This study investigated the leaves of Clinacanthus nutans for its bioactive compounds and acute and subacute toxicity effects of C. nutans ethanolic leaf extract (CELE) on blood, liver and kidneys of ICR mice. A total of 10 8-week-old female mice were divided into groups A (control) and B (2000 mg/kg) for the acute toxicity study. A single dose of 2000 mg/kg was administered to group B through oral gavage and mice were monitored for 14 days. In the subacute toxicity study, mice were divided into five groups: A (control), B (125 mg/kg), C (250 mg/kg), D (500 mg/kg) and E (1000 mg/kg). The extract was administered daily for 28 days via oral gavage. The mice were sacrificed, and samples were collected for analyses. Myricetin, orientin, isoorientin, vitexin, isovitexin, isookanin, apigenin and ferulic acid were identified in the extract. Twenty-eight days of continuous oral administration revealed significant increases (p < 0.05) in creatinine, ALT and moderate hepatic and renal necrosis in groups D and E. The study concluded that the lethal dose (LD50) of CELE in mice is greater than 2000 mg/kg and that repeated oral administrations of CELE for 28 days induced hepatic and renal toxicities at 1000 mg/kg in female ICR mice.

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Chemical carcinogens are commonly used to investigate the biology and prognoses of various cancers. This study investigated the mechanism of leukaemogenic effects of n-ethyln-nitrosourea (ENU) in a mouse model. A total of 14 3-week-old male Institute of Cancer Research (ICR)-mice were used for the study. The mice were divided into groups A and B with seven mice each. Group A served as the control while group B received intraperitoneal (IP) injections of 80 mg/kg ENU twice with a one-week interval and were monitored monthly for 3 months for the development of leukaemia via blood smear examination. The mice were sacrificed humanely using a CO 2 chamber. Blood, spleen, lymph nodes, liver, kidney and lung samples were collected for blood smear examination and histopathological evaluation. The expression of angiogenic protein (VEGF), and pro and anti-apoptotic proteins (BCL2 and BAX), was detected and quantified using Western blot technique. Leukaemia was confirmed by the presence of numerous blast cells in the peripheral blood smear in group B. Similarly, the VEGF and BCL2 proteins were significantly (p < 0.05) upregulated in group B compared to A. It is concluded that IP administration of 80 mg/kg ENU induced leukaemia in ICR-mice 12 weeks post administration through upregulation of angiogenic and anti-apoptotic proteins: VEGF and BCL2.

Animal models have been providing invaluable contributions to the better understanding of mechanisms of cancer (including leukaemias) development and effectiveness of most of the treatments. Chemical carcinogens are generally used to study the biology of cancers including leukaemias in many animal models, including rats and mice. The studies in most cases are aimed at the development and evaluation of cancer treatments and preventions. Some of the most common chemical carcinogens used in animal models for leukaemias include N-ethyl-N-nitrosourea (ENU), N-methyl-N-nitrosourea (MNU), dimethyl benz(a)anthracene (DMBA) and benzo(a)pyrene (BaP). This review provides highlights on different animal models of leukaemia induced by the chemical carcinogens mentioned earlier, at the same time discussing the contributions of these models to the leukaemia diagnosis in laboratory animal models for subsequent development of treatment.

Lawsonia inermis is one of the most significant plants used in traditional medicine. However, many details of the dermal toxicity of L. inermis remain unknown. The objective of this study is to evaluate the in vivo acute and sub-acute dermal toxicity of ethanolic extract of L. inermis leaves. In acute experiment, a total of 20 rats were divided into four groups of five rats. A total of 30 rats were divided into five groups of six rats for the sub-acute experiment. The extract at a single dose of 2000 and 5000 mg/kg of body weight did not produce treatment-related signs of toxicity or mortality in all rats tested during the 14-day observation period. However, in a repeated dose 28-day study, the application of 500, 1000 and 2000 mg/kg of body weight/day of leaves extract revealed no significant change (p > 0.05) in bodyweight, haematological and biochemical parameters compared with the control group. Similarly, gross pathology and histopathology examinations of liver, kidneys, and skin did not reveal any morphological alteration. Overall, the results show that the close application of L. inermis leaves extract did not have any critically dangerous impact on rats. Subsequently, the concentrate may be employed for pharmaceutical plans.

