Showing papers by "Peter A. Akah published in 2001"

Evaluation of methanolic extract of Ficus platyphylla on gastrointestinal activity.

Abstract: Methanolic extract of Ficus platyphylla was tested on isolated rabbit jejunum, rat duodenum and gastrointestinal motility in mice. The extract showed a biphasic effect on isolated smooth muscle. Lower concentration of extract caused contraction, while higher concentrations produced relaxation. The contractile phase was attenuated by atropine, while relaxant phase attenuated histamine induced contraction of guinea pig ileum. The extract also exhibited a dose-dependent inhibition of gastrointestinal motility. Acute toxicity test in mice established LD50 value (i.p.) of the extract to be 2000 mg/kg. Preliminary phytochemical screening of the extract gave positive test for flavonoids, tannins and saponins.

Pharmacological Activity of the Methanolic Extract of Cassia nigricans Leaves

Abstract: Results: The extract markedly protected rats against cold-stress and aspirin-induced gastric mucosal damage. The extract exhibited significant (p <0.05) anti-inflammatory and anti-nociceptive activities in rats and mice respectively. Furthermore, the extract decreased the amplitude of contraction of the isolated rabbit jejunum and inhibited histamine-induced contractions, but did not affect ACh induced responses. The intraperitoneal LD50 values of the extract was 210+4.5 mg/kg in mice. Conclusion: The extract shows good analgesic, anti-inflammatory effects and protected rats against gastric mucosal damage. The anti-ulcer activity might be via histaminergic receptor inhibition.

Anthelmintic Screening of the Stem Bark of Berlina grandiflora

Abstract: Objective: To screen the anthelmintic properties of Berlina grandiflora . Materials and methods: The dried stem bark of Berlina grandiflora was extracted with 95% ethanol. Hexane, ethyl acetate and methanolic fractions were obtained successively from crude 95% ethanolic extract, leaving behind a crystalline residue. The crude extract and the resulting fractions were screened for anthelmintic activity and compared with piperazine using rats infected with Nippostrongylus brasiliensis . Qualitative phytochemical analysis was performed on the ethanolic extract and the residue. Results: At a dose of 100 mg/kg orally, the extracts have caused over 50% deparasitization in rats infected with Nippostrongylus brasiliensis. The highest anthelmintic activity was recorded in rats treated with the residue. The residue was found to be rich in tannins. Conclusion: Berlina grandiflora exhibits remarkable anthelmintic activity against N. brasiliensis and the results substantiate its traditional use as an anthelmintic.

Potentials of Plant Products as Anticancer Agents

Abstract: Cancer has remained a major health concern. Advances in existing therapeutic modalities have failed to provide cure, prevent a relapse and are always accompanied by serious and often times debilitating side effects. Extensive screening of plants for anticancer activity has produced some encouraging and impressive results. More than 40,000 plant species have reportedly been screened for anticancer effects. Some of such plants include - Podophyllum hexandrum, Podophyllum petatum, Catharanthus rosea, Taxus brevifolia, Taxus baccata, Camptotheca accuminata etc. Anticancer principles from plants include among others, alkaloids of Vinca rosea (Vinblastine and Vincristine), Ocheosia elliptica (ellipticine and I± - methoxyellipticine), toxin of Ipomea batatas and ricin from Ricinus communis . Mechanisms proposed to underlie the anticancer effect of these plants include mitotic arrest in the S, G, and metaphase phases, inhibition of normal mitotic spindle formation, inhibition of microtubule depolymerization and topoisomerase inhibition. Some of these plants/principles are already in use while some are in the clinical trial stages of drug development. Active plant principle can also provide templates upon which synthetic and semi-synthetic derivatives can be produced such as the active analogue of Camptothecin: 9-aminocamptothecin, topotecan and irinotecan. The success recorded from the relatively small number of plant species so far screened out of an estimated plant population of half a million worldwide indicate the enormous therapeutic potential inherent in natural endowments of plant origin. With more than 90% of the plant population still unexploited, plants definitely hold hope for the discovery of potent anticancer agents with minimal side effects/toxicity profile and capable of preventing a relapse.

Evaluation of the Antiulcer Properties of Pseudocedrela kotschyi Stem Bark Extract

Abstract: Aqueous stem bark extract of Pseudocedrela kotschyi, Harms (Meliaceae) was investigated for antiulcer activity. The extract neither contracted nor relaxed the isolated guinea pig ileum. It however, inhibited the contraction evoked by acetylcholine and histamine in a doserelated manner. Gastrointestinal motility in mice was significantly (p Discovery and Innovation Vol. 13 no. 3/4 December (2001) pp. 132-135 KEY WORDS: antiulcer, Pseudocedrela kotschyi, stem bark

Cardiovascular Effects of the Aqueous Extract of Chrysanthellum indicum

Abstract: Objective: To study the effects of the aqueous extract of Chrysanthellum indicum on cat blood pressure and isolated rat atria. Materials and methods: Cardiovascular activity was evaluated directly on anaesthetised cat, isolated rat atria and isolated rabbit jejunum. Safety assessments were carried out in mice and preliminary phytochemical screening was also carried out on the extract. Results: The aqueous extract of Chrysanthellum indicum (2-32 mg/kg i.v.) were found to cause a dose dependent decrease in blood pressure. The fall in blood pressure was attenuated by atropine. The extract also exhibited a concentration - dependent decrease in the force of contraction of the spontaneously beating atria. The extract evoked a concentration - dependent contraction of the isolated rabbit jejunum, which was abolished by atropine. The intraperitoneal LD 50 of the extract was found to be 282.2 ± 5.2 mg/kg and the extract gave positive reactions to flavonoids, tannins, glycosides and alkaloids. Conclusion: The aqueous extract of C. indicum may contain some biologically active principle(s), which may be relevant in the management of cardiovascular disorders, thereby agreeing with some aspects of the traditional use of this plant as a remedy for heart troubles.

Purgative Activity of the Aqueous Leaf Extract of Peninanthus longifolius Miers

Abstract: Objective: To investigate the claimed purgative property of aqueous leaf extract of Peninanthus longifolius . Materials and methods: Safety profile was evaluated using acute toxicity test (mice). Phytochemical constituents were determined using standard procedures. Effect of extract on the intestinal muscle was studied in isolated guinea pig ileum in the presence and absence of agonists and antagonists. Activity of the extract on intestinal motility was assessed by charcoal meal test (mice) and faecal output determination (mice). Doses of 125, 250 and 500 mg/kg of the extract were used orally. Results: LD 50 of the extract of P. longifolius was 3.0 ± 0.85 g/kg. Phytochemical constituents include carbohydrates, proteins, tannins, saponins, alkaloids, steroidal aglycones and glycosides. The extract produced contraction in the guinea pig ileum in a dose-related manner. The contraction was antagonized only by atropine but not by hexamethonium or mepyramine. It also increased intestinal motility and faecal output. Conclusion: Aqueous leaf extract of P. longifolius produced significant (p < 0.05) degree of purgation predominantly through stimulation of cholinergic pathway. This may be attributed to one or more bioactive constituents found in the leaf.