Phytochemical Study and Evaluation of the Biological Activity of Anorectic Plants Used in the Seno Province (Burkina Faso)

Background: In Africa plants have always been a good source of medicine for health care. Obesity is a pathology that is growing dramatically in developing countries. Anorectic plants are likely to cause a reduction of exaggerated weight gain. The aim of the study is to determine the phenolic compound content of five anorectic potential plants of Burkina Faso (Ceratotheca sesamoïdes, Gardenia erubescens, Brachystelma bingeri Raphionacme daronii and Vernonia kotschyana), to determine also their antioxidant potential and their acethylcholinesterase inhibitory capacity.

Place and Duration of Study: Laboratory of Biochemistry and Applied Chemistry (LABIOCA), Research Institute for Health Sciences (IRSS).

Methodology: For the determination of the acute toxicity of the extracts a group of six (6) mice NMRI race were constituted for each plant extract. A dose of 3000 mg / kg of weight was administered to the animals. The methods of screening were used to detect secondary metabolites like tannins, steroids and terpen, flavonoids, coumarins. For the phenol content, the concentration of total phenolics, flavonoids and tannins were determined. The antioxidant property of the extracts was evaluated in vitro using 2,2-diphenyl-1-picrylhydrazyl acid (DPPH), 2,2-azino-bis (3-ethylbenzthiazoline-6-sufonic) (ABTS) and Ferric Reducing Antioxidant Power (FRAP). The acetylcholinesterase activity of the extracts 0.1 mg / ml was determined by a spectrometric assay method.

Results: Acute toxicity evaluated in NMRI mice showed that the methanolic extracts of five extracts show no toxicity. The coumarins and tannins were detected in all five species of plants. The polyphenol contents of Ceratotheca sesamoides gave the highest total phenolic compound content with 221.97 ± 1.206 mg EAG / g and also the best flavonoids content with 39.58 ± 0.068 mg EQ / g. Antioxidant tests show that Vernonia kotschyana Sch-Bip and Ceratotheca sesamoïdes Endl presented the best inhibitions of the DPPH radical with 82.63 ± 3.29% and 83.62 ± 2.12% at 100µg/ml. This activity is also better than that of quercetin which is a reference substance. For the reducing power of radical cation ABTS .+ the most active macerates of our extracts were obtained with Vernonia kotschyana (51,388 ± 0,133 mmol ET / g extract) and Ceratotheca sesamoides (50,748 ± 0,395 mmol ET / g extract). Ceratotheca sesamoides showed a best activity on reducing power of the ferric ion (7.03 ± 0.44 mmol EAA / g extract), this activity on ferric ion is superior to that of quercetin, which is a reference substance. Raphionacme daronii exhibited the greatest inhibition of acetylcholinesterase with a percentage inhibition of 53.542 ± 4.053 at 100 μg / ml.

Conclusion: The study demonstrated that anorexigenic plant extracts have a good antioxidant potential that is necessary for any weight-reducing activity. They also have an ability to inhibit acetylcholinesterase.