Comparative studies of phytochemical analysis and pharmacological activities of wild and micropropagated plant ethanol extracts of Manihot esculenta

Structural characterisation of bioactive compounds of Gymnosporia senegalensis (Lam.) Loes. using advanced analytical technique like FT-IR, GC-MS and 1H-NMR spectroscopy

The present investigation was carried out to characterise bioactive components from G. senegalensis by using Fourier-transform infra-red (FT-IR) spectroscopy, 1H-nuclear magnetic resonance spectroscopy, and gas chromatography-mass spectrometry (GC-MS). The FTIR analysis confirmed the presence of > CH2, -CH3, C = C-C, C-H, C-F, C = C, -C = N-, C-C = N-, and -OH functional groups. The 1H-NMR spectrum revealed the presence of structures of four bioactive compounds i.e. tetratetracontana derivative, β-carotene, amyrin, and terpineol. GC-MS revealed the presence of different types of high and low molecular weight chemical entities with varying quantities including volatile and essential oil, monoterpenoid, tetraterpenoid, carotenoid, terpenoid, triterpenes, and nortriterpenes. From the results, it could be concluded that G. senegalensis contains various bioactive compounds of biological and pharmacological importance. Overall, this study will provide insight into the characterisation and development of drugs from medicinal plants.

Phytochemical Composition and Antibacterial Activity of Barleria albostellata C.B. Clarke Leaf and Stem Extracts

Barleria albostellata (Acanthaceae) is a shrub located in South Africa and is relatively understudied. However, plants within this genus are well known for their medicinal and ethnopharmacological properties. This study aimed to characterise the phytochemical compounds and antibacterial efficacies of B. albostellata. Phytochemical analysis, fluorescence microscopy and gas chromatography-mass spectrometry (GC-MS) analysis were performed to determine the composition of compounds that may be of medicinal importance. Crude leaf and stem extracts (hexane, chloroform and methanol) were subjected to an antibacterial analysis against several pathogenic microorganisms. The qualitative phytochemical screening of leaf and stem extracts revealed the presence various compounds. Fluorescence microscopy qualitatively assessed the leaf and stem powdered material, which displayed various colours under bright and UV light. GC-MS chromatograms represents 10-108 peaks of various compounds detected in the leaf and stem crude extracts. Major pharmacologically active compounds found in the extracts were alpha-amyrin, flavone, phenol, phytol, phytol acetate, squalene and stigmasterol. Crude extracts positively inhibited Gram-positive and Gram-negative bacteria. Significance was established at p < 0.05 for all concentrations and treatments. These results indicate that the leaves and stems of B. albostellata are rich in bioactive compounds, which could be a potential source of antibacterial agents for treating various diseases linked to the pathogenic bacteria studied. Future discoveries from this plant could advance the use of indigenous traditional medicine and provide novel drug leads.

Antioxidant Activity of Flavonoids from Cassava Leaves (Manihot esculenta Crantz)

The community uses cassava leaves for cooking because of their high protein content, β-carotene, Fe, Mg, Zn, S, Ca, Zn, Ni, and K. Cassava leaves contain various secondary metabolites, including flavonoids, saponins, tannins, phenolics, steroids, anthocyanins, and anthraquinones. The antioxidant activity of flavonoid compounds in cassava leaves (Manihot esculenta Crantz) has been successfully investigated. This study consisted of six stages: the preparation of ethanol extract of cassava leaves, phytochemical screening, determination of total flavonoid content in the extract, isolation of flavonoids, and purity testing of flavonoid isolates using the chromatographic method, identification of the structure of pure flavonoid isolates using a UV-Vis spectrophotometer with the addition of a shear reagent, FTIR, and LC-MS/MS. As well as test the antioxidant activity using the DPPH method. The yield of ethanol extract from cassava leaf in this study was 14.67%. The results of the phytochemical screening showed that the cassava leaves and the ethanol extract of cassava leaves contained alkaloids, flavonoids, saponins, tannins, quinones, steroids, phenolics, and triterpenoids. The total content of flavonoids in the ethanol extract was 35.71 mg EQ/g extract. UV-Vis, FTIR, and LC-MS/MS analysis revealed that the flavonoid isolate was quercetin. The results of the antioxidant activity of the ethanol extract and BC isolate showed IC50 of 81.76 ± 0.505 mg/L and 77.85 ± 4.708 mg/L.

Cassava (Manihot esculenta Crantz): A Systematic Review for the Pharmacological Activities, Traditional Uses, Nutritional Values, and Phytochemistry

Cassava (Manihot esculenta Crantz) is considered one of the essential tuber crops, serving as a dietary staple food for various populations. This systematic review provides a comprehensive summary of the nutritional and therapeutic properties of cassava, which is an important dietary staple and traditional medicine. The review aims to evaluate and summarize the phytochemical components of cassava and their association with pharmacological activities, traditional uses, and nutritional importance in global food crises. To collect all relevant information, electronic databases; Cochrane Library, PubMed, Scopus, Web of Science, Google Scholar, and Preprint Platforms were searched for studies on cassava from inception until October 2022. A total of 1582 studies were screened, while only 34 were included in this review. The results of the review indicate that cassava has diverse pharmacological activities, including anti-bacterial, anti-cancer, anti-diabetic, anti-diarrheal, anti-inflammatory, hypocholesterolemic effects, and wound healing properties. However, more studies that aim to isolate the phytochemicals in cassava extracts and evaluate their pharmacological property are necessary to further validate their medical and nutritional values.

