Marigold Extracts and Their Cytotoxic Effects on Cancer Cells: A Review

Both Singh et al. (2016) and Barhoi et al. (2021) agree that cancer is a main health concern.  [1] Its distinguishing characteristic is the rapid proliferation of cells that evades cell cycle checkpoints.  Even though cancer biology is advancing at a rapid pace, the cancer incidence and mortality rate are still going up.  [3] These diagnostic methods, unfortunately, failed to yield the desired outcomes.   Further complications associated with these treatments include cancer recurrence, non-target organ harm, and drug resistance (Choudhari et al., 2020).   In order to fight this deadly disease, scientists are continuously seeking out novel anticancer medicines that show promise, ideally with better efficacy and less side effects [7].   To skilfully evade cell death by apoptosis, cancer cells accumulate a number of genetic and epigenetic changes (Klein, 2004).   The development of anticancer chemotherapeutics may thus depend on substances that may induce cell death in cancer cells (Lee, 1999).  [8] Several cancer treatments derived from plants account for about 75% of the total (Craig, 1999).  [9] Surprisingly, essential oils, which are widely distributed in nature, have never been used for their anticancer properties while being widely used in aromatherapy, perfumery, food and flavoring, and other fields. It is generally known that several essential oils or their components have strong antibacterial and antifungal properties. [10] Asteraceae family includes the genus Tagetes, which has 56 species, including 29 perennials and 27 annuals.  Around the world, Tagetes sp. are cultivated as multipurpose plants, with the most popular species being T. minuta, T. erecta, T. patula, and T. tenuifolia (Vasudevan et al., 1997). [11] Folk medicine has utilized Tagetes sp. to treat stomach and intestinal disorders. Carotenoids, which are utilized as food coloring and feed additives, are among the highly intriguing biologically active chemicals that come from this species.and having antiaging and anticancer benefits (Block et al., 1992), flavonoids with pharmacological qualities (Tereschuk et al., 1997), and essential oils with antibacterial and insecticidal qualities (Piscaglia et al., 1996).  T. minuta L. volatile oils have a suppressive biological action and are utilized as food flavorings and perfumes (Chamorro et al., 2008), as well as antibacterial agents (Senatore et al., 2004).   in opposition to certain diseases and insects (Vasudevan et al., 1997).  The Lamiaceae family includes the genus Ocimum. [12] When it comes to cancer-related deaths, pancreatic cancer is second to none in the world.   in [13]   Chronic pancreatitis, obesity, heavy alcohol use, cigarette smoking, and a diet rich in red meat are some of the risk factors for pancreatic cancer. [14] Because there are no symptoms of the disease, pancreatic cancer is frequently discovered in its advanced stages. [15] Surgery is still the most effective treatment, although as previously said, the patient's chances of survival are low. [16] The next step is radiation and chemotherapy. [17] The herb is used to treat the common cold, bronchitis, and the common cold.  The leaves' juice is used to make sarache. [18-19] The roots' extract is used as a laxative.  Traditionally, Tagetes erecta and Tagetes patula leaf juice has been utilized as an antimalarial and antipyretic.  Tagetes minuta has a potent larvicidal activity and has long been used to ward off mosquitoes. [20] Tagetes patula juice is used to treat cuts and wounds because it contains iodine. Its floral juice is used as a carminative.  In addition to being utilized in food, Tagetes lucida is also used to scent bath water with its leaves and flower heads. [21] Traditional Mexican teas made from Tagetes lucida and Tagetes filifolia shoots are popular beverages and natural cures for indigestion and colic. In the perfumery industry, Tagetes minuta oil is well-liked due to its powerful and piercing scent.  Terpenoids, thiophenes, flavonoids, carotenoids, and phenolic chemicals are found in Tagetes species [22] The herbaceous genus Tagetes includes over fifty species of annual and perennial plants belonging to the Compositae and Asteraceae families.  Genda Phool (Marigold) is the local name for Tagetes erecta L.  Indian marigolds are a traditional spice. [23] The A foundational ingredient in the majority of Indian curries, marigold is a flavor-enhancing spice.  Using marigolds in curry dishes has a history that spans over five thousand years.  [24] The tall, branching plant originally hails from Mexico and other warmer regions of the United States but has since been eradicated from the subtropics and tropics, including Bangladesh and India.  [25]

OBJECTIVES:

1.The primary objective of anticancer activity research involving marigold (Tagetes erecta) is to explore its potential as a natural source of therapeutic agents for cancer treatment. [26]

2.Identifying Bioactive Compounds: Isolating and characterizing the specific compounds6 responsible for marigold's anticancer activity. [27]

Taxonomical classification [28]

Morphological Characters

Marigolds can be either annual or perennial. The marigold stem is upright or branching, and its leaves are dark green and glossy, with opposed or alternating arrangements. [29] The marigold stem is 12 to 30 inches tall. Marigold flowers can be solitary or clustered, and they are bright yellow, orange, or red when simple or pinnately split. [30]

Microscopic Characters

Features of Microscopic Marigold's transverse section demonstrates the structure of leaves In order to prevent water loss, the leaf surface is covered by a single layer of epidermal cells, frequently with a waxy cuticle. Although they are found on both the upper and lower epidermis, stomata are usually more prevalent on the lower side. Spongy mesophyll and palisade make up mesophyll, the internal leaf tissue. [31] Under a microscope, the xylem and phloem tissue found in veins is visible as a vascular bundle. Epidermis: Stem's outermost layer is made up of epidermal cells. Cortex: The parenchyma cells that make up the cortex, which lies beneath the epidermis, may retain starch. Structure of a flower: petals Usually spherical ovules, stamens are specialized cells for producing pigment and may be found in the thickly epidermis petals. Ovules can be seen inside the ovary. Marigold pollen grains are typically spherical, while species-specific variations exist in size and surface roughness. [32]

