Chemical Composition of Essential Oils Obtained from Heteromorpha arborescens (Spreng.) Cham. and Schltdl Leaves Using Two Extraction Methods.

This study was aimed at comparing the essential oils obtained from Heteromorpha arborescens leaves by Solvent-Free Microwave Extraction (SFME) and Hydrodistillation (HD) methods in terms of their chemical compositions, yield, CO2 emission, and energy consumption. The solvent-free microwave extraction method indicated a higher oil yield of 0.7 mL/200 g (0.35%) as compared to 0.59 mL/200 g (0.295%) obtained through hydrodistillation. GC-MS analysis of the oils revealed a total of 52 chemical components from both methods with the presence of 35 (96.52%) and 30 (71.15%) chemical constituents for HD and SFME, respectively. The major constituents observed in the essential oil extracted by SFME methods include α-pinene (6%), D-limonene (11.27%), ß-ocimene (9.09%), ß-phellandrene (6.33%), ß-mycene (8.49%), caryophyllene (5.96%), and camphene (4.28%). However, in the hydrodistillation method, the oil was majorly composed of a-pinene (4.41%), ß-pinene (10.68%), ß-ocimene (6.30%), germacrene-D (5.09%), humulene (5.55%), and α-elemene (6.18%). The SFME method was better in terms of saving energy (0.25 kWh against 4.2 kWh of energy consumed), reduced CO2 emission (200 g against 3360 g of CO2), a higher yield, and better quality of essential oil due to the presence of higher valuable oxygenated compounds (8.52%) against that of the hydrodistillation method (2.96%). The SFME method is, therefore, a good alternative for extracting the oils of H. arborescens leaves since the essential oil yield is higher with more oxygenated compounds, considerable energy savings, lower cost, and reduced environmental burden at substantially reduced extraction time (30 min as opposed to 180 min).

Assessment of the phytochemical, antioxidant and antibacterial activities of Heteromorpha arborescens (Spreng.) Cham & Schltdl. leaf extracts.

Background:Heteromorpha arborescens (Spreng.) Cham. and Schltdl (Apiaceae) is widely used traditionally for the treatment of a wide range of diseases in Southern and Eastern Africa. Although previous studies have reported the biological activities of hexane, ethyl acetate and methanol extracts of H. arborescens leaves, there is no scientific information on the phytochemical contents, antioxidant and antibacterial activities of acetone, ethanol, aqueous and blanched extracts. This study is therefore aimed to investigate and compare the phytochemical contents, antioxidant and antibacterial activities of acetone, ethanol, aqueous and blanched extracts of H. arborescens leaves. Methods: Phytochemical analysis for the total phenolic, flavonoid, proanthocyanidin, alkaloid and saponin contents of all the fractions were determined by spectroscopic methods, while the free radical scavenging potential of the extracts were evaluated using DPPH, ABTS radical scavenging and total antioxidant capacity assays. Micro dilution method was used to determine the Minimum Inhibitory Concentrations (MIC) of H. arborescens leaf extracts against Bacillus pumilus, Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae. Results: Total phenol content of the extracts ranged between 15.10 mg GAE/g- 42.50 mg GAE/g, proanthocyanidin was 459-8402.1 mg QE/g, and flavonoid content of 109.24-235.79 mg QE/g. In addition, alkaloids (5.59%) and saponins (23.33%) were present in significant amounts. Based on the IC 50 values, the ethanol extract exhibited the highest total antioxidant activity (0.013 mg/mL) with highest inhibition against DPPH and ABTS radicals (0.06 and 0.049 mg/mL respectively). Considerable antibacterial activities were observed in the acetone, ethanol and blanched extracts with MIC values ranging from 1.563-12.5 mg/mL; however, the aqueous extract was inactive against all the bacteria strains. Conclusion: The study suggests that H. arborescens leaves could be a valuable source of bioactive compounds. Although the blanching process significantly decreased polyphenolic contents and antioxidant activities of the extracts, it increased the antibacterial compounds.

Anti-inflammatory and cytotoxic evaluation of extracts from the flowering stage of Celosia argentea.

