Abiotic stresses, including drought and heavy metals, are detrimental to plant growth and development and enormously reduce agricultural yields. Plants may quickly change their transcriptome in response to various stressful conditions. Plants develop many defense mechanisms to respond to various stresses that can be classified into morphological, physiological, and biochemical responses. Polyphenol oxidases (PPOs) are one of the self-protective enzymes found in plants except for Arabidopsis. Currently, drought and heavy metals were applied exogenously to transgenic A. thaliana lines (transformed with Oryza sativa PPO promoter fused to the GUS reporter gene). The current study mainly focused on the systematic pathway by which plants respond to stressors. The aim of this study is to investigate the effect/expression of PPO and antioxidant defense system against abiotic stresses. A. thaliana was treated with different concentrations of polyethylene glycols. At 30% PEG, maximum fold induction (1.9) was seen after 12 h. Overall, various concentrations (5%, 20%, and 30%) induced PPO expression after 6, 12, and 24 h. Moreover, three different concentrations of Cu (50 µM, 100 µM, 200 µM) and Ni (50 µM, 100 µM, 200 µM) for 6, 12, and 24 h were also applied. It was observed that the expression profiling of the OsPPO promoter induced GUS gene expression in response to Cu and Ni treatments. The maximum fold induction (15.03) of GUS was observed in 100 µM of Cu after 24 h. In the case of Ni, maximum fold induction of (7.78) was observed at 100 µM after 24 h. So, both Cu and Ni showed a similar pattern of induction at 100 µM after 24 h. In conclusion, the efficiency of the PPOGUS promoter can be operated to assess the response of plants to various abiotic stimuli.

The current study attempts to evaluate the formation, morphology, and physico-chemical properties of zinc oxide nanoparticles (ZnO NPs) synthesized from Clinopodium vulgare extract at different pH values and to investigate their antimicrobial and biomedical application potential. The reduction of zinc ions to ZnO NPs was determined by UV spectra, which revealed absorption peaks at 390 nm at pH 5 and 348 nm at pH 9, respectively. The spherical morphology of the nanoparticles was observed using scanning electron microscopy (SEM), and the size was 47 nm for pH 5 and 45 nm for pH 9. Fourier-transformed infrared spectroscopy (FTIR) was used to reveal the presence of functional groups on the surface of nanoparticles. The antibacterial activity was examined against Staphylococcus aureus, Streptococcus pyogenes, and Klebsiella pneumonia via the agar-well diffusion method. Comparatively, the highest activities were recorded at pH 9 against all bacterial strains, and among these, biogenic ZnO NPs displayed the maximum inhibition zone (i.e., 20.88 ± 0.79 mm) against S. aureus. ZnO NPs prepared at pH 9 exhibited the highest antifungal activity of 80% at 25 mg/mL and antileishmanial activity of 82% at 400 mg/mL. Altogether, ZnO NPs synthesized at pH 9 show promising antimicrobial potential and could be used for biomedical applications.

Background. Different parts of Taraxacum officinale (L.) were used in traditional medicine in various parts of the world for the treatment of health problems, and they possess significant biological activities. The present study aimed to estimate phytochemical and biological activities of T. officinale using different extraction solvents. Methods. Methanolic, acetone, and n-hexane extracts of selected species were prepared, and ten secondary metabolites were examined using standard protocols. The antioxidant activity was performed using three in vitro methods, namely, DPPH assay, total reducing power (TRP) assay, and total antioxidant capacity (TAC). Toxicological analysis was done using the brine shrimp cytotoxic assay and radish seed phytotoxic assay. Results. The T. officinale methanolic extract showed the highest phenolic (178.27±17.17mg/GAE/g) and flavonoid (18.50±1.64mg QE/g) contents. Similarly, the methanolic extract also revealed the highest DPPH activity (32.80±9.66 IC₅₀), reducing potential (0.53±0.02mg/g), and TAC (19.42±0.97mg/g) as compared to the acetone and n-hexane extracts. The Pearson correlation analysis confirmed a strong positive correlation (r>0.9) between total phenolic content (TPC), total flavonoid content (TFC), and all antioxidant assays. Furthermore, a heat map displayed the methanolic extract (red color) as a valuable source of phytochemicals and antioxidant agents. Moreover, the T. officinale methanolic extract also showed the highest (7.12ppm) cytotoxic potential whereas both methanolic and acetone extracts were revealed as moderate phytotoxic agents when compared with the standard. Conclusion. The T. officinale methanolic extract exhibited comparatively notable phytochemicals that are actively involved in antioxidant activities and possess toxicological properties. This upholds the folkloric use of T. officinale as a possible source to develop natural plant-based drugs. Further investigations to isolate bioactive compounds and elements and on their safety need to be conducted.

