Upregulation of endogenous erythropoietin expression by DLBS6747, a bioactive fraction of Ipomoea batatas L. leaves, via increasing HIF1α transcription factor in HEK293 kidney cells

Nephroprotective plant species used in traditional Mayan Medicine for renal-associated diseases

ETHNOPHARMACOLOGICAL RELEVANCE

The prevalence of kidney disease has increased rapidly in recent years and has emerged as one of the leading causes of mortality worldwide. Natural products have been suggested as valuable nephroprotective agents due to their multi-target and synergistic effects on modulating important proteins involved in kidney injury. There is a large number of plant species that have been used traditionally for kidney-related conditions in Mesoamerican medicine by different cultural groups that could provide a valuable source of nephroprotective therapeutic candidates and could lead to potential drug discovery.

AIM OF REVIEW

This review aims to provide an overview of the currently known efficacy of plant species used traditionally in Mesoamerica by Mayan groups to treat kidney-related conditions and to analyze the phytochemical, pharmacological, molecular, toxicological, and clinical evidence to contribute to public health efforts and for directing future research.

METHODS

Primary sources of plant use reports for traditional kidney-related disorders in Mesoamerica were searched systematically from library catalogs, theses, and scientific databases (PubMed, Google Scholar; and Science Direct), and were filtered according to usage frequency in Mayan groups and plant endemism. The database of traditional plants was further analyzed based on associations with published reports of the phytochemical, pharmacological, molecular, toxicological, and clinical evidence.

RESULTS

The most reported kidney-related conditions used traditionally in Mayan medicine involve reducing renal damage (a cultural interpretation that considers an inflammatory or infectious condition), cleaning or purifying the blood and kidney, reducing kidney pain, and eliminating kidney stones. A total of 208 plants used for kidney-related problems by 10 Mayan groups were found, representing 143 native species, where only 42 have reported pharmacological activity against kidney damage, mainly approached by in vitro and in vivo models of chemical- or drug-induced nephrotoxicity, diabetes nephropathy, and renal injury produced by hypertension. Nephroprotective effects are mainly mediated by reducing oxidative stress, inflammatory response, fibrosis mechanisms, and apoptosis in the kidney. The most common nephroprotective compounds associated with traditional Mayan medicine were flavonoids, terpenoids, and phenolic acids. The most widely studied traditional plants in terms of pharmacological evidence, bioactive compounds, and mechanisms of action, are Annona muricata L., Carica papaya L., Ipomoea batatas (L.) Lam., Lantana camara L., Sechium edule (Jacq.) Sw., Tagetes erecta L., and Zea mays L. Most of the plant species with reported pharmacological activity against kidney damage were considered safe in toxicological studies.

CONCLUSION

Available pharmacological reports suggest that several herbs used in traditional Mayan medicine for renal-associated diseases may have nephroprotective effects and consistent pharmacological evidence, nephroprotective compounds, and mechanisms of action in different models of kidney injury. However, more research is required to fully understand the potential of traditional Mayan medicine in drug discovery given the limited ethnobotanical studies and data available for most species with regards to identification on bioactive components, pharmacological mechanisms, and the scarce number of clinical studies.

Molecular mechanism of DLBS3733, a bioactive fraction of Lagerstroemia speciosa (L.) Pers., on ameliorating hepatic lipid accumulation in HepG2 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Lagerstroemia speciosa (L.) Pers., commonly known as banaba and locally known as bungur, is widely used in Indonesia and other countries as a folk remedy for various chronic diseases such as diabetes mellitus and hypertension. L. speciosa (L.) Pers. has been used and evaluated on conditions associated to liver diseases by altering cholesterol absorption, lipid metabolism, as well as the related gene expressions.

AIM OF THE STUDY

The aim of this study is to evaluate the effect of DLBS3733, a standardized bioactive fraction of Lagerstroemia speciosa (L.) Pers. leaves, on ameliorating hepatic steatosis induced by oleic acid, and elucidate its mechanism of action to ameliorate lipid accumulation in HepG2 cells.

MATERIALS AND METHODS

Effects of DLBS3733 on expression of genes and proteins associated with lipid metabolism were evaluated in HepG2 cells in this study. Genes associated with lipid metabolism were evaluated using PCR, while the protein levels were revealed using western blot and ELISA. Cellular lipid accumulations and triglyceride (TG) synthesis were measured using ELISA, and antioxidant assay was conducted using DPPH assay.

RESULTS

DLBS3733 significantly reduced lipid accumulation and TG synthesis by 51% and 32% (p < 0.01), respectively, through the significant increment of adiponectin expression by 58% (p < 0.01). Subsequently, adiponectin enhanced PPARα expression and AMPK phosphorylation which further regulate the downstream signaling pathway of lipogenesis and lipolysis. Moreover, 2.5 µg/mL DLBS3733 was found to significantly downregulate the expression of HMGCR, ACC and SREBP by 66%, 61% and 36%, respectively (p < 0.01), as well as significantly upregulate CPT-1 by 300% at the protein level (P < 0.05). DLBS3733 was also found to possess high antioxidant activity, where the highest concentration exhibited DPPH inhibition activity by up to 93% (P < 0.01).

CONCLUSIONS

We propose that DLBS3733 may provide a prevention on hepatic steatosis through its activity as anti-lipogenesis, anti-cholesterologenesis and pro-lipolysis in HepG2 cells. This is the first report that revealed the molecular mechanism of L. speciosa (L.) Pers. as a potential treatment of hepatic steatosis-related diseases.