Discovering the regulators of heat stress tolerance in Ziziphus nummularia (Burm.f) wight and walk.-arn

Ziziphus nummularia an elite heat-stress tolerant shrub, grows in arid regions of desert. However, its molecular mechanism responsible for heat stress tolerance is unexplored. Therefore, we analysed whole transcriptome of Jaisalmer (heat tolerant) and Godhra (heat sensitive) genotypes of Z. nummularia to understand its molecular mechanism responsible for heat stress tolerance. De novo assembly of 16,22,25,052 clean reads yielded 276,029 transcripts. A total of 208,506 unigenes were identified which contains 4290 and 1043 differentially expressed genes (DEG) in TGO (treated Godhra at 42 °C) vs. CGO (control Godhra) and TJR (treated Jaisalmer at 42 °C) vs. CJR (control Jaisalmer), respectively. A total of 987 (67 highly enriched) and 754 (34 highly enriched) pathways were obsorved in CGO vs. TGO and CJR vs. TJR, respectively. Antioxidant pathways and TFs like Homeobox, HBP, ARR, PHD, GRAS, CPP, and E2FA were uniquely observed in Godhra genotype and SET domains were uniquely observed in Jaisalmer genotype. Further transposable elements were highly up-regulated in Godhra genotype but no activation in Jaisalmer genotype. A total of 43,093 and 39,278 simple sequence repeats were identified in the Godhra and Jaisalmer genotypes, respectively. A total of 10 DEGs linked to heat stress were validated in both genotypes for their expression under different heat stresses using quantitative real-time PCR. Comparing expression patterns of the selected DEGs identified ClpB1 as a potential candidate gene for heat tolerance in Z. nummularia. Here we present first characterized transcriptome of Z. nummularia in response to heat stress for the identification and characterization of heat stress-responsive genes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12298-024-01431-y.

Fractionation and phytochemical composition of an ethanolic extract of Ziziphus nummularia leaves: antioxidant and anticancerous properties in human triple negative breast cancer cells

Natural products have long been utilized in traditional medicine as remedies to improve health and treat illnesses, and have had a key role in modern drug discovery. Recently, there has been a revived interest in the search for bioactives from natural sources as alternative or complementary modalities to synthetic medicines; especially for cancer treatment, which incidence and mortality rates are on the rise worldwide. Ziziphus nummularia has been widely used in traditional medicine for the treatment of various diseases. Its traditional uses and numerous ethnopharmacological properties may be attributed to its richness in bioactive metabolites. However, its phytochemical composition or chemopreventive effects against the aggressive triple-negative breast cancer (TNBC) are still poorly explored. Here, phytochemical composition of an ethanolic extract of Z. nummularia leaves (ZNE) and its chromatographically isolated fractions was identified both qualitatively by spectrophotometric assays and analytically by HPLC-PDA-MS/MS. The anti-proliferative effects of ZNE were tested in several cancer cell lines, but we focused on its anti-TNBC effects since they were not explored yet. The anti-cancerous potential of ZNE and its fractions was tested in vitro in MDA-MB-231, a TNBC cell line. Results showed that ZNE and its Fraction 6 (F6) reduced the viability of MDA-MB-231 cells. F6 decreased MDA-MB-231 viability more than crude ZNE or its other fractions. ZNE and F6 are rich in phytochemicals and HPLC-PDA-MS/MS analysis identified several metabolites that were previously reported to have anti-cancerous effects. Both ZNE and F6 showed potent antioxidant capacity in the DPPH assay, but promoted reactive oxygen species (ROS) production in MDA-MB-231 cells; an effect which was blunted by the antioxidant N-acetyl cysteine (NAC). NAC also blunted ZNE- and F6-induced reduction in TNBC cell viability. We also demonstrated that ZNE and F6 induced an arrest of the cell cycle, and triggered apoptosis- and autophagy-mediated cell death. ZNE and F6 inhibited metastasis-related cellular processes by modifying cell migration, invasion, and adhesion. Taken together, our findings reveal that Z. nummularia is rich in phytochemicals that can attenuate the malignant phenotype of TNBC and may offer innovative avenues for the discovery of new drug leads for treatment of TNBC and other cancers.

