Isolation, characterization and anti-inflammatory activity of compounds from the Vernonia amygdalina

The need to explore the abundance of natural products cannot be overemphasized particularly in the management of various disease conditions. In traditional medical practice, Vernonia amygdalina has been widely adopted in the management of various inflammatory disorders. The objective of this investigation was to isolate the bioactive principles from the stem-bark and root of V. amygdalina and assess the anti-inflammatory (in vitro) activity of both the crude extracts and the isolated compounds. Following extraction with the methanol, the extract was subjected to gravity column chromatography and the resultant fractions was further purified to obtained pure compounds. The structural elucidation of the compounds were based on data obtained from 1H to 13C nuclear magnetic resonance (NMR) spectroscopies as well as fourier transform infrared (FT-IR). Using diclofenac as a control drug, the albumin denaturation assay was used to determine the in vitro anti-inflammatory activity of the extracts and isolates. Three distinct compounds characterized are vernoamyoside D, luteolin-7-α-o-glucuronide, and vernotolaside, a new glycoside. When compared to diclofenac, which has an IC50 of 167.8 μg/mL, luteolin-7-α-o-glucuronide, vernoamyoside D, and vernotolaside all showed significant inhibitions with respective IC50 values 549.8, 379.5, and 201.7 μg/mL. Vernotolaside is reported for the first time from the root. The assertion that the plant is used in traditional medicine for the management of inflammatory disorder is somewhat validated by the confirmation of the existence of the compounds with the biochemical actions. Further validation of the isolated compounds would be required in animal studies.

Chemical dataset of levels of heavy metals in vineyard soil and grapevine leaf samples from Cape Winelands, South Africa

The chemical analysis of vineyards is an essential tool for the early detection of risks, such as excessive fertilization and heavy metal and pesticide contamination in farm management. Soil and plant samples were collected in summer and winter from six different vineyards with varying agricultural practices in the Cape Winelands of the Western Cape Province, South Africa. The samples were pretreated in a microwave using CEM MARS 6™ Microwave Digestion and Extraction System (CEM Corporation, Matthews, NC, USA). Chemical element data were obtained using an inductively coupled plasma optical emission spectrometer (ICP-OES) (ICP Expert II, Agilent Technologies 720 ICP-OES). The data will be valuable for selecting and improving farming practices and gaining insights into the influence of seasonal variation and agricultural practices on the elemental accumulation in farmlands.

Natural antioxidants from some fruits, seeds, foods, natural products, and associated health benefits: An update

Antioxidants are compounds that inhibit the oxidation of other molecules and protect the body from the effects of free radicals, produced either by normal cell metabolism or as an effect of pollution and exposure to other external factors and are responsible for premature aging and play a role in cardiovascular disease. degenerative diseases such as cataracts, Alzheimer's disease, and cancer. While many antioxidants are found in nature, others are obtained in synthetic form and reduce oxidative stress in organisms. This review highlights the pharmacological relevance of antioxidants in fruits, plants, and other natural sources and their beneficial effect on human health through the analysis and in-depth discussion of studies that included phytochemistry and their pharmacological effects. The information obtained for this review was collected from several scientific databases (ScienceDirect, TRIP database, PubMed/Medline, Scopus, Web of Science), professional websites, and traditional medicine books. Current pharmacological studies and evidence have shown that the various natural antioxidants present in some fruits, seeds, foods, and natural products have different health-promoting effects. Adopting functional foods with high antioxidant potential will improve the effective and affordable management of free radical diseases while avoiding the toxicities and unwanted side effects caused by conventional medication.

