Hairy root induction and benzylisoquinoline alkaloid production in Macleaya cordata

Phyto-factories of anti-cancer compounds: a tissue culture perspective

Background

Cancer is one of the most critical but ubiquitous causes of death grappled from past decades. Widely used chemotherapy with cytotoxic activity blocks/ kills the cancer cell. The compounds targeted for anticancerous activity are either derived synthetically or naturally (through plants or microbial origin). Current day, versatile role of plants in medicinal field has been attributed to the secondary metabolites it produces, known for their anticancer activity. Therefore, discovery, identification and commercial production of such novel anticancer drugs is escalated and are centerpiece for pharmaceuticals.

Main body

A biotechnological approach, principally tissue culture, leads the candidacy to be an alternative method for production of anticancer compounds. A wide range of bioactive agents like alkaloids, steroids, phenolics, saponins, flavonoids, and terpenoids are in huge demand commercially. Plant tissue culture applications are constructively more advantageous over conventional methods in terms of their continuous, controlled, aseptic production, large scale and de novo synthesis opportunity. Various bioreactors are used for mass cultivation of bioactive compound at commercial level. For example: stirred tank reactors are used for production of shikonin from Lithospermum erythrorhizon, vincristine from Catharanthus roseus, podophyllotoxin from Podophyllum etc. Strategies like callus culture, suspension culture and hairy root culture are opted for mass cultivation of these bioactives.

Conclusions

This review summarizes plant tissue culture as a promising strategy proven to be a colossal breakthrough in reliable and continuous production of existing and novel anticancer compounds and help in combating the increasing future demands.

Preliminary Phytochemical Analysis and Evaluation of the Biological Activity of Leonotis nepetifolia (L.) R. Br Transformed Roots Extracts Obtained through Rhizobium rhizogenes-Mediated Transformation

According to the present knowledge, this is the first report on establishing transformed root cultures of Leonotis nepetifolia after Rhizobium rhizogenes-mediated transformation. The preliminary phytochemical analysis showed differences in the content of phenols and flavonoids in transformed and nontransformed roots. The dominant compounds in the analyzed extracts were (+)-catechin (5464 and 6808 µg/g DW), p-coumaric acid (2549 and 4907 µg/g DW), m-coumaric acid (1508 and 2048 µg/g DW) and rosmarinic acid (1844 and 2643 µg/g DW) for nontransformed (LNNR) and transformed (LNTR4) roots, respectively. Initial biological studies carried out on LNNR, and LNTR4 extracts showed a cytotoxic effect on the A549 lung, HCC1937 breast and leukemia NALM-6 cell lines, antioxidants, as well as repair and protection against DNA damage induced by H₂O₂ in HUVEC cells. Due to the stronger effect of the LNTR4 root extract, which can be a relatively efficient and cheap source of bioactive secondary metabolites, further biological analyses are needed to discover in detail their potentially valuable biological properties.

Ethoxysanguinarine, a Novel Direct Activator of AMP-Activated Protein Kinase, Induces Autophagy and Exhibits Therapeutic Potential in Breast Cancer Cells

Ethoxysanguinarine (Eth) is a benzophenanthridine alkaloid extracted from Macleaya cordata (Willd) R. Br. It possesses antibacterial and antiviral activities and offers therapeutic benefits for the treatment of respiratory syndrome virus-induced cytopathic effects. However, the effect of Eth on human tumors and its pharmacological effects remain to be elucidated, together with its cellular target. Here, we examined the effects of Eth on breast cancer (BC) cells. We found that at low doses, Eth strongly inhibited the viability of BC cell lines and induced autophagy. Mechanistic studies showed that Eth induced autophagy by upregulating the activity of the AMP-activated protein kinase (AMPK). The AMPK inhibitor compound C significantly attenuated Eth-induced autophagy and inhibited proliferation. Meanwhile, the AMPK activator metformin significantly enhanced Eth-induced autophagy and inhibited proliferation. Computational docking and affinity assays showed that Eth directly interacted with the allosteric drug and metabolite site of AMPK to stabilize its activation. AMPK was less activated in tumor samples compared to normal breast tissues and was inversely associated with the prognosis of the patients. Moreover, Eth exhibited potent anti-BC activity in nude mice and favorable pharmacokinetics in rats. These characteristics render Eth as a promising candidate drug for further development and for designing new effective AMPK activators.