Abstract: Numerous researches conducted in Russia, Bulgaria, Japan, and China on B.pubescens, B. pendula, B.rezniczenkoana (Litv) Schischk, B.humilis Schrank, B.mandshurica Rgl Nakai found that birch barks and leaves contain antioxidants and they have anti-cancer, anti-fungi, antibac- terial and anti-inflammatory properties, protect liver and promote bile secretion. Flat leaved birch (B.platyphylla Sukacz) cortex contains betulin and lupeol of triterpenoids and it’s leaves contain flavonoid and polyphenol compounds. The amounts of compounds found in the cortex are smaller than leaves. Specifically, the amount of flavonoid in leaves is more contained than the that of cortex and leaf buds. In any pharmacology study of new medicines, determination and evaluation of toxicity is the first priority. According to scientific evidences that birch leaves are considered to have less toxins. Not many studies have been conducted on determining toxicity of birch leaves in Mongolia. Therefore, the purpose of this research is to study the species of birches, hippolytii birch (B.hippolytii. Sukacz) and flat leaved birch (B.platyphylla. Sukacz), that were noted to have medical properties in traditional medications and identify their acute toxicity using dry extract and determine mortality dosage (LD₅₀) on animals. Research materials and methods: Evaluation of the acute toxicity of birch leaves was conducted in Pharmacology laboratory of Monos group’s Drug Research Institute between June 19, 2020 and August 10. In this research, 150-204 g of WISTAR breed non-linear 44 white rats were used and 20 g of B.Hippolytii’s dry extract and 20 g of B. Platyphylla ‘s dry extract were injected.
The experiments to determine the toxicity of dry extracts of B. hippolytii and B. platyphylla (LD₅₀) were conducted according to Litchfield and Wilcoxon’s method and subcutaneous injects were per formed in the pelvic area of the rats. Results of determining acute toxicity level The experiments to determine the acute toxicity level of the birch’s dry extracts followed Litchfield and Wilcoxon’s method with 2-stage. LD₅₀ level was determined from the first stage of the research using G.N.Pirshen’s method and the toxicity level was identified using K.K.Sidorov’s toxicity categorization.
From the acute toxicity research, no-observed-adverse-effect level (NOAEL), animal daily dosage and human daily dosage (experimental) were determined. LD₅₀ 2950 mg/kg was determined as a result of acute toxicity research of B.hippolytii and B.platyphilla leaves’ dry extract.

Abstract: The birch leaves were used as a substitute for birch bark, buds and chaga of birch in traditional medicine because the birch leaves are considered to be less toxic. Numerous researches conducted in Russia, Bulgaria, Japan, and China on B.pubescens, B. pendula, B.Rezniczenkoana (Litv) Schischk, B.humilis Schrank, and B.mandshurica Rgl Nakai found that birch barks and leaves contain antioxidants and they have anti-cancer, anti-yeast, antibacterial, anti-inflammatory, liver protective and bile secretion induction properties. The studies conducted on animals with diseases showed that the birch leaves had anti-inflammatory properties on the gastric mucosa during acute stress, as well as anti-biliary and giardiasis. The birch leaf phytopreparations experimentations used on animals showed reduced peripheral tissue insulin resistance and lowered blood sugar. Mongolian traditional medicinal journals noted that the birch barks are used to treat inflammatory acute diseases. Therefore, this study was performed to determine the effects of two species of birch leaves on blood sugar and antioxidant activities in diabetes-induced rats. The study materials and methods: The study was conducted in the Pharmacology Research Laboratory of the Monos Group’s Institute of Pharmacology. 40 WISTAR, non-linear white rats weighing 150-204 g were used in the experiments. Dry extract of birch leaves of the two species (Alloxan monohydrate Tokyo Chemical Industry LTD), IGM-100 3A blood glucose meter (Blood glucose test meter, Infopia LTD, Brussels Belgium) and sugar test (Blood glucose test strip only, province, China) were used for the experiment. Lenzen’s (2008) method was used to induce Alloxan diabetes in the rats and the antioxidant properties were determined by the antioxidant activity kit (Rat Malondialchehyche Elisa KIT, cat. № EKRAT- 0266, Jilin). Study Result: The blood glucose level of the control group with diabetes lowered from 31.5 mmol/l to 17.1 mmol/l in 14 days. As for the B.platyphylla Sukacz group, the blood glucose level reduced to 6.3 mmol/l and the B.hippolytii. Sukacz group’s blood glucose level reduced to 6.9 mmol/l in 14 days.
The study results showed that B.hippolytii Sukacz birch leaves and B.platyphilla Sukacz birch leaves’ extracts reduced the maximum level of MDA dilution (4.8 nmol/ml) of B.hippolytii Sukacz and B.platyphilla Sukacz groups by 33.9% and 53.5% respectively. This suggests that the birch leaves had antioxidant effect. Conclusion B.hippolytii Sukacz birch leaves and B. platyphilla (Sukacz) birch leaves lowered the blood glucose level and had antioxidant properties on diabetes.

BACKGROUND OF STUDY: For the past 10 years, accidents and trauma are ranking third in the cause of Mongolian population’s death. Russian scientists have defined that skull and brain trauma comprise of 40% of the total traumas and is one of the serious injuries that have damaging effect to the health. Defining its creation, injury period, death cause in the leading direction of science of forensic medicine in our country are still the urgent issues. Nowadays little research which studied case mortality due to accident and trauma has been studied, this became background of our research work. PURPOSE OF STUDY: To study cause and peculiarity of pathology of case mortality due to brain trauma, in the condition of our country and to consider the result. OBJECTIVE OF STUDY: To study the cause, some risks of head injury. To define pathology of case mortality due to head injury. MATERIAL AND METHODOLOGY: We did retrospective study in 555 case material of an autopsy of case mortality of head injury of forensic medicine and research department of national institute of forensic science. Statistical work out was done by Microsoft excel and extensive index. RESULT OF STUDY: 84.5% (n=459) is male and 15.5% (n=86) is female out of our 555 involved cases and the gender ratio is 5:1. The most or 81% of the research participants had head injuries due to hitting with firm and dull stuffs and 15.9% head injury as a result of traffic accident follows in the second place. To analyze from the characteristics of mortality, 93% is subarachnoid hemorrhage, subdural, epidural hematoma, 64% is brain tissue injury were detected. CONCLUSION: Young manhood men mortality that has head injury resulted from the firm and dull things occupies most of the percentage in our research. The head injury can lead to the mortality of his ordinary process.