Antioxidant properties of methanolic extracts from Diospyros mespiliformis (jackal berry), Flacourtia indica (Batoka plum), Uapaca kirkiana (wild loquat) and Ziziphus mauritiana (yellow berry) fruits

Traditional Uses, Pharmacological Activities, and Phytochemical Analysis of Diospyros mespiliformis Hochst. ex. A. DC (Ebenaceae): A Review

Diospyros mespiliformis Hochst. ex. A. DC is widely distributed throughout Africa and around the world. It is utilized ethnobotanically to treat fevers, wounds, malaria, diabetes mellitus, and other diseases. This review aims to provide an exhaustive overview of the traditional uses, pharmacology, and phytochemical analysis of D. mespiliformis, with the objective of identifying its therapeutic potential for further research. Scientific resources, including Google Scholar, Science Direct, Web of Science, Pub Med, and Scopus, were used to find pertinent data on D. mespiliformis. Secondary metabolites tentatively identified from this species were primarily terpenoids, naphthoquinones, phenolics, and coumarins. D. mespiliformis has been reported to demonstrate pharmacological activities, including antimicrobial, antiproliferative, antiparasitic, antioxidant, anti-inflammatory, antiviral, anti-hypersensitivity, and antidiabetic properties. The phytochemicals and extracts from D. mespiliformis have been reported to have some pharmacological effects in in vivo studies and were not toxic to the animal models that were utilized. The D. mespiliformis information reported in this review provides researchers with a comprehensive summary of the current research status of this medicinal plant and a guide for further investigation.

Unveiling major ethnopharmacological aspects of genus Diospyros in context to its chemical diversity: A comprehensive overview

Diospyros species (DS), "Ebenaceae," were known for their therapeutic uses in folk medicine since days of yore. Thereafter, scientific evidence related their health benefits to a myriad of chemical classes, for instance, naphthoquinones, flavonoids, tannins, coumarins, norbergenin derivatives, sterols, secoiridoids, sesquiterpenes, diterpenoids, triterpenoids, volatile organic compounds (VOCs), and carotenoids. The available literature showed that more than 200 compounds were isolated and identified via spectroscopic techniques. Many pharmacological activities of DS have been previously described, such as antioxidant, neuroprotective, antibacterial, antiviral, antiprotozoal, antifungal, antiinflammatory, analgesic, antipyretic and cosmeceutical, investigated, and confirmed through versatile in vitro and in vivo assays. Previous studies proved that genus Diospyros is a rich reservoir of valuable bioactive compounds. However, further comparative studies among its different species are recommended for more precise natural source-based drug discovery and clinical application. Accordingly, this review is to recall the chemical abundance and diversity among different members of genus Diospyros and their ethnopharmacological and pharmacological uses. PRACTICAL APPLICATIONS: Practically, providing sufficient background on both secondary metabolites divergence and pharmacological properties of genus Diospyros has many fruitful aspects. As demonstrated below, extracts and many isolated compounds have significant curative properties, which can lead to the discovery of pharmaceutically relevant alternative substitutes to conventional medicine. Consequently, molecular docking on various receptors can be applied. On the grounds, Naoxinqing tablets, a standardized herbal product containing D. kaki leaves extract, have been patented and recorded in Chinese Pharmacopeia as an approved Traditional Chinese Medicine (TCM) for the treatment of cerebro- and cardiovascular diseases, although the underlying mechanism remains under advisement. Moreover, the antimicrobial applications of DS are of considerable concern; since the widespread use of antibiotics resulted in different forms of bacterial resistance, hence, limiting and compromising effective treatment. In addition, as a result of contemporary rampant memory disorders, neuroprotective activities of different extracts of DS became of great emphasis.

