Biochemical profile and in vitro biological activities of extracts from seven folk medicinal plants growing wild in southern Tunisia

Phytochemical, antileishmanial, antifungal and cytotoxic profiles of Thymelaea tartonraira (L.) All. extracts

Extracts from leaves and stems of Thymelaea tartonraira (L.) All. growing in Tunisia were characterised for the presence of flavonoids and phenolic acids by LC-ESI-MS analysis. Twelve flavonoids and ten phenolic acids were detected for the first time in the aerial parts of this plant species, the most abundant compounds being gallic acid, kaempferol, catechin, chlorogenic acid, naringenin and acacetin. The extracts were subjected to in vitro antileishmanial, antifungal and cytotoxic assays, showing promising antileishmanial activity for the E6 dichloromethane extract from the stems (IC50 values of 1.12 ± 0.50 and 5.41 ± 1.84 µg/mL on L. donovani axenic and intramacrophagic amastigotes, respectively) at the level of the reference drug miltefosine for axenic model. No antifungal activity was observed against Candida albicans (CAAL) and Aspergillus fumigatus (ASFU) strains, with the exception of the E6 dichloromethane extract (IC50 value of 25.28 ± 4.89 µg/mL on CAAL93 strain). Low toxicity was also highlighted against macrophages Raw 264.7 cells. These promising results point out Thymelaea tartonraira (L.) All. extracts as a valuable source of new natural products to combat leishmaniasis.

Phenolic Profiling, Antioxidant, and Antibacterial Activities of Selected Medicinal Plants from Tunisia

Phytochemical screening of aqueous extract from six medicinal wild plants grown in South-eastern of Tunisia: Atriplex halimus, Teucrium polium, Moricandia arvensis, Deverra tortuoa, Haplophyllum tuberculatum and Polygonum equisetiforme were evaluated. Both decoction and ultrasound assisted extraction were used. Antioxidant, antibacterial proprieties, and phenolic profiling, using LC-ESI-MS method, were assessed. Total polyphenols, flavonoids, and condensed tannins contents ranged from 7.47±0.19 to 22.25±0.49 mg GAE/g Dw, 5.47±0.06 to 7.55±0.07 mg RE/g Dw, and 0.33±0.02 to 19.43±0.64 mg TAE/g Dw, respectively. Moreover, the reducing power and DPPH tests showed that P. equisetiforme (EC50 : 12.50±0.50 μg/ml; DPPH⋅+ : 213.49±4.24 mg TEAC/g DW), T. polium (EC50 : 25.00±1.00 μg/ml; DPPH⋅+ : 181.39±9.47 mg TEAC/g DW) as well as H. tuberculatum (EC50 : 56.25±0.25 μg/ml; DPPH⋅+ : 177.83±5.85 mg TEAC/g DW) extracts were the most effective natural antioxidants. For anti-bacterial activity, the ultrasonic extract of H. tuberculatum showed the highest activity against both P. aeruginosa (13.50±0.71 mm) and S. aureus (13.00±0.00 mm) at 10 mg/ml. Furthermore 24 phenolic compounds were identified, with predominance of quinic acid, gallic acid, protocatechuic acid, syringic acid, p-coumaric acid, trans-ferulic acid, catechin (+), trans-cinnamic and silymarin. These results were further consolidated by to heatmap clustering with P. equisetiforme, H. tuberculatum, T. polium as the main antioxidant and antibacterial sources which supports their domestication and industrial use.

Development and Optimization of Culture Medium for the Production of Glabridin by Aspergillus eucalypticola: An Endophytic Fungus Isolated from Glycyrrhiza glabra L. (Fabaceae)