Phytochemical constituents

Phytochemical analyses of its constituent parts have allowed for the isolation of a number of chemical components, including as thiophenes, flavonoids, carotenoids, and triterpenoids.   [33]   You can find quercetagetin and its glucoside among the recognised residues in T. erecta.   It is one of the most important parts of Tagetes erecta and the main pigment, according to Dixit et al. (2013).   The flower contains several carotenoids.  [34-35]

Lutein

Quercetagetin

Medicinal uses

1. Anti-inflammatory reduce inflammation and pain.

2. Antioxidant protect against cell damage.

3. Anticancer inhibit tumor growth and induces apoptosis.

4. Wound healing: topical application for cuts, burns, and ulcers.

5. Digestive issues: relieves constipation, diarrhea and indigestion.

6. Antimicrobial

7. Also used in eye problems respiratory issues, cardiovascular health, menstrual disorder.

MECHANISM

1. One of the many therapeutic uses for the marigold plant is its anti-cancer properties.  The anti-cancer and elastase/tyrosinase enzyme inhibitory properties of marigold flower extracts in ethanol and ethyl acetate are well-documented.  Cancers of the colon and lung have been found to be resistant to these two extracts.  [36]

2. Anti-oxidant activity- Three tests for antioxidant activity were conducted on ethanolic extract of marigold (Tagetes erecta) flowers: reducing power, DPPH & superoxide radical scavenging. Tagetes erecta outperforms conventional ascorbic acid in terms of reducing power, but showing lower than average DPPH antioxidant & superoxide anion scavenging activities.  Additionally, Tagetes erecta flower essential oil reveals [37]

3.The antioxidant action of marigold is typically attributed to carotenoids, such as luteins.  The healing properties of marigold have made it an ancient medicinal herb.  An investigation was conducted into the cytotoxic activity and inhibitory effects of marigold flower extracts in ethanol and ethyl acetate on the elastase and tyrosinase enzymes.  Two cancer cell lines: the H460 lung cancer and the CaCO₂ colon cancer were used.  Compounds known as antioxidants can aid in cellular protection against free radical damage.  The extract dramatically increases blood and liver glutathione levels.

4. Induction of Apoptosis: Marigold extracts can promote programmed cell death (apoptosis) in cancer cells. This process may be mediated by the activation of caspases & modulation of apoptotic signaling pathways. [38]

5. Cell Cycle Arrest: Certain compounds in marigolds can interfere with the cell cycle, causing cancer cells to halt their proliferation. For example, they may induce arrest at specific phases of the cell cycle, preventing cancer cells from dividing and growing

In Vivo Studies

The in vivo effects of starting, continuing, and stopping treatments with marigold and basil essential oils on the quantity of EACC (all, dead, and viable), survival of tumor-transplanted female mice, and LDH activity in the tumour cell suspension supernatant.  The control group without tumour treatment had an average survival time of 14±0.45 days.  The MST of tumor-transplanted female mice was found to be considerably (p<0.05) higher after receiving various essential oils of marigold and basil compared to the tumour control group.  The current investigation indicated that essential oils of marigold and basil were more effective before treatment began than during or after therapy began.  in the text.  The marigold and beginning treatments had the longest mean survival times (in days), at 48 and 37.17 days, respectively, while the basil treatments had the shortest at 34 and 30 days, respectively.  The MST of tumour transplanted rats showed few impacts from medications administered after the transplant had begun.  The group who took marigolds before starting the treatment had the greatest increase in longevity (242.86%).

In vitro Studies

Research conducted using in vitro methods; Assay for cell proliferation and survival:  This study employed three distinct cancer cell lines: HL-60 and NB4, which are derived from human promyelocytic leukaemia, and EACC, which are derived from experimental animal’s model cancer cells.  Cell lines HL-60 and NB4, which were acquired from the American Type Culture Collection (ATCC), were cultured for 24 hours in RPMI 1640 medium that was supplemented with 10% foetal bovine serum (FBS), 2 mmol/L glutamine, penicillin (100 U/ml), and streptomycin (100 µg/ml) in a humidified environment with 5% CO2.  We counted the cells.  A density of 3 × 10³ cells/ml was used for seeding HL-60 and NB4 cells.  Following this, the cells were exposed to varying amounts of marigold and basil essential oils to achieve final concentrations of 25, 50, 75, 100, and 200 µg/ml. They were then left to incubate under the identical conditions for an additional day.  The amount of fluid containing 1% DMSO was increased until each experiment reached a final volume of 100 µl.  The vehicle dimethyl sulfoxide concentration was kept constant for the control cells.  The trypan blue assay was used to assess cell viability after this time. In accordance with Bennett et al. (1976), the viability percentages were computed.  The capacity of trypan blue dye to provide a blue stain onto the dead cells was crucial to this technique.  Then a hemocytometer slide was utilised (under a microscope) for simple counting.  Triplicates of each experiment were performed.  At the National Cancer Institute (NCI) in Cairo, Egypt, female Swiss albino mice were used to maintain the Experimental Animal Model Cancer Cell Line (EACC) through weekly intraperitoneal (1p) injection of 2.5 x 106 cells.  Our division followed a similar procedure for the identical cells.  After 7 days following tumour transplantation, cells were harvested from the animals and counted using the proper microscopy technique to determine the number of cells/ml. This number was then used for both in vivo and in vitro experiments.  Before being rinsed with saline, the cells were spun at 1000 rpm for 5 minutes.