Comprehensive chemical characterization and biological evaluation of two Acacia species: A. nilotica and A. ataxacantha.

The genus Acacia (Family Leguminosae) is composed of several medicinal plants used for treating miscellaneous diseases. Amid the important members of this genus, A. nilotica and A. ataxacantha are widely employed for their tremendous healing properties. Hence, this present work aimed to determine the total phenolic and flavonoid contents and investigate the antioxidant, antiproliferative, anti-enzyme and antimicrobial potentials of methanolic and water extracts of leaves and stem bark of A. nilotica and A. ataxacantha obtained by maceration and ultrasonication. The total phenolic and flavonoid contents were obtained in the range of 33.35-116.60 mg GAE/g and 0.26-49.90 mg RE/g, respectively, with the methanolic leaf extracts of both species showing the highest contents. Moreover, the methanolic extracts were observed to display higher antioxidant potentials in almost all antioxidant assays performed compared to the water extracts (ABTS: 52.66-943.81 mg TE/g, DPPH: 8.51-493.90 mg TE/g, CUPRAC: 106.39-1193.75 mg TE/g; FRAP: 31.38-416.21 mg TE/g, and phosphomolybdenum: 0.90-4.17 mM TE/g). However, the water extracts were seen to be better metal chelators than the methanolic extracts (8.47-36.85 mg EDTAE/g). Additionally, all extracts were found to exhibit anti-tyrosinase (30.79-74.80 mg KAE/g) and anti-amylase (0.10-1.10 mM ACAE/g) properties. With the exception of a few extracts, glucosidase and acetylcholinesterase inhibitions (1.69-2.12 mg ACAE/g and 0.42-2.61 mg GALAE/g, respectively) were also demonstrated. While the methanolic extracts of both species showed antimicrobial potency against all the 18 tested microorganisms (gram positive, gram negative, and fungi), the water extracts were effective only against the gram positive bacteria. The extracts were also found to exhibit antiproliferative effects on SH-SY5Y human neuroblastoma cells, with the methanolic extracts showing higher cytotoxic potential than the water extracts. Therefore, this study showed these species to be good sources of antioxidants, enzyme inhibitors, antimicrobials and antiproliferative agents, which could be of great interest for their applications as natural bioactive ingredients in the development of pharmaceuticals and nutraceuticals.

Comprehensive evaluation of two Astragalus species (A. campylosema and A. hirsutus) based on biological, toxicological properties and chemical profiling.

Astragalus L. (Fabaceae) is an important genus with numerous species having various traditional medicinal uses making them of interest for scientific investigations to ascertain their therapeutic benefits. In the present study, the quantitative polyphenolic profiles of methanolic extracts from different parts (leaves, flowers, and roots) of two endemic Astragalus species growing in Turkey, i.e. A. campylosema Boiss. and A. hirsutus Vahl were determined, along with their antioxidant and enzyme inhibitory properties. A. campylosema and A. hirsutus extracts showed varying total phenolic (25.80-40.60 and18.59-29.46 mg GAE/g, respectively) and total flavonoid (11.21-105.91 and 16.06-131.91 mg RE/g, respectively) contents. HPLC-MS/MS revealed rutin to be the predominant phenolic compound in all the extracts of A. campylosema and leaf extract of A. hirsutus (133.53-752.42 µg g-1), while hyperoside was the major one in the flower and root extracts of A. hirsutus (2014.07 and 123.13 µg g-1, respectively). In DPPH and ABTS assays, radical scavenging capacity was demonstrated by all extracts of A. campylosema (47.13-48.10 and 87.03-115.36 mg TE/g, respectively) and A. hirsutus (17.82-38.67 and 47.84-57.29 mg TE/g, respectively). Reducing activity was also displayed by the extracts in CUPRAC and FRAP assays (A. campylosema: 83.06-135.20 and 59.15-90.19 mg TE/g, respectively; A. hirsutus: 53.02-83.42 and 31.25-43.25 mg TE/g, respectively). All extracts were also found to act as metal chelators (12.32-21.45 mg EDTAE/g) and exhibited total antioxidant capacity ranging from 1.16 to 1.60 mmol TE/g, in phosphomolybdenum assay. Acetyl- and butyryl-cholinesterase inhibitory effects were observed by all the extracts of the two species (1.56-4.99 mg GALAE/g). Anti-hyperpigmentation potential by inhibiting tyrosinase (54.55-67.35 mg KAE/g) was reported as well. Carbohydrate hydrolyzing enzymes, amylase and glucosidase were also inhibited (0.22-1.03 mmol ACAE/g). Overall, A. campylosema extracts showed relatively better antioxidant and enzyme inhibitory potentials compared to A. hirsutus extracts. Strikingly, A. hirsutus extracts was found to have higher AGE inhibition activity than A. campylosema. Although the cytotoxic effect of three different organs obtained from A. campylosema and A. hirsutus increased depending on the dose (from 10 to 200 µg/mL), it was found that both plant extracts did not show a genotoxic effect at the highest concentration of 200 µg/mL. Indeed, data amassed from this current scientific work showed the two selected Astragalus species to be rich in bioactive polyphenols that could be responsible for the various pharmacological activities and hence demands to be further explored for their possible applications as natural health promoting agents.