Levels of Heavy Metals in Grapevine Soil and Leaf Samples in Response to Seasonal Change and Farming Practice in the Cape Winelands

Heavy metal toxicity is a major threat to the health of both humans and ecosystems. Toxic levels of heavy metals in food crops, such as grapes, can have devastating effects on plant health and the market value of the produce. Two important factors that may influence the prevalence of heavy metals in grapevines are seasonal change and farming practices. The objectives of this study were (i) to conduct a detailed pioneer screening of heavy metal levels in soils and grapevine leaf tissues in selected wine farms and (ii) to study the influence of season and farming on heavy metal levels in soils and grapevine leaf tissues. Soil and grapevine leaf samples were collected from demarcated areas in selected vineyards in the Cape Winelands region of South Africa. The sampling was conducted in winter and summer from the same sites. The soil and leaf samples were analysed using inductively coupled plasma mass spectrometry (ICP-MS) techniques. The pooled data from the farms practising conventional or organic farming showed that seasonal variation had no significant effect (DF = 1, 22; p > 0.05) on the heavy metal contents in the soil. When the soil data from the winter and summer months were compared separately or pooled, the influence of agricultural practice was well-pronounced in As (DF = 1, 22, or 46; p < 0.05) and Cu (DF = 1, 22, or 46; p <0.05). The agricultural practice greatly influenced (DF = 1, 22; p< 0.05) Cu, As, Cr, and Hg uptake, with little effect on Ni, Co, Cd, and Hg leaf contents. Generally, the heavy metals studied (Cr, Co, Ni, Zn, As, Cd, Hg, and Pb) were substantially below the maximum permitted levels in plant and soil samples, per the recommendations of the WHO and E_r indices, respectively. However, moderate contamination of the soils was recorded for Cr, Ni, Zn, and Pb. Remarkably, the Cu levels in the organic vineyard soils were significantly higher than in the conventional vineyards. Furthermore, based on the I_geo index, Cu occurred at moderate to heavy contamination levels.

Comparing Crop Yield, Secondary Metabolite Contents, and Antifungal Activity of Extracts of Helichrysum odoratissimum Cultivated in Aquaponic, Hydroponic, and Field Systems

The overexploitation of wild plants for medicinal uses and conventional agricultural farming methods, which use high amounts of water, fertilizers, and pesticides, have had devastating environmental consequences. This study aimed to evaluate the prospects of using aquaponics and hydroponics as alternative approaches to soil cultivation by comparing the crop yields, secondary metabolite contents, and the antifungal activities of ethanol extracts of Helichrysum odoratissimum (L.) Sweet, a widely used medicinal plant species in Southern Africa. Six-week-old H. odoratissimum seedlings were grown in aquaponic and hydroponic systems. The growth parameters, secondary metabolite contents, and antifungal activity against Fusarium oxysporum were assessed. The results for crop yield (plant height, fresh and dry weights) and the tissue nutrient contents did not change substantially (p > 0.05) between aquaponic and hydroponic treatments. Gas chromatography−mass spectrometry (GC−MS) analysis showed that monoterpenes and sesquiterpenes were the most abundant compounds in H. odoratissimum; however, no statistical difference was observed among the field, hydroponic, and aquaponic plants (DF = 2; χ2 = 2.67; p > 0.05). While there was no significant difference in polyphenol contents among the three treatments, remarkably, the flavonol contents in the leaves varied significantly (DF = 2; χ2 = 6.23; p < 0.05) among the three treatments. A higher flavonol content occurred in leaves from the hydroponic system than in leaves from the aquaponic (p < 0.05) and field (p > 0.05) systems. The MIC results showed that the ethanolic extract of H. odoratissimum was fungistatic against F. oxysporum; however, this effect was more prominent in the ethanol extracts of plants grown in the aquaponic system, with a mean MIC value of 0.37 ± 0.00 mg/mL The key findings of this study are that aquaponically cultivated plants exhibited the best antifungal activity, while higher total flavonol contents occurred in the hydroponically cultivated plants. In conclusion, aquaponics and hydroponics performed better or similar to field cultivation and are viable alternative methods for cultivating H. odoratissimum plants.