Ziziphus nummularia Attenuates the Malignant Phenotype of Human Pancreatic Cancer Cells: Role of ROS

Pancreatic cancer (PC) is the fourth leading cause of all cancer-related deaths. Despite major improvements in treating PC, low survival rate remains a major challenge, indicating the need for alternative approaches, including herbal medicine. Among medicinal plants is Ziziphus nummularia (family Rhamnaceae), which is a thorny shrub rich in bioactive molecules. Leaves of Ziziphus nummularia have been used to treat many pathological conditions, including cancer. However, their effects on human PC are still unknown. Here, we show that the treatment of human pancreatic ductal adenocarcinoma cells (Capan-2) with Ziziphus nummularia ethanolic extract (ZNE) (100–300 μg/mL) attenuated cell proliferation in a time- and concentration-dependent manner. Pretreatment with N-acetylcysteine, an ROS scavenger, attenuated the anti-proliferative effect of ZNE. In addition, ZNE significantly decreased the migratory and invasive capacity of Capan-2 with a concomitant downregulation of integrin α₂ and increased cell–cell aggregation. In addition, ZNE inhibited in ovo angiogenesis as well as reduced VEGF and nitric oxide levels. Furthermore, ZNE downregulated the ERK1/2 and NF-κB signaling pathways, which are known to drive tumorigenic and metastatic events. Taken together, our results suggest that ZNE can attenuate the malignant phenotype of Capan-2 by inhibiting hallmarks of PC. Our data also provide evidence for the potential anticancer effect of Ziziphus nummularia, which may represent a new resource of novel anticancer compounds, especially ones that can be utilized for the management of PC.

Synthesis of silver nanoparticles using Ziziphus nummularia leaf extract and evaluation of their antimicrobial, antioxidant, cytotoxic and genotoxic potential (4-in-1 system)

This study reports the synthesis of silver nanoparticles (AgNPs) from silver nitrate by leaf extract of a medicinal plant Ziziphus nummularia. The leaf extract acts as a reducing and stabilizing agent for the formation of nanoparticles. The green synthesized AgNPs were characterized by ultraviolet-visible (UV-vis) spectroscopy, Fourier transform infrared (FITR) spectroscopy, Thermogravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM) analysis and evaluated their antimicrobial, antioxidant, cytotoxic and genotoxic potential. The UV-Vis spectroscopy showed a characteristic absorption peak at 430 nm due to surface plasma resonance. TEM analysis showed that synthesized AgNPs were spherical and oval with an average size of 25.96 nm. AgNPs showed effective antimicrobial activity (lowest MIC-0.625 µg/mL against Escherichia coli), synergistic antimicrobial activity (lowest ΣFIC 0.09 with chlormaphenicol against Corynebacterium rubrum) and antibiofilm activity. AgNPs showed strong DPPH activity with IC₅₀ - 520 µg/mL and ABTS activity IC₅₀ - 55 µg/mL and reducing capacity assessment. In vitro cytotoxic effect was evaluated by MTT assay against HeLa cells, breast cells and fibroblast cells. Genotoxic effect was evaluated by comet assay. AgNPs displayed dose-dependent cytotoxic and genotoxic effect. Our findings indicated that synthesized AgNPs could be considered as multifunctional and have great potential for use in biomedical applications.HighlightsSilver nanoparticles were synthesized using leaf extract of Ziziphus nummulariaCharacterization was done by various spectral techniquesAntimicrobial efficacy was demonstrated against an array of bacteriaAgNPs exhibited significant cytotoxic effect against HeLa cell lineAgNPs showed cytotoxicity and genotoxicity in a dose-dependent manner.

Heat stress inducible cytoplasmic isoform of ClpB1 from Z. nummularia exhibits enhanced thermotolerance in transgenic tobacco

Previously, we isolated CDS of Ziziphus nummularia isoform ZnJClpB1-C from heat stress-tolerant genotype Jaisalmer. To further functionally validate ZnJClpB1-C assumed function in tobacco and to generate novel germplasm for heat stress tolerance, this gene was transformed in the Nicotiana tabacum. ClpB proteins are the major key player required for basal and induced heat stress tolerance in plant cells under heat stress. In Ziziphus nummularia ClpB1-C transcript from genotype Jaisalmer was highly upregulated under heat stress conditions, as reported earlier. Nine transgenic lines (T1) from three transgenic tobacco events with single-copy integration (T0 stage) were taken for heat stress analysis at seedling stage. Mature tobacco transgenic plants did not show any deformity as compared to wild plants when grown under normal conditions. Overexpression of ZnJClpB1-C in tobacco significantly increased the tolerance to heat stress. Under heat stress conditions (42 °C), T1 transgenic tobacco seedlings showed higher photosynthetic rate, relative water content, membrane stability index and lower levels of MDA, compared to the wild type untransformed plants. The qRT-PCR analysis revealed different level of transgene expression (1.08 to 3.89 folds) in 9 T1 transgenic lines. In vitro roles of ZnJClpB1-C regulating thermotolerance is not reported so far. These results demonstrated the positive roles of ZnJClpB1-C in enhancing thermotolerance and its use as a genomic resource in the near future for developing heat stress-tolerant germplasm.