Chemical Composition and Biological Properties of Two Jatropha Species: Different Parts and Different Extraction Methods.

Jatropha L. species, in particular, J. curcas and J. gossypiifolia, are well known medicinal plants used for treating various diseases. In the present study, leaf and stem bark extracts of J. curcas and J. gossypiifolia obtained by maceration or homogenizer assisted extraction, were investigated for their phytochemical contents and biological potential as antioxidants, enzyme inhibitors and neuromodulators. In this regard, the gene expression of tumor necrosis factor α (TNFα) and brain-derived neurotrophic factor (BDNF) was investigated in hypothalamic HypoE22 cells. Finally, a bioinformatics analysis was carried out with the aim to unravel the putative mechanisms consistent with both metabolomic fingerprints and pharmacological effects. The leaf extracts of J. curcas showed higher total phenolic content (TPC) and total flavonoid content (TFC) than the stem bark extracts (range: 5.79-48.95 mg GAE/g and 1.64-13.99 mg RE/g, respectively), while J. gossypiifolia possessed TPC and TFC in the range of 42.62-62.83 mg GAE/g and 6.97-17.63 mg RE/g, respectively. HPLC-MS/MS analysis revealed that the leaf extracts of both species obtained by homogenizer assisted extraction are richer in phytochemical compounds compared to the stem bark extracts obtained by the same extraction method. In vitro antioxidant potentials were also demonstrated in different assays (DPPH: 6.89-193.93 mg TE/g, ABTS: 20.20-255.39 mg TE/g, CUPRAC: 21.07-333.30 mg TE/g, FRAP: 14.02-168.93 mg TE/g, metal chelating activity: 3.21-17.51 mg EDTAE/g and phosphomolybdenum assay: 1.76-3.55 mmol TE/g). In particular, the leaf extract of J. curcas and the stem bark extract of J. gossypiifolia, both obtained by homogenizer assisted extraction, showed the most potent antioxidant capacity in terms of free radical scavenging and reducing activity, which could be related to their higher TPC and TFC. Furthermore, anti-neurodegenerative (acetylcholinesterase inhibition: 1.12-2.36 mg GALAE/g; butyrylcholinetserase inhibition: 0.50-3.68 mg GALAE/g), anti-hyperpigmentation (tyrosinase inhibition: 38.14-57.59 mg KAE/g) and antidiabetic (amylase inhibition: 0.28-0.62 mmol ACAE/g; glucosidase inhibition: 0.65-0.81 mmol ACAE/g) properties were displayed differentially by the different extracts. Additionally, the extracts were effective in reducing the gene expression of both TNFα and BDNF, which could be partially mediated by phenolic compounds such as naringenin, apigenin and quercetin. Indeed, the scientific data obtained from the present study complement the several other reports highlighting the pharmacological potentials of these two species, thus supporting their uses as therapeutically active plants.

Deeper Insights on Alchornea cordifolia (Schumach. & Thonn.) Müll.Arg Extracts: Chemical Profiles, Biological Abilities, Network Analysis and Molecular Docking.

Alchornea cordifolia (Schumach. & Thonn.) Müll. Arg. is a well-known African medicinal plant traditionally used for various healing purposes. In the present study, methanolic, ethyl acetate and infusion extracts of A. cordifolia leaves were studied for their total phenolic and flavonoid contents and screened for their chemical composition. Moreover, the enzyme (acetyl- and butyryl-cholinesterases, α-amylase, α-glucosidase, and tyrosinase) inhibitory and cytotoxicity activities on HepG2: human hepatocellular carcinoma cells, B16 4A5: murine melanoma cells, and S17: murine bone marrow (normal) cells of extracts were evaluated. Finally, components-targets and docking analyzes were conducted with the aim to unravel the putative mechanisms underlying the observed bio-pharmacological effects. Interestingly, the infusion and methanolic extracts showed significantly higher total phenolic and flavonoid contents compared with the ethyl acetate extract (TPC: 120.38-213.12 mg GAE/g and TFC: 9.66-57.18 mg RE/g). Besides, the methanolic extracts followed by the infusion extracts were revealed to contain a higher number of compounds (84 and 74 compounds, respectively), while only 64 compounds were observed for the ethyl acetate extract. Gallic acid, ellagic acid, shikimic acid, rutin, quercetin, myricetin, vitexin, quercitrin, kaempferol, and naringenin were among the compounds that were commonly identified in all the studied extracts. Additionally, the methanolic and infusion extracts displayed higher antioxidant capacity than ethyl acetate extract in all assays performed. In ABTS and DPPH radical scavenging assays, the methanol extract (500.38 mg TE/g for DPPH and 900.64 mg TE/g for ABTS) exhibited the best ability, followed by the water and ethyl acetate extracts. Furthermore, the extracts exhibited differential enzyme inhibitory profiles. In particular, the methanolic and infusion extracts showed better cytotoxic selectivity activity against human hepatocellular carcinoma cells. Overall, this study demonstrated A cordifolia to be a species worthy of further investigations, given its richness in bioactive phytochemicals and wide potentialities for antioxidants and pharmacological agents.