Glabridin is a well-known active isoflavone found in the root of licorice (Glycyrrhiza glabra L.) that possess a wide range of biological activity. Plant cells, hairy roots, and fungal endophytes cultures are the most important alternative methods for plant resources conservation and sustainable production of natural compounds, which has received much attention in recent decades. In the present study, an efficient culture condition was optimized for the biomass accumulation and glabridin production from fungal endophyte Aspergillus eucalypticola SBU-11AE isolated from licorice root. Type of culture medium, range of pH, and licorice root extract (as an elicitor) were tested. The results showed that the highest and lowest biomass production was observed on PCB medium (6.43 ± 0.32 g/l) and peptone malt (5.85 + 0.11 g/l), respectively. The medium culture PCB was produced the highest level of glabridin (7.26 ± 0.44 mg/l), while the lowest level (4.47 ± 0.02 mg/l) was obtained from the medium peptone malt. The highest biomass (8.51 ± 0.43 g/l) and glabridin (8.30 ± 0.51 mg/l) production were observed from the PCB medium adjusted with pH = 6, while the lowest value of both traits was obtained from the same medium with pH = 7. The highest production of total glabridin (10.85 ± 0.84 mg/l) was also obtained from the culture medium treated with 100 mg/l of the plant root extract. This information can be interestingly used for the commercialization of glabridin production for further industrial applications.

Pharmacological Activities and In-Silico Studies of Bioactive Compounds Identified in Organic Fractions of the Methanolic Extract of Citrullus Colocynthis

Medicinal plants have been extensively exploited for their immense pharmacological and immune-supporting potential. Fruit of Citrullus colocynthis has several active secondary metabolites such as phenolics, flavonoids, and essential oils that are used in traditional medicines as antidiabetic, anti-inflammatory, antioxidant, and antimicrobial agents. In this study, phytoconstituents in organic fractions (n-hexane, chloroform, and ethyl acetate) of the methanolic extract of C. colocynthis were analyzed and identified by FT-IR, HPLC, and GC-MS analysis. Ethyl acetate fraction showed the highest antioxidant scavenging (76 ± .769%) and anti-inflammatory (40 ± .473%) activities at the concentration of 3 mg/mL. Similarly, antidiabetic effect was measured by inhibition of α-amylase where, ethyl acetate fraction (77 ± .844%) exhibited the highest antidiabetic activity. Among all organic fractions, ethyl acetate exhibited strong antimicrobial potential followed by n-hexane and chloroform fractions against selected pathogenic bacteria. Various concentrations of the ethyl acetate extract were tested in-vivo for cytotoxicity and results indicated minor morphological changes in liver cells including ballooning, fatty droplets, and slight accumulation of extracellular matrix even at concentrations of 400 mg/kg. In-silico study showed that stigmasta-7,16-dien-3-ol had a strong interaction with COX-1 and COX-2 to reduce inflammation. The abovementioned results indicate the pharmacological strengths of C. colocynthis to fight several diseases.

Deep eutectic solvent-ultrasound assisted extraction as a green approach for enhanced extraction of naringenin from Searsia tripartita and retained their bioactivities

Background

Naringenin (NA) is a natural flavonoid used in the formulation of a wide range of pharmaceutical, fragrance, and cosmetic products. In this research, NA was extracted from Searsia tripartita using an environmentally friendly, high efficiency extraction method: an ultrasound-assisted extraction with deep eutectic solvents (UAE-DES).

Methods

Six natural deep eutectic solvent systems were tested. Choline chloride was used as the hydrogen bond acceptor (HBA), and formic acid, ethylene glycol, lactic acid, urea, glycerol, and citric acid were used as hydrogen bond donors (HBD).

Results

Based on the results of single-factor experiments, response surface methodology using a Box-Behnken design was applied to determine the optimal conditions for UAE-DES. According to the results, the optimal NA extraction parameters were as follows: DES-1 consisted of choline chloride (HBA) and formic acid (HBD) in a mole ratio of 2:1, an extraction time of 10 min, an extraction temperature of 50°C, an ultrasonic amplitude of 75 W, and a solid-liquid ratio of 1/60 g/mL. Extracted NA was shown to inhibit the activity of different enzymes in vitro, including α-amylase, acetylcholinesterase, butyrylcholinesterase, tyrosinase, elastase, collagenase, and hyaluronidase.

Conclusion

Thus, the UAE-DES technique produced high-efficiency NA extraction while retaining bioactivity, implying broad application potential, and making it worthy of consideration as a high-throughput green extraction method.