Nectar secretion dynamics of Ziziphus nummularia: A melliferous species of dry land ecosystems

Nectar is used as raw material for the production of honey and as significant reward in the relationship between bees and plants during pollination. Therefore, it is important to investigate its abundance, dynamics and associated governing factors. Weather conditions are known to influence nectar production, and predicted climate changes may be responsible for future declining in total yield from beekeeping activities. We investigated nectar production as total soluble solids (TSS) of well-known species for honey production, Ziziphus nummularia in a hot-arid environment of Saudi Arabia. Data on nectar samples from bagged flowers of different stages during two blooming seasons, 2013 and 2015 were collected on weekly bases, and the data were correlated with weather conditions (temperature, relative humidity, and wind). A significant difference in TSS amount has been obtained, with 1-day old flowers displaying the higher content. TSS production was varied along the different day intervals, for both years, with a peak of production in the afternoon. In our results, nectar production was not correlated to temperature and wind, but was significantly negatively correlated with relative humidity. According to the current and future weather forecasting conditions, understanding of the relationship between weather conditions and nectar availability turned out to be important predictive information that may be interpreted into an economic projection of incomes from beekeeping activities.

Isolation and structure elucidation of cyclopeptide alkaloids from Ziziphus nummularia and Ziziphus spina-christi by HPLC-DAD-MS and HPLC-PDA-(HRMS)-SPE-NMR

Seven cyclopeptide alkaloids were isolated from the stem bark of Ziziphus nummularia and Ziziphus spina-christi. Three previously undescribed compounds were identified: nummularine-U, spinanine-B and spinanine-C, together with the known compounds mauritine-F, nummularine-D, nummularine-E and amphibine-D. For their purification either semi-preparative HPLC with DAD and ESIMS detection or HPLC-PDA-(HRMS)-SPE-NMR was applied, together with conventional separation methods. Their structures were elucidated by spectroscopic means.

Characterization, antifungal and cytotoxic evaluation of green synthesized zinc oxide nanoparticles using Ziziphus nummularia leaf extract

Zinc oxide nanoparticles (ZnO NPs) were synthesized using Ziziphus nummularia leaf extract. The characterization was done by various spectral analysis and antifungal (anti-candidal) activity against multidrug resistant clinical isolates and their cytotoxic potential was evaluated. The ZnO NPs were 17.33 nm in size and were spherical/irregular in shape. The antifungal activity of ZnO NPs was better than four standard azole antibiotics and they also showed potent cytotoxic effect against HeLa cancer cell line. The results strongly suggest the applicability of green synthesized ZnO NPs as antifungal agent and also its use in cancer diagnosis and treatment.

Emerging CAM Ziziphus nummularia with in vivo sedative-hypnotic, antipyretic and analgesic attributes

Ziziphus nummularia from Rhamnaceae family is traditionally used for sedative-hypnotic, antipyretic and analgesic purposes; however, scientific validations are lacking. This in vivo study was undertaken to verify the above ameliorative properties of Z. nummularia root methanolic extract. Various fractions of the extract were assayed on Balb/c mice by open field, Brewer’s yeast-induced hyperthermia and acetic acid-induced writhing experiments. The significance of the outcomes was analyzed with statistical tests. Various fractions of the extract exhibited marked dose-dependent (p < 0.05) sedative-hypnotic and antipyretic activities. The biological efficacies were most pronounced between 50 and 100 mg/kg. Further, the acetic acid-induced abdominal constrictions were significantly (p < 0.05) attenuated by the extract. Chloroform fraction of the extract was most dominant followed by ethyl acetate. The demonstrated therapeutic attributes of Z. nummularia extract can be exploited to isolate pharmaceutically relevant compounds.

Molecular cloning and characterization of drought stress responsive abscisic acid-stress-ripening (Asr 1) gene from wild jujube, Ziziphus nummularia (Burm.f.) Wight & Arn

Drought is a calamitous abiotic stress hampering agricultural productivity all over the world and its severity is likely to increase further. Abscisic acid-stress-ripening proteins (ASR), are a group of small hydrophilic proteins which are induced by abscisic acid, stress and ripening in many plants. In the present study, ZnAsr 1 gene was fully characterized for the first time from Ziziphus nummularia, which is one of the most low water forbearing plant. Full length ZnAsr 1 gene was characterised and in silico analysis of ZnASR1 protein was done for predicting its phylogeny and physiochemical properties. To validate transcriptional pattern of ZnAsr 1 in response to drought stress, expression profiling in polyethylene glycol (PEG) induced Z. nummularia seedlings was studied by RT-qPCR analysis and heterologous expression of the recombinant ZnAsr1 in Escherichia coli. The nucleotide sequence analysis revealed that the complete open reading frame of ZnAsr 1 is 819 bp long encoding a protein of 273 amino acid residues, consisting of a histidine rich N terminus with an abscisic acid/water deficit stress domain and a nuclear targeting signal at the C terminus. In expression studies, ZnAsr 1 gene was found to be highly upregulated under drought stress and recombinant clones of E. coli cells expressing ZnASR1 protein showed better survival in PEG containing media. ZnAsr1 was proven to enhance drought stress tolerance in the recombinant E.coli cells expressing ZnASR1. The cloned ZnAsr1 after proper validation in a plant system, can be used to develop drought tolerant transgenic crops.