Anti-Ulcerative Colitis Activity of the Aqueous Leaves Extract of Khaya Senegalensis in Acetic Acid-Induced Colitis Rat Model

intestinal tract mainly colon. The disease is characterized by diarrhoea, blood in the stool, abdominal pain, and weight loss. Khaya senegalensis a plant commonly called dry zone Mahogany has been used as a remedy for several human gastrointestinal ailments. Objectives: To investigate the effect of aqueous leaves extract of Khaya senegalensis in the acetic acid-induced ulcerative colitis rat model. Study design: Preclinical randomised controlled trial. Methods: extraction was done using water, initial phytochemical screening and oral LD50 were determined. Colitis was induced in rats using 4% acetic acid administered intra rectally. The rats were divided into five groups, group 1 received water, groups 2, 3, and 4 received graded doses of leaves extract while group 5 received prednisolone as the positive control. Symptomatic parameters like the daily stool consistency and appearance and histological parameters such as ulcer area, lesson severity score, ulcer index, weight/length ratio and percentage cure were measured. Results; The leaves extract showed presence of alkaloids, tannins, flavonoids, saponins, steroids, volatile oil etc. The oral LD50 was greater than 5000mg/kg and the efficacy of the 400mg/kg extract administered group was not statistically significantly different from the positive control group that received the standard drug prednisolone. Conclusion: It can be concluded that the aqueous leaves extract of Khaya senegalensis possess significant anti-ulcerative colitis activity on acetic acid-induced ulcerative colitis rat models and appears to be safe.

Effects of pH and Electrolytes on Castor Oil Emulsions with Various Stabilisers Using Khaya senegalensis Gum as an Emulsifier

Dispersed systems such as emulsions are easily destabilised during processing and storage since they are thermodynamically unstable systems. It is for this reason emulsifiers/stabilisers are frequently employed in pharmaceutical emulsion formulations to increase their short- and long-term kinetic stability. This current study seeks to investigate the potential emulsifying property of gums obtained from Khaya senegalensis (family: Meliaceae) trees. Gums were collected, authenticated, oven-dried, milled, filtered, and purified using 96% ethanol. The microbial quality of the gum was assessed following the BP (2013) specifications. The purified gum was free from some selected pathogenic microorganisms, rendering the gum safe for consumption. The emulsifying property was investigated by formulating emulsions using castor oil and employing the dry gum method. The ratios of oil-to-water-to-gum for the formulation of a stable emulsion were determined. The stability of the emulsion was evaluated, and an effort was made to improve the stability by incorporating Tween 80, hydroxypropyl methylcellulose, and xanthan gum. From the results, it can be inferred that Tween 80 (0.5%) was able to stabilise the emulsion. Addition of xanthan gum worsened the creaming. The effects of pH (4.0, 5.5, 7.2, 9.0, and 11.0) and electrolytes (0.1 M of NaCl, KCl, and CaCl2) on the physical stability of oil-in-water emulsions were studied during 12 weeks of storage. Percentage creaming volume and whether there was phase inversion were the criteria used as the evaluation parameter. From the percentage creaming volume data, emulsions formulated with both gums showed the lowest creaming volumes at pH of 7.2, followed by the acidic regions (pH 4.0, 5.5), with the basic regions (pH 9.0, 11.0) recording the highest creaming volumes. The effects of the various electrolytes at a constant concentration of 0.1 M on the o/w emulsions were found in this order NaCl < KCl < CaCl2. This study proves that Khaya senegalensis gum can successfully be employed as an emulsifying agent in pharmaceutical formulations.

Species Diversity and Decorative Features of Plants Used in the Landscaping of Hanoi

The article presents the results of studies on species diversity and decorative features of plantations in Hanoi. The relevance of this research is justified by the failure to meet the standards of landscaping in the city in accordance with global recommendations and standards. The dendroflora of central Hanoi has 304 species (including varieties and forms) belonging to 253 genera and 104 families. The leading families are Fabaceae, Arecaceae, Asteraceae, Apocynaceae, Bignoniaceae, Meliaceae, Verbenaceae, Myrtaceae, Moraceae, Caesalpiniaceae, Rosaceae, and Magnoliaceae. The Fabaceae family predominates by the the number of genera and species; and is followed by the Moraceae family. The greatest species diversity is observed among trees (151 species – 49.67 % of the total number). The most commonly used species in the urban gardening are Peltophorum pterocarpum, Delonix regia, Khaya senegalensis, Chukrasia tabularis, Ceiba pentandra, Pterocarpus macrocarpus, Hopea odorata, Dracontomelon mangiferum, Alstonia scholaris, Lagerstroemia speciosa, and Terminalia mantaly. Evergreen species predominate among plantations of Hanoi; while deciduous (including shrubs and trees) have a smaller proportion. Of 151 species of trees, 70 are classified as decorative. Shrubs and herbs are inferior to trees by the number of species (58 species each – 19.08 %). Palm trees are the least numerous – 11 species (3.62 %). The decorative features of the main species have been determined. A list of trees with 3 or more decorative features, shrubs and herbs with 2 or more decorative features was compiled. In order to create a unique urban landscape in different seasons of the year it is recommended to use the species included in this list. For citation: Nguyen Thi Yen, Dang Van Ha, Parinova T.A. Species Diversity and Decorative Features of Plants Used in Landscaping of Hanoi. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 5, pp. 65–75. DOI: 10.37482/0536-1036-2021-5-65-75