A review on potentiality of medicinal plants as the source of new contraceptive principles

Total Phenolic Content, Antioxidant Capacity and UV Radiation Protection Properties of Marigold (Calendula officinalis), Carrot (Daucus carota), Tomato (Solanum lycopersicum) and Hop (Humulus lupulus) Extracts

Total phenolic content using Folin–Ciocalteu method, antioxidant capacity by CUPRAC method and sun protection properties were measured for four different extracts of selected plants: marigold petals, carrot roots, tomato fruits and hop cones. Three types of extracts: water, oil and water-glycolic (1:4) were studied. Assessment of sun protection properties for extracts obtained from selected plants was first done by mathematical indication method and subsequently done spectrophotometrically. In a method of mathematical indication of UV protection based on absorption spectra, four parameters were determined regarding sun protection properties at different concentrations of selected plant extracts. Absorbance generally increased with an increase of concentration of extracts, but an expected increase of particular parameters was not obtained in all samples. The water-glycolic extract from hop cones was characterized by the highest content of phenolic compounds (among all studied samples) and high antioxidant activity. It also showed high radiation protection. Data for four parameters like UVA/UVB parameter, UVA1/UV parameter, SUI parameter and critical wavelength was generated, and the three first parameters were the highest for water and water-glycolic extracts of marigold. Among all plants, hop cones were characterized by the highest SPF for all types of extracts. SPF values increased with the concentration of extracts, but an increase of the weight of dried plants used to prepared extracts did not influence sun protection factor.

The Potential of Jatropha variegata Fruits as a Natural Contraceptive: Antifertility Activity and Phytochemical Analysis

Background

Jatropha variegata (family, Euphorbiaceae) is native to Yemen, where it is commonly known as the Ebki shrub. The fruits of the plant are traditionally ingested by local women as a natural method of contraception. This study was undertaken to investigate the phytochemical content of the methanol extract of J. variegata fruits and to evaluate its antifertility potential.

Methods

Isolation of the chemical constituents was performed by chromatographic techniques, and the chemical structures of these compounds were identified by spectroscopy. The antifertility activity of the methanol extract was assessed in two experimental rat models to explore both the anti-implantation and the estrogenic/antiestrogenic activities in females. In these models, the number of successful implants, the size of litter, and body/ovary weights were all recorded. The development of ovarian follicles was also monitored via histological staining.

Results

Phytochemical work on the fruit extract of J. variegata led to the isolation of two oils (JF1 and JF2) and methyl elaidate. GC-MS analysis of the JF1 oil revealed that the major chemical constituents were fatty acid esters (43.77%), hydrocarbon alkanes (20.65%), and terpenoids (4.65%), while terpenoids (28.8%), fatty acids and their esters, (29.47%), and phytosterol (10.49%) were the major components found in the JF2 oil. The methanol extract of J. variegata fruit exhibited 50% and 93% abortifacient activity at 150 and 300 mg/kg doses, respectively. The extract also showed significant estrogenic activity as evidenced by the increase in rat ovary weight at a dose of 300 mg/kg compared to the control group. Histological analyses further confirmed this estrogenic activity.

Conclusions

J. variegata fruits possess an antifertility activity that appeared to result from its antiembryo implantation potential and from its estrogenic activity. The bioactive constituents involved in these activities may need to be further explored and exploited in the pursuit of newer contraceptives.

Natural Products with Potential for Nonhormonal Male Contraception

Despite increased access to contraception over the last 60 years, unplanned pregnancies continue to contribute to economic disparities and overpopulation. Additionally, the burden of family planning falls primarily on women, as a reliable pharmaceutical male contraceptive has yet to be developed. The objective of this literature-based systematic review was to identify compounds for future study from natural sources with potential nonhormonal male contraceptive activity. After the exclusion of extracts and compounds with known hormonal mechanisms, 26 unique compounds were identified from natural species. The plant source, compound class, structure, target, mechanism of action, safety/toxicity profile, and in vitro, in vivo, and human studies for each compound were evaluated and discussed. β-Caryophyllene, embelin, oleanolic acid, triptonide, and N-butyldeoxynojirimycin (NB-DNJ) were selected as the five most promising compounds for future study using prespecified criteria such as number of studies, efficacy and safety profile, reversibility, and previous use in humans for any indication. In order to move forward with development of a male contraceptive from a natural source, additional studies are needed to determine the predicted safety and efficacy for in vivo and human clinical trials.

The status of fertility control for rodents-recent achievements and future directions

Management of overabundant rodents at a landscape scale is complex but often required to sustainably reduce rodent abundance below damage thresholds. Current conventional techniques such as poisoning are not species specific, with some approaches becoming increasingly unacceptable to the general public. Fertility control, first proposed for vertebrate pest management over 5 decades ago, has gained public acceptance because it is perceived as a potentially more species-specific and humane approach compared with many lethal methods. An ideal fertility control agent needs to induce infertility across one or more breeding seasons, be easily delivered to an appropriate proportion of the population, be species specific with minimal side-effects (behavioral or social structure changes), and be environmentally benign and cost effective. To date, effective fertility control of rodents has not been demonstrated at landscape scales and very few products have achieved registration. Reproductive targets for fertility control include disrupting the hormonal feedback associated with the hypothalamic-pituitary-gonadal axis, gonad function, fertilization, and/or early implantation. We review progress on the oral delivery of various agents for which laboratory studies have demonstrated efficacy in females and/or males and synthesize progress with the development and/or use of synthetic steroids, plant extracts, ovarian specific peptides, and immunocontraceptive vaccines. There are promising results for field application of synthetic steroids (levonorgestrel, quinestrol), chemosterilants (4-vinylcyclohexene diepoxide), and some plant extracts (triptolide). For most fertility control agents, more research is essential to enable their efficient and cost-effective delivery such that rodent impacts at a population level are mitigated and food security is improved.

Discovery of nano-piperolactam A: A nonsteroidal contraceptive lead acting through down-regulation of interleukins

Elevated serum interleukins (IL-6, IL-1β) over baseline concentration help in blastocyst adhesion to the uterine endometrium in the early phase of pregnancy. A nano PLA (Piperolactam A)-HPBCD (2-hydroxy-propyl-β-cyclodextrin) inclusion complex was developed as an interleukin down-regulator that exhibited 100% anti-implantation activity in rodents at a dose as low as 2.5-5.0 mg/kg. On metabolomics study, among major glyco-lipo-protein metabolites, only serum low-density lipoprotein (LDL) or very low-density lipoprotein (VLDL) levels revealed alteration by the formulation. Administration of PLA-HPBCD did not cause changes in serum estrogen and progesterone levels. However, IL-6 and IL-1β failed to increase post PLA-HPBCD administration; hence, it is assumed to be the mode of the drug's abortifacient action. In addition, absence of signs of either acute or chronic toxicity suggests the formulation was considerably non-toxic. Therefore, the nano-PLA conjugate promises as a non-steroidal contraceptive lead apart from ormeloxifene, the only non-steroidal anti-fertility agent currently available globally.

Fertility control of rodent pests: a review of the inhibitory effects of plant extracts on ovarian function

BACKGROUND

Plant extracts can inhibit fertility by adversely affecting, directly or indirectly, reproductive processes ranging from gonadal function and development to gestation. This review focuses on plant extracts that disrupt ovarian function in rodents.

RESULTS

Extracts from at least 40 plant species exert some of their disruptive reproductive effects at the ovarian level. Of those, 13 plants induce a reduction in the number and type of ovarian follicles and also cause disruption to the oestrous cycle. Their effects are short term and reversible once treatment ceases.

CONCLUSIONS

Protection of plant extracts to prevent their degradation before uptake in the gastrointestinal tract could enhance short-term efficacy but would not enhance the longevity of their effects. Identification and further testing of the specific chemicals responsible for reproductive effects would be beneficial. The adoption of a standard protocol for treatment and assessment of the inhibitory effects of potential control agents on reproductive function in rodents is essential. Treatment with higher concentrations of extracts in conjunction with other extracts or with other chemosterilants could have potential complementary effects and lead to more rapid and permanent changes in ovarian function. An orally delivered agent(s) that causes major depletion of all follicle types, and particularly of non-regenerating primordial follicles, could be an ideal fertility control product and serve as an additional tool for population control of pest rodents.

Local uses of Aristolochia species and content of nephrotoxic aristolochic acid 1 and 2--a global assessment based on bibliographic sources

AIMS OF THE STUDY

More than 100 cases of nephropathy over the last 10 years caused by the systemic and longer term application of Chinese snakeroot (Aristolochia fangchi) highlighted the risk of using preparations which contain aristolochic acids. On the other hand anecdotal evidence highlights the widespread use of Aristolochia species (Aristolochiaceae) in many regions of the world. Therefore, it was our objective to systematically assess the scientific literature available on the local and traditional use of Aristolochia spp. on a worldwide scale. Our review identifies core species which need to be investigated and which may need monitoring (esp. in national and international trade).

METHODS

An extensive review of the literature available in libraries in London on the uses of species of Aristolochia was undertaken. Relevant information was extracted and entered into a database for analysis.

RESULTS

Based on the assessment of 566 reference sources 685 individual sets of data were recorded. Seven species--Aristolochia indica L. (Asia), Aristolochia serpentaria L. (North America), Aristolochia debilis Sieb & Zucch. (China), Aristolochia acuminata Lam (India), Aristolochia trilobata L. (Central/South America, Caribbean), Aristolochia clematitis L. (Europe) and Aristolochia bracteolata Lam. (Africa)--are reported widely as being used medicinally. The medical uses vary, but of particular interest are uses in case of gastrointestinal problems, which is likely to result in repeated exposure to the botanical drugs by an individual. About half of all records relate to uses of Aristolochia species in Asia, one-third to the Americas, a continent which has so far received practically no attention in terms of assessing the risk of using species of Aristolochia. Of the 99 species (plus several identified at genus level only) for which we were able to summarise ethnobotanical information, preliminary phytochemical information is only available for 24 species and some of the most common ones including Aristolochia acuminata have so far not been studied phytochemically.

CONCLUSIONS

Species of Aristolochia are used medicinally in many regions of the world and both from an ethnopharmacological and a public health perspective this poses a risk. A systematic assessment of the content of aristolochic acids in the most widely used species is needed to evaluate whether their uses pose a potential health risk. In China and Europe species of Aristolochia have been associated with nephropathy and it is important to evaluate whether nephropathy occurs in other parts of the world, especially India and Central America where the use of species of Aristolochia are reported to be commonly used in traditional medicine.

Immobilization effect of Ruta graveolens L. on human sperm: a new hope for male contraception

AIM OF THE STUDY

Contraceptive plants which were introduced by folk in traditional remedies are investigated worldwide. In this study, the contraceptive effects of Ruta graveolens L., which has been mentioned for male contraceptive in Iranian traditional folk medicine, was experimented on human sperm.

MATERIALS AND METHODS

Different doses of lyophilized aqueous extract of Ruta graveolens L. were added to an amount of fresh semen, containing 10(6) cells in a 1:1 volumic ratio. Motility and viability of cells, DNA status, mitochondrial activity and sperm revival tests were carried out.

RESULTS

The sperm immobilization effects of the extract appeared immediately in a does-dependent manner and 100% of the sperms became immotile at a concentration of 100mg/ml but other parameters were intact. After washing the sperms, motility was returned in 30.8+/-3.2% of the sperms, besides coiled tails in 38.6+/-5.5% of the treated cells, in comparison to 12.5+/-2.0% of the control group (p=0.001). The part of the extract, responsible for immobilization of the sperms was stable upon boiling.

CONCLUSIONS

As the cells were alive and immotile, probably some ionic currents are blocked by a thermostable component of the plant which can be promising as a new male channel blocker contraceptive.

Nuevas opciones en anticoncepción: posible uso espermicida de plantas colombianas

Currently there exists increasing preoccupation concerning sexual and reproductive health among teenagers; in spite of the availability of different contraceptive methods, the number of undesired pregnancies is steadily increasing. Among the products presently available for birth control, spermicides are a means that can be totally controlled by the woman and are very reliable compared to other contraceptives in common use. However, they cause irritation in the vaginal epithelium due to their tensoactive effect on cellular membranes which might enhance the risk of acquiring sexually transmissible diseases. In searching for new alternatives, it was observed that a wide variety of plants have spermicidal activity. Hence it is interesting to consider potential contraceptives of vegetable origin, as they may constitute a key tool to prevent undesired pregnancies in general, and in particular in vulnerable groups such as teenagers and young women.

Structural modifications of plumieride isolated from Plumeria bicolor and the effect of these modifications on in vitro anticancer activity

Plumieride was isolated as one of the major components from the biologically active methanolic extract of the bark of Plumeria bicolor (family Apocynaceae). For investigating the effect of substituents on cytotoxic activity it was modified into a series of compounds. Replacing the methyl ester functionality of plumieride with alkyl amides of variable carbon units improved the cytotoxic activity, and a correlation between overall lipophilicity and cytotoxic activity was observed. In plumieride, the glucose moiety was converted into a di- and trisaccharide by following the protection and deprotection approach, and the resulting compounds produced enhanced cytotoxicity. However, these compounds were found to be less effective than plumeiride containing a dodecyl (12 carbon units) amide group. Among all of the derivatives, the naturally occurring plumieride showed the least cytotoxicity (50% cell kill = 49.5 microg/mL), and the dodecyl amide analogue of plumieridepentaacetate produced the best efficacy (50% cell kill = 11.8 microg/mL). The di- and trisaccharide analogues were found to be slightly less effective than the dodecyl derivative (50% cell kill = 15-17 microg/mL). The in vitro cytotoxicity of the plumieride analogues was determined in radiation-induced fibrosarcoma (RIF) tumor cells.