BACKGROUND: This study was aimed at investigating the possible anti-inflammatory and cytotoxic effects of extracts from the flowering stage of C. argentea. This growth stage was chosen because of its high polyphenolic content and high antioxidant capacity. METHODS: Anti-inflammatory potential of the aqueous, acetone and methanol extracts of C. argentea was evaluated through the inhibition of nitric oxide production (LPS-induced) on stimulated macrophages (RAW 264.7), while MTT assay was used to assess cell viability with Silymarin as standard. Cytotoxicity of the plant extracts was evaluated on murine preadipocyte cell line (3 T3-L1) using the image-based method of two DNA-binding dyes; Hoechst 33342 and propidium iodide (PI) with melphalan as standard. RESULTS: Acetone extract exhibited moderate, dose-dependent anti-inflammatory activity with no significant toxicity to activated macrophages, however the aqueous and methanol extracts were unable to inhibit nitric oxide production at both trials. MTT assay and the toxicity assay revealed that the flowering stage extracts of C. argentea were not toxic to the RAW 264.7 macrophages and 3 T3-L1 cells at all the tested concentrations (0, 2, 50, 100 and 200 µg/mL). CONCLUSIONS: These findings corroborate the traditional use of C. argentea for painful inflammatory conditions and encourage its possible use as lead for the development of novel, non-toxic, anti-inflammatory agents.

Proximate and elemental composition of leaf, corm, root and peel of Hypoxis hemerocallidea: A Southern African multipurpose medicinal plant.

Hypoxis hemerocallidea also known as African potato is a medicinal plant widely distributed in Southern Africa, which has enjoyed long usage as a traditional multipurpose herbal medicine. This study evaluated the leaf, corm, peel and root of H. hemerocallidea for their nutritional attributes. Crude protein was highest in leaf (5.56%), followed by peel (2.79%), root (2.30%) and corm (1.79%) respectively. Crude fat ranged from 0.40% in root to 1.88% in leaf, while ash and acid detergent fibre (ADF) were highest in corm (16.77% and 49.75%) and lowest in root (3.20% and 5.46%) respectively. Neutral detergent fibre (NDF) was highest in leaf (55.47%), followed by corm (52.38%), peel (35.23%) and root (10.51%); while total carbohydrate calculated as non-fibre carbohydrate was highest in the root. The corm had the highest content (P<0.05) of calcium, zinc, copper and manganese, the root exhibited the highest content of magnesium, potassium and iron, while sodium and phosphorus content was highest in the leaf. The study revealed that H. hemerocallidea leaf, corm, peel and root are good sources of nutrients and minerals for humans and animals. This implies that the plant as a whole could be more effective therapeuticaly than the corm alone.

Phytochemical and Antioxidant Activities of Cucumis africanus L.f.:: A Wild Vegetable of South Africa.

OBJECTIVE: To evaluate the phytochemical content and antioxidant potential of the acetone, aqueous, and methanol extracts of the fruit, leaf, and root of Cucumis africanus L.f. METHODS: Total phenolic, flavonoid, and proanthocyanidin contents were evaluated using spectrophotometric methods. The free radical scavenging activity of the acetone, methanol, and aqueous extracts of the fruit, leaf, and root were evaluated against DPPH+, ABTS+, and phosphomolybdenum. Alkaloid and saponin contents were also determined. RESULTS: The acetone extract of the fruit revealed the highest polyphenol content when compared with the other solvent extracts analyzed. Total phenol content of the parts tested ranged from 3.66 ± 0.17 to 44.98 ± 3.41, flavonoid content ranged from 4.63 ± 3.33 to 401.33 ± 7.89, and proanthocyanidin content ranged from 8.84 ± 2.65 to 504 ± 36.6. Significant amount of alkaloids present was observed in the fruits, leaf, and root (10.68 ± 0.68, 14.12 ± 1.67, and 12.15 ± 4.74), respectively, while saponin content was 33.33 ± 11.55, 26.67 ± 11.55, and 20.00 ± 0.00 for the fruit, leaf, and root, respectively. Solvent extracts showed significant antioxidant activity, with acetone showing highest antioxidant ability in correlation with the polyphenol contents. Based on the IC50 values, acetone extract of the root revealed the best DPPH radical scavenging ability, the leaf aqueous extract had the highest IC50 value for ABTS, and the methanol extract of the leaf was best for phosphomolybdenum assays. CONCLUSION: This study suggests that fruit, leaf, and root of Cucumis africanus could be a potential source of natural antioxidant and justifies its use in ethnomedicine.

Evaluation of acute and subacute toxicity of whole-plant aqueous extract of Vernonia mespilifolia Less. in Wistar rats.