Flacourtia indica fruit extract modulated antioxidant gene expression, prevented oxidative stress and ameliorated kidney dysfunction in isoprenaline administered rats

This study evaluated the effect of Flacourtia indica fruit extract against isoprenaline (ISO) induced renal damage in rats. This investigation showed that ISO administration in rats increased the level oxidative stress biomarkers such as malondialdehyde (MDA), nitric oxide (NO), advanced protein oxidation product (APOP) in kidneys followed by a decrease in antioxidant enzymes functions. Flacourtia indica fruit extract, which is rich in strong antioxidants, also reduced the MDA, NO and APOP level in kidney of ISO administered rats. Inflammation and necrosis was also visible in kidney section of ISO administered rats which was significantly prevented by atenolol and Flacourtia indica fruit extract. Moreover, atenolol and Flacourtia indica fruit extract also modulated the genes expressions related to inflammation and oxidative stress in kidneys. The beneficial effects could be attributed to the presence of a number of phenolic antioxidants. This study suggests that Flacourtia indica fruit extract may prevent kidney dysfunction in ISO administered rats, probably by preventing oxidative stress and inflammation.

Elephantorrhiza elephantina: Traditional Uses, Phytochemistry, and Pharmacology of an Important Medicinal Plant Species in Southern Africa

Elephantorrhiza elephantina is used in southern Africa as traditional remedy for a wide range of human diseases and ailments including dermatological diseases, gastrointestinal system disorders, sexual dysfunction, sexually transmitted infections, and wounds. The rhizome decoction of E. elephantina is widely used by small-scale farmers in Botswana and South Africa as ethnoveterinary medicine for cattle, goats, horses, pigs, poultry, and sheep. Several classes of phytochemical compounds including anthocyanidins, anthraquinones, esters, fatty acids, phenolic compounds, flavonoids, glycosides, polysterols, saponins, sugars, tannins, and triterpenoids have been isolated from E. elephantina. Scientific studies on E. elephantina indicate that it has a wide range of biological activities including anthelmintic, antibacterial, antifungal, anti-inflammatory and antinociceptive, antiplasmodial, antioxidant, antibabesial, and antirickettsial activities. Elephantorrhiza elephantina is a valuable source of traditional medicine in southern Africa that it is worth additional research attention because of its wide ethnomedicinal applications and promising biological activities. However, the current health-related information on E. elephantina is not sufficiently explored as diverse studies on its chemical and pharmacological activities are required to understand its mechanism of action and to characterize the metabolites responsible for these activities.

Bioactivities and Health Benefits of Wild Fruits

Wild fruits are exotic or underutilized. Wild fruits contain many bioactive compounds, such as anthocyanins and flavonoids. Many studies have shown that wild fruits possess various bioactivities and health benefits, such as free radical scavenging, antioxidant, anti-inflammatory, antimicrobial, and anticancer activity. Therefore, wild fruits have the potential to be developed into functional foods or pharmaceuticals to prevent and treat several chronic diseases. In the present article, we review current knowledge about the bioactivities and health benefits of wild fruits, which is valuable for the exploitation and utilization of wild fruits.

Estimation of Bioactive Compound, Maslinic Acid by HPTLC, and Evaluation of Hepatoprotective Activity on Fruit Pulp of Ziziphus jujuba Mill. Cultivars in India

Fruits of Ziziphus jujuba Mill. (family: Rhamnaceae), known as Indian jujube or “Ber,” are of potential nutritional and medicinal value. The objectives of the present study were to estimate bioactive compound maslinic acid by HPTLC method and to evaluate in vitro antioxidant and hepatoprotective activity of eight cultivars of Indian jujube. Maslinic acid and the fruit pulp of various cultivars of Indian jujube, namely, Gola, Sannur, Umaran, Mehrun, and Chhuhara, exhibited significantly high antioxidant and hepatoprotective activity. HPTLC-densitometric method was developed for quantification of maslinic acid from fruits of Indian jujube cultivars. The trend of occurrence of maslinic acid in fruits pulp extracts was as follows: Gola > Sannur > Umaran > Mehrun > Chhuhara > Wild > Kadaka > Apple. A significant correlation was shown by maslinic acid content and prevention of oxidative stress induced by CCl₄ in liver slice culture cell treated with extract. Maslinic acid along with its other phytoconstituents like phenols, flavonoids, and ascorbic acid may act as a possible therapeutic agent for preventing hepatotoxicity caused by oxidative stress generated due to the prooxidants like CCl₄. This is the first report of fruit pulp extracts of Z. jujube cultivars in India and maslinic acid preventing CCl₄ induced damage in liver slice culture cell of mice.

