rendered B16F10 cells more sensitive to apoptosis via generating ceramide and subsequently triggering caspase pathway. Hence our data suggested a reciprocal PKC signaling operational in B16F10 melanoma cells, which regulates ceramide generation and provide important clues to target melanoma cancer by manipulating the PKCδ-ceramide axis

<span style="font-size:15.0pt;mso-bidi-font-size: 14.0pt" lang="EN-GB">Low cost single-step purification of endoglucanase from <i style="mso-bidi-font-style:normal">Aspergillus fumigatus </i>ABK-9 </span>

954-959<span style="font-size: 9.0pt;mso-bidi-font-size:11.0pt" lang="EN-GB">Low cost agro-waste was used as adsorption support for single-step purification of endoglucanase from the culture filtrate of A. fumigatus ABK-9. Among various agro-waste substrates, 1% NaOH pretreated rice bran was proved to be the best for adsorbing about 74.8 and 71.1% of endoglucanase at 4 °C and 10 °C respectively. Langmuir type adsorption isotherm at 4 °C showed maximum adsorption of enzyme at pH 5.0, which was in the range of optimum pH of the enzyme. The rice bran column bound enzyme was maximally eluted by a mixture of acetate buffer (0.05 M, pH 5.5) and ethanol (40%, v/v) at a ratio of 3:2 and a flow rate of 1 mL/min. A 5.52-fold purification of the enzyme was achieved from culture supernatant. The specific activity and recovery yield after purification were <span style="mso-bidi-font-weight: bold">294.0 U/mg and 40.15%, respectively, which were comparable with other contemporary protocols. The homogeneity of the enzyme was tested through sodium dodecyl sulphate polyacrylamide gel electrophoresis and a single band of 56.3 kDa was observed. Zymogram analysis finally confirmed the occurrence of endoglucanase in the single band. </span

Differential expression of various PKC isotypes in B16F10 melanoma tumor.

<p>(A) Cell lysates from primary melanocytes and B16F10 melanoma cells were subjected to western blot analysis with anti PKCα, PKCβ, PKCδ, PKCθ, PKCε and PKCζ specific antibodies. GAPDH was used as a reference. Representative figure and bar diagram of densitometric analysis from three independent experiments are presented. (B) 2×10⁶ primary melanocytes and B16F10 melanoma cells were separately collected in Trizol for mRNA extraction and semi quantitative RT-PCR analyses for PKCα, PKCβ, PKCδ, PKCθ, PKCε and PKCζ were done. Representative figure and bar diagram of densitometric analysis of target gene with respect to GAPDH was presented. (C) 2×10⁶ B16F10 melanoma cells were treated with PMA (100 nM) for 1 hr. Expression of PKCα and PKCδ along with GAPDH in cytosolic and membrane protein fraction was analyzed by Western blot. Representative data from three independent experiments was given. (D) Cell lysates of B16F10 cells transfected with empty vector (EV), overexpressed full-length mouse PKCα (PKCαOV) or PKCδ (PKCδOV) isotypes as mentioned in materials and methods were subjected to SDS PAGE and western blot analysis to check the respective expression of PKCα, PKCβ, PKCδ, PKCε, PKCθ and PKCζ isotypes. Representative figure from three independent experiments and bar diagram of densitometric analysis was depicted. GAPDH was used as a reference.</p