Phytochemical Analysis and Demonstration of Antioxidant, Antibacterial, and Antibiofilm Activities of Ethnomedicinal Plants of North East India

Ethnomedicinal plants are a rich reservoir of active compounds with potent pharmacological properties. Therefore, plants could serve as a source for the discovery of active antimicrobial and antioxidant agents and are focused because of their low toxicity, economic viability, easy availability, etc. In this regard, phytochemical analyses, viz. β-carotene, total sugar, reducing sugar, vitamin C, total carotenoids, protein, total phenolic content (TPC), and total flavonoid content (TFC) of 20 ethnomedicinal plants of North East India (NEI) were evaluated in this study. The antibacterial activity against human pathogens and antioxidant potential of plant extracts was also demonstrated. The minimum inhibitory concentration (MIC₈₀), minimum bactericidal concentration (MBC), and total antibacterial activity (TAA) of the active extracts were evaluated against Pseudomonas aeruginosa and Chromobacterium violaceum. The active extracts were also examined for antibiofilm as well as anti-pyocyanin activities against P. aeruginosa and anti-QS activity against C. violaceum at sub-MICs. The study demonstrated variable concentration of phytochemicals of the extracts, viz. β-carotene (0.29-8.91 mg g^-1), total sugar (2.92-30.6 mM), reducing sugar (0.44-14.5 mM), vitamin C (8.41-31.3 mg g^-1), total carotenoids (14.9-267.0 mg g^-1), protein (5.65-283 mg g^-1), TPC (5.32-31.0 mg GAE/g DW), and TFC (1.74-68.2 mg QE/g DW). The plant extracts also exhibited potent antioxidant and antibacterial activities against both Gram-positive and Gram-negative bacteria. Some of the extracts also demonstrated significant biofilm inhibition and eradication, anti-pyocyanin, and anti-QS activities at sub-MICs. The selected ethnomedicinal plants are rich in phytochemicals and demonstrated potent antioxidant, antibacterial, and antibiofilm activities, thus could serve as the important source of novel antioxidant and antimicrobial agents.

Physical Fruit Traits, Proximate Composition, Antioxidant Activity, and Profiling of Fatty Acids and Minerals of Wild Jujube (Ziziphus lotus L. (Desf.)) Fruits from Eleven Moroccan Origins

This study aimed at investigating the effects of geographical origin on physical fruit traits, proximate composition, fatty acid, and elemental profiling of Moroccan wild jujube (Ziziphus lotus) fruits. Likewise, solvent effects on total phenolic content (TPC), total flavonoid content (TFC), tannin content, and antioxidant activity were also studied. Fruits were sampled from eleven sites where the species grows widely across Morocco (Tafraoute, Taroudant, Zagora, Rhamna, Beni Mellal, Zaouit Cheikh, Khenifra, B-Jaad, Lkhmissat, Sidi Hrazm, and Taounat). Physical fruit traits (length, width, and weight), proximate composition, and minerals were investigated. Fatty acid profiling of extracted oil was also evaluated. TPC and TFC as well as antioxidant activity (ABTS, DPPH, and FRAP) were determined on four different extracts, namely, ethanol extract (EE), methanol extract (ME), acetone extract (AE), and water extract (WE). Our outcomes revealed significant differences ( $p<0.05$ ) among different origins for the measured fruit traits including ash (1.69–2.31%), moisture (2.56–5.69%), proteins (2.63–4.64%), oil (1.59–2.91%) and carbohydrates (86.82–89.20%). The most abundant minerals were K (548.93–828.44 mg/100 g) and Ca (137.50–211.78 mg/100 g). Major fatty acids were oleic acid (50.65 –60.25%), palmitic acid (12.03–18.67%), and linoleic acid (12.63–17.21%). Acetone performed better in terms of TPC (12.77–21.67 mg GAE/g DM), TFC (11.00–18.92 mg QE/g DM), and antioxidant activity using ABTS (22.96–29.32 mg TE/g DM), DPPH (27.96–96.64%), and FRAP (8.37–37.59 mg AAE/g DM). In conclusion, Z. lotus fruit could be considered as a source of carbohydrates and minerals and also natural antioxidants.

