Phytochemical composition, and analgesic and antiinflammatory properties of essential oil of Chamaemelum nobile (Asteraceae L All) in rodents

Purpose: To investigate the in vivo analgesic and anti-inflammatory activities of essential oil of dried flowers of Chamaemelum nobile (Asteraceae L. All) in Swiss mice and Wistar rats, respectively.Methods: The volatile oil of the dried flowers of C. nobile obtained by hydrodistillation was analyzed by gas chromatography-mass spectrometry (GC-MS). Animals were assigned to the following experimental groups: C. nobile (180 mg/kg), ibuprofen (100 mg/kg) and vehicle-treated groups. Chemical and thermal pain models were used for the antinociceptive study in mice while fresh egg albumin-induced acute inflammation model in rats was used for anti-inflammatory study of the essential oil.Results: The most abundant components of the oil were α-bisabolol (50 %) and farnesene (5.35 %). Oral administration of essential oil (180 mg/kg, po) significantly (p < 0.05) reduced pain and prevented inflammation in the different test models used in this study.Conclusion: The essential oil of the dried flowers of C. nobile shows in vivo analgesic and antiinflammatory activities in rodents, and therefore, possesses potentials for development into effective analgesic and anti-inflammatory agent.Keywords: Chamaemelum nobile, Asteracea, essential oil, anti-inflammatory, antinociceptiv

Insecticidal activities and chemical composition of the essential oil from Tarchonanthus camphoratus (L.), leaves against Sitophilus zeamais Motschulsky, and Sitophilus oryzae (L.)

The essential oil of Tarchonanthus camphoratus dry leaves growing in Kwa-Zulu Natal, South Africa was obtained by hydrodistillation and evaluated for its repellent effect, contact and fumigation toxicity against both Sitophilus zeamais and Sarocladium oryzae. Chemical composition of the essential oil was analysed by gas chromatography mass spectrometry (GC/MS). The study revealed that the essential oil of T. camphoratus had no contact and fumigation toxicity against stored insect pests, S. zeamais and S. oryzae. The oil, however, showed good repellent activity of over 50% after 24 h for all the concentrations used on both S. zeamais and S. oryzae. A total of 27 compounds accounting for 73% of the total oil composition were identified of which sesquiterpene hydrocarbons, (59.18%), were the most dominant. These results suggest that the essential oil of T. camphoratus could be considered a potential control agent of stored grain pests as a repellent

Acute toxicity study and prevention of Nω-nitro-L-arginine methyl ester-induced hypertension by Osteopermum imbricatum

Purpose: To determine the phytochemical content, toxicity and hypertension prevention effects of Osteospermum imbricatum leaf and root extracts.Methods: Phytochemical screening of leaf and root extracts of O. imbricatum was performed by colorimetric procedure. Acute toxicity of leaf and root extracts was conducted in two phases; phase I consisted of three groups of mice (n = 3) for each dose level of 10, 100 and 1000 mg/kg while phase II had three mice that received 1600, 2900 or 5000 mg/kg. Wistar rats were grouped into 7 groups that were co-treated with L-NAME and normal saline or L-NAME and hydroethanolic leaf extract (150 and 300 mg/kg) or L-NAME and hydroethanolic root extract (150 and 300 mg/kg) or L-NAME and amlodipine (5 mg/kg) or normal saline only for 4 weeks. Treatment was carried out via the oral route while blood pressure was measured weekly for 4 weeks by non-invasive tail cuff method.Results: The phytochemical profile of the leaf and root extracts revealed the presence of phenols, terpenoids, flavonoids, glycosides, tannins, steroids and saponins. Both the leaf and root extracts were toxic at 5000 mg/kg with an LD50 of 3807.89 mg/kg. In the fourth week of the study, only the leaf extract significantly (p < 0.01) prevented the progression of L-NAME induced hypertension; systolic and diastolic blood pressure of the group treated with L-NAME and leaf extract (300 mg/kg) were 183 ± 1 and 140 ± 1 mmHg, respectively, compared to the group that was treated with L-NAME and normal saline which produced systolic and diastolic BP values of 213 ± 3 and 172 ± 4 mmHg, respectively. The extracts, especially OIR300, exhibited diuretic effects in the second and third week of study by promoting excretion of 16 and 19 ml urine, respectively, compared to 11 and 14 ml for LN group.Conclusion: The results suggest that O. imbricatum is moderately toxic at a high dose and contains a wide range of phytochemicals which offer partial protection against the development of nitric oxide deficiency hypertension.Keywords: Hypertension, Phytochemicals, Acute toxicity, Nω-Nitro-L-arginine methyl ester (L-NAME), Osteospermum imbricatu

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