In pursuit of new anti-malarial candidates: novel synthesized and characterized pyrano-benzodioxepin analogues attenuated Plasmodium berghei replication in malaria-infected mice

Malaria, a parasitic disease, is one of the major causes of morbidity and mortality, particularly in the tropics. Following the increased resistance of the primary causative parasite, Plasmodium sp, to the mainstream drug, artemisinin combination therapies (ACTs), combating malaria incidences, morbidity and mortality have remained elusive. Novel pyrano-benzodioxepin derivatives (DHA-PABA and DHA-LEVO) were synthesized and characterized using Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopies. The compounds were subjected to standard in vivo antimalarial screening (using chloroquine-sensitive strain) in mice, and the toxicity was also determined using a standard assay. The observed elevation in serum alkaline phosphatase and acid phosphatase activity in the untreated and the group administered lower doses of DHA-LEVO is an indication of the hepatic stage of the parasite in the experimental animal, which is accompanied by significant perturbation in the membrane of the hepatocyte leading to leakage of this enzyme out of the liver cells. The semisynthetic pyrano-benzodioxepin derivatives act rapidly by clearing the parasite load from the blood. The novel pyrano-benzodioxepin candidates containing endoperoxide functionality hold promise in the pursuit of new monotherapy drug candidates against the virulent strain of the plasmodium.

Toxicity assessment of sub-acute and sub-chronic oral administration and diuretic potential of aqueous extract of Hibiscus sabdariffa calyces

Background

Food and herbal usage of Hibiscus sabdariffa (HS) is attaining improved global relevance and acceptance without recourse to its potential toxic effects. This study investigated the safety profile of acute, sub-acute, sub-chronic administrations and diuretic potential of aqueous extract of Hibiscus sabdariffa calyces (AEHSC).

Method

Acute oral toxicity, sub-acute and sub-chronic toxicity as well as diuretic studies were carried out on HS. A total of 20 Wistar rats were used for each toxicity study and assigned into four groups of five rats. The extract was administered as a single daily dose of 125, 250 and 500 mg/kg body weight (bwt) for 28 and 90 days respectively. To evaluate diuretic activity, 25 rats were divided into five groups of five rats and administered normal saline, hydrochlorothiazide 10 mg/kg, AEHSC 67.5, 125 and 250 mg/kg via the oral route. Urine sample was collected after 18 h, volume measured and concentration of electrolytes analyzed. The hematological and biochemical parameters were evaluated as well as the histopathology of kidney and liver.

Results

The acute oral toxicity was found to be >2000 mg/kg. AEHSC did not alter concentration of WBC, MCV, MCHC, lymphocyte as well as total and direct bilirubin in the sub-acute study. However, AEHSC significantly (p < 0.05) increased total protein, albumin, globulin, Na⁺, Cl⁻, HCO₃^- and platelet levels, while levels of uric acid, creatinine, K⁺, RBC, Hb, total cholesterol, triglycerides, LDL-C, HDL-C and atherogenic index were decreased significantly (p < 0.05). In the sub-chronic study, AEHSC significantly (p < 0.05) increased the levels of globulin, urea, creatinine, MCH and atherogenic index. The concentrations of uric acid, WBC, platelets and HDL-C were significantly (p < 0.05) decreased. In both the sub-acute and sub-chronic studies, activities of ALP, ALT, AST, GGT and LDH in selected organs were altered without significant increase (P < 0.05) in activity of these enzymes in the serum. The AEHSC at all the doses showed remarkable diuretic activity during 18 h period comparable to hydrochlorothiazide. The extract also showed a non-dose-dependent increase in excretion of electrolytes. Histological analysis of sections of the liver and kidney for both sub-acute and sub-chronic studies showed normal histology comparable to the control group.

Conclusion

This study revealed AEHSC has some toxic effects in rats on sub-chronic administration. In addition, the extracts produced a significant diuretic activity. Hence, prolonged oral consumption of the extract may not be recommended.

Chemical characterization, antioxidant, cytotoxicity, Anti-Toxoplasma gondii and antimicrobial potentials of the Citrus sinensis seed oil for sustainable cosmeceutical production

