Chemical and biological studies of Lobelia flaccida (C. Presl) A.DC leaf: a medicinal plant used by traditional healers in Eastern Cape, South Africa

Purpose: To investigate the phytochemical constituents, acute toxicity and biological activities of Lobelia herb (dried leaf of Lobelia flaccida; family: Campanulaceae), a popular medicinal agent used to manage pain and epilepsy among other indications in Eastern Cape Region of South Africa.Methods: Essential oil (EO) obtained from the dried leaf was analysed with gas chromatography-mas spectroscopy GC/MS while an infusion extract of the herb was obtained by soaking in hot boiled water (100 oC) for 24 h, filtered and the filtrate dried in vacuo. Phytochemical screening of the infusion extract was performed to detect the presence of secondary plant metabolites and relative abundance of some of the metabolites. The aqueous extract was evaluated for oral (p.o.) acute toxicity (LD50) using the Lorke’s method [30];, thereafter the extract was tested for anti-inflammatory activity on carrageenaninduced rat paw oedema at 250 and 500 mg/kg, p.o., normal saline and aspirin (100 mg/kg, p.o.) used as negative and positive controls respectively. Finally, the extract at 500 and 1000 mg/kg, p.o. was tested for anticonvulsant activity on pentylene tetrazol (85 mg/kg, intraperitoneally)-induced convulsion model in mice, normal saline and diazepam (1 mg/kg, i.p.) served as negative and positive control groups respectively.Results: EO yield was 0.022 % w/w and the two major compounds identified were acetophenone (26.37 %) and caryophyllene (17.35 %). Phytochemical screening showed high concentration of alkaloids, saponins and flavonoids among other constituents. LD50 of the aqueous extract was ≥ 5000 mg/kg per oral while the aqueous extract exhibited significant (p < 0.01) anti-inflammatory activity on carrageenan-induced rat paw oedema comparable to aspirin but insignificant anticonvulsant activity on pentylene tetrazol-induced convulsion when compared with diazepam.Conclusion: Lobelia herb is non-toxic, and possesses significant anti-inflammatory and mild anticonvulsant activities. It is suggested that the essential oil of this herb should be screened for pharmacological activities.Keywords: Lobelia flaccida, Essential oil, Gas chromatography/mass spectroscopy analysis , Infusion extract, Acute toxicity, Anti-inflammatory, Anti-convulsan

CHEMICAL ANALYSIS AND BIOLOGICAL POTENTIAL OF VALERIAN ROOT AS USED BY HERBAL PRACTITIONERS IN THE EASTERN CAPE PROVINCE,

Background: Herbal practitioners in the Eastern Cape of South Africa use valerian root (Valeriana capensis, Valerianaceae) to manage pains, arthritis and inflammation. The herb prepared from this plant was studied to determine the chemical composition of it’s essential oil, carried out phytochemical screening and biological activities on its infusion extract as used by the herbal practitioner. Materials and Methods: Essential oil of Valerian root was obtained by hydrodistillation and subjected to chemical analyses. Infusion extract of the Valerian root was screened to determine its secondary metabolites and the relative abundance of some major metabolites. The infusion extract was further evaluated for acute toxicity (LD50), anti-inflammatory and analgesic activities in rodents. Results: The yield of the essential oil was 0.18% w/w. The GC/MS analysis indicated the presence of 42 compounds with major ones being caryophyllene oxide (18.11%), viridiflorol (9.37%) and bornyl acetate (8.84%). Phytochemicals found in the infusion extract were alkaloids, saponins, tannins and flavonoids while quantitative screenings showed saponins and flavonoids accounted for 6.39% and 7.40% respectively. The LD50 of the extract was found to be 3808 mg/kg per oral. The infusion extract of the root (250-500 mg/kg, p.o.) caused significant (

Chemical analysis and biological potential of Valerian root as used by herbal practitioners in the Eastern Cape Province, South Africa

Background: Herbal practitioners in the Eastern Cape of South Africa use valerian root (Valeriana  capensis, Valerianaceae) to manage pains, arthritis and inflammation. The herb prepared from this plant was studied to determine the chemical composition of its essential oil, carried out phytochemical  screening and biological activities on its infusion extract as used by the herbal practitioner.Materials and Methods: Essential oil of Valerian root was obtained by hydrodistillation and subjected to chemical analyses. Infusion extract of the Valerian root was screened to determine its secondary  metabolites and the relative abundance of some major metabolites. The infusion extract was further evaluated for acute toxicity (LD50), anti-inflammatory and analgesic activities in rodents.Results: The yield of the essential oil was 0.18% w/w. The GC/MS analysis indicated the presence of 42 compounds with major ones being caryophyllene oxide (18.11%), viridiflorol (9.37%) and bornyl acetate (8.84%). Phytochemicals found in the infusion extract were alkaloids, saponins, tannins and flavonoids while quantitative screenings showed saponins and flavonoids accounted for 6.39% and 7.40%  respectively. The LD50 of the extract was found to be 3808 mg/kg per oral. The infusion extract of the root  (250-500 mg/kg, p.o.) caused significant (p<0.01) activity in the carrageenan-induced rat paw oedema model comparable to aspirin, indicating anti-inflammatory activity; but lacked analgesic activity on the acetic acid-induced writhing test.Conclusion: The infusion extract possessed significant anti-inflammatory but lacked analgesic activity; the present data justify the use of this herbal agent by the herbal practitioners from the Eastern Cape  region of South Africa.Key words: Valeriana capensis, essential oil, caryophyllene oxide, infusion extract, anti-inflammatory, analgesi

Synthesis of Silver Nanoparticles Using Buchu Plant Extracts and Their Analgesic Properties

We herein report for the first time the synthesis and analgesic properties of silver nanoparticles (Ag-NPs) using buchu plant extract. The as-synthesised Ag-NPs at different temperatures were characterised by UV-Vis spectroscopy, Fourier transform infra-red spectroscopy (FTIR) and transmission transform microscopy (TEM) to confirm the formation of silver nanoparticles. Phytochemical screening of the ethanolic extract revealed the presence of glycosides, proteins, tannins, alkaloids, flavonoids and saponins. The absorption spectra showed that the synthesis is temperature and time dependent. The TEM analysis showed that the as-synthesised Ag-NPs are polydispersed and spherical in shape with average particle diameter of 19.95 ± 7.76 nm while the FTIR results confirmed the reduction and capping of the as-synthesised Ag-NPs by the phytochemicals present in the ethanolic extract. The analgesic study indicated that the combined effect of the plant extract and Ag-NPs is more effective in pain management than both the aspirin drug and the extract alone