Anti-inflammatory and mutagenic evaluation of medicinal plants used by Venda people against venereal and related diseases

ETHNOPHARMACOLOGY RELEVANCE

Inflammation is a major risk factor for various human diseases including venereal diseases, often resulting in treatment complications. Plants have been traditionally used for treatment of many different diseases and have been successfully proven to be an alternative source in treatment of infectious diseases.

AIM OF THE STUDY

This study was aimed at evaluating the anti-inflammatory activities and the mutagenic properties of 12 medicinal plants used by the Venda people against venereal and related diseases.

MATERIALS AND METHODS

The plants were evaluated for their anti-inflammatory activity against the cyclooxygenase (COX-1 and -2) enzymes and genotoxicity using the Ames test, with and without S9 (metabolic activation) against Salmonella typhimurium tester strain TA98.

RESULTS

DCM and PE extracts of Adansonia digitata bark, Bolusanthus speciosus bark, Pterocarpus angolensis bark and Pappea capensis leaves and EtOH and water extracts of Bolusanthus speciosus stem and Ekebergia capensis bark showed the best anti-inflammatory activity in both COX-1 and -2 assays at 250 μg/ml. These were further evaluated at three other concentrations (31.25, 62.5, and 125 μg/ml) to determine IC50 values. Water extracts of Ekebergia capensis bark showed the best IC50 value towards COX-1. The Ames test revealed that all plant extracts were non-mutagenic towards Salmonella typhimurium strain TA98 except for Elephantorrhiza burkei and Ekebergia capensis that showed weak mutagenicity.

CONCLUSION

The active plants may offer a new source of chemicals for the effective treatment of anti-inflammatory conditions related to venereal diseases.

Antimicrobial properties and phenolic contents of medicinal plants used by the Venda people for conditions related to venereal diseases

ETHNOPHARMACOLOGY RELEVANCE

Many people are infected by venereal diseases and the human immunodeficiency virus (HIV) in rural areas. Sexual transmitted diseases are considered a disgrace in the community because of the stigmas attached to them. Indigenous people tend to use several medicinal plants to treat these infectious diseases rather than western medicines.

AIM OF THE STUDY

This study was aimed to evaluate the antibacterial, antifungal, antigonococcal, HIV-type 1 reverse transcriptase (RT) and to determine phenolic content of twelve medicinal plants used by the Venda people to treat venereal diseases.

MATERIALS AND METHODS

The dried plant materials of twelve medicinal plants were extracted with petroleum ether (PE), dichloromethane (DCM), 80% ethanol (EtOH) and water. The extracts were evaluated for their antimicrobial properties against two Gram-positive (Bacillus subtilis and Staphylococcus aureus), three Gram-negative (Neisseria gonorrhoeae, Escherichia coli and Klebsiella pneumoniae) bacteria and a fungus Candida albicans. The phenolic contents including total phenolics, flavonoids, gallotannins and condensed tannins of the methanolic extracts of the same plants were also determined.

RESULTS

DCM and EtOH extracts of Bolusanthus speciosus bark and stems exhibited good activity (<0.1mg/ml) against Escherichia coli and Staphylococcus aureus with MIC values ranging from 0.098 to 0.012 mg/ml. The DCM extracts of Bolusanthus speciosus bark showed the best activity against Candida albicans with MIC and MFC values of 0.012 mg/ml. Water and 50% methanol extracts of Acacia karroo bark, Bolusanthus speciosus stems and Ximenia caffra roots and leaves showed good RT inhibition percentages (>70%) at 1mg/ml. All tested extracts exhibited dose dependent IC(50) values ranging from (0.1 to 0.6 mg/ml). Almost all plant species investigated contained phenolic compounds, which were greater than 5mg/g with the exception of Adansonia digitata bark and Aloe chabaudii roots. The highest level of flavonoids (11.9 μg/g) were detected in Ximenia caffra leaves. Whereas the highest amount of gallotannins were detected in Ekebergia capensis bark (69 μg/g). Condensed tannins were higher in Ekebergia capensis bark and Ximenia caffra roots (0.47 and 0.48% respectively). Adansonia digitata bark and Aloe chabaudii roots exhibited low levels of phenolic compounds as well as antimicrobial activities.

CONCLUSION

The presented results offer supporting evidence for effective use of selected plant extracts. More in vitro confirmatory tests using other assays and/or in vivo tests are required. Toxicity studies are urgently needed to support the safe usage of these plants.