There are growing concerns about the chronic and acute effects of synthetic additives such as antibacterial, fragrances, colourants and stabilizing agents used in the production of various household products. Many household products and materials including cosmetic products are reportedly suspected to be carcinogenic with some acting as endocrine disruptors among other effects. Thus, environmental-friendly alternatives such as products that are rich in bioactive phytochemicals are becoming consumers' preferred choice especially in the beauty and cosmetic sector. 'Green' preparation of medicinal soaps devoid of any synthetic additives was made from underutilized tropical seed of Citrus sinensis seed oil and some natural additives comprising of natural honey, Ocimum gratissimum leaves extract, Moringa oleifera seed oil and coconut oil. Precisely, the seed oil of the underexplored C. sinensis was obtained via soxhlet extraction and saponified with natural lye solution at different ratios to produce soaps of varying characteristics. The incorporation of honey and Ocimum gratissimum leaf extract provided additional antimicrobial, antioxidant and fragrance properties. Physico-chemical parameters of the oil and soaps were determined following standard procedures while the fatty acid profile of the trans-esterified oil was determined using GC-MS. The antimicrobial potential of the oil and soaps were assessed using agar diffusion method at concentrations 200 mg/mL and below. Linoleic acid (36%) and oleic acid (27%) were the most prominent in C. sinensis seed oil. The soap had antimicrobial potential comparable to commercial product. The soap samples recorded highest anti-bacteria activities (22.0 ± 1.0-23.0 ± 1.0) against Staphylococcus aureus and Bacillus subtilis and notable anti-fungi activities (18.0 ± 1.0) against Penicillium notatum and Candida albicans. Additionally, the oil showed moderate anti-parasite (anit-toxoplasma gondii) activity (EC50 ≤ 500 μg/mL) but with improved selectivity that precludes oxidative stress while the prepared medicinal soaps exhibited remarkable antioxidant property. The utilization of these locally sourced resources will prevent the daily introduction of synthetic antimicrobial and antioxidant chemicals into the environment. The initiative avail a sustainable production of environmentally-benign cosmetic products besides conversion of waste to wealth agrees which aligns with the Sustainable Development Goals (SDGs).

Chemical composition, anti-toxoplasma, cytotoxicity, antioxidant, and anti-inflammatory potentials of Cola gigantea seed oil

CONTEXT

Cola gigantea A. Chev. (Sterculiaceae) is an important medicinal tropical flora.

OBJECTIVE

The seed oil of C. gigantea, an underutilized tropical plant was investigated for its antioxidant, anti-inflammatory, anti-Toxoplasma, and cytotoxicity activities as well as the chemical composition.

MATERIALS AND METHODS

The physicochemical parameters of the seed oil obtained via Soxhlet extraction was determined while the fatty acid and non-fatty acid component were analyzed by gas chromatography-mass spectrometry. The antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays (10-50 µg/mL) while the anti-inflammatory property was determined through Cell Membrane Stabilization assay. The anti-parasite and cytotoxicity activity were evaluated (0-1000 µg/mL) using Toxoplasma gondii and mammalian cell line assays, respectively.

RESULTS

The oil had fatty acids which ranged from C-12 to C-23 with linoleic (18:2) and palmitic acids (16:0) being dominant. The oil had 89.41% unsaturated fatty acids with sterolic acid, an uncommon acetylenic fatty acid reported for the first time. Non-fatty acids obtained include cholesterol (2.12%), campesterol (14.12%), stigmasterol (34.07%) and β-sitosterol (49.68%). The oil had a significantly (p < 0.05) low scavenging activity against DPPH radicals (IC₅₀ > 50 µg/mL) compared with ascorbic acid. In contrast, the oil showed better activity against ABTS radicals (IC₅₀ 44.19 ± 6.27 µg/mL) compared with ascorbic acid or quercetin. Furthermore, the oil showed anti-T. gondii and dose-dependent cytotoxicity in HFF cells with selectivity index (IC₅₀/EC₅₀ < 1).

DISCUSSION AND CONCLUSIONS

The antioxidant potential of the oil suggests that it may serve as a potential source for various preparations for pharmaceuticals and cosmeceuticals.

