Nutritional composition and antinutrient content of Heteromorpha arborescens (Spreng.) Cham. & Schltdl. leaves: An underutilized wild vegetable.

The nutritional and antinutrient composition of Heteromorpha arborescens (Spreng.) Cham. & Schltdl. leaves was reported in this study. Proximate analysis revealed the presence of 8.5% total ash, 4.92% crude fat, 8.41% moisture, 15.74% crude protein, 21.48% crude fiber, 40.95% carbohydrates, and 271.04 kcal/100 g energy value. Mineral analysis showed that H. arborescens leaves are very rich in K, Ca, and Fe. Considerable amounts of Mg, Mn, Na, P, Cu, and Zn were also present. Vitamin analysis showed that the plant has a high content of vitamins A, C, and E. The antinutrients evaluated were phytate, oxalate, saponin, and alkaloids, all of which were below toxic levels except for saponin which was observed at moderately high level. The results credibly indicate that H. arborescens leaves are nutrient-rich and can contribute effectively to the daily nutrient requirements alongside its therapeutic properties.

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.

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.