The important elements in rearing dairy young stock are good farm management, proper growth and optimal costs of rearing. A survey on these important elements was conducted at two commercial farms in Johor and Sabah in 2019. The farm herd size is 214 heads and 2,221 heads with 163,682 litres and 4.2 mil. litres of milk production, in Johor and Sabah respectively. In addition, the body weight data of 188 dairy young stock was collected and analysed to determine the growth performance using polynomial growth function. The results showed the two farms have youngstock with different Friesian blood levels (60% and 70% in Johor, and 87.5% in Sabah) with different growth performance. The average weight of dairy young stock with 60%, 70% and 87.5% Friesian blood levels at birth were 21.31±3.70kg, 22.33±2.23kg and 26.55±2.68kg, respectively, while average weight at 3 months of age were 45.00±7.07kg, 55.57±8.36kg and 75.84±12.54kg, respectively. Heifers with 87.5% Friesian blood levels was bred at 15 months of age (444kg) while heifers with lower Friesian blood levels was bred 6 months later (250kg). The average rearing (feed) cost was RM4,932 (USD1,194)/heifer. The findings of this study can give awareness and insights in the performance and costs of rearing crossbreed dairy young stock in tropics.

Clinacanthus nutans has been used traditionally in the treatment of herpes simplex viral infection. This research evaluated the toxicity effects of sub-chronic oral administration of Clinacanthus nutans ethanolic leaf extract in Institute of Cancer Research mice. A total 50, 8 w old female mice were divided into five groups of 10 mice each; Group A (control), Group B (125 mg/kg), Group C (250 mg/kg), Group D (500 mg/kg) and Group E (1000 mg/kg). The extract was administered orally for 90 d. The mice were monitored and sacrificed on d 91. Blood, liver and kidney samples were collected for analyses. There was significant (p<0.05) alterations in the haematological parameters of the mice in Group E and a significant increase in creatinine levels in groups B, C, D and E compared to A. The plasma level of alanine aminotransferase was significantly (p<0.05) higher in Groups D and E, compared to A. Histopathological evaluation of liver and kidneys revealed a moderate cytoplasmic vacuolation, eosinophilic cytoplasm and pyknosis of hepatocytes, as well as mild to moderate activated Kupffer cells in Group E. Similarly, the renal tubular cells showed mild to moderate renal cytoplasmic vacuolation, eosinophilic cytoplasm, pyknotic and karyolytic cells in Group E. It is concluded that repeated oral doses of Clinacanthus nutans ethanolic leaf extract for 90 d induced hepato-renal toxicities in female Institute of Cancer Research mice.

Melastoma malabathricum is an important plant commonly used in traditional medicine. Until recently, the dermal toxicity profile of M. malabathricum remained unknown. The objective of this study is to investigate the in vivo acute and sub-acute dermal toxicity of ethanolic leaves extract of M. malabathricum in rats. In acute experiment, a total of 20 female rats were divided into four groups, each group had five rats. While, a total of 30 male rats were divided into five groups, each group consisted of six rats in sub-acute experiment. Single doses of the extract at 2000 and 5000 mg/kg of body weight failed to produce treatment-related signs of toxicity or mortality during the 14-day observation period. In a repeated dose 28-day study, 500, 1000 and 2000 mg/kg of body weight/day applications of leaf extract lead to no significant change (p >0.05) in bodyweight or haematological and biochemical parameters compared with the control group. Similarly, gross pathology and histopathology examinations of liver, spleen, kidneys, and skin did not reveal any morphological alteration. Results indicate that the close application of M. malabathricum leaves extract had no critically dangerous effect on the rats tested. Therefore, the concentrate may be used pharmaceutically.