Properties of new exotic traditional Chinese medicinal Vernonia amygdalina leaves:a literature research / 中国中药杂志

The leaves of Vernonia amygdalina Delile of the family Asteraceae(also known as "bitter leaf"), rich in biological activities, are used as both medicine and food for a long time in West tropical Africa. They have been introduced into Southeast Asia and Fujian and Guangdong provinces of China in recent years. However, little is known about the properties of the plant in traditional Chinese medicine(TCM), which limits its combination with other Chinese medicinal herbs. In this study, 473 articles on V. amygdalina leaves were selected from PubMed, Web of Science, CNKI, Wanfang Data and VIP to summarize their components, pharmacological effects and clinical research. V. amygdalina leaves presented anti-microbial, hypoglycemic, anti-hypertensive, lipid-lowering, anti-tumor, anti-inflammatory, antioxidant, and other pharmacological effects. On the basis of the theory of TCM properties, the leaves were inferred to be cold in property and bitter and sweet in flavor, acting on spleen, liver, stomach and large intestine and with the functions of clearing heat, drying dampness, purging fire, removing toxin, killing insects and preventing attack of malaria. They can be used to treat dampness-heat diarrhea, interior heat and diabetes, malaria, insect accumulation and eczema(5-10 g dry leaves by decoction per day and an appropriate amount of crushed fresh leaves applying to the affected area for external use). Due to the lack of TCM properties, V. amygdalina leaves are rarely used medicinally in China. The determination of medicinal properties of the leaves is conducive to the introduction of new exotic medicinal herbs and the development of new TCM resources, which facilitated further clinical application and research and development of Chinese medicinal herbs.

Evaluation of Phytochemical and Antibacterial Potential of Vernonia amygdalina and Elaeis guineensis on Some Bacteria Associated with Diarrhea

Background: Bitter leaf and palm oil combination in treating diarrhoea is common in Africa. The aim of this study is to determine the synergistic and antimicrobial potential of Vernonia amygdalina and Elaeis guineensis on bacteria isolates from diarrheic stool.Methodology: One hundred and fifty (150) diarrheic stool samples from the Diagnostic Laboratory in Rivers State University Teaching Hospital (RSUTH), Port Harcourt, were inoculated in Selenite F broth, MacConkey, Nutrient and Salmonella-Shigella agar plates using standard methods. Fresh and dry bitter leaf extracts were prepared by mashing, weighing and dissolving 100 grams(g) and 150 g concentrations of each in 100 milliliters(mls) of ethanol and sterile distilled water respectively. Undiluted mixture of bitter leaf and palm oil were prepared by mixing 2 mls of each in a sterile beaker. Zero-point one milliliter (0.1ml) of each undiluted extract, their mixture, ethanol and palm oil were separately dispensed into appropriately labeled wells using sterile pipette for sensitivity test on the isolated bacteria. The pH, temperatures and the phytochemical contents of the bitter extracts and palm oil were determined using pH meter, thermometer and spectrophotometric method.Results: Escherichia coli, Staphylococcus aureus and Salmonella sp. were isolated. The pH and temperature of bitter leaf extract and palm oil were 7.2 and 26?C and 6.7 and 26?C respectively while the pH and temperature for bitter leaf and the palm oil mixture was 6.9 and 26?C. The bitter leaf and palm oil extracts, their combination, ethanol and distilled water used on the isolates as antibiotics did not show any sensitivity. The phytochemicals identified in the bitter leaf were saponins, alkaloids and tannins while carotene was detected in the palm oil.Conclusion: It can be concluded that the bitter leaf extract, palm oil and their combination did not inhibit the growth of bacteria as a result of lack of bioactive components from the bitter leaf. The nature of the diluents used for the extraction may not have been the right one as it would have caused the low concentration, dilution and disfiguring of the molecules of the bioactive compounds that prevented the proper reaction between the bacteria and the extracts used.

Microflora of Three Dehydrated Vegetables.

Consumption of fresh vegetables is very common in Nigeria. One of the methods of increasing the availability of vegetables all year round is drying. There is need to determine the microbial quality/safety of the dehydrated vegetables in order to determine the risk of food borne diseases. The microorganisms associated with three dehydrated vegetables (bitter leaf, bell pepper and okra) were isolated, identified and enumerated. The moisture contents of the vegetables were determined and the effects of varying temperature levels on growth of microbial isolates recovered from the samples were studied. A total of nine bacteria, namely: Staphylococcus aureus, Acinetobacter iwoffi, Corynebacterium sp., Bacillus pumilus, Micrococcus sp., Pseudomonas aeruginosa, Flavobacterium sp., Bacillus sp., Micrococcus kristianae and eleven fungi: Aspergillus niger, A. flavus, Aspergillus spp., Penicillium spp., Cladosporium sp., Fusarium spp. were isolated. The mean for total colony forming units (cfu/g) for bacteria were 2.1x107cfu/g, 6.1x105cfu/g, 2.2x106 cfu/g for bell pepper, bitter leaf and okra, respectively while the mean for total colony forming unit (cfu/g) for fungi were highest (1.3 x 106cfu/g) in bell pepper while bitter leaf recorded the least (7 x 103cfu/g) mean for total colony unit for fungi. The mean for percentage (%) moisture content ranged between 16.6-25.8%.The optimum growth was recorded for all the bacteria and fungi at 37ºC and 30ºC; nearly all the isolates had their growth retarded at 45ºC. The recovery of several harmful microorganisms in this study suggest the need for proper handling of vegetables during processing and storage to minimize microbial contamination in order to protect consumers’ health.