Functional roles of ammonium (NH4+) and nitrate (NO3-) in regulation of day- and night-time transpiration in Phaseolus vulgaris

Nitrogen may regulate transpiration and consequently the delivery of nutrients to root surfaces. It remains unclear whether both NO3- and NH4+ regulate transpiration and nutrient acquisition. In this study we investigated the functional role of NO3- or NH4+ in regulating both day- and night-time transpiration for potential 'mass-flow' delivery of nutrients. Phaseolus vulgaris L. plants were grown in troughs with a poly vinyl chloride (PVC) 'root-barrier' with a 25-µm mesh window designed to create an N-availability gradient by restricting roots from intercepting a slow-release NO3- or NH4+ fertiliser. 'Root-barrier' plants had their fertiliser placed at one of four distances behind the mesh from which nutrient acquisition was by diffusion or mass-flow. Control plants had direct access to fertiliser, termed 'no root-barrier' plants. NO3--fed 'root-barrier' plants closest to the N source had 2-fold higher stomatal conductance, 2.6-fold higher transpiration, 1.8-fold higher night-time stomatal conductance, and 1.5-fold higher night-time transpiration than NO3--fed 'no-barrier' plants, despite having comparable photosynthetic rates and biomass. Day- and night-time transpiration of NO3--fed 'root-barrier' plants, however, was downregulated with further distance from the N source. All NH4+-fed plants displayed ammoniacal toxicity symptoms. NH4+-fed 'no root-barrier' plants had higher root biomass, 2-fold higher stomatal conductance and photosynthetic rate, 1.7-fold higher transpiration but had the same night-time stomatal conductance and transpiration compared with NH4+-fed 'root-barrier' plants closest to the N source. Unlike with NO3--fed 'root-barrier' plants, NH4+-fed 'root-barrier' plants continuously increased their water fluxes with distance of N source. Thus, under N-limited conditions plants may be opportunistic in their water uptake, transpiring more when the water is available, in order to acquire nutrients through mass-flow. NH4+-fed plants prone to ammoniacal toxicity allocated their biomass towards the roots at non-limiting N levels, which may be linked to their extensive root system and enhanced photosynthetic rate. Thus, root hydraulic conductivity in response to NH4+-N requires further scrutiny, given that previous studies indicated that NH4+ may not alter the expression of root aquaporins or root hydraulic conductance.

Cytotoxicity of selected medicinal plants used in Mt. Frere District, South Africa

BACKGROUND

In South African traditional medicine, some are plants known to combat pediatric diseases and are commonly used by traditional healers. The aim was to evaluate cytotoxicity effects of plants.

MATERIALS AND METHODS

The ground plant material was exhaustively extracted using methanol, acetone and water separately for 72 hrs. These organic solvents were removed from filtrates using a rotavapour. Stock solutions were prepared at 40 mg/ml Dimethyl sulfoxide (DMSO) and test solutions were transferred into vials and 10 brine shrimps introduced in each. The number of dead shrimps was counted to ascertain toxicity. Ten A. salina nauplii (larva) were transferred into each sample vial and filtered brine solution was added to make 5 ml. The nauplii were counted macroscopically in the stem of the pipette against a lighted background. A drop of dry yeast suspension was added as food to each vial. Probit analysis was used to determine the concentration at which lethality to brine shrimp represents 50 % (LC50).

RESULTS

All the tested extracts showed that the concentration is directly proportional to death of brine shrimps. Fifty percent lethality (LC50) of the tested crude extract ranged between 4.1 and 4.6 µg/ml with methanol extract of B. abyssinica being the lowest and T. acutiloba the highest.

CONCLUSION

This study revealed that 100% of plant crude extracts screened for activity against Artemisia salina larvae showed strong cytotoxicity below 10 µg/ml and plant species with LC50 values < 1000 µg/ml may not make good paediatric remedies due to their inherent toxicity.

Investigation of the antinociceptive and anti-inflammatory properties of Heteromorpha arborescens (Apiaceae)

