Isolation and characterization of β-sitosterol, oleanolic, 19- dehyroursolic and yarumic acids, from Plectranthus esculentus leaves and tubers

Plectranthus esculentus N.E.Br. (family Lamiaceae) also known as Livingstone potato (vat or rizga in Nigeria), is a dicotyledonous perennial shrub growing up to 2 m tall. While it is cultivated mainly for its edible tubers, the plant is potentially valuable as phytomedicine. Three varieties (vat-long’at, vat-riyom and vat-bebot) are well known among the Berom of Plateau State, Nigeria. The vat-bebot variety (which showed good promise in bioactivity studies) was used in this study. The leaves and tubers were extracted successively with hexane, ethyl acetate, methanol and water. Fractionation of the active ethyl acetate extracts was carried out using open column and preparative High Performance Liquid Chromatography (prep HPLC). This led to the isolation of β-sitosterol and oleanolic acid from the leaves; while 19-dehydroursolic acid and yarumic acid, as well as β-sitosterol were isolated from the tubers. Nuclear Magnetic Resonance (NMR) and Electron Impact Mass Spectroscopy (EIMS) were used to characterize isolated compounds. Comparing acquired spectral data of isolated compounds with those from literature helped to confirm the identity of the compounds. The isolation and characterisation of these compounds, from Plecthranthus esculentus, have not been hitherto reported in literature

Antiproliferative, antioxidant and antiplasmodial activities of the root bark of Adenodolichos paniculatus (Hua) Hutch (Fabaceae)

Adenodolichos paniculatus Hua & Hutch (Fabaceae) is a plant whose roots are traditionally employed for the treatment of non-communicable diseases such as diabetes and cancer. The powdered root bark of Adenodolichos paniculatus were extracted with dichloromethane followed by 70% methanol to afford dichloromethane (DCM) and hydromethanolic (HME) extracts respectively. Thereafter, fresh powdered root was extracted with water via decoction method and lyophilized to afford aqueous extract (AQE). The extracts were then subjected to standard phytochemical studies, antiproliferative (A2780 ovarian cancer cell assay), antiplasmodial (Dd2 strain of Plasmodium falciparum), antioxidant (DPPH, FRAP and ABTS methods) and brine shrimp lethality assay studies. The DCM extract was found to possess high levels of total phenolics and flavonoids with notable potential antiproliferative (IC50 = 0.14 μg/ml), antiplasmodial (IC50 = 7.50 μg/ml) and cytotoxic (brine shrimp, IC50 = 0.547 μg/ml) activities. However, HME had significant antioxidant (DPPH, IC50 = 17.54 ± 0.03 μg/ml; ABTS, IC50 = 8.08 ± 0.05 μg/ml). Both HME and AQE were found to be inactive against the drug-resistant Dd2 strain of Plasmodium falciparum with an IC50 value ˃100μg/mL. The study revealed the potential of Adenodolichos paniculatus as a promising antiproliferative agent and also corroborated the ethnomedical uses of the plant