Antiulcer activity of methanolic extract and fractions of Picralima nitida seeds(Apocynacaea) in rats

Potential Antiulcer Agents From Plants: A Comprehensive Review

Background:

Peptic ulcer is a deep gastrointestinal erosion disorder that involves the entire mucosal thickness and can even penetrate the muscular mucosa. Nowadays, several plants and compounds derived from it have been screened for their antiulcer activity. In the last few years, there has been an exponential growth in the field of herbal medicine. This field has gained popularity in both developing and developed countries because of their natural origin and less side effects.

Objective:

This review aims to provide a comprehensive summary of currently available knowledge of medicinal plants and phytoconstituents reported for their anti-ulcer properties.

Methods:

The worldwide accepted database like SCOPUS, PUBMED, SCIELO, NISCAIR, ScienceDirect, Springerlink, Web of Science, Wiley, SciFinder and Google Scholar were used to retrieve available published literature.

Results:

A comprehensive review of the present paper is an attempt to list the plants with antiulcer activity. The review narrates the dire need to explore potential chemical moieties that exert an antiulcer effect, from unexploited traditional plants. Furthermore, the present study reveals the intense requirement to exploit the exact mechanism through which either the plant extracts or their active constituents exhibit their antiulcer properties.

Conclusion:

This article is the compilation of the plants and its constituents reported for the treatment of peptic ulcers. The Comprehensive data will surely attract the number of investigators to initiate further research that might lead to the drugs for the treatment of ulcers. As sufficient scientific data is not available on plants, most of the herbals cannot be recommended for the treatment of diseases. This can be achieved by research on pure chemical structures derived from plants or to prepare new lead compounds with proven beneficial preclinical in vitro and in vivo effects. However, a lot remains to be done in further investigations for the better status of medicinal plants.

Picralima nitida seeds suppress PGE2 production by interfering with multiple signalling pathways in IL-1β-stimulated SK-N-SH neuronal cells

ETHNOPHARMACOLOGICAL RELEVANCE

The dried seed of Picralima nitida is used in rheumatic fever and as an antipyretic in West Africa. In this study we have investigated the effects of an extract obtained from the seeds of Picralima nitida (PNE) on PGE2 production in IL-1β-stimulated cells.

MATERIALS AND METHODS

Prostaglandin E2 (PGE2) was measured in supernatants of IL-1β-stimulated SK-N-SH cells using enzyme immunoassay (EIA) for PGE2. In Cell ELISA and western blot were used to evaluate the effects of PNE on protein expressions of COX-2, mPGES-1, IκB and IKK. To determine the effect of the extract on NF-κB transactivation, a reporter gene assay was carried out in HEK293 cells stimulated with TNFα. An ELISA was used to measure the roles of p38, ERK1/2 and JNK Mitogen Activated Protein Kinases (MAPKs) on anti-neuroinflammatory actions of PNE.

RESULTS

Results show that PNE significantly inhibited PGE2 production, as well as COX-2 and mPGES-1 protein expressions in IL-1β-stimulated SK-N-SH cells. Molecular targeting experiments showed that PNE interfered with NF-κB signalling pathway through attenuation of TNFα-stimulated NF-κB transcriptional activation in HEK 293 cells. Furthermore, IL-1β-mediated phosphorylation of IκB and IKK were inhibited in SK-N-SH cells. PNE (50-200 μg/ml) also produced significant inhibition of IL-1β-induced p38 MAPK phosphorylation in SK-N-SH cells. However, phosphorylation of ERK1/2 and JNK MAPKs were achieved at 100 and 200 μg/ml of the extract.

CONCLUSIONS

Taken together, these results clearly demonstrate that Picralima nitida suppresses PGE2 production by targeting multiple pathways involving NF-κB and MAPK signalling in IL-1β-stimulated SK-N-SH neuronal cells.

Anti-hyperglycemic effects of three medicinal plants in diabetic pregnancy: modulation of T cell proliferation

Background

Populations in Africa mostly rely on herbal concoctions for their primarily health care, but so far scientific studies supporting the use of plants in traditional medicine remain poor. The present study was undertaken to evaluate the anti-hyperglycemic effects of Picralima nitida (seeds), Nauclea latifolia (root and stem) and Oxytenanthera abyssinica (leaves) commonly used, in diabetic pregnancy.

Methods

Pregnant wistar rats, rendered diabetic by multiple low injections of streptozotocin, were treated with selected plant extracts based on their antioxidant activities. Vitamin C concentrations, fatty acid compositions and phytochemical analysis of plants extracts were determined. Effect of selected plant extracts on human T cell proliferation was also analysed.

Results

All analysed plant extracts exhibited substantial antioxidant activities probably related to their content in polyphenols. Picralima nitida exhibited the highest antioxidant capacity. Ethanolic and butanolic extracts of Picralima nitida, butanolic extract of Nauclea latifolia and ethanolic extract of Oxytenanthera abyssinica significantly decreased hyperglycemia in the diabetic pregnant rats. Butanolic extract of Picralima, also appeared to be the most potent immunosuppressor although all of the analysed extracts exerted an immunosuppressive effect on T cell proliferation probably due to their linolenic acid (C18:3n-3) and/or alkaloids content. Nevertheless, all analysed plants seemed to be good source of saturated and monounsaturated fatty acids.

Conclusion

By having antioxidant, anti-hyperglycemic and immunosuppressive activities, these plants could be good candidates in the treatment of diabetes and diabetic pregnancy.