OBJECTIVE: To determine direct targeting of localized adiposity through Morus alba Linne bark injection based on pharmacology network analysis.

METHODS: Male C57BL/6J mice were fed a high-fat diet (HFD) to induce obesity. After 6 weeks on HFD, the water extract of Morus alba L.bark (MAB, 2 mg/mL) was locally injected into one inguinal fat pad, while saline was injected into the other side, 3 times/week for 6 weeks (n = 6/group). The water extract of MAB was freeze-dried and then diluted in saline before use.

RESULTS: HFD-fed mice treated with local MAB topical injection showed reduced adipocyte weight and size in inguinal fat pads by dual-energy X-ray absorptiometry. No toxicity changes seen in liver, spleen, kidney tissue, or alanine aminotransferase / aspartate aminotransferase levels in serum by MAB injection. Protein levels of phosphorylated insulin receptor substrate-1 and glucose transporter type 4, and mRNA expression of adiponectin, were increased in inguinal adipose tissue injected with MAB locally. Locally MAB injection led to a decrease in glucose-6-phosphatase and phosphoenolpyruvate carboxykinase, linked to gluconeogenesis, while forkhead box protein O1, which regulates these factors, was increased. Moreover, there was an increase in adenosine 5‘-monophosphate-activated protein kinase, related to lipogenesis, as well as elevated levels of hormone-sensitive lipase and fatty acid synthase, both associated with lipolysis. These results support the 'insulin signaling pathway' and 'regulation of lipolysis in adipocytes' identified in the Kyoto Encyclopedia of Genes and Genomes pathway through network analysis.

CONCLUSION: This study suggests that MAB topical injection exhibits localized fat reduction by inhibiting insulin resistance, gluconeogenesis and lipogenesis mediator, while activating lipolysis enzymes within targeted adipose site.