Flavored waters: influence of ingredients on antioxidant capacity and terpenoid profile by HS-SPME/GC-MS

The antioxidant profiles of 39 water samples (29 flavored waters based on 10 natural waters) and 6 flavors used in their formulation (furnished by producers) were determined. Total phenol and flavonoid contents, reducing power, and DPPH radical scavenging activity were the optical techniques implemented and included in the referred profile. Flavor extracts were analyzed by HS-SPME/GC-MS to obtain the qualitative and quantitative profiles of the volatile fraction of essential oils. Results pointed out a higher reducing power (0.14-11.8 mg of gallic acid/L) and radical scavenging activity (0.29-211.5 mg Trolox/L) of flavored waters compared with the corresponding natural ones, an interesting fact concerning human health. Bioactive compounds, such as polyphenols, were present in all samples (0.5-359 mg of gallic acid/L), whereas flavonoids were not present either in flavored waters or in flavors. The major components of flavor extracts were monoterpenes, such as citral, α-limonene, carveol, and α-terpineol.

Natural antioxidants: fascinating or mythical biomolecules?

Research on the use, properties, characteristics and sources of antioxidants especially phenolic compounds, flavonoids, vitamins, synthetic chemicals and some micronutrients began in the late 18^th century. Since then antioxidant research has received considerable attention and over a hundred thousand papers have been published on the subject. This has led to a rampant use of antioxidants in order to try to obtain and preserve optimal health. A number of nutraceuticals and food supplements are frequently fortified with synthetic or natural antioxidants. However, some research outcomes have led to the belief that antioxidants exist as mythical biomolecules. This review provides a critical evaluation of some common in vitro antioxidant capacity methods, and a discussion on the role and controversies surrounding non-enzymatic biomolecules, in particular phenolic compounds and non-phenolic compounds, in oxidative processes in an attempt of stemming the tidal wave that is threatening to swamp the concept of natural antioxidants.

Antimicrobial, anti-inflammatory and mutagenic investigation of the South African tree aloe (Aloe barberae)

ETHNOPHARMACOLOGY RELEVANCE

In recent times, many products ranging from aloe drinks to aloe gels, powders, capsules, and creams have appeared on the commercial market prepared from different aloe species including Aloe barberae. These products are used in ethnomedicine to treat various conditions including gastrointestinal disorders, insect bites, skin burns and other skin injuries by traditional communities.

AIM OF THE STUDY

This study was aimed at evaluating the antibacterial, antifungal and anti-inflammatory activities as well as genotoxic effects of different extracts of Aloe barberae.

MATERIALS AND METHODS

Organic and water extracts of the upper stem, young bark, mature bark, leaves and roots of the South African tree aloe (Aloe barberae) were evaluated for their antimicrobial [gram-positive (Bacillus subtilis and Staphylococcus aureus), gram-negative (Escherichia coli and Klebsiella pneumoniae) bacteria as well as the fungus Candida albicans], anti-inflammatory (COX-1 and COX-2) and mutagenic properties (Ames test). Thin layer chromatography (TLC) was used to compare the phytochemical profiles of different extracts of Aloe barberae.

RESULTS

The petroleum ether (PE) and dichloromethane (DCM) extracts of the mature bark, leaves and roots exhibited good activity against all the bacteria and fungus Candida albicans with minimum inhibitory concentrations (MIC) ranging from 0.195 to 1.56 mg/ml. All the PE extracts evaluated showed a high activity (>70%) in both COX-1 and COX-2 assays. Apart from the organic extracts of the root with consistently good activity (>70%), all the remaining extracts showed moderate activity (40-69%) in COX-1 assay. The PE extracts also showed a dose dependent increase in activity. Ultraviolet (UV) spectrum of the leaves and root EtOH extracts indicated the presence of compounds that could absorb UV light (wavelength: 190-820 nm). None of the extracts had a mutagenic effect in the Salmonella/microsome assay against a tester strain, TA98.

CONCLUSION

Activity observed in the bark, leaves and roots of Aloe barberae validates its use in commercial herbal products, ethnobotany and ethnoveterinary medicine by South African communities and small scale farmers to treat various conditions.