Present study established the biological potential of Schweinfurthia papilionacea, Tricholepis glaberrima and Viola stocksii extracts for their potential applications in drug formulations. Initially, FTIR was performed to ascertain functional groups and then plant extracts were prepared using five solvents depending on the polarity. Total phenolic contents were observed in the range of 36.36 ± 1.08 mg GAE/g to 95.55 ± 2.46 mg GAE/g while flavonoid contents were found in the range of 10.51 ± 0.25 mg QE/g to 22.17 ± 1.79 mg QE/g. Antioxidant activity was determined using TRP, CUPRAC, TAC and DPPH assays and was recorded highest in S. papilionacea followed by T. glaberrima extracts. TPC and TFC were found to be strongly correlated with TRP (r > 0.50), CUPRAC (r > 0.53) and DPPH (r = 0.31 and 0.72) assay while weakly correlated with TAC (r = 0.08 and 0.03) as determined by Pearson correlation analysis. Anticancer activity showed that S. papilionacea chloroform extracts possess highest cell viability (85.04 ± 4.24%) against HepG2 cell lines while T. glaberrima chloroform extracts exhibited highest activity (82.80 ± 2.68%) against HT144 cell lines. Afterwards, highest PXR activation was observed in T. glaberrima (3.49 ± 0.34 μg/mL fold) at 60 μg/mL and was correlated with increase in CYP₃A₄ activity (15.0 ± 3.00 μg/mL IC₅₀ value). Furthermore, antimalarial activity revealed >47600 IC₅₀ value against P. falciparum D6 and P. falciparum W2 and antimicrobial assay indicated highest activity (32 ± 2.80 mm) in S. papilionacea against C. neoformans. At the end, GC‐MS analysis of n‐hexane plant extracts showed 99.104% of total identified compounds in T. glaberrima and 94.31% in V. stocksii. In conclusion, present study provides insight about the different biological potentials of S. papilionacea and T. glaberrima extracts that rationalize the applications of these extracts in functional foods and herbal drugs for the management of oxidative‐stress related diseases, antimicrobial infections and liver and skin cancer.

The Fabaceae is renowned for its diverse range of chemical compounds with significant biological activities, making it a valuable subject for pharmacological studies. The chemical composition and biological activities of three Fabaceae species were investigated using methanol separately and in combination with dimethyl sulfoxide (DMSO) and glycerol for extraction. The results revealed the highest phenolic (49.59 ± 0.38 mg gallic acid equivalent/g), flavonoid (29.16 ± 0.39 mg rutin equivalent/g), and alkaloid (14.23 ± 0.54 mg atropine equivalent/g) contents in the Caesalpinia decapetala methanol extracts. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and DNA protection activity were the highest (0.88 ± 0.43 μg/mL IC₅₀ and 2149.26 band intensity) in Albizia julibrissin methanol extracts. The α-amylase activity was highest in all methanol extracts (<15 μg/mL IC₅₀ values), while the α-glucosidase inhibition potential was highest (<1 μg/mL IC₅₀ value) in the methanol–glycerol and methanol–DMSO extracts. Pearson coefficient analysis showed a strong positive correlation between the DPPH and α-amylase assays and phytochemicals. Anti-leishmanial activity was observed in decreasing order: A. julibrissin (74.75 %) > C. decapetala (70.86 %) > Indigofera atropurpurea (65.34 %). Gas chromatography-mass spectrometry revealed 33 volatile compounds and, aamong these (Z)-9-octadecenamide was detected in the highest concentration ranging from 21.85 to 38.61 %. Only the methanol extracts of the examined species could be assessed for in vivo studies for immediate applications.