Heteromorpha arborescens belongs to the family Apiaceae. It is commonly known as the parsley tree. One of its uses in the Eastern Cape Province of South Africa is for the treatment of abdominal pains. The therapeutic effects of the methanolic and aqueous root extracts of H. arborescens were investigated at two dose levels respectively on experimental models of pain and inflammation in rodents. The antinociceptive activity was evaluated using the hot-plate, abdominal constriction and formalin tests. The anti-inflammatory properties of these extracts were assessed using albumin and carrageenan as phlogistic agents. Both extracts produced significant (P<0.05, P<0.01) inhibition of thermal nociception induced by a hot plate. On chemical nociception induced by intraperitoneal acetic acid and subplantar formalin injection, both extracts significantly (P<0.05, P<0.01) decreased the number of writhing episodes and the licking time in a dose dependent manner. Treatment with the extracts at the same doses produced a significant (P<0.05, P<0.01) pain inhibition of the carrageenan induced inflammatory pain. Similarly, both extracts produced a significant (P<0.05, P<0.01) reduction of edema induced by albumin and carrageenan. These results suggest that both extracts of H. arborescens may act by inhibition of the mediators of inflammation. These findings seem to justify the use of the plant in traditional medicine in the management of pain and inflammation related diseases.

Evaluation of the antibacterial and anticancer activities of some South African medicinal plants

BACKGROUND

Several herbs are traditionally used in the treatment of a variety of ailments particularly in the rural areas of South Africa where herbal medicine is mainly the source of health care system. Many of these herbs have not been assessed for safety or toxicity to tissue or organs of the mammalian recipients.

METHODS

This study evaluated the cytotoxicity of some medicinal plants used, inter alia, in the treatment of diarrhoea, and stomach disorders. Six selected medicinal plants were assessed for their antibacterial activities against ampicillin-resistant and kanamycin-resistant strains of Escherichia coli by the broth micro-dilution methods. The cytotoxicities of methanol extracts and fractions of the six selected plants were determined using a modified tetrazolium-based colorimetric assay (3-(4, 5-dimethylthiazol)-2, 5-diphenyl tetrazolium bromide (MTT) assay).

RESULTS

The average minimum inhibitory concentration (MIC) values of the plants extracts ranged from 0.027 mg/mℓ to 2.5 mg/mℓ after 24 h of incubation. Eucomis autumnalis and Cyathula uncinulata had the most significant biological activity with the least MIC values. The in vitro cytotoxicity assay on human hepatocarcinoma cell line (Huh-7) revealed that the methanol extract of E. autumnalis had the strongest cytotoxicity with IC(50) of 7.8 μg/mℓ. Ethyl acetate and butanol fractions of C. uncinulata, Hypoxis latifolia, E. autumnalis and Lantana camara had lower cytotoxic effects on the cancer cell lines tested with IC(50) values ranging from 24.8 to 44.1 μg/mℓ; while all the fractions of Aloe arborescens and A. striatula had insignificant or no cytotoxic effects after 72 h of treatment.

CONCLUSIONS

Our results indicate that the methanol fraction of E. autumnalis had a profound cytotoxic effect even though it possessed very significant antibacterial activity. This puts a query on its safety and hence a call for caution in its usage, thus a product being natural is not tantamount to being entirely safe. However, the antibacterial activities and non-cytotoxic effects of A. arborescens and A. striatula validates their continuous usage in ethnomedicine.

An ethnobotanical study of plants used for the treatment of sexually transmitted diseases (njovhera) in Guruve District, Zimbabwe

The use of medicinal plants in Guruve District, Zimbabwe, contributes significantly to primary health care of the people of the area. This paper presents findings of a survey of plants used for the treatment of sexually transmitted diseases (STDs) in the district. Ethnobotanical information obtained from traditional herbalists and other knowledgeable rural dwellers, has revealed 15 plant species belonging to 10 families as medicinal plants used for the treatment of these infections in the area. Six of these are the commonest and most frequently prescribed by the healers. Roots are the most frequently used parts of the plants constituting 53% of preparations while oral administration of extracts is the main method of prescription. Based on the information gathered from the traditional healers, Acacia nilotica (L.) Willd. ex Delile, Cassia abbreviata Oliv. Dichrostachys cinerea Wight and Arn, Solanum incanum L., Vernonia amygdalina Del. and Zanha africana (Radlk) Excell. are the most frequently used plants for the treatment of STDs. The methanol extracts of Cassia abbreviata, Zanha africana and Acacia nilotica showed significant inhibition against Gram-positive and Gram-negative bacteria, while acetone extracts of these plants inhibited most of the species. Generally the water extracts show less activity than acetone and methanol extracts.