Antibacterial activities of plant leaf extracts against multi-antibiotic resistant Staphylococcus aureus associated with skin and soft tissue infections

Background

The antibacterial activities of aqueous leaf extracts of Moringa oleifera, Vernonia amygdalina, Azadirachta indica and Acalypha wilkesiana against multidrug resistance (MDR) Staphylococcus aureus associated with skin and soft tissue infections were investigated.

Methods

Staphylococcus aureus (n = 183) from the skin and soft tissue infections with evidence of purulent pus, effusions from aspirates, wounds, and otorrhea were biotyped, and evaluated for biofilm production. The phenotypic antibiotic resistance and MDR strains susceptibility to plant leaves extract were determined using disc diffusion and micro-broth dilution assays respectively. The correlation of plant extract bioactive components with inhibitory activities was determined.

Results

High occurrence rate of S. aureus were recorded among infant and adult age groups and 13.2% mild biofilm producers from the wound (p < 0.05). Of 60.2% MDR strains with overall significant MARI of more than 0.85 (p < 0.05), high resistant rates to linozidine (92.7%; 95% CI:7.27–10.52), ofloxacin (94.2%; 95% CI:6.09–8.15), chloramphenicol (91.2%; 95% CI:6.11–8.32), gentamicin (97.3%; 95% CI:6.20–8.22), ciprofloxacin (92.7%; 95% CI: 5.28–7.99) and vancomycin (86.6%; 95% CI:6.81–9.59) were observed. Vernonia amygdalina and Azadirachta indica showed significant antimicrobial activity at 100 mg/ml and 75 mg/ml, with low susceptibility of less than 10% to 25 mg/ml, 50 mg/ml, and 75 mg/ml Moringa oleifera. Alkaloids, saponin and terpenoids were significant in Moringa oleifera, Acalypha wilkesiana, Azadirachta indica and Vernonia amygdalina leaves extracts (p < 0.05). High inhibitory concentrations at IC50; 3.23, 3.75 and 4.80 mg/ml (p = 0.02, CI: − 0.08 – 11.52) and IC90; 12.9, 7.5, and 9.6 mg/ml (p = 0.028, CI: 2.72–23.38) were shown by Acalypha wilkesiana, Vernonia amygdalina and Moringa oleifera respectively. Comparative outcome of the plant extracts showed Acalypha wilkesiana, Vernonia amygdalina and Moringa oleifera to exhibit significant inhibition activities (p < 0.05) compared to other extracts. Significant median inhibitory concentration (15.3 mg/ml) of Azadirachta indica were observed (p < 0.01) and strong associations of phytochemical compounds of Azadirachta indica (eta = 0.527,p = 0.017), Vernonia amygdalina (eta = 0.123,p = 0.032) and Acalypha wilkesiana (eta = 0.492,p = 0.012) with their respective inhibitory values.

Conclusion

Observed high occurrence rate of skin and soft tissue infections caused by biofilm-producing MDR S. aureus requires alternative novel herbal formulations with rich bioactive compounds from Moringa oleifera, Acalypha wilkesiana, Azadirachta indica and Vernonia amygdalina as skin therapeutic agents.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-022-03527-y.

In Vitro Technology in Plant Conservation: Relevance to Biocultural Diversity

Plant diversity is critical to the functioning of human societies, and evidence shows that plant conservation success is driven by integrative approaches that include social and biological factors. Plants have a unique capacity to reproduce asexually, and propagation practices can yield large numbers of plantlets. These plantlets can be used in several ways to fulfil conservation goals including the repopulation of regions with declining densities of threatened species that hold cultural meaning. However, the potential of in vitro technologies in the conservation of plants that hold cultural meaning is understudied. In this paper we focus upon the roles of in vitro technologies in the conservation of plants relevant to biocultural environments and provide an overview of potential knowledge gaps at the interface of in vitro and plants used traditionally, including those meaningful to Indigenous Peoples. We conclude that in vitro technologies can be powerful tools in biocultural conservation if they are deployed in a manner respectful of the socio-cultural context in which plants play a role, but that further research is needed in this regard. We suggest several epistemological points to facilitate future research.

Phytochemical screening and determination of phenolics and flavonoids in Dillenia pentagyna using UV-vis and FTIR spectroscopy

Here, we report an ultrasonic-assisted extraction (UAE) of phytochemicals from bark, leaves, sepals, fruits, and seeds of Dillenia pentagyna (Roxb) using different organic solvents such as chloroform, ethanol, and n-hexane. The preliminary phytochemical screening results showed that the ethanolic extract is enriched with phenolics, flavonoids, tannin, saponin, alkaloid, and terpenoids. The profiling of phytochemicals is carried out employing UV-Vis and Fourier-transform infrared (FTIR) spectroscopy analyses. The higher amount of phenolic compounds obtained in the ethanolic extract of bark and leaves as compared to other parts of the plant. Consequently, a higher amount of total flavonoid compounds unveiled in the bark of targeted species. The ethanolic extract of bark and leaves showed good free radical scavenging activity using DPPH with inhibition percentage of 90.58 ± 1.89% and 76.46 ± 1.58%, respectively, in comparison to standard ascorbic acid at 10 μg/mL. Moreover, the half-maximal inhibitory concentration (IC₅₀) value of bark and leaves are 5.64 and 6.54 μg/mL, respectively, in comparison to standard ascorbic acid. With the best of our knowledge, it is the first report pertaining to characterization and quantification of phenols and flavonoids as well as the investigation of the medicinal property in D. pentagyna.