Determination of phenolic profiles of Herniaria polygama and Herniaria incana fractions and their in vitro antioxidant and anti-inflammatory effects

The study is based on phytochemical profiling and in vitro evaluation of biological effects of phenolic acid derivatives-rich Herniaria fractions, isolated from two rupturewort (Herniaria L.) species, i.e. Herniaria incana Lam. (syn. H. besseri Fisch. ex Hornem) and H. polygama J. Gay (syn. H. odorata). For the first time, the composition of phenolic compounds of these species was extensively evaluated by both LC-HR-QTOF-ESI-MS and Nuclear Magnetic Resonance spectroscopy (NMR). LC-MS analyses of H. polygama revealed 72 tentatively identified compounds, while H. incana - 63. Only 8% of the metabolites reported in this work have been previously described for Herniaria spp. Most of the identified specialized metabolites were cinnamic and benzoic acid derivatives. Phenolic fraction of H. incana herb contained flavonoids as well. A multi-step chromatographic separation of phenolic fractions from H. polygama yielded three known cinnamic and one benzoic acid derivates, and from H. incana - 4 known flavonoids and one previously undescribed, i.e. rhamnocitrin-3-O-[3-hydroxy-3-methylglutaryl-(1 → 6'')]-[α-rhamnopyranosyl-(1 → 2'')]-β-glucopyranoside. Antioxidant properties of the examined fractions (1-50 μg/ml) were assessed in human blood plasma under the conditions of peroxynitrite-induced oxidative stress. Measurements of well-known biomarkers such as 3-nitrotyrosine, protein thiol groups, thiobarbituric acid-reactive substances and the ferric reducing ability of blood plasma revealed the protective effect of Herniaria fractions against oxidative damage to blood plasma components. Furthermore, the examined fractions effectively ameliorated the inflammatory response of the concanavalin A-stimulated human peripheral blood mononuclear cells (PBMCs). Additionally, cellular safety of the fractions was confirmed in PBMCs.

Metabolic profiling, in vitro propagation, and genetic assessment of the endangered rare plant Anarrhinum pubescens

Background

Anarrhinum pubescens Fresen. (Plantaginaceae) is a rare plant, endemic to the Saint Catherine area, of South Sinai, Egypt. Earlier studies have reported the isolation of cytotoxic and anti-cholinesterase iridoid glucosides from the aerial parts of the plant. The present study aimed to investigate the chemical profiling of the wild plant shoots as well as establish efficient protocols for in vitro plant regeneration and proliferation with further assessment of the genetic stability of the in vitro regenerated plants.

Results

Twenty-seven metabolites have been identified in wild plant shoots using the Nuclear Magnetic Resonance (NMR) spectroscopy. The metabolites include alkaloids, amino acids, carbohydrates, organic acids, vitamins, and a phenol. In vitro propagation of the plant was carried out through nodal cutting-micropropagation and leaf segment-direct organogenesis. The best results were obtained when nodal cutting explants were cultured on Murashige and Skoog medium with Gamborg B5 vitamins supplemented with 6-benzylaminopurine (BAP) (1.0 mg/L) and naphthaleneacetic acid (NAA) (0.05 mg/L), which gave a shoot formation capacity of 100% and a mean number of shoots of 27.67 ± 1.4/explant. These shoots were successfully rooted and transferred to the greenhouse and the survival rate was 75%. Genetic fidelity evaluation of the micropropagated clones was carried out using random amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) molecular markers. Jaccard’s similarity coefficient indicated a similarity as high as 98% and 95% from RAPD and ISSR markers, respectively.

Conclusions

This study provides the chemical profiling of the aerial part of Anarrhinum pubescens. Moreover, in vitro regeneration through different tissue culture techniques has been established for mass propagation of the plant, and the genetic fidelity of the in vitro regenerated plants was confirmed as well. Our work on the in vitro propagation of A. pubescens will be helpful in ex situ conservation and identification of bioactive metabolites.

Phytochemical Investigation, Antimicrobial, Antioxidant and Anticancer Activities of Acer cappadocicum Gled

