Lotus leaf flavonoids induce apoptosis of human lung cancer A549 cells through the ROS/p38 MAPK pathway

BACKGROUND: Leaves of the natural plant lotus are used in traditional Chinese medicine and tea production. They are rich in flavonoids. METHODS: In this study, lotus leaf flavonoids (LLF) were applied to human lung cancer A549 cells and human small cell lung cancer cells H446 in vitro to verify the effect of LLF on apoptosis in these cells through the ROS/p38 MAPK pathway. RESULTS: LLF had no toxic effect on normal cells at concentrations up to 500 µg/mL, but could significantly inhibit the proliferation of A549 cells and H446 cells. Flow cytometry showed that LLF could induce growth in A549 cells. We also found that LLF could increase ROS and MDA levels, and decrease SOD activity in A549 cells. Furthermore, qRT-PCR and western blot analyses showed that LLF could upregulate the expression of p38 MAPK (p-p38 MAPK), caspase-3, caspase-9, cleaved caspase-3, cleaved caspase-9 and Bax and downregulate the expression of Cu/Zn SOD, CAT, Nrf2, NQO1, HO-1, and Bcl-2 in A549 cells. Results of HPLC showed that LLF mainly contain five active substances: kaemp-feritrin, hyperoside, astragalin, phloridzin, and quercetin. The apoptosis-inducing effect of LLF on A549 cells came from these naturally active compounds. CONCLUSIONS: We have shown in this study that LLF is a bioactive substance that can induce apoptosis in A549 cells in vitro, and merits further research and development.

Inhibitory effect of lotus seedpod oligomeric procyanidins on advanced glycation end product formation in a lactose-lysine model system

Background Industrial food processing induces protein glycation modifications and toxic advanced glycation end products (AGEs) which affect human health. Therefore, it is of interest to monitor AGEs in food processing. The present study was carried out to investigate the influence of lotus seedpod oligomeric procyanidin (LSOPC) concentrations, solution pH value and metal ions on AGE formation by heat treatment of lactose-lysine model solutions. Ne-(carboxymethyl) lysine (CML), as one of the common AGEs was also determined by HPLC-MS/MS in this experiment. Results The results showed that LSOPC can inhibit the formation of AGEs effectively at higher concentrations, lower temperature, and it can reverse the promotion function of metal ions because of its high inhibition activity. Also, LSOPC can inhibit CML formation in the Maillard reaction as well. Conclusion These results indicated that LSOPC could be used as functional food ingredients to inhibit AGE formation.

Antiplatelet activity of white and pink Nelumbo nucifera Gaertn flowers / Atividade antiplaquetária de flores Nelumbo nucifera Gaertn branco e rosa

Nelumbo nucifera Gaertn (Nelumbonaceae) a plant used in Ayurvedic medicine (common name: lotus), is a perennial, large and rhizomatous aquatic herb most prevalent in South India. Preliminary phytochemical screening of both white and pink Nelumbo nucifera flowers revealed the presence of phytochemical constituents (flavonoids, alkaloids, phenols etc,). Hence, an attempt has been made to screen the effect of Nelumbo nucifera flowers (both types) on platelet aggregation. The antiplatelet activity of hydroethanolic extract of both types of flowers was studied using platelet-rich plasma in different concentrations (100-500µg/ml). Both white and pink Nelumbo nucifera flower extracts showed dose-dependent effective antiplatelet activity with maximum activity at 500µg/ml concentration; prevention of platelet aggregation was 50 percent of that achieved with standard aspirin. Furthermore, the antiplatelet activity of white flowers was relatively high (p<0.05; ANOVA) compared to pink flowers. In conclusion, these observations suggest that both varieties of Nelumbo nucifera flower extracts exert different levels of inhibitory action on platelets in vitro (secretion and platelet aggregation suppression) due to differences in phytochemical content (alkaloids, flavonoids, phenols, tannins, phytosteroids, glycosides and saponins).

Nelumbo nucifera Gaertn (Nelumbonaceae, planta utilizada na medicina Ayurvédica, é erva aquática rizomatosa grande, predominante no sul da Índia. A triagem fitoquímica preliminar das flores brancas e cor-de-rosa de Nelumbo nucifera revelou a presença de constituintes fitoquímicos (flavonoides, alcaloides, fenóis etc). Assim, tentou-se a triagem do efeito das flores de Nelumbo nucifera de ambos os tipos na agregação plaquetária. A atividade antiplaquetária dos extratos hidroetanólico de ambos os tipos de flores foi estudada, utilizando-se plasma rico em plaquetas em duas diferentes concentrações (100 - 500 µg/mL). Tanto os extratos das flores brancas quanto daquelas de cor-de-rosa mostraram atividade antiplaquetária dose-dependente, com o máximo na concentração de 500 µg/mL. A prevenção da agregação plaquetária foi 50 por cento daquela alcançada com o padrão de ácido acetilsalicílico. Além disso, a atividade antiplaquetária das flores brancas foi, relativamente, alta (p<0,05; ANOVA), comparativamente às flores cor-de-rosa. Estas observações sugerem que ambas as variedades de extratos de flores de Nelumbo nucifera exercem diferentes níveis de ação inibitória nas plaquetas in vitro (supressão da secreção e da agregação plaquetária) devido a diferentes constituintes fitoquímicos (alcaloides, flavonoides, fenóis, taninos, fitoesteróides, glicosídeos e saponinas).

Lotus (Nelumbo nuficera) flower essential oil increased melanogenesis in normal human melanocytes

In this study, the essential oil from lotus flower extract, including petals and stamens, was assessed with regard to its effects on melanogenesis in human melanocytes. The lotus flower essential oil was shown to stimulate melanin synthesis and tyrosinase activity in a dose-dependent manner. The lotus flower essential oil induced the expression of tyrosinase, microphthalmia-associated transcription factor M (MITF-M), and tyrosinase-related proten-2 (TRP-2) proteins, but not tyrosinase mRNA. Moreover, it increased the phosphorylation of ERK and cAMP response element binding protein (CREB). In order to verify the effective components of the lotus flower oil, its lipid composition was assessed. It was found to be comprised of palmitic acid methyl ester (22.66%), linoleic acid methyl ester (11.16%), palmitoleic acid methyl ester (7.55%) and linolenic acid methyl ester (5.16%). Among these components, palmitic acid methyl ester clearly induced melanogenesis as the result of increased tyrosinase expression, thereby indicating that it may play a role in the regulation of melanin content. Thus, our results indicate that lotus flower oil may prove useful in the development of gray hair prevention agents or tanning reagents.