OBJECTIVE: This study investigated the acute and subacute toxicity of whole-plant aqueous extract of Vernonia mespilifolia Less. (AEVM) in rats for evaluating its safety profile. METHODS: AEVM for the acute (2000 and 5000 mg/kg) and subacute (200, 400 and 600 mg/kg) toxicity studies was administered orally to rats according the guidelines 425 and 407 of Organization for Economic Cooperation and Development, respectively. Food and water intake as well as body and organ weight of animals were recorded. Signs of toxicity were assessed, and hematological, biochemical and histopathological analyses were performed. RESULTS: In the acute toxicity study, a single dose of the aqueous extract at 2000 or 5000 mg/kg caused no mortality in the animals, suggesting that the median lethal dose is greater than 5000 mg/kg. In the subacute toxicity study, administration of the extract for 28 d, at all doses, caused no significant changes in the body weights or organ weights of rats in the treated groups when compared with the control group. In addition, hematological and biochemical parameters also revealed no toxic effects of the extract on rats. Histological sections of the heart, liver and kidney from test animals showed no signs of degeneration. CONCLUSION: These results showed that AEVM at dosage levels up to 600 mg/kg is nontoxic and could also offer protection on some body tissues. AEVM could, therefore, be considered safe.

Polyphenolic Content, Antioxidant and Antimicrobial Activities of Vernonia mespilifolia Less. Used in Folk Medicine in the Eastern Cape Province, South Africa.

Vernonia mespilifolia Less. is a shrub of the Asteraceae family used in the South African traditional medicine system for the management of weight loss, hypertension, and heartwater disease. There is a need for scientific evaluation to validate its ethnomedicinal usage. In vitro assays were conducted to evaluate the polyphenolic content, antioxidant and antimicrobial properties of different solvent extracts (acetone, aqueous, and ethanol) of the whole plant of Vernonia mespilifolia spectrophotometric and agar dilution techniques, respectively. The result revealed varying amounts of polyphenolics in the different solvent extracts corresponding to the antioxidant activities. Also, only the acetone and ethanol extracts inhibited the growth of the selected bacteria and fungi. These findings reveal that the extracts have strong bioactive compounds and hence support its ethnomedicinal application.

Acute and subacute toxicity of aqueous extract of the tuber of Kedrostis africana (L.) Cogn in Wistar rats.

Kedrostis africana (L.) Cogn (Cucurbitaceae) is used in South African traditional medicine and pharmacopoeia as an emetic, purgative and diuretic, and it is used against dropsy in the management of obesity. Aim of the study In this study, acute and subacute toxicity of aqueous extract of K. africanatuber was evaluated in male and female Wistar rats in order to assess its safety profile. Materials and methods In acute toxicity, the effects of a single oral dose (2,000 and 5,000 mg/kg) of aqueous extract was determined in both sexes. General behavior, adverse effects and mortality were determined for 3 h and then periodically for 14 days. The subchronic toxicity test was performed in rats. The effects of the extract in daily single oral administration at the doses of 200, 400 and 600 mg/kg for 28 days were determined. Food and water intakes were monitored daily while body weight was monitored on a weekly bases. Hematological, biochemical and organ parameters were determined at the end of the 28-day administration. Results In the acute study, a single administration of the aqueous extract at the doses of 2,000 and 5,000 mg/kg did not induce mortality. Thus, the LD50 of the aqueous extract of K. africana (AEKA) has been estimated to be higher than 5,000 mg/kg. In the subchronic study, daily oral administration of the AEKA did not result in death of the rats or significant changes in hematological or biochemical parameters at the highest dose of 600 mg/kg. No alteration was observed in body weight, food and water intake. Liver, kidney and heart histopathology did not reveal morphological alteration. Conclusions The results showed that the aqueous tuber extract of K. africana did not cause any death, nor did it cause abnormalities in necropsy and histopathology findings. There were no acute or subchronic toxicity observed, and this indicates that the plant extract could be considered safe for oral medication.

Therapeutic effect of aqueous extracts of three dietary spices and their mixture on lipid metabolism and oxidative stress in a rat model of chronic alcohol consumption.

The protective effect of aqueous extracts of three dietary spices, garlic, (Allium sativum), ginger (Zingiber officinale) and pepper (Capsicum frutescens) singly and combined was investigated using a rat model of chronic alcohol intake. Rats were given 30% ethanol, with or without aqueous extracts of garlic, ginger, pepper or mixture of the three administered at 200mg/kg body weight by oral gavage for 28 days. Lipid profile, lipid peroxidation, oxidative and antioxidative profiles of serum, faecal, liver, kidney, heart and brain tissues of the rats were analyzed. Alcohol treatment significantly elevated liver enzymes, lipid peroxidation, depleted antioxidant system and induced histopathological changes in the liver. These alterations were markedly ameliorated by treatment with aqueous extracts of the three spices singly or mixed at 200mg/kg body weight. These results suggest that aqueous extracts of garlic, ginger, pepper or a blend of the three protects against alcohol- induced hypercholesterolemia, lipid peroxidation, oxidative stress and liver damage.