The appearance of novel microbial resistance, diverse cancer ailment and several other morbidities such as appetite loss, hair loss, anemia, cell damage, etc., are among most critical situation that keeps the phytochemical quest on. Thus, this study characterized the antimicrobial, antioxidant, and anticancer potentials of a rarely accessed Acer cappadocicum gled (AC) population thriving in a remote Palas Valley in northern Pakistan. Leaf extracts of the plant were prepared in organic solvents with different polarities through maceration. Extracts were subjected to antimicrobial, antioxidant, and anticancer activities using agar well, DPPH and cell viability assays. A. cappadocicum methanolic extract (ACM) significantly inhibited bacterial growth, followed by n-butanolic extract (ACB) with the second-highest bacterial inhibition. Similar activity was observed against mycelial growth inhibition in plant-fungal pathogen by ACM and ACB. However, human pathogenic fungi did not affect much by extracts. In antioxidant assessment, the chloroform extract (ACC) showed strong scavenging activity and in cytotoxic evaluation, extracts restricted growth proliferation in cancer cells. The inhibitory evidence of extracts, potent scavenging ability, and low cell viability of human-derived cell lines supports the antimicrobial, antioxidant and anticancerous potential of A. cappadocicum. It advances our quest for natural product research.

African Herbal Medicines: Adverse Effects and Cytotoxic Potentials with Different Therapeutic Applications

The African continent is naturally endowed with various plant species with nutritional and medicinal benefits. About 80% of the people in developing countries rely on folk medicines to treat different diseases because of indigenous knowledge, availability, and cost-effectiveness. Extensive research studies have been conducted on the medicinal uses of African plants, however, the therapeutic potentials of some of these plants has remained unexploited. Over the years, several studies have revealed that some of these African floras are promising candidates for the development of novel drugs. Despite the plethora of studies on medicinal plant research in Africa, there is still little scientific data supporting the folkloric claims of these plants. Besides, safety in the use of folk medicines has been a major public health concern over the year. Therefore, it has become mandatory that relevant authority should take measures in safeguarding the populace on the use of herbal mixtures. Thus, the present review extracted relevant information from different scientific databases and highlighted some problems associated with folk medicines, adverse effects on reproductive systems, issue about safety due to the toxicity of some plants and their toxicity effects with potential therapeutic benefits are discussed.

The polyphenol/saponin-rich Rhus tripartita extract has an apoptotic effect on THP-1 cells through the PI3K/AKT/mTOR signaling pathway

Background

Hyperactivation of mechanistic target of rapamycin (mTOR) signaling pathway is involved in the regulation of cellular growth, proliferation, and more in general, is a common phenomenon in most types of cancers. Thus, natural substances targeting this pathway can be of great therapeutic potential in supporting the treatment of tumor patients. Rhus tripartita (Ucria) Grande is a plant growing in desertic areas which is traditionally used for the treatment of several diseases in Tunisia. In the present work, the biochemical profile of the main compounds present in the plant leaf extract was determined and the anti-leukemic potential of the plant extracts against acute monocytic leukaemia (AML) THP-1 cells was investigated.

Methods

After HPLC identification of some phenolic compounds present in the plant extract and the quantification of saponin content, the cytotoxic effect of Rhus tripartita extracts on THP-1 cell culture was evaluated using the colorimetric MTT assay for cell viability. THP-1 cells were incubated with medium containing the relative IC₅₀ concentrations of total plant extract, saponin extract and some standard compounds (rutin (R); kaempferol (K); mixture of catechin, epicatechin, and epicatechin-gallate (CEEG); ellagic acid (EA). Finally, qRT-PCR and western blotting analysis were used to evaluate the effect of some flavonoids present in a crude extract of polyphenols and the total extract of saponins on cell survival and apoptosis.

Results

Analysis of expression level of some gene (PIK3CA, PTEN, AKT1, mTOR, EIF4E, RPS6KB1, and TSC1) involved in the mTOR pathway and the phosphorylation of S6 and AKT proteins allowed to observe that a total Rhus tripartita extract and some of the compounds found in the extract controls THP-1 cell proliferation and apoptosis via regulation of the PI3K-Akt-mTOR signaling pathway.

Conclusion

Rhus tripartita-induced inhibition of cell cycle and induction of apoptosis may involve the mTOR pathway. Therefore, Rhus tripartita extract may be a useful candidate as a natural anti-cancer drug to support the treatment of AML.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03328-9.

Antioxidant and Cytoprotective Properties of Plant Extract from Dry Flowers as Functional Dyes for Cosmetic Products

Nowadays, natural dyes are expected by the cosmetic and food industries. In contrast to synthetic dyes, colorants derived from natural sources are more environmentally friendly and safer for human health. In this work, plant extracts from Gomphrena globasa L., Clitoria ternatea L., Carthamus tinctorius L., Punica granatum L. and Papaver rhoeas L. as the natural and functional dyes for the cosmetics industry were assessed. Cytotoxicity on keratinocyte and fibroblast cell lines was determined as well as antioxidant and anti-aging properties by determining their ability to inhibit the activity of collagenase and elastase enzymes. In addition, the composition of the extracts was determined. The obtained extracts were also applied in face cream formulation and color analyses were performed. It has been shown that the obtained extracts were characterized by no cytotoxicity and a high antioxidant potential. The extracts also show strong ability to inhibit the activity of collagenase and moderate ability to inhibit elastase and provide effective and long-lasting hydration after their application on the skin. Application analyses showed that the extracts of P. rhoeas L., C. ternatea L. and C. tinctorius L. can be used as effective cosmetic dyes that allow for attainment of an intense and stable color during the storage of the product. The extracts of P. granatum L. and G. globasa L., despite their beneficial effects as active ingredients, did not work effectively as cosmetic dyes, because cosmetic emulsions with these extracts did not differ significantly in color from emulsions without the extract.

Scanning electron microscopy of Sophora alopecuroides L. seeds and their cytotoxic, antimicrobial, antioxidant, and enzyme inhibition potentials

Sophora alopecuroides L. is a highly medicinal plant. The aim of the current study was to determine the phytochemical screening, pharmacological potentials and application of scanning electron microscope (SEM) of S. alopecuroides (SA) seeds. To achieve this purpose, six different solvents were used to prepare SA seed extracts. Phytochemical and antioxidant activities were determined calorimetrically. To investigate the antidiabetic activity, α-amylase inhibition assay was determined. Brine shrimp assay was used to determine cytotoxicity potential. Anti-leishmanial potential was confirmed using MTT assay. Disc-diffusion method was used to detect protein kinase inhibitory, antibacterial and antifungal activities and showed significant results. SEM analysis was used as an identification tool. Considerable amount of phenolic and flavonoid contents were identified in methanol extract (SASM) (93.76 ± 2.71 GAE/mg) and (77 ± 3.60 QE/mg). Highest DPPH scavenging potential (82%) was reported for SASM. Significant total antioxidant capacity (90.60 ± 1.55 alpha amylase enzyme [AAE]/mg) and total reducing power (94.44 ± 1.38 AAE/mg) were determined for LOSM. Highest α-amylase inhibition was reported in SASM (78.20 ± 1.58%). Highest LD₅₀ of brine shrimp was found for n-hexane extract (SASH) 13.03 μg/ml. All extracts showed strong anti-leishmanial activity except SASH. The seeds of SA were seen to be oblong to obovate, projections, wavy slightly straight, anticlinal wall was raised with apex acuminate. In conclusion, our experimental findings highly support the ethnomedicinal and biological potentials of the SA seeds. Moreover, SA seeds need to be explored for identification and isolation of bioactive compounds. In future, we recommend further in vivo toxicity assays and clinical efficacies to further evaluate its different biomedical properties.

Marrubium vulgare L.: A Phytochemical and Pharmacological Overview

Marrubium vulgare is a plant with high bioactive potential. It contains marrubiin, a labdane diterpene that is characteristic for this genus, as well as a complex mixture of phenolic compounds. According to numerous studies, M. vulgare acts as a good antioxidant agent, and due to this, it could potentially be useful in treatments of cancer, diabetes mellitus, and liver diseases. In addition, its anti-inflammatory, wound-healing, antihypertensive, hypolipidemic, and sedative potential are discussed. Apart from that, its antimicrobial activity, especially against Gram+ bacteria, fungi, herpes simplex virus, and parasites such as Toxoplasma gondii, Trichomonas vaginalis, and Plasmodium berghei-berghei was recorded. Additionally, it could be used as a chicken lice repellent, herbicide, and natural insecticide against mosquito larvae and natural molluscicide. In veterinary medicine, M. vulgare can be used as an anthelmintic against the eggs and larvae of bovine strongyles parasites, and as an antibiotic against bovine mastitis caused by resistant bacterial strains. Due to the mentioned benefits, there is a tendency for the cultivation of M. vulgare in order to ensure high-quality raw material, but more firm scientific evidence and well-designed clinical trials are necessary for the well-established use of M. vulgare herb and its preparations.