Elemental profiles of herbal plants commonly used for cancer therapy in Ogun State, Nigeria. Part I

Levels of toxic and trace metals in the breast milk of lactating mothers in Abeokuta, Ogun State, Nigeria

Background and objectives

Breast milk is an essential source of nutrients and energy for infants. The study analyzed for the levels of essential, toxic and rare earth elements in the breast milk of lactating mothers within Abeokuta metropolis.

Materials and methods

Thirty-seven (37) breast milk samples were collected with consents of lactating mothers at Ogun State General Hospital in Abeokuta. The samples were digested using standard method and analyzed for essential, toxic and rare earth elements using Inductively Coupled Plasma Mass Spectrometer (ICP-MS). The data were subjected to descriptive analysis.

Results

The results showed higher concentrations of toxic elements than essential elements in the breast milk of lactating mothers, where five toxic metals: Ag, Ti, V, Pb and Ba were observed to be present in 11, 14, 15, 17 and 23 breast milk samples respectively. Two essential (P and S) and two toxic (Cd and Hg (except sample 19)) elements were observed to be present in all the breast milk samples. Rare Earth Elements (except Sr, U and Rb) were below the detection limit of the instrument. Though three breast milk samples (12, 14 and 17) were observed safe, they contained two toxic (Cd and Hg) and a rare earth trace (Rb) element.

Conclusion

It could be concluded that despite the inherent benefits of human breast milk with essential elements to the infants, it can still be a source of toxic and trace earth metals contamination.

Study on Trace Elements Concentration in Medicinal Plants Using EDXRF Technique

Ten medicinal plants used as ingredients of folklore and Ayurvedic medicine belonging to the Malnad Kerala region of South India, were analysed for concentrations of trace elements Fe, Cr, Mn, Co, Ni, Cu, Zn, As, and Pb using the Energy Dispersive X-ray Fluorescence (EDXRF) technique. The soil from the root area of these medicinal plants was also analysed, and the soil to plant transfer factor (TF) of the elements was estimated. Iron (Fe) recorded higher concentration than the other trace elements estimated in the medicinal plants, followed by manganese (Mn) and zinc (Zn). The mean TF was found to be highest for Zn. Plectranthus amboinicus (Lour.) Spreng recorded the maximum value of TF for Zn. Most of the essential elements were found to be present in Centella asiatica (L.) Urban and indicated its medicinal importance. The data obtained in the present investigation may add up to the trace elemental database of medicinal plants in the world.

Acridone alkaloids from the stem bark of Citrus aurantium display selective cytotoxicity against breast, liver, lung and prostate human carcinoma cells

ETHNOPHARMACOLOGICAL RELEVANCE

Citrus aurantium L. (Rutaceae) is used, either singly or as a part of a polyherbal preparation, in Nigerian traditional medicine for the management of cancer and inflammatory diseases. Currently, there is a dearth of knowledge demonstrating its anticancer potential.

AIM OF THE STUDY

This study was carried out to determine the in vitro cytotoxicity of the crude extract of the stem bark of C. aurantium, identify and isolate the bioactive constituents and to establish the cytotoxicity of such constituents.

MATERIALS AND METHODS

The powdered bark of C. aurantium was extracted by MeOH at room temperature (25-34 °C) and the crude extract was partitioned successively, with n-hexane, dichloromethane and methanol. Amongst the fractions, the DCM fraction was the most active and compounds were isolated from this fraction using a combination of chromatographic techniques. The structures of the isolated compounds were elucidated by spectroscopic means (MS, 1D and 2D NMR). The cytotoxicity of the extract, and the isolated compounds were evaluated by the MTT assay against four human cancer cell lines: A549 (lung), HepG2 (liver), MCF7 (breast) and PC3 (prostate). The selectivity of the isolated compounds was assessed using the normal human prostate epithelium cells (PNT2).

RESULTS AND DISCUSSION

Of the three plant fractions, the DCM fraction showed significant cytotoxicity, with its highest activity against A549 cells (IC₅₀ = 3.88 µg/mL) and the least activity on HepG2 cells (IC₅₀ = 5.73 µg/mL). Six acridone alkaloids, citrusinine-I (1), citracridone-I (2), 5-hydroxynoracronycine (3), natsucitrine-I (4), glycofolinine (5) and citracridone-III (6), were isolated from the DCM fraction of C. aurantium. The isolated compounds demonstrated potent to moderate cytotoxicity (IC₅₀ = 12.65-50.74 µM) against the cancer cells under investigation. It is noteworthy that the compounds exerted cytotoxicity at least four times more selective towards the carcinoma cells than the PNT2 cells.

CONCLUSION

The results obtained from this study have provided some evidence for the ethnomedicinal use of C. aurantium against cancer and the acridone alkaloids present in its stem bark, have appeared to be responsible for the anticancer effects.