Medicinal plants in Africa and other parts of the world have been used for the managements of different ailments. This study was aimed at investigating the antibacterial and antihypertensive effects of the aqueous and ethanolic extracts of H. umbellata seeds on experimental animals. The phytochemical studies were carried out according to the methods of Association of Official Analytical Chemist (A.O.A.C), while the antibacterial and physiological studies were done using the standard microbiological and physiological methods.
The results of the mineral composition of H. umbellata seeds revealed the presence of K, Na, P, Mg, Ca, Fe, Mn, Zn, Cu, while the highest percentage was recorded for Fe 24.56 %. The proximate composition of the crude extract contains crude protein, residual moisture content, lipid, crude fibre, ash content, carbohydrate, with carbohydrate recording the highest value (71.55 %). The results of the quantitative phytochemical components of aqueous and ethanolic extracts revealed the presence of oxalate, phytate, tannins, flavonoids, saponins, alkaloids, phenols, cyanogenic glycoside and anthraquinones. The highest value for aqueous extract was 20.8 mg/kg for alkaloid and phenols 37.90 mg/kg for ethanolic extract. The minimum inhibitory concentration (MIC) of aqueous and ethanolic extracts at concentration of 15 mg/ml were bacteriostatic against Proteus sp., Staphylococcus sp., Candida albicans. The minimum bacteriocidal concentration (MBC) of aqueous and ethanolic extracts at a concentration of 50 mg/ml were bacteriocidal against Staphylococcus aureus, Micrococcus sp., Bacillus sp. Proteus sp. Streptococcus pneumoniae. The extracts showed better bacteriostatic and bacteriocidal effects compared with the conventional antibiotics drugs used in the study.
The administration of the standard drug (propranolol) caused a reduction in high systolic blood pressure of the hypertensive experimental animals from 162.00 mmHg to 134.00 mmHg, while the diastolic pressure was recorded to fall from 103.00 mmHg to 73.67 mmHg. The administration of aqueous extract of H. umbellata seeds caused a reduction of the systolic blood pressure of the hypertensive experimental animals from 159.20 mmHg to 136.25 mmHg, while the diastolic blood pressure was recorded to fall from 103.80 mmHg to 80.25 mmHg. The administration of ethanolic extract of H. umbellata seeds caused a reduction in systolic blood of the hypertensive experimental animals from 160.20 mmHg to 133.00 mmHg, while the diastolic pressure was recorded to drop from 102.20 mmHg to 76.75 mmHg. The results of the aqueous and ethanolic extracts of H. umbellata seeds on the haematological and biochemical parameters showed no significance compared to normal control. The histological results of both aqueous and ethanolic extracts of H. umbellata seeds revealed appreciable recovery of the degenerating tissues. Medicinal plants have become a great source of medicine for the treatments and management of various ailments. In this study it could be inferred that the relevance of medicinal plants in the treatments and managements of hypertension cannot be overemphasized, it is therefore recommended that further researches on the medicinal values of H. umbellata seedsand its therapeutic effects to health sector be encouraged.
