Phytochemical composition, and antioxidant potential of Frerea indica Dalz.: A critically endangered, endemic and monotypic genus of the Western Ghats of India

Caralluma pauciflorabased Ag-NPs activate ROS - induced apoptosis through down-regulation of AKT, mTOR and pI3K signaling in human gastric cancer (AGS) cells

The phytochemicals found inCaralluma pauciflorawere studied for their ability to reduce silver nitrate in order to synthesise silver nanoparticles (AgNPs) and characterise their size and crystal structure. Thunbergol, 1,1,6-trimethyl-3-methylene-2-(3,6,9,13-tetram, Methyl nonadecanoate, Methyl cis-13,16-Docosadienate, and (1R,4aR,5S)-5-[(E)-5-Hydroxy-3-methylpent were the major compounds identified in the methanol extract by gas chromatography-mass spectrum analysis. UV/Vis spectra, Fourier-transform infrared spectroscopy, x-ray diffraction, scanning electron microscope with Energy Dispersive Xâray Analysis (EDAX), Dynamic Light Scattering (DLS) particle size analyser and atomic force microscope (AfM) were used to characterise theCaralluma paucifloraplant extract-based AgNPs. The crystal structure and estimated size of the AgNPs ranged from 20.2 to 43 nm, according to the characterization data. The anti-cancer activity of silver nanoparticles (AgNPs) synthesised fromCaralluma paucifloraextract. The AgNPs inhibited more than 60% of the AGS cell lines and had an IC50 value of 10.9640.318 g, according to the findings. The cells were further examined using fluorescence microscopy, which revealed that the AgNPs triggered apoptosis in the cells. Furthermore, the researchers looked at the levels of reactive oxygen species (ROS) in cells treated with AgNPs and discovered that the existence of ROS was indicated by green fluorescence. Finally, apoptotic gene mRNA expression analysis revealed that three target proteins (AKT, mTOR, and pI3K) were downregulated following AgNP therapy. Overall, the findings imply that AgNPs synthesised from Caralluma pauciflora extract could be used to treat human gastric cancer.

Conservation linkages of endangered medicinal plant and exploration of phytochemicals, pharmaceutical screening and in silico validation against diabetics using in vivo wild and in vitro regenerated plant Boucerosia diffusa Wight

Boucerosia diffusa Wight. is an important endangered medicinal plant belonging to the family Asclepiadaceae. In this study, an efficient protocol has been developed for B. diffusa using nodal explants for callus induction and direct organogenesis. The optimal callus induction (83.7%) was observed on 0.6 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) in Murashige and Skoog medium. The shoot regeneration was observed on different concentrations and combinations of 6-benzylaminopurine (BAP) and 2,4-D using shoot induction (88.5%) was observed on 0.5 mg/L BAP and 0.6 mg/L 2,4-D. Maximum root induction frequency (85.6%) was obtained on 0.6 mg/L α-naphthalene-acetic acid (NAA) and 0.5 mg/L BAP. The fully developed plants were acclimatized (98.86% survival rate) and transferred to natural photoperiod conditions. The phytochemical and pharmacological activity was determined in in vitro-regenerated plants (IRP) and was compared to in vivo wild plants (IWP). The primary and the secondary metabolite contents of bioactive compounds were significantly higher in the methanolic extract of IRP. A comparative antioxidant activity study shows IRP exhibited better scavenging activity. The antidiabetic activity of α- amylase (IC50 - 71.56 ± 15.4 µg/mL) and α-glucosidase (IC50 - 82.94 ± 12.84 µg/mL) inhibitor activity also exhibited maximum in methanolic extract of IRP. Furthermore, chemical composition was analyzed using gas chromatography-mass spectroscopy (GC-MS). Antibacterial activity against human pathogenic bacteria, IRP methanolic extracts showed a maximum zone of inhibition (75 µg/mL) observed against Salmonella typhi (23.5 ± 0.5 mm) compared to the IWP. Molecular docking analysis of B. diffusa inhibition of antidiabetic activity showed better affinity in β-Sitosterol.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03645-5.

Bioprospection and secondary metabolites profiling of marine Streptomyces levis strain KS46

The quest for novel broad spectrum bioactive compounds is needed continuously because of the rapid advent of pathogenic multi drug resistant organisms. Actinomycetes, isolated from unexplored habitats can be a solution of this problem. The motive of this research work was isolation of actinomycetes having potential antimicrobial activities from unexplored regions of Devbag and Tilmati beach. The isolated actinomycetes were screened against pathogenic microbes for antimicrobial activities through cross streak method. Enzyme production activity was checked for these actinomycetes for amylase, protease, cellulase and lipase enzymes. Further antimicrobial activity of ethyl acetate extract of the potent strain KS46 was performed. The strain KS46 was identified with 16S rRNA gene sequencing and secondary structure was analysed. Gas chromatography–Mass spectrometry (GC–MS) profiling was conducted to ascertain the presence of bioactive metabolites in the ethyl acetate extract. The collected samples were pre-treated and 70 actinomycetes were isolated. The Streptomyces sp. strain KS46 showed the best antimicrobial activity in primary screening. Ethyl acetate extract of the strain KS46 revealed antimicrobial activity against S. aureus, B. subtilis, B. cereus, E. faecalis, K. pneumoniae, E. coli, S. flexneri, C. albicans and C. glabrata. The 16S rRNA gene sequencing identified the strain KS46 as Streptomyces levis strain KS46. The GC–MS metabolite profiling of the ethyl acetate extract revealed the availability of 42 compounds including fatty acid esters, fatty acid anhydrides, alkanes, steroids, esters, alcohols, carboxylic ester, etc. having antibacterial, antifungal, antiproliferative, antioxidant activities. This study indicated that Devbag and Tilmati beaches being untapped habitats have enormous diversity of promising antimicrobial metabolite producing actinomycetes. Therefore, further exploration should be carried out to characterize the potential actinomycetes, which can be optimistic candidates for generation of novel antimicrobial drugs.