Experts highlight 28 antimalarial plants that lower men’s fertility

MALARIA is still a health problem mainly because of the cost of effective antimalarial drugs and the growing parasite resistance to conventional antimalarial drugs, making a great proportion of the people in malaria-endemic countries dependent on plants for its treatment.

Corollary, a large number of the rural populations consume antimalarial herbal preparations indiscriminately, despite the fact that some of these antimalarial medicinal plants have deleterious side effects on a man’s fertility.

Infertility is described as the inability of a woman to conceive after a year of rightly timed unprotected sex.

Male-factor infertility is a growing global health concern and herbal medicines are not subjected to the same regulatory scrutiny as conventional drugs.

Also, most users of antimalarial herbal remedies believe that “anything herbal medicine is safe” even though several of these remedies have been found to be potentially toxic.

While poisonous plants are known, based on folkloric knowledge, it is those plants with subacute or chronic toxic implications that constitute major sources of danger for people who are heavily dependent on them.

Wondering what those antimalarial plant remedies that have been scientifically confirmed to have male-factor antifertility effects maybe? Researchers, in a 2019 review in Journal of Complementary and Integrative Medicine, have highlighted 28 of such plants that tell on a man’s fertility even though they are good malaria remedies.

These include Abrus precatorius (rosary pea or Oju-ologboin Yoruba), garlic, Alstonia boonei (Stool wood, Egbuora in Ibo and Ahun in Yoruba), Wild custard apple (Annona senegalensisis), Aspilia Africana (Orangila in Igbo, Tozalin in Hausa and Yunyun in Yoruba) and neem.

It includes Bridelia ferruginea (Oha in Ibo, Ira or Iradan in Yoruba), Cajanus cajan (Pigeon pea), pawpaw tree leaf, Chromolaena odorata (Siam Weed, Ewe Akintola taku in Yoruba or ishero in Urhobo), Crossopteryx febrifuga (crown-berry), Cryptolepis sanguinolenta (paran pupa in Yoruba) and curcumin.

Others are Cylicodiscus gabunensi (Okan in Yoruba or African greenheart), Ficus thonningii (wild fig), Gossypium barbadense (Cotton), Khaya senegalensis  (mahogany (English) or aganwo (Yoruba), Lippia multiflora (Efirin-gogoro), Morinda lucida (Brimstone tree or oruwo in Yoruba), Nauclea latifolia (Egbo egbesi  in Yoruba or Ubulu inu  in Ibo) and Ocimum gratissimum (scent leaf or efirrin).

It includes Phyllanthus amarus (Iyin Olobe in Yoruba), Picralima nitida (Erin (Yoruba) or Osuigwe (Igbo), Quassia amara (omu aja or gboyin gboyin in Yoruba, amunketa in Igbo), Solenostemon monostachyus (Ntorikwot (Ibibio) and Olojogbodu (Yoruba), Sphenocentrum jollyanum (Akerejupon in  Yoruba), Tithonia diversifolia (Wild Sunflower) and bitter leaf.

In the review, the researchers said some of these antimalarial medicinal plants have deleterious side effects that may be as a result of toxic constituents, the quantity consumed, the part consumed, the species, the soil and climate, the time of exposure and individual susceptibility.

They added, “Indiscriminate use of such antimalarial plants is discouraged when a male contraception is not desired.”

Abrus precatorius, studies, have reported causing degeneration of the testis and reduction of sperm cells in experimental rats after 18-day of its intake.

It was reported that garlic extract is spermicidal when tested on sperm cells, while it was also reported that ingestion of garlic for one month negatively affected testosterone secretion and sperm production.

Alstonia booneiis is popular in folklore medicine for the treatment of other health conditions. But when it was tested in rats, the alcohol extract of its stem bark altered sperm viability, motility and counts.

On the male antifertility effects, it was reported that administration extract of Aspilia Africana adversely affected male fertility parameters in Wistar rats.

After a 52-day administration, the extract caused a significant reduction of the weight of testis, epididymis, seminal vesicle, prostate gland and serum testosterone while the histology of the testis was also distorted.

Various parts of the neem tree have been studied extensively. For example, it was reported that the powdered leaf of neem orally administered significantly affect the production of androgen, the male hormone. It also significantly reduced sperm motility, sperm count, as well as increase the number of abnormal sperm cells.

The antifertility effects of pawpaw leaf and root have also been reported. Studies found that it caused a reduction in sperm viability, motility and count, and the degeneration of the lining of the seminiferous tubule following the administration of water extract of its leaves to Wistar rats.

This was also evidence of Cryptolepis sanguinolenta suppressing testosterone production and decreasing sperm count following administration of the extract. In a study that employed male mice, the water extract of its root was shown to adversely affect sperm count and the weight of the testes and epididymis.

Experimental evidence showed that ethanolic extract of the stem bark of F. Thonningii adversely affected the structural integrity of the testes of Wistar rat following a 42-day oral administration, suggesting that its stem bark might have a male antifertility effect.

Likewise sperm production is reduced by Morinda lucida leaf extract. Administration of the extract led to reduced sperm motility, viability, sperm counts, increased sperm distortion, damaged seminiferous tubules and reduced fertility typified by reduced litter size in albino rats.

Although evidence suggests that scent leaf elicit increased sexual activity in male mice, other studies revealed that its water extract caused decreased sperm count and motility and increased sperm cells abnormality in mice and rats after four weeks of administration.

The root of Sphenocentrum jollyanum is a sexual stimulant; however, its use caused a reduction in sperm motility, viability and counts and increase testosterone levels in the blood.

Also, prolonged use of bitter leaf has been shown to be toxic to the testis in rats. It had adverse effects on sperm parameters and